bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein kinase C‐induced disorganization and endocytosis of photosensitive membrane in Limulus ventral photoreceptors
Authors: Dabdoub Alain , Payne Richard , Jinks Robert N.
Published: August 2002

Protein kinase C (PKC) desensitizes the light response in photoreceptors from the ventral optic nerve of the horseshoe crab Limulus. Photoisomerization of Limulus rhodopsin leads to phosphoinositide hydrolysis, resulting in the production of inositol trisphosphate and diacylglycerol (DAG). Inositol trisphosphate mobilizes intracellular stores of Ca2+, resulting in photoreceptor excitation in Limulus, while DAG may activate PKC. We investigated whether PKC‐mediated desensitization of the photoresponse is accompanied by ultrastructural changes in the rhodopsin‐bearing photosensitive membrane (rhabdom) in Limulus ventral photoreceptors. PKC activation by (–)‐indolactam V in darkness induces disorganization and swelling of the rhodopsin‐containing microvilli and endocytosis of rhabdomeral membrane. The effects of (–)‐indolactam V on dark‐adapted photoreceptor ultrastructure are reversible, are stereospecific, are blocked by coapplication of PKC inhibitors, and closely match those induced by continuous, bright light. Rhabdom disorganization and endocytosis via PKC activation may, therefore, contribute to desensitization of the light‐adapted photoreceptor. J. Comp. Neurol. 442:217–225, 2002. © 2001 Wiley‐Liss, Inc.
Chemically and morphologically identifiable glomeruli in the rat olfactory bulb
Authors: St. John James A. , Key Brian
Published: August 2002

Primary olfactory neurons that express the same odorant receptor are distributed mosaically throughout the olfactory neuroepithelium lining the nasal cavity, yet their axons converge and form discrete glomeruli in the olfactory bulb. We previously proposed that cell surface carbohydrates mediate the sorting out and selective fasciculation of primary olfactory axons en route to glomeruli. If this were the case, then axons that terminate in the same glomerulus would express the same complement of cell surface carbohydrates. In this study, we examined the expression of a novel carbohydrate (NOC‐3) on neural cell adhesion molecule in the adult rat olfactory system. NOC‐3 was expressed by a subset of neurons distributed throughout the olfactory neuroepithelium. The axons of these neurons entered the nerve fiber layer and terminated in a subset of glomeruli. It is interesting to note that we identified three unusually large glomeruli in the lateral, ventrolateral, and ventromedial olfactory bulb that were innervated by axons expressing NOC‐3. NOC‐3‐expressing axons sorted out and fasciculated into discrete fascicles prior to entering these glomeruli. Each of these glomeruli was in a topographically fixed position in the olfactory bulbs of the same animal as well as in different animals, and their lengths were approximately 10% of the total length of the bulb. They could be identified reliably by both their topographical position and their unique morphology. These results reveal that axons expressing the same cell surface carbohydrates consistently target the same topographically fixed glomeruli, which supports a role for these molecules in axon navigation in the primary olfactory nerve pathway. J. Comp. Neurol. 436:497–507, 2001. © 2001 Wiley‐Liss, Inc.
Distribution and ultrastructure of tachykinin‐like immunoreactivity in the frog (rana esculenta) spinal cord, notably, the dorsal horn
Authors: Salio Chiara , Fischer Jacqueline , Wijkhuisen Anne , Franzoni Maria Fosca , Conrath Marie
Published: August 2002

Tachykinins are involved in pain transmission at the spinal level. In frog, at least four tachykinins [TK] have been isolated from the brain, but their organization in the dorsal horn of the spinal cord is still poorly known. We have reexamined TK distribution by immunocytochemistry using an antibody recognizing the sequence common to all tachykinins in the spinal cord and dorsal root ganglia of the green frog Rana esculenta. A dense tachykinin‐like immunoreactivity (TK‐LI) was observed in the dorsolateral fasciculus or Lissauer's tract running ventromedial to the entry of the dorsal root and in numerous small and medium‐sized dorsal root ganglion cells showing a primary afferent origin for part of TK‐LI of the dorsal horn. The observation of numerous cell bodies in the dorsal horn, in addition, suggested a local or propriospinal origin. One group of cells was localized at the entrance of the Lissauer's tract TK‐LI fibers into the dorsal horn, and another group was localized in the upper dorsal horn, a region with a low density of TK‐LI fibers. It was suggested that the latter group may correspond to neurokinin B. Electron microscopic examination of the Lissauer's tract showed numerous immunoreactive axons, some located at the center of glomerular‐like arrangements, suggesting that the information brought by these fibers may be transmitted and most probably modulated before their entry in the dorsal horn. In conclusion, the functional organization of tachykinins in the frog spinal cord seems to be similar to that of mammals, albeit with a different morphological organization. J. Comp. Neurol. 433:183–192, 2001. © 2001 Wiley‐Liss, Inc.
Targeting of serotonin 1a receptors to dopaminergic neurons within the parabrachial subdivision of the ventral tegmental area in rat brain
Authors: Doherty Michael D. , Pickel Virginia M.
Published: August 2002

