bluuebunny/crossref_metadata_2025 huggingface dataset:
Ontogeny of angiotensin II type 1 receptor mRNAs in fetal and neonatal rat brain
Authors: Nuyt Anne Monique , Lenkei Zsolt , Corvol Pierre , Palkovits Miklós , Llorens‐Cortés Catherine
Published: August 2002

Studies have demonstrated a specific function of the angiotensin II (Ang II) type 1 receptor (AT1) in regulation of adult central cardiovascular, fluid, and pituitary hormone release and a predominant role of the renin‐angiotensin system in fetal and neonatal cardiovascular homeostasis. The pattern of brain AT1 mRNA expression during fetal and neonatal development is currently unknown. We used radiolabeled cRNA probes for in situ hybridization histochemistry to determine the ontogenic development of the two AT1 subtypes (AT1a and AT1b) mRNA in rat brain, from 11 days of gestation (E11) to 28 days after birth (P28). No AT1b mRNA was detected in the developing brain, whereas AT1a mRNA was first detected at E19. The age at which AT1a mRNA is first detected varied among different brain areas and expression predominates in areas involved in fluid homeostasis, pituitary hormone release, and cardiovascular regulation, where it persists until P28. AT1a mRNA expression is present from E19 onward in the median preoptic nucleus, the vascular organ of the lamina terminalis, the paraventricular nucleus, the periaqueductal gray, the nucleus raphe pallidus, the motor facial nucleus, and very weakly in the nucleus of the solitary tract and the ambiguus nucleus, and at E21 in the subfornical organ, the anterior olfactory nucleus and the piriform cortex. AT1a mRNA expression is present after birth in many regions, including the preoptic and lateral hypothalamic areas, the area postrema and medullary reticular nuclei. In conclusion, during brain development, expression of AT1a mRNA, appears in late gestation at E19, predominantly in forebrain areas involved in fluid homeostasis and cardiovascular regulation. In contrast, AT1a mRNA expression is absent or present only in very small amounts until after birth in many medullary nuclei, known to play an important role in cardiovascular modulation. Our results suggest that, in perinatal life, AT1a is involved in fluid and perhaps cardiovascular homeostasis and that the role of Ang II in modulating medullary cardiovascular centers matures later in postnatal life. J. Comp. Neurol. 440:000–000, 2001. J. Comp. Neurol. 440:192–203, 2001. © 2001 Wiley‐Liss, Inc.
On the well‐posedness of the Euler equations in the Triebel‐Lizorkin spaces
Authors: Chae Dongho
Published: August 2002

We prove local‐in‐time unique existence and a blowup criterion for solutions in the Triebel‐Lizorkin space for the Euler equations of inviscid incompressible fluid flows in ℝn,n≥ 2. As a corollary we obtain global persistence of the initial regularity characterized by the Triebel‐Lizorkin spaces for the solutions of two‐dimensional Euler equations. To prove the results, we establish the logarithmic inequality of the Beale‐Kato‐Majda type, the Moser type of inequality, as well as the commutator estimate in the Triebel‐Lizorkin spaces. The key methods of proof used are the Littlewood‐Paley decomposition and the paradifferential calculus by J. M. Bony. © 2002 John Wiley & Sons, Inc.
A multicast group communication protocol, engine, and bridge for CORBA
Authors: Moser L. E. , Melliar‐Smith P. M. , Narasimhan P. , Koch R. R. , Berket K.
Published: August 2002

Multicast group communication is needed for fault‐tolerant distributed systems and, in particular, for the new Fault Tolerant CORBA standard, to maintain strong replica consistency. However, different multicast group communication protocols are appropriate for different environments, which makes it difficult to define a single standard multicast protocol. In this paper, we present a multicast group communication engine and bridge for CORBA that allows multiple group communication protocols to be used concurrently. We also present the Fault Tolerant Multicast Protocol, a group communication protocol that allows different fault tolerance systems to interoperate.

The group communication engine and bridge places Lamport timestamps on messages, and multicasts messages to groups, using one or more group communication protocols. The group communication protocols reliably deliver the timestamped messages in timestamp order to the group communication engine, which integrates these streams of messages into a single stream for delivery in timestamp order. The Fault Tolerant Multicast Protocol operates over IP Multicast, and consists of the Reliable Multicast Protocol which provides reliable source‐ordered message delivery, the Reliable Ordered Multicast Protocol which provides reliable totally ordered message delivery, and the Host Group Membership Protocol which provides host group membership services. Copyright © 2001 John Wiley & Sons, Ltd.
Verified lightweight bytecode verification
Authors: Klein Gerwin , Nipkow Tobias
Published: August 2002

Eva and Kristoffer Rose proposed a (sparse) annotation of Java Virtual Machine code with types to enable a one‐pass verification of well‐typedness. We have formalized a variant of their proposal in the theorem prover Isabelle/HOL and proved soundness and completeness. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis and optimization of a novel biasing for constant‐gain CMOS open‐loop amplifiers
Authors: Palmisano G. , Salerno R.
Published: August 2002

A replica biasing circuit is presented which allows open‐loop gain in CMOS amplifiers to be accurately set. The proposed solution is a new biasing which takes advantage of a triode‐biased transistor instead of the ΔVGSapproach which is the traditional one. The circuit can be applied to both RF and IF amplifiers which are based on resistive loads in order to achieve high‐frequency and/or low‐noise performance. A detailed analysis of second‐order effects is then given which emphasizes the effects due to mobility degradation, channel‐length modulation and threshold voltage mismatches. Simulated results show a good sensitivity to process variations. Copyright © 2001 John Wiley & Sons, Ltd.
Adaptive least mean squares block Volterra filters
Authors: Haweel Tarek I.
Published: August 2002