Serotonin (5‐hydroxytryptamine [5‐HT]) modulates dopamine‐related cognitive functions and motor activity through activation of selective receptor subtypes including 5‐HT1A. Potential targets for these 5‐HT1A‐mediated actions of 5‐HT include mesocortical and mesolimbic dopaminergic neurons having partially segregated distribution in the parabrachial and paranigral subdivisions of the ventral tegmental area (VTA), respectively. We therefore examined the ultrastructural immunocytochemical localization of the 5‐HT1A receptor in the parabrachial (VTApb) and paranigral (VTApn) subdivisions of rat VTA, to determine 1) the functional sites for receptor activation, and 2) the cellular associations between this receptor and dopaminergic neurons identified by their tyrosine hydroxylase (TH) content. In each region, 5‐HT1A immunoreactivity was mainly observed in somatodendritic profiles, but it was also present in small unmyelinated axons and in a few axon terminals and glia, suggesting a role for 5‐HT1A receptors in presynaptic and glial functions, as well as postsynaptic neuronal activation, in VTA. In somatodendritic profiles, 5‐HT1A gold particles were mainly localized to tubulovesicles presumed to be smooth endoplasmic reticulum. In addition, however, in distal dendrites receiving multiple inputs the receptor was targeted to selective postsynaptic junctions, or more randomly distributed on nonsynaptic portions of the plasma membrane. Of the 5‐HT1A‐labeled dendrites, 64% in VTApb and 44% in VTApn contained TH. These findings suggest a reserve of cytoplasmic 5‐HT1A receptors that are mobilized to functional postsynaptic sites on the plasma membrane by afferent input to distal dendrites in the VTA. They also indicate that 5‐HT1A activation may affect a larger population of dopaminergic neurons in VTApb compared with VTApn, thus having a potentially greater impact on cognitive functions modulated by mesocortical dopaminergic neurons. J. Comp. Neurol. 433:390–400, 2001. © 2001 Wiley‐Liss, Inc.
Neuropeptide Y immunoreactivity in cutaneous sympathetic and sensory neurons during development of the guinea pig
Authors: Morris Judy L. , Anderson Rebecca L. , Gibbins Ian L.
Published: August 2002

Different levels of the cutaneous vasculature are innervated selectively by subpopulations of sympathetic neurons distinguished by the presence or absence of immunoreactivity (‐IR) for neuropeptide Y (NPY). This study used multiple‐labelling immunohistochemistry to examine the appearance of NPY‐IR in neurons innervating cutaneous vessels in the ear pinna of embryonic, fetal, and neonatal guinea pigs. NPY‐immunoreactive axons were detected in the ear bud at embryonic day 25. However, these axons lacked IR for tyrosine hydroxylase (TH) and often ran in bundles with substance P (SP)‐immunoreactive axons close to the epidermis. Many neuronal somata in the cervical dorsal root ganglia (DRG) at late embryonic stages contained NPY‐IR with or without SP‐IR, but no NPY‐IR was detected in DRG or subepidermal axons by late fetal stages. IR for calcitonin gene‐related peptide increased in DRG neurons from midfetal to late fetal stages, after the decrease in NPY‐IR. Populations of TH‐IR neurons with or without NPY‐IR were present in the superior cervical ganglion (SCG) from midembryonic stages. TH‐immunoreactive axons were not detected in the ear pinna until midfetal stages, when axons with TH‐IR and NPY‐IR innervated proximal arteries and TH‐immunoreactive axons without NPY‐IR innervated distal vessels. Vasoactive intestinal peptide‐IR was detected transiently in most fetal SCG neurons with TH‐IR and NPY‐IR but was not detected in cutaneous axons. These results demonstrate that selective expression of NPY by subpopulations of sympathetic neurons occurs prior to innervation of their targets. This suggests that target contact is not required to establish appropriate patterns of expression of peptide neurotransmitters by cutaneous sympathetic neurons. J. Comp. Neurol. 437:321–334, 2001.© 2001 Wiley‐Liss, Inc.
Identification of a nonmammalian Golf subtype: Functional role in olfactory signaling of airborne odorants in Xenopus laevis
Authors: Mezler Mario , Fleischer Jörg , Conzelmann Sidonie , Korchi Ahmed , Widmayer Patricia , Breer Heinz , Boekhoff Ingrid
Published: August 2002

Attempts to identify the Gα subtypes in the two compartments of the olfactory system from Xenopus, which are supposed to be specialized for detecting aquatic and volatile odorous compounds, revealed that a Gαo1 subtype is characteristic for the “water nose,” the lateral diverticulum, whereas a novel Gαs subtype predominates in the “air nose,” the medial diverticulum. The newly identified Gαs‐type is more closely related to Gαolf of rat and human than to the known Gαs‐isoform of Xenopus; it is therefore considered the first identified nonmammalian Gαolf subtype. Sequence comparison of Gαolf from amphibia and mammals revealed a particular conservation within the α‐helical domains, which are supposed to control the GDP/GTP‐exchange rate. The selective expression of different Gα subtypes in the two anatomically separated and functionally specialized nasal compartments parallels the expression of distinct classes of olfactory receptors. Moreover, biochemical analysis revealed that stimulation with appropriate odorous compounds elicits the formation of inositol trisphosphate in the lateral diverticulum. In contrast, cyclic adenosine monophosphate signals were induced in the medial diverticulum, and this response appears to be mediated by the novel Gαolf subtype. The data indicate that olfactory sensory neurons in each of the nasal cavities are equipped not only with defined sets of receptor types but also with a distinct molecular machinery for the chemo‐electrical transduction process. J. Comp. Neurol. 439:400–410, 2001. © 2001 Wiley‐Liss, Inc.
Numerical solution of Rayleigh equation in non‐linear vibration
Authors: Chen Y. Z. , Lee Kang Yong
Published: August 2002

Numerical solution of the Rayleigh equation in non‐linear vibration is studied in this paper. The differential equation is integrated on a particular interval (0, Tp2) with the initial value condition, u=Ai and du/dt=0 at the time t=0. The value Tp2 is determined from the condition such that the trajectory of motion on the phase plane is a unclosed path around the original point with the both starting and the end point on the positive real axis. The target function method is developed to obtain the particular value Tp2. The obtained Ai+1(=u(Tp2)) will be used in the initial value condition of the next round integration. A stable periodic motion is obtained after some rounds of integration. The solution technique is out of the small parameter assumption in the Rayleigh equation. Finally, numerical examples and results are given. Copyright © 2001 John Wiley & Sons, Ltd.
A large time incremental finite element method for finite deformation problem
Authors: Liu Y. , Peng X.
Published: August 2002

Based on the process optimal control variational principle, some new ideas for finite deformation analysis using large increment are proposed. Combined with hyperelastic–plastic constitutive equation, the governing equations and the corresponding numerical algorithm are formulated. The proposed approaches are validated with the application to the analysis for finite deformation involving contact and friction. Copyright © 2001 John Wiley & Sons, Ltd.
Improving convergence to steady state of implicit SUPG solution of Euler equations
Authors: Catabriga L. , Coutinho A. L. G. A.
Published: August 2002

A procedure to improve convergence towards steady state in inviscid flow simulations is presented. This procedure detects convergence stagnation as the solution progresses, and freezes the shock‐capturing term of an implicit, semi‐discrete SUPG finite element formulation in conservation variables with local time‐stepping. Numerical experiments show that machine zero solutions are obtained with a small number of time steps, without loss of accuracy. Copyright © 2002 John Wiley & Sons, Ltd.
Study of the reconstruction of reflectance curves based on tristimulus values: Comparison of methods of optimization
Authors: Dupont Daniel
Published: August 2002

This article presents and compares different methods applied to the reconstruction of reflectance curves. These are optimization methods such as the simplex method, simulated annealing, genetic algorithms, neural networks, and Hawkyard's method, which is specific to colorimetry. Improvements have been made to these methods to maximize their application, notably to ensure a convergence toward the global optimum by avoiding being trapped in local optima and to obtain physically viable reflectance curves. Objective and subjective criteria were used to compare these methods; the study used textile samples (cotton fibers), with a panel of 15 samples covering the CIELAB L*a*b* space. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 88–99, 2002; DOI 10.1002/col.10031
A study of color conspicuity for ease‐of‐use inference in visualization
Authors: Cooper Eric W. , Kamei Katsuari
Published: August 2002