Adaptive filtering has found many applications in situations where the underlying signals are changing or unknown. While linear filters are simple from implementation and conceptual points of view, many signals are non‐linear in nature. Non‐linear filters based on truncated Volterra expansions can effectively model a large number of systems. Unfortunately, the resulting input auto‐moment matrix is ill conditioned, which results in a slow convergence rate. This paper proposes a class of block adaptive Volterra filters in which the input sequences are Hadamard transformed to improve the condition number of the input auto‐moment matrix and consequently improve the convergence rate. This is achieved by the decorrelation effect produced by the orthogonality of the transform. Since Hadamard transformation employs only ±1's, the additional required computational and implementation burdens are few. The effect of additive white Gaussian noise is introduced. Simulation experiments are given to illustrate the improved performance of the proposed method over the conventional Volterra LMS method. Copyright © 2001 John Wiley & Sons, Ltd.
ACE4k: An analog I/O 64×64 visual microprocessor chip with 7‐bit analog accuracy
Authors: Liñán G. , Espejo S. , Domínguez‐Castro R. , Rodríguez‐Vázquez A.
Published: August 2002

This paper describes a full‐custom mixed‐signal chip which embeds distributed optical signal acquisition, digitally‐programmable analog parallel processing, and distributed image memory cache on a common silicon substrate. This chip, designed in a 0.5 µm standard CMOS technology contains around 1.000.000 transistors, of which operate in analog mode; it is hence one the most complex mixed‐signal chip reported to now. Chip functional features are: local interactions, spatial‐invariant array architecture; programmable local interactions among cells; randomly‐selectable memory of instructions (elementary instructions are defined by specific values of the cell local interactions); random storage/retrieval of intermediate images; capability to complete algorithmic image processing tasks controlled by the user‐selected stored instructions and interacting with the cache memory, etc. Thus, as illustrated in this paper, the chip is capable to complete complex spatio‐temporal image processing tasks within short computation time (<300 ns for linear convolutions) and using a low power budget (<1.2 W for the complete chip). The internal circuitry of the chip has been designed to operate in robust manner with >7‐bits equivalent accuracy in the internal analog operations, which has been confirmed by experimental measurements. Such 7‐bits accuracy is enough for most image processing applications. ACE4k has been demonstrated capable to implement up to 30 templateσ‐either directly or through template decomposition. This means the 100% of the 3×3 linear templates reported in Roska et al. 1998, [1]. Copyright © 2002 John Wiley & Sons, Ltd.
Use of phycoerythrin and allophycocyanin for fluorescence resonance energy transfer analyzed by flow cytometry: Advantages and limitations
Authors: Batard Pascal , Szollosi Janos , Luescher Immanuel , Cerottini Jean‐Charles , MacDonald Rob , Romero Pedro
Published: August 2002

Background

This study validates the use of phycoerythrin (PE) and allophycocyanin (APC) for fluorescence energy transfer (FRET) analyzed by flow cytometry.

Methods

FRET was detected when a pair of antibody conjugates directed against two noncompetitive epitopes on the same CD8α chain was used. FRET was also detected between antibody conjugate pairs specific for the two chains of the heterodimeric α 4β1 integrin. Similarly, the association of T‐cell receptor (TCR) with a soluble antigen ligand was detected by FRET when anti‐TCR antibody and MHC class I/peptide complexes (〈〈tetramers〉〉) were used.

Results

FRET efficiency was always less than 10%, probably because of steric effects associated with the size and structure of PE and APC. Some suggestions are given to take into account this and other effects (e.g., donor and acceptor concentrations) for a better interpretation of FRET results obtained with this pair of fluorochromes.

Conclusions

We conclude that FRET assays can be carried out easily with commercially available antibodies and flow cytometers to study arrays of multimolecular complexes. Cytometry 48:97–105, 2002. © 2002 Wiley‐Liss, Inc.
Distinctive patterns of Her‐2/neu, c‐myc, and cyclin D1 gene amplification by fluorescence in situ hybridization in primary human breast cancers
Authors: Janocko Laura E. , Brown Kathryn A. , Smith Charles A. , Gu Ling Ping , Pollice Agnese A. , Singh Sarita G. , Julian Thomas , Wolmark Norman , Sweeney Lillian , Silverman Jan F. , Shackney Stanley E.
Published: August 2002

Background: Human solid tumors undergo clonal evolution as they progress, but evidence for specific sequences of genetic changes that occur in individual tumors and are recapitulated in other tumors is difficult to obtain. Methods: Patterns of amplification of Her‐2/neu, c‐myc, and cyclin D1 were determined by fluorescence in situ hybridization (FISH) in relation to the presence of p53 dysfunction and ploidy in 60 primary human breast cancers. Results: We show that there are clusters of genophenotypic abnormalities that distinguish lobular breast cancers from nonlobular tumors; that cyclin D1 amplification occurs prior to the divergence of lobular breast cancers from nonlobular cancers; that p53 dysfunction, Her‐2/neu amplification, and c‐myc amplification are characteristic features of nonlobular breast cancers, but not of lobular breast cancers; and that the frequencies of amplification of all three oncogenes examined increase progressively with increasing aneuploidy, but that each gene exhibits a different profile of increasing amplification in relation to tumor progression. Early amplification of c‐myc appears to be an especially prominent feature of hypertetraploid/hypertetrasomic tumors. Conclusions: The data suggest that in tumors containing multiple abnormalities, these abnormalities often accumulate in the same cells within each tumor. Furthermore, the same patterns of accumulation of multiple genophenotypic abnormalities are recapitulated in different tumors. Cytometry (Comm. Clin. Cytometry) 46:136–149, 2001. © 2001 Wiley‐Liss, Inc.
A congestion control framework for available bit rate service in ATM networks
Authors: Chan Sammy , Zukerman Moshe , Wong Eric W. M. , Ko K. T. , Yeung Edmund , Wydrowski Bartek
Published: August 2002