Novice designers of visualizations need support to find easy‐to‐use color schemes for visualizations. This article introduces a method of conspicuity inference for a color selection support system that is applicable to a wide variety of visualizations. In previous research, data on color conspicuity by computer GUI interface were collected by having subjects adjust the relative sizes of two figures on a ground in order to find conspicuity balance. This article outlines a new conspicuity inference system, which uses a neural network to produce a color conspicuity value from the system RGB values of two figures and a potential ground. The output value is the ideal relative area of the two figures. This value is applied to visualization designs by weighting each conspicuity value with a ground coefficient, the relative size of every color in a design. Color selection and evaluation experiments show a significant relationship of conspicuity balance, as inferred by this system, for subjective ease‐of‐use evaluation scores for 200 novice designs. Topics for future research include developing the system's characteristically simple parameters within the limited scope and integrating conspicuity balance with other factors such as visibility, discriminability, and color harmony. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 74–82, 2002; DOI 10.1002/col.10033
Investigation of colour appearance models for illumination changes across media
Authors: Sueeprasan Suchitra , Luo M. Ronnier , Rhodes Peter A.
Published: August 2002

The key to achieving successful cross‐media colour reproduction is a reliable colour appearance model, which is capable of predicting the colour appearance across a variety of imaging devices under different viewing conditions. The two most commonly used media, CRT displays (soft copy) and printed images (hard copy), were included in this study using four complex images. The original printed images were captured using a digital camera and processed using eight colour appearance models (CIELAB, RLAB, LLAB, ATD, Hunt96, Nayatani97, CIECAM97s, and CAM97s2) and two chromatic adaptation transforms (von Kries and CMCCAT97).

Psychophysical experiments were carried out to assess colour model performance in terms of colour fidelity by comparing soft‐copy and hard‐copy images. By employing the memory‐matching method, observers categorized the reproductions displayed on a CRT and compared them to the original printed images viewed in a viewing cabinet. The experiment was divided into three phases according to the different colour temperatures between the CRT and light source, i.e., print (D50, A, and A) and CRT (D93, D93, and D50), respectively). It was found that the CIECAM97s‐type models performed better than the other models. In addition, input parameters for each model had a distinct impact on model performance. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 428–435, 2001
An additional Gibbs' state for the cubic Schrödinger equation on the circle
Authors: Vaninsky K. L.
Published: August 2002

An invariant Gibbs' state for the nonlinear Schrödinger equation on the circle was constructed by Bourgain [2,3] and McKean [6] out of the basic Hamiltonian using a trigonometric cutoff. The cubic nonlinear Schrödinger equation is a completely integrable system having an infinite number of additional integrals of motion. In this paper we construct the second invariant Gibbs' state from one of these additional integrals for the cubic NLS on the circle. This additional Gibbs' state is singular with respect to the Gibbs' state previously constructed from the basic Hamiltonian. Our approach employs the Ablowitz‐Ladik system, a completely integrable discretization of the cubic Schrödinger equation. © 2001 John Wiley & Sons, Inc.
Modeling and testing object‐oriented distributed systems with linear‐time temporal logic
Authors: Dietrich F. , Logean X. , Hubaux J.‐P.
Published: August 2002

We present a framework for constructing formal models of object‐oriented distributed systems and a property language to express behavioral constraints in such models. Most of the existing models have their origin in specific mathematical notations and/or concepts. In contrast, we have developed our model such that it accounts for a large set of phenomena associated with industrial implementations of object‐oriented distributed systems. The model that we propose, while closer to industrial concerns and practice, still has the powerful features of formal approaches. It also offers the possibility to automatically check at service run‐time that the final service implementation has not violated and is not violating properties expressed at the abstraction level of our model. In our model, which relies on event‐based behavioral abstraction, we use linear‐time temporal logic as the underlying formalism for the specification of properties. We introduce two novel operators which are especially useful for object‐oriented systems and which provide a number of advantages over the well‐known temporal logic operators. A recent decision of one of our industrial partners to adopt our proposal into one of their development platforms can be seen as a strong evidence of the relevance of our work and as a promising step towards a better understanding between the academic formal methods community and industry. Copyright © 2001 John Wiley & Sons, Ltd.
Space–time tradeoffs for parallel 3D reconstruction algorithms for virus‐structure determination
Authors: Marinescu Dan C. , Ji Yongchang , Lynch Robert E.
Published: August 2002

The 3D electron‐density determination of viruses, from experimental data provided by electron microscopy, is a data‐intensive computation that requires the use of clusters of PCs or parallel computers. In this paper we report on three parallel algorithms used for 3D reconstruction of asymmetric objects from their 2D projections. We discuss their computational, communication, I/O, and space requirements and present some performance data. The algorithms are general and can be used for 3D reconstruction of asymmetric objects for applications other than structural biology. Copyright © 2001 John Wiley & Sons, Ltd.
Advanced concurrency control in Java
Authors: Felber Pascal , Reiter Michael K.
Published: August 2002