Fair packet discarding (FPD) is a mechanism which provides incentives to users to co‐operate in congestion control, so that ATM networks can operate more efficiently. In this paper, we propose asimplecongestion control framework consisting of a combination of FPD and ATM Forum's explicit‐rate flow control scheme. We show by simulations that this frame‐work achieves all objectives of congestion control: (1) control congestion, (2) achieve high user‐perceived throughput, (3) maintain fairness and (4) provide protection from misbehaving users. In addition, we equip this framework with two enhancements to improve efficiency, and reduce end‐to‐end delay. Copyright © 2002 John Wiley & Sons, Ltd.
Fine‐needle aspiration biopsy of alveolar rhabdomyosarcoma of the parotid: A case report and review of the literature
Authors: Valencerina Gopez Evelyn , Dauterman John , Layfield Lester J.
Published: August 2002

The cytologic features of an alveolar rhabdomyosarcoma arising within the parotid gland are described. The occurrence of this neoplasm as a primary malignancy in the parotid gland is very rare, and the tumor is usually not included in the cytologic differential diagnosis of parotid tumors. The diagnosis of the current case was achieved by a combination of fine‐needle aspiration biopsy and frozen sections. Realizing the difficulty of recognizing this tumor both histologically and cytologically, we present this case to increase the awareness of this tumor's occurrence within the parotid gland and other salivary glands, and to highlight cytomorphologic features that will aid the pathologist in making the correct diagnosis. Diagn. Cytopathol. 24:249–252, 2001. © 2001 Wiley‐Liss, Inc.
Presence of proliferating (MiB‐1‐positive) cells in cervical smears of women infected with HIV is associated with clinical outcome: A study of Brazilian women
Authors: Boon Mathilde E. , van der Veen Gerrita , Barlow Yvonne , Graudenz Marcia Silveira , Kok Lambrecht P.
Published: August 2002

The hypothesis tested was that there is an association between the presence of proliferating (MiB‐1‐positive) cervical cells and clinical outcome of women infected with human immunodeficiency virus (HIV). Female partners (attending the Gynecology Outpatients Clinic of the University Hospital of Rio Grande, Brazil) of known HIV‐positive (HIV+) men were used for this pilot study. Among these women, 25 were also HIV+. Papanicolaou smears of these 25 HIV+ women and of 44 HIV− women were graded as negative, CIN I, CIN II, or CIN III, using neural network screening. MiB‐1 grading and HPV identification were also performed. The immune status of patients was determined using the current Centers for Disease Control classification. In agreement with the scientific literature, in these Brazilian women both CIN and HPV were associated with HIV. In the HIV+ women, the immune status tends to correlate with MiB‐1 grading. Also, in the one case in whom progression from CIN I to invasive cervical carcinoma was observed, the smear contained many MiB‐1‐positive cells. Staining cervical smears of HIV+ women is a simple procedure to get an indication of clinical outcome of the patient. Diagn. Cytopathol. 24:373–377, 2001. © 2001 Wiley‐Liss, Inc.
Cytologic features of tubular adenocarcinoma of the breast by aspiration biopsy
Authors: Cangiarella Joan , Waisman Jerry , Shapiro Richard L. , Simsir Aylin
Published: August 2002

Tubular adenocarcinoma is an invasive mammary adenocarcinoma associated with an excellent prognosis and a low incidence of axillary metastases. However, identification of tubular adenocarcinoma by fine‐needle aspiration (FNA) biopsy has proven difficult. One hundred five patients with documented “pure” tubular adenocarcinoma were diagnosed at Tisch Hospital from August of 1992 to December of 1998. Twenty‐one of these patients had an FNA before excision. We reviewed the smears of these cases and compared them with cases of fibroadenoma and fibrocystic change to identify criteria for diagnosis. Moderately to highly cellular smears with angular cellular clusters with sharp borders and oval cells outlining these clusters, dispersed single cells with minimal atypia, and the absence or paucity of dispersed bare oval nuclei in the background were features that suggest a diagnosis of tubular adenocarcinoma in our study. Attention to these features in combination with appropriate mammographic findings should preclude a false‐negative diagnosis in the majority of cases of tubular adenocarcinoma diagnosed by aspiration biopsy. We point to the presence of the peripheral perpendicular cells in the characteristic tubular arrays as an important clue to the diagnosis of tubular adenocarcinoma. Diagn. Cytopathol. 25:311–315, 2001. © 2001 Wiley‐Liss, Inc.
Gabapentin: A novel analgesic targeting voltage‐gated calcium channels
Authors: Sutton Kathy G. , Snutch Terrance P.
Published: August 2002

Given their vital roles in mediating neuronal excitability, it is not surprising that voltage‐gated calcium channels have been implicated in contributing to the development and maintenance of pain processes. Gabapentin, a synthetic analog of the neurotransmitter γ‐aminobutyric acid (GABA), is a clinically effective anticonvulsant recently shown to be efficacious also for a variety of neuropathic pain conditions. While its mechanism of action is incompletely understood, current evidence suggests that gabapentin does not directly interact with GABA receptors but rather modulates the activity of high threshold calcium channels. Although gabapentin binds to the calcium channel α2δ ancillary subunit, it remains to be determined whether this interaction solely accounts for its therapeutic effects. Drug Dev. Res. 54:167–172, 2002. © 2002 Wiley‐Liss, Inc.
Recent progress in the study of the intracellular functions of diadenosine polyphosphates
Authors: McLennan Alexander G. , Barnes Larry D. , Blackburn G. Michael , Brenner Charles , Guranowski Andrzej , Miller Andrew D. , Rovira Juan Manuel , Rotllán Pedro , Soria Bernat , Tanner Julian A. , Sillero Antonio
Published: August 2002

Recent developments in the effort to understand the metabolism and function of the intracellular dinucleoside polyphosphates were described by nine speakers from some of the world’s leading laboratories in this field in a workshop at the Purines 2000 International Symposium on Nucleosides and Nucleotides held in Madrid in July, 2000. Topics were wide‐ranging and included phenotypic analyses of yeast mutants defective in enzymes of dinucleoside polyphosphate degradation, virally encoded catabolic enzymes, the structure and function of the Fhit tumor suppressor and Fhit‐nitrilase fusion proteins and the relationship of Fhit to human diadenosine triphosphate hydrolase, site‐directed mutagenesis of diadenosine tetraphosphate hydrolase, novel nucleotide analogs for studying hydrolase function, the synthesis of dinucleoside polyphosphates by ligases, and the possible roles of diadenosine tri‐ and tetraphosphates in insulin function and of diadenosine tetraphosphate in the heat‐shock response of Escherichia coli. The results presented and the ensuing discussions showed that, while considerable progress is being made in the field, it still has the capacity to tease and frustrate and produce the unexpected result. Drug Dev. Res. 52:249–259, 2001. © 2001 Wiley‐Liss, Inc.
Evolutionary thinking as a tool in pharmaceutical development
Authors: LeGrand Edmund K.
Published: August 2002

The rapidly expanding technologies involving chemical synthesis and screening, genomics, and bioinformatics are leading to the point where every gene product can be modulated as a therapeutic target. Thus, pharmaceuticals increasingly offer the potential to control disease processes. While great strides in understanding disease processes can come from this mechanistic approach (addressing “how?” questions), complete understanding is impossible without addressing the ultimate causation of disease processes. By addressing ultimate (“why?”) questions, evolutionary thinking provides a firm theoretical framework for all biological processes, including those relating to disease. Of practical relevance for pharmaceutical development is an increased awareness of evolved responses and potential consequences of bypassing these defenses. Examples involving reproductive medicine, components of the acute phase response, apoptosis, and axonal regeneration are discussed. Drug Dev. Res. 52:439–445, 2001. © 2001 Wiley‐Liss, Inc.
Third‐generation dihydropyridine‐type calcium channel blocker labedipinedilol‐B displays α/β‐adrenoceptor blocking activities
Authors: Yeh Jwu‐Lai , Tsai Chieh‐Ho , Liang Jhy‐Chong , Wu Jiunn‐Ren , Huang Yeun‐Chih , Chen Ing‐Jun
Published: August 2002

The pharmacological properties of labedipinedilol‐B {N‐[4‐[2‐hydroxy‐3‐(2‐methoxy‐1‐oxyethylaminobenzene) propoxy]‐benzyl]‐2,6‐dimethyl‐3,5‐dicarbomethoxy‐1,4‐dihydropyridine} were investigated in vivo and in vitro in comparison with labedipinedilol‐A. Intravenous labedipinedilol‐B (0.5, 1.0, and 3.0 mg kg–1), produced dose‐dependent hypotensive and bradycardia responses in pentobarbital‐anesthetized Wistar rats. Pretreatment with labedipinedilol‐B (1.0 mg kg–1, iv) also inhibited phenylephrine (10 μg kg–1)‐induced hypertensive and (–)isoproterenol (0.5 μg kg–1)‐induced tachycardia effects. In the isolated Wistar rat right and left atria and guinea pigs tracheal strips experiments, labedipinedilol‐B (10–7, 10–6, and 10–5 M) competitively antagonized the (–)isoproterenol‐induced positive chronotropic and inotropic effects and tracheal relaxation responses in a concentration‐dependent manner. The parallel shift to the right of the concentration–response curve of (–)isoproterenol suggested that labedipinedilol‐B was a β1/β2‐adrenoceptor competitive antagonist. Labedipinedilol‐B (10–7, 10–6, and 10–5 M) also prevented the rate‐increasing effects of increased extracellular Ca2+ (3.0–9.0 mM) in a concentration‐dependent manner. In the isolated rat aorta, labedipinedilol‐B (10–7, 10–6, and 10–5 M) competitively antagonized the CaCl2 and norepinephrine‐induced contractions with pKCa–1 and pA2 values of 8.02 ± 0.04 and 7.55 ± 0.05 in a concentration‐dependent manner. The parallel shift to the right of the concentration–response curves of norepinephrine suggested that labedipinedilol‐B was an α‐adrenoceptor competitive antagonist. Furthermore, labedipinedilol‐B, in an equal antagonist activity, inhibited norepinephrine‐induced phasic and tonic contraction. In the isolated rat aorta, labedipinedilol‐B also competitively antagonized CaCl2‐induced contractions and made the parallel shift to the right of the concentration–response curve of CaCl2. In cultured blood vessel smooth muscle cells (A7r5 cell lines), Bay K 8644‐induced intracellular calcium changes were decreased after application of labedipinedilol‐B, suggesting that the compound was a calcium channel blocker. The binding characteristics of labedipinedilol‐B were evaluated in [3H]CGP‐12177 binding to ventricle and lung and [3H]prazosin binding to brain membranes in rats. Labedipinedilol‐B also was evaluated in [3H]nitrendipine binding to brain membranes in rats. These results indicated that labedipinedilol‐B, similar to labedipinedilol‐A, has α‐adrenoceptor blocking, β‐adrenoceptor blocking, and calcium entry blocking activities in a single compound. We suggest that these two compounds represent a new generation of 1,4‐dihydropyridine‐type calcium channel blockers. Drug Dev. Res. 52:462–474, 2001. © 2001 Wiley‐Liss, Inc.
Synthesis of 1‐(2‐deoxy‐β‐D‐ribofuranosyl)‐2,4‐ difluoro‐5‐(2‐halo‐1‐hydroxyethyl)benzenes and related derivatives: “thymine replacement” analogs of deoxythymidine for evaluation as antiviral and anticancer agents
Authors: Naimi Ebrahim , Wiebe Leonard I. , Balzarini Jan , De Clercq Erik , Knaus Edward E.
Published: August 2002