Developing concurrent applications is not a trivial task. As programs grow larger and become more complex, advanced concurrency control mechanisms are needed to ensure that application consistency is not compromised. Managing mutual exclusion on a per‐object basis is not sufficient to guarantee isolation of sets of semantically‐related actions. In this paper, we consider ‘atomic blocks’, a simple and lightweight concurrency control paradigm that enables arbitrary blocks of code to access multiple shared objects in isolation. We evaluate various strategies for implementing atomic blocks in Java, in such a way that concurrency control is transparent to the programmer, isolation is preserved, and concurrency is maximized. We discuss these concurrency control strategies and evaluate them in terms of complexity and performance. Copyright © 2002 John Wiley & Sons, Ltd.
Dissociation and autobiographical memory specificity
Authors: Wessel Ineke , Merckelbach Harald , Kessels Chantal , Horselenberg Robert
Published: August 2002

Overgeneral autobiographical memory refers to a relative inability to respond to cue‐words with memories for specific events. The present study explored the relation between overgeneral memories and dissociative tendencies. Autobiographical memory performance of college students with high self‐reported dissociation was compared to that of students with low dissociation scores. Two different hypotheses were tested. The first assumes that dissociation reflects an avoidant information processing style. If true, the high dissociation group would be expected to display fewer specific memories than low‐dissociative individuals. The second hypothesis builds on the finding that dissociation overlaps with fantasy proneness. To the extent that fantasy proneness implicates good story‐telling abilities, one expects high dissociation individuals to display more rather than less specific memories. The results show that autobiographical memory did not differ between high and low dissociation groups, although group differences were found with regard to fantasy proneness. Copyright © 2001 John Wiley & Sons, Ltd.
BD Biosciences contributions in CD4 counting and immune status for HIV/AIDS
Authors: Hoffman Robert A. , Maino Vernon C. , Recktenwald Diether J. , Webster H. Kyle
Published: August 2002

BD Biosciences is a leader in the use of flow cytometry for determining immune system status and for counting CD4 cells in patients with human immunodeficiency virus (HIV) infection. The company has gained this position through many years of basic research and product development in immunology and cell biology, dye chemistry, immunoassays, instrumentation, and software. Some of the highlights of these developments and their historical perspective are described in this review. Cytometry (Clin. Cytometry) 50:129–132, 2002. © 2002 Wiley‐Liss, Inc.
Concatenated coding schemes and interleaving techniques over Rayleigh fading ionospheric channels
Authors: Nissopoulos I. K. , Dimakis C. E. , Kouris S. S.
Published: August 2002

In this paper the performance of a concatenated coding scheme is evaluated over a slow Rayleigh fading HF ionospheric link with additive white Gaussian noise (AWGN). Well‐known Ungerboeck TCM techniques onto an 8‐PSK signal set are used as inner codes and Reed–Solomon block codes as outer codes. The coded/modulated signal is further differentially encoded before transmission to combat random phase changes. Block interleaving techniques are necessary to randomise long bursts of errors caused by the fading channel. The performance of the proposed concatenated coding system is investigated for various Doppler spreads. Significant coding gains are achieved over uncoded, diversity or other conventionally coded systems with a small bandwidth expansion. Finally the interesting effects of interleaving on the behaviour of the proposed systems are analysed. Copyright © 2001 John Wiley & Sons, Ltd.
Design alternatives for wireless local area networks
Authors: Nicopolitidis P. , Papadimitriou G. I. , Pomportsis A. S.
Published: August 2002

In this paper an overview of the wireless local area network (LAN) area is provided. The two types of wireless LAN topologies used today, infrastructure and ad hoc, are presented. The requirements that a wireless LAN is expected to meet are discussed. These requirements impact on the implementation of both the Physical and MAC layer of a wireless LAN. The unique characteristics of wireless physical layers are discussed and the five technology alternatives used today are presented. MAC layer issues are discussed and the two existing standards, IEEE 802.11 and HIPERLAN 1, are examined. Polling‐based MAC protocols (RAP, GRAP) are also reviewed. Finally, an introduction is made to wireless technologies that interact with WLANs, such as personal area networking (PAN) and wireless ATM and an overview of HIPERLAN 2, a WLAN using ATM technology, is provided. Copyright © 2001 John Wiley & Sons, Ltd.
Real‐time bandwidth renegotiation through learnt behaviour
Authors: Griffiths J. M. , Cuthbert L. G.
Published: August 2002