A group of unnatural 1‐(2‐deoxy‐β‐D‐ribofuranosyl)‐2,4‐difluorobenzenes having a variety of C‐5 substituents, designed as thymidine mimics, were synthesized for evaluation as antiviral and anticancer agents. The regiospecific addition of HOBr (generated from N‐bromosuccinimide in aqueous dioxane) across the 5‐vinyl substituent (4) afforded the corresponding 5‐[‐CH(OH)CH2Br] product (5), whereas reaction of 4 with iodine in the presence of iodic acid (HOI) yielded the 5‐[CH(OH)CH2I] product (6). The related 5‐[‐CH(OH)CHX2 (X = Br, I)] analogs (11, 12) were similarly prepared from the (E)‐5‐(2‐halovinyl) precursors (9, 10). Treatment of the 5‐[‐CH(OH)CH2X (X = Br, I)] compounds (5, 6) with NaOH in aqueous dioxane afforded the 5‐oxiranyl product (8). The 5‐[‐CH(OMe)CH2I] compound (7) was prepared by reaction of the 5‐vinyl compound (4) with ICl in MeOH (MeOI). This group of compounds (5–8, 11, 12) showed similar (marginal) activity against varicella‐zoster virus thymidine kinase positive (VZV/TK+) and thymidine kinase deficient (VZV/TK–) infected cells. Thus, the viral TK enzyme did not provide a gene therapeutic effect. This group of compounds, which were evaluated using a wide variety of antiviral assay systems [(herpes simplex virus HSV‐1, HSV‐2), varicella‐zoster virus (VZV), vaccinia virus, vesicular stomatitis, cytomegalovirus (CMV), and human immunodeficiency virus (HIV‐1, HIV‐2)], showed that these unnatural C‐aryl nucleoside mimics are inactive antiviral agents. Their failure to exhibit antiviral/anticancer activity could be due to the fact that they are not phosphorylated to the 5′‐monophosphate, or that incorporation of the active 5′‐triphosphate into DNA does not produce a cytotoxic effect, and/or that these C‐aryl nucleoside mimics do not act as inhibitors of thymidylate synthase, which may be required to produce a cytotoxic effect. Drug Dev. Res. 52:492–499, 2001. © 2001 Wiley‐Liss, Inc.
Developmental differences in temporal patterns and potentiation of isolation‐induced ultrasonic vocalizations: Influence of temperature variables
Authors: Kraebel Kimberly S. , Brasser Susan M. , Campbell James O. , Spear Linda P. , Spear Norman E.
Published: August 2002

The present study examined the relationship between the thermal environment and core body temperature in producing age‐related patterns of ultrasonic vocalizations (USVs). Implanted telemetry devices allowed on‐line measurement of core body temperature during an extended period of isolation and after maternal contact, both as a function of age and thermal environment. At 12 or 17 days of age, rat pups were isolated for 30 min in either a cool or a warm environment, returned home for 5 min, and then re‐isolatedj for 10 min. Number of USVs, body temperature, and behavioral activity were measured. During initial isolation in a cool environment, 12‐day‐olds displayed relatively stable patterns of ultrasounding and body temperature across time whereas older animals showed a time‐dependent increase in USV calling and in core temperature. During re‐isolation, 12‐day‐olds potentiated their USV calling at both ambient temperatures while 17‐day‐olds did not. The overall results suggest a strong dependence between USV calling, core body temperature, and ambient temperature during initial isolation at both ages—a finding in agreement with interpretations of USVs as an acoustic by‐product of thermal challenge. In contrast, during re‐isolation, USV calls, core body temperature, and ambient temperature functioned independently—a finding in agreement with interpretations of USVs as a representation of an emotional state. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 147–159, 2002. DOI 10.1002/dev.10022
Effects of chronic and acute methylphenidate hydrochloride (ritalin) administration on locomotor activity, ultrasonic vocalizations, and neuromotor development in 3‐ to 11‐day‐old CD‐1 mouse pups
Authors: Penner Marsha R. , McFadyen Melanie P. , Carrey Normand , Brown Richard E.
Published: August 2002