In many cases traffic is aggregated from several sources, or simply has no well‐understood characteristics, and so it is difficult for the user to decide the basis on which bandwidth should be demanded. A strategy is described to determine the optimum way to decide when to renegotiate the traffic capacity provided in ATM and similar systems. The performance of the strategy is evaluated using simulations on traffic with theoretical distributions and also on recorded real traffic. The strategy appears to work and the results give insights into the very limited benefits obtained by increasing the granularity of the rates provided. Copyright © 2001 John Wiley & Sons, Ltd.
Asynchronous orthogonal decision‐feedback multiuser detector (AODFD) and its alternative decoding strategies
Authors: Chen Hsiao‐Hwa
Published: August 2002

This paper proposes a new CDMA multiuser detector, asynchronous orthogonal decision‐feedback detector (AODFD), and its alternative decoding schemes. The proposed AODFD does not require an infinitely long whiten filter in its feed‐forward stage, however, which is necessary in the traditional ADDFD detector reported in the literature. The updating algorithm of the AODFD detector is also much simplified if compared with that of ADDFD that requires computational intensive z‐transformed matrix inversion and spectral factorization. Results show that, despite its low complexity, the AODFD performs very well under multiple access interference. The proposed two new decoding strategies can also be chosen to cater for different operating scenarios. Copyright © 2001 John Wiley & Sons, Ltd.
Performance evaluation of LIBTA/hybrid time‐slot selection algorithm for cellular systems
Authors: Wen Jyh‐Horng , Chen Wen‐Jiang , Lin Shang‐Yo , Huang Kuo‐Ting
Published: August 2002

This paper studies the performance of radio assignment algorithms for portable access in cellular systems. Several channel access procedures are proposed and simulated using block oriented network simulator (BONeS) simulation of a model 36‐port system. Simulation results exhibit that load‐sharing system with LIBTA algorithm is better than directed retry system with the same algorithm by around 0.9 erlangs while better than quasi‐fixed channel assignment (QFCA) system by around 2 erlangs if the grade of service (GOS) is constrained to less than 10 per cent. Plus, a hybrid time‐slot selection procedure is proposed to enhance the system performance. It is observed that systems with hybrid time‐slot selection perform better than those with LIBTA algorithm in GOS under heavy load. It is also observed that load sharing system with hybrid time‐slot selection algorithm is better than directed retry system with the same algorithm by around 0.7 erlangs and better than QFCA system by around 2 erlangs. Copyright © 2001 John Wiley & Sons, Ltd.
Unfairness of measurement‐based admission controls in a heterogeneous environment
Authors: Lai Yuan‐Cheng , Tsai Sheng‐Fu
Published: August 2002

Admission controls are required to determine whether new connections should be admitted to networks. These controls ensure the quality of service (QoS) for data transmission. This paper introduces three measurement‐based admission control algorithms called Measured Sum, Hoeffding Bound, and Adaptive Weight Factor. The unfairness of these algorithms in a heterogeneous environment is investigated. Simulation results indicate that the fairness of the Measured Sum exceeds that of the other methods. Admission of connections with large peak rates or travelling many hops can be difficult. Copyright © 2001 John Wiley & Sons, Ltd.
Usefulness of Auto Cyto Fix (membrane filter method) for the application of immunohistochemistry
Authors: Iijima Junko , Shiina Yoshio , Ohkoudo Mitsuaki , Sakuma Kanae
Published: August 2002

We developed the Auto Cyto Fix (ACF) 1000 as an experimental model, which was adapted as a membrane filter method for automatically making smear preparations fixed with 95% ethanol. In this study, immunohistochemistry was applied to the cells smeared on the membrane filter, and effectiveness was examined.

Twenty‐four effusions and HeLa 229 cells were used. These cell samples were produced by the ACF1000 on the membrane filter and stained by the Papanicolaou method. After observation, these were decolored and stained by immunohistochemical techniques. Antibodies included CEA, EMA, and MIB‐1. CEA and EMA were detected by the indirect method, and were colored by DAB, AEC, and new fuchsin. MIB‐1 was detected by the immunoperoxidase (LSAB) and the immunofluorescence method.

A uniformly stabilized immunoreaction was obtained and was equivalent to or better than that of the conventional technique. In addition, there was no background staining on the membrane filter.