The present study examined the effects of chronic and acute treatment with methylphenidate hydrochloride (Ritalin) on isolation‐induced ultrasonic vocalizations, spontaneous locomotor activity, and neuromotor coordination in 3‐ to 11‐day‐old CD‐1 mouse pups. In Experiment 1, 3‐ to 11‐day‐old pups received daily injections of saline, 5 mg/kg or 20 mg/kg of methylphenidate hydrochloride, or no injection and were tested on postnatal Days 3, 5, 7, 9, and 11. Both doses of methylphenidate resulted in significant increases in locomotor activity at all ages, but had no significant effect on body weight, neuromotor development, or emission of ultrasonic vocalizations. In Experiment 2, pups were given a single dose of methylphenidate (5 or 20 mg/kg), saline, or no injection on one of postnatal Days 5, 7, 9, or 11. This acute methylphenidate treatment increased locomotor activity, but had no significant effects on ultrasonic vocalizations or neuromotor coordination. These results indicate that short‐term, chronic methylphenidate treatment elevates locomotor responses, but has no immediate effects on anxietylike responses or on the development of neuromotor behavior of CD‐1 mice in the first 11 days of life. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 216–228, 2001
Regulation of cardiac transient outward potassium current by norepinephrine in normal and diabetic rats
Authors: Gallego Mónica , Casis Oscar
Published: August 2002

Background

α‐Adrenergic stimulation regulates cardiac contractility by reducing repolarising K+ currents. Despite this, no published work exists on the effects of norepinephrine on isolated cardiac transient outward current, responsible for action potential duration in the rat and human. Besides, diabetes alters cardiac inotropic responses to sympathetic innervation, and this can result from altered responsiveness of the transient outward current to norepinephrine.

Methods

Transient outward K+ current was measured using the whole‐cell configuration of the patch‐clamp technique. Myocytes were isolated from the right ventricle of healthy and streptozotocin‐induced diabetic rats.

Results

Norepinephrine, through α1‐adrenoceptors, reduces current amplitude in a concentration‐dependent way, with no effects on current kinetics or voltage dependence of inactivation. Diabetes reduces current amplitude and accelerates its inactivation process. Norepinephrine also reduces current amplitude in diabetic cells; however diabetes shifts to the right the concentration–response curve and reduces the maximum effect of the neurotransmitter.

Conclusions

Norepinephrine reduces the amplitude of isolated ventricular transient outward K+ current with no effects on current properties in myocytes isolated from either healthy or diabetic hearts. Diabetes shifts the concentration–response curve; thus diabetic myocytes are more resistant to sympathetic regulation than are healthy cells. Copyright © 2001 John Wiley & Sons, Ltd.
Frizzled‐7 and limb mesenchymal chondrogenesis: Effect of misexpression and involvement of N‐cadherin
Authors: Tufan A. Cevik , Daumer Kathleen M. , Tuan Rocky S.
Published: August 2002

Products of the Frizzled family of tissue polarity genes have been identified as putative receptors for the Wnt family of signaling molecules. Wnt‐signaling is implicated in the regulation of limb mesenchymal chondrogenesis, and our recent study indicates that N‐cadherin and related activities are functionally involved in Wnt‐7a‐mediated inhibition of chondrogenesis. By using an in vitro high‐density micromass culture system of chick limb mesenchymal cells, we have analyzed the spatiotemporal expression patterns and the effects on chondrogenesis of RCAS retroviral‐mediated misexpression of Chfz‐1 and Chfz‐7, two Frizzled genes implicated in chondrogenic regulation. Chfz‐1 expression was localized at areas surrounding the cartilaginous nodules at all time points examined, whereas Chfz‐7 expression was limited to cellular aggregates during initial mesenchymal condensation, and subsequently was down‐regulated from the centers toward the periphery of cartilage nodules at the time of chondrogenic differentiation, resembling the pattern of N‐cadherin expression. Chondrogenesis in vitro was inhibited and limited to a smaller area of the culture upon misexpression of Chfz‐7, but not affected by Chfz‐1 misexpression. Analyses of cellular condensation and chondrogenic differentiation showed that the inhibitory action of Chfz‐7 is unlikely to be at the chondrogenic differentiation step, but instead affects the earlier precartilage aggregate formation event. At 24 hr, expression of N‐cadherin, a key component of the cellular condensation phase of chondrogenesis, was delayed/suppressed in Chfz‐7 misexpressing cultures, and was limited to a significantly smaller cellular condensation area within the entire culture at 48 hr, when compared with control cultures. Chfz‐1 misexpressing cultures appeared similar to control cultures at all time points. However, neither Chfz‐1 nor Chfz‐7 misexpression affected mesenchymal cell proliferation in vitro. These results suggest that Chfz‐7 is active in regulating N‐cadherin expression during the process of limb mesenchymal chondrogenesis and that Chfz‐1 and Chfz‐7 are involved in different Wnt‐signaling pathways. © 2002 Wiley‐Liss, Inc.
Gamma‐tubulin in chicken erythrocytes: Changes in localization during cell differentiation and characterization of cytoplasmic complexes
Authors: Linhartová Irena , Novotná Božena , Sulimenko Vadym , Dráberová Eduarda , Dráber Pavel
Published: August 2002