Based on these results, the membrane filter preparation produced by the ACF1000 was also effectively applied to immunohistochemical observations. Diagn. Cytopathol. 2002;26:56–60. © 2002 Wiley‐Liss, Inc.
Fine‐needle aspiration biopsy in diagnosis of follicular lymphoma: Cytomorphologic and immunohistochemical analysis
Authors: Saikia Uma Nahar , Dey Pranab , Saikia Biman , Das Ashim
Published: August 2002

Follicular lymphoma is a relatively uncommon type of non‐Hodgkin's lymphoma (NHL) thought to derive from follicular center cells. There are limitations to fine‐needle aspiration in the diagnosis of follicular NHL, and very few studies are available on it. We describe here the cytomorphologic features of eight biopsy‐proven cases of follicular NHLs and five biopsy‐proven cases of intermediate‐grade NHLs. Five cases of reactive lymphoid hyperplasia (RLH) diagnosed on cytology were also studied cytomorphologically. Image morphometry was done in follicular and intermediate‐grade NHLs, immunocytochemistry was done in follicular and intermediate‐grade NHLs, and immunocytochemistry for bcl‐2 expression was studied in five cases of follicular NHLs. The aspirate smears of follicular NHL showed the presence of higher grades, many to abundant (++ to +++) monomorphic lymphoid aggregates, with an increased number of mast cells. Lymphohistiocytic tangles and tingible body macrophages were not observed in any of the cases. Cytomorphologically, all the cases of intermediate‐grade NHL showed a predominantly monomorphic population of lymphoid cells with absent or few grades (+) of lymphoid aggregates. Image morphometric data analysis of each cell parameter for follicular and intermediate‐grade NHLs were found to be statistically insignificant (P > 0.05) and hence of little help in diagnosis of follicular vs. low‐grade NHLs. Immunocytochemistry for bcl‐2 expression in follicular NHL showed variable results, ranging from 0–90% (expressed as bcl‐2 index). Certain characteristic cytomorphological features such as the presence of monomorphic lymphoid cell aggregates and an increased number of mast cells are soft indicators for the diagnosis of follicular NHL on aspiration smears. Immunocytochemistry for bcl‐2 expression may be of help in cases with clinical and cytological suspicion of lymphoma. Image morphometry has a small role in this regard. Diagn. Cytopathol. 2002;26:251–256. © 2002 Wiley‐Liss, Inc.
Amylase crystalloids in salivary gland lesions: Report of a case with a review of the literature
Authors: López‐Ríos Fernando , Díaz‐Bustamante Teresa , Serrano‐Egea A. , Jiménez Juan , de Agustín Pedro
Published: August 2002

Several types of crystalloids may be found in fine‐needle aspiration cytology of salivary gland lesions. Amylase crystalloids (sometimes referred to as nontyrosine crystalloids) are tabular structures with frequent pointed ends that have received little attention until recent years. We report on a parotid cyst containing the latter type of crystalloids in a 51‐yr‐old white woman. The cytologic and radiologic findings were diagnostic of sialolithiasis. To the best of our knowledge, amylase crystalloids have been observed only in benign salivary gland lesions. Although this statement may be helpful in the diagnostic workup of patients presenting with parotid lumps, we do not recommend rendering a specific diagnosis based on the presence of such crystalloids. Good clinical and radiological correlation, as well as close follow‐up, is mandatory in this setting. Diagn. Cytopathol. 25:59–62, 2001. © 2001 Wiley‐Liss, Inc.
Extraction of DNA from oral cytological samples by scraping and smear method suitable for restriction site mutation analysis: A pilot study
Authors: Mollaoglu N. , Wilson M.J. , Cowpe J.G.
Published: August 2002

The restriction site mutation assay (RSM) can be used to measure base changes which occur in the DNA coding for bacterial restriction enzymes. The aim of this study was to investigate whether DNA, of sufficient quantity and quality for analysis by RSM, could be extracted from cells collected from precancerous lesions using a cytological smear technique. Six smears were collected from each of five lesions of leukoplakia displaying a variety of clinical appearances. Three methods for the extraction of DNA were compared. The commercial extraction method was shown to be most convenient and reproducible, routinely providing 1–5 μg of DNA per sample. Cell populations collected by a cytological smear technique can provide DNA of sufficient quantity and quality for analysis of RSM. Diagn. Cytopathol. 2001;25:83–85. © 2001 Wiley‐Liss, Inc.
Routine use of ThinPrep® method in fine‐needle aspiration material as an adjunct to standard smears
Authors: Salhadar Alia , Massarini‐Wafai Razan , Wojcik Eva M.
Published: August 2002