The mechanism of marginal band (MB) formation in differentiating erythroid cells is not fully understood, and the proteins involved in nucleation of MB microtubules are largely unknown. To gain insights into the function of γ‐tubulin in MB formation, we have followed its distribution in developing chicken erythrocytes and characterized soluble forms of the protein. In early stages of erythroid cells differentiation, γ‐tubulin was present in microtubule‐organizing centers, mitotic spindles, as well as on MB. Its subcellular localization changed in the course of differentiation, and in postnatal peripheral erythrocytes γ‐tubulin was found only in soluble forms. After cold‐induced depolymerization γ‐tubulin in erythroid cells formed large clusters that were not observed in matured cells, and re‐growth experiments demonstrated that γ‐tubulin was not present in distinct nucleation structures at the cell periphery. Soluble γ‐tubulin formed complexes of various size and large complexes were prone to dissociation in the presence of high salt concentration. Interaction of γ‐tubulin with tubulin dimers was revealed by precipitation experiments. γ‐Tubulin occurred in multiple charge variants whose number increased in the course of erythrocyte differentiation and corresponded with decreased binding to MB. The presented data demonstrate for the first time that γ‐tubulin is a substrate for developmentally regulated posttranslational modifications and that the binding properties of γ‐tubulin or its complexes change during differentiation events. © 2002 Wiley‐Liss, Inc.
Expression of Ol‐KIP, a cyclin‐dependent kinase inhibitor, in embryonic and adult medaka (Oryzias latipes) central nervous system
Authors: Nguyên Vân , Suárez Eva María Candal , Sharif Ariane , Joly Jean‐Stéphane , Bourrat Franck
Published: August 2002

From an expression screen in a fish model, the medaka, we have isolated Ol‐KIP (Oryzias latipes‐kinase inhibitor protein), a new member of the KIP subfamily of cyclin‐dependent kinase (Cdk) inhibitors. We have analysed its expression in the developing and adult brain by in situ hybridization and by double labeling with Ol‐KIP mRNA and proliferating cell nuclear antigen (PCNA) antibodies. Ol‐KIP presents a complex expression pattern in several areas of the embryonic central nervous system, most often in close vicinity to proliferative neuroepithelia. We studied in great detail its expression in the optic tectum: Ol‐KIP is expressed in a ring‐shaped domain lying exactly between the proliferative and the postmitotic zones of this structure and is, therefore, potentially involved in cell cycle exit. In the adult CNS, Ol‐KIP expression persists in numerous nuclei, both close and distant from proliferative ventricular areas. So, Ol‐KIP expression is in part compatible with a sustained “stop signal” role for proliferation, but its expression in postmitotic zones suggests that KIP proteins may have late neuronal function(s), in addition to inhibiting Cdks. This first detailed study of the expression profile of a KIP gene in a nonmammalian vertebrate, thus, opens perspectives for analysing the role of these regulators in brain development and function. © 2001 Wiley‐Liss, Inc.
The relationship of self‐esteem and body esteem in women with and without eating disorders
Authors: Mendelson Beverley K. , McLaren Lindsay , Gauvin Lise , Steiger Howard
Published: August 2002

Objective

We investigated the predictive utility of three dimensions of body esteem in explaining self‐esteem in samples of eating‐disordered (ED) and nonclinical women.

Method

Participants comprised 74 ED women and 103 female university students. All women completed questionnaires measuring body esteem and self‐esteem and all provided information on height and weight. We ran hierarchical multiple regression analyses with self‐esteem as the outcome variable and participant status (clinical or non), body mass index (BMI), body esteem, and interaction terms as predictors.

Results

The main finding was a Body Esteem x Participant Status interaction involving the attribution dimension of body esteem. Specifically, among ED women, the higher their body esteem attribution (i.e., the more they endorsed items such as “I think my appearance would help me get dates”), the higher their self‐esteem; whereas this relationship was not found among the students.

Discussion

Our results contribute to an emerging profile of ED patients as highly socially sensitive. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 318–323, 2002; DOI 10.1002/eat.10011
Does environment matter? A review of nonshared environment and eating disorders
Authors: Klump Kelly L. , Wonderlich Stephen , Lehoux Pascale , Lilenfeld Lisa R.R. , Bulik Cynthia
Published: August 2002

Objective

Nonshared environmental influences are experiences that are unique to siblings reared in the same family. We review studies highlighting the importance of nonshared factors for the development of eating disorders and suggest areas for future research.

Methods

Findings from behavioral genetic studies of eating disorders as well as methodological issues are reviewed.

Results

Twin studies suggest that approximately 17%–46% of the variance in both anorexia nervosa (AN) and bulimia nervosa (BN) can be accounted for by nonshared environmental factors. Studies directly examining these influences are scarce, although initial data indicate that differential paternal relationships, body weight teasing, peer group experiences, and life events may account for the development of eating pathology in one sibling versus another.

Discussion

Additional research is needed to identify specific nonshared environmental influences on eating disorders such as differential parental and sibling treatment, disparate peer group characteristics, and differential experience of life events such as physical and sexual abuse. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 118–135, 2002; DOI. 10.1002/eat.10024
Preoccupation with weight and disordered eating behaviors of entering students at a University in Lebanon
Authors: Afifi‐Soweid Rema A. , Najem Kteily Martine B. , Shediac‐Rizkallah Mona C.
Published: August 2002

Objectives

This research explores the prevalence of preoccupation with weight indicators and disordered eating behaviors among entering university students, and identifies factors associated with these indicators and behaviors.

Method

Data was collected by means of a self‐administered questionnaire. Comparisons were made by gender, mother's education, and body mass index (BMI).

Results

The final sample included 954 students. The indicators held most “often” included a desire to be thinner, and an awareness of caloric content. The behaviors engaged in “most” often included strenuous exercising, and avoiding particular foods. Both indicators and behaviors varied by gender and body mass index.

Discussion

The prevalence of indicators and behaviors is high. Body mass index is a critical variable to consider in the development of interventions. Further research should explore the context surrounding these indicators and behaviors. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 32: 52–57, 2002.
A method of push‐based communications scheduling for minimum latency time
Authors: Aono Masahiro , Ueda Takasumi , Takubo Akio , Watanabe Takashi , Mizuno Tadanori
Published: August 2002

It is desirable in data broadcast that, when data are updated, a server outputs the updated data as soon as possible in order to deliver the latest data to clients. When two or more data updates take place at the same time, the server has to choose which data to output first. We first define the latency time, which is the elapsed time from the time data are updated to the time they are broadcast. Then, we propose methods to reduce mean latency time under the circumstance that each datum has various user request ratios and update probabilities. Furthermore, we discuss output data selecting algorithms which can decrease the computational load of the server. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(8): 40–48, 2001
A study of the decision of control parameters for adaptive automatic‐repeat request strategy
Authors: Tsukamoto Ken‐ichiro , Matsushima Toshiyasu , Hirasawa Shigeichi
Published: August 2002

In many practical transmission systems, transmission error rate of the channel is time‐varying. In previous works for controlling the time‐varying channel, the state of the channel is estimated and is uniquely determined. Then, the optimum value is chosen as a control parameter for the determined state. However, there is a discrepancy between the actual channel state and estimated state. The optimum control parameter determined for the estimated state does not necessarily provide the best performance presented by some object function in error control such as throughput efficiency. In this study, the expected value of throughput is calculated by using the posterior probability for each state and an algorithm in which the control parameter is selected to maximize the expected performance is proposed. From the viewpoint of the statistical decision theory, it is shown that this selection is the optimum in maximizing the throughput under the Bayes criterion. Using simulation, the proposed method is evaluated and its effectiveness is shown. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(11): 61–70, 2001
Single‐fed crossed v‐dipoles with four masts for circular polarization
Authors: Nakamura Takashi , Honjo Takahiro
Published: August 2002

In this paper, a new single‐fed crossed V‐dipole antenna for a circular polarization is proposed. This antenna is single‐fed with four arms supporting the two V‐dipoles on the reflector used as a balun as well as a 90° phase shift divider. The symmetrically placed supporting arms can be viewed as transmission lines. From the current distributions of the equivalent circuit of these lines, the input impedance of the V‐dipoles and the circular polarization condition with regard to the antenna height and the stub location are derived. Based on these quantities, a circularly polarized antenna is designed and its characteristics are derived. It is found that there exists a structure for which the axial ratio can be made substantially wider than other antennas with a size of one‐half wavelength. By means of experiments, the validity of the theoretical results is confirmed. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(11): 44–51, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1136
Analysis of scattering by means of atomic model
Authors: Hosono Hiroyuki , Hosono Toshio
Published: August 2002

An atomic model has been proposed to analyze scattering problems by a dielectric cylinder of arbitrary cross section. The advantages and differences from the usual method of moments are: (1) the field exiting an atom is that due to all the sources other than that atom, (2) the cause‐and‐effect relationship is clear and no singularity occurs, (3) various scatterers, from dielectrics to conductors, can be handled, (4) dielectric scatterers mixed with conductors can be treated, (5) all the information about the inhomogeneity of the scatterer appears only on the diagonal of the matrix, and (6) the theory smoothly connects with the atomic theory, which is educationally desirable. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(7): 31–38, 2001
An analysis of higher‐order of a GaAs FET depending on IMD source impedance and its application to a design of low‐distortion MMIC power amplifiers
Authors: Kusunoki Shigeo , Furuta Takeshi , Murakami Yoshikazu
Published: August 2002

Although the π/4 phase shift modulation schemes used in quadrature phase shift keying (QPSK) are important approaches to ensuring efficient frequency usage in digital portable telephone systems, they also require linearity of the power amplifiers, they also require linearity of the power amplifiers, which is an undesirable constraint from the standpoint of efficiency. In this work, we describe a unified approach to this problem based on the idea that distortion can be effectively decreased by creating dips or “bumps” in the intermod characteristics, due to the dependence of the adjacent channel power (ACP) leakage on input power. For the special case of an impedanceZesconnected to the gate of a FET, we use Volterra series to quantitatively demonstrate how the appearance of such dips or bumps is related both toZesand to the fifth intermod (IM5). We then show analytically that when these dips or bumps are generated effectively, they can suppress IM5. Finally, we show that the resulting decrease in intermodulation distortion and improved efficiency make this method useful in the design of MMIC power amplifiers used in Personal Handy Phone (PHS) service. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(4): 10–21, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1100
Multimodal independent component analysis—A method of feature extraction from multiple information sources
Authors: Akaho Shotaro , Umeyama Shinji
Published: August 2002

We propose a method to extract features from a pair of multivariate information sources. CCA (canonical correlation analysis) is a traditional method for this purpose, but it does not always succeed in producing features that are nonlinearly related, because of a Gaussian assumption. We extend the framework of CCA by introducing a criterion used in ICA (independent component analysis). The proposed framework MICA (multimodal ICA) maximizes mutual information between a pair of extracted features from the two modalities, with the features extracted from each modality being statistically independent. The cost function is given by a weighted sum of the two criteria, and it is approximated by Gram–Charlier expansion. The gradient descent learning algorithm is derived to optimize this approximated function by taking a natural gradient. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(11): 21–28, 2001