The purpose of this study was to evaluate the efficacy of routine use of ThinPrep® in fine‐needle aspiration (FNA) material as an adjunct to standard smears. We reviewed 50 consecutive, satisfactory‐for‐evaluation FNA materials in which ThinPrep® slides were obtained. In each case, Diff‐Quik‐stained and Papanicolaou‐stained smears were initially prepared, and the ThinPrep® slide was made from the needle/syringe rinse. Smears and ThinPrep® slides were evaluated for the presence of diagnostic material. In addition, the following questions were addressed: could the final diagnosis be made based on smears only, and did the ThinPrep® method add any additional information to the diagnosis? Smears were satisfactory for evaluation in 49/50 cases, and in one case diagnostic material was present on the ThinPrep® slide only. Thirty‐two out of 50 ThinPrep® slides contained material sufficient for evaluation. In 46/50 (92%) cases, final diagnoses could be made based on smears only. In 2 cases, ThinPrep® slides showed additional diagnostic material, and in another 2 cases were critical for the diagnosis. The routine use of ThinPrep® as an adjunct preparatory method to FNA material is not justified, and is associated with an additional, potentially nonreimbursable cost. Diagn. Cytopathol. 2001;25:101–103. © 2001 Wiley‐Liss, Inc.
Usefulness of concurrent Papanicolaou smear at time of cervical biopsy
Authors: Panos John C. , Jones Bruce A. , Mazzara Paul F.
Published: August 2002

The reliability and cost‐effectiveness of a repeat Papanicolaou (Pap) smear performed at the time of colposcopic biopsy is uncertain. To evaluate the usefulness of this practice, Pap smear and biopsy results of 718 patients were reviewed and compared: 619 patients had Pap smears performed prior to colposcopy with a 1.1% false‐negative rate, 97.5% sensitivity, and 83.6% positive predictive value. Ninety‐nine patients had Pap smears performed at the time of colposcopy with a 19.1% false‐negative rate, 56.8% sensitivity, and 92.6% positive predictive value. Repeat Pap smear at the time of colposcopy resulted in significant changes in the management of only 2 patients (2%) and more careful follow‐up in one (1%). Pap smears performed at colposcopic biopsy are less sensitive than those done prior to biopsy (P < 0.001). The clinical benefit of this practice is marginal, considering the added costs and potential detrimental effects to the colposcopic examination, provided patients receive adequate follow‐up. Diagn. Cytopathol. 25:270–273, 2001. © 2001 Wiley‐Liss, Inc.
Genetic polymorphisms of the human P2X7 receptor and relationship to function
Authors: Wiley James S. , Gu Ben J. , Zhang Weiyi , Worthington Rebecca A. , Dao‐Ung Phuong , Shemon Anne N. , Sluyter Ronald , Liang Simon , Barden Julian A.
Published: August 2002

Extracellular ATP has been shown to induce apoptotic death of many cell types of hematopoietic origin. This action of ATP is mediated via activation of P2X7 purinergic receptors, which show the unusual property of time‐dependent channel dilation to accept permeants as large as ethidium cation (314 Da). P2X7 function, measured by area under the ATP‐induced ethidium uptake curve, was 5‐fold greater for monocytes than lymphocytes, while polymorphs and platelets showed no ethidium uptake. Expression of P2X7 receptor, measured by the binding of a monoclonal antibody, was also 5‐fold greater on monocytes than lymphocytes. However, in some subjects, both normal and with chronic lymphocytic leukemia, the P2X7 receptor was nonfunctional despite good expression of P2X7 protein. Three single nucleotide polymorphisms were found in the P2X7 cDNA coding region, one of which correlated with P2X7 function. Thus, the homozygous substitution of alanine for glutamic acid at amino acid 496 led to complete loss of function of the P2X7 receptor, while the heterozygous polymorphism gave function half that of the germline P2X7 receptor. Drug Dev. Res. 53:72–76, 2001. © 2001 Wiley‐Liss, Inc.
Potent P2X7 receptor antagonists: Tyrosyl derivatives synthesized using a sequential parallel synthetic approach
Authors: Ravi R. Gnana , Kertesy Sylvia B. , Dubyak George R. , Jacobson Kenneth A.
Published: August 2002

Novel analogs of 1‐(N,O‐bis[5‐isoquinolinesulfonyl]‐N‐methyl‐L‐tyrosyl)‐4‐phenylpiperazine (KN‐62, 1) were synthesized and found to be potent antagonists in a functional assay, inhibition of ATP‐induced K+ efflux in HEK293 cells expressing recombinant human P2X7 receptors. Antagonism of murine P2X7 receptors was also observed. The analogs consisted of L‐tyrosine derivatives, of the general structure R1‐Tyr(OR2)‐piperazinyl‐R3, in which three positions were systematically varied in structure through facile acylation reactions. Each of the three positions was optimized in sequence through parallel synthesis alternating with biological evaluation, leading to the identification and optimization of potent P2X7 antagonists. The optimal groups at R1 were found to be large hydrophobic groups, linked to the α‐amino position through carbamate, amide, or sulfonamide groups. The benzyloxycarbonyl (Cbz) group was preferred over most sulfonamides and other acyl groups examined, except for quinoline sulfonyl. At R2, an arylsulfonate ester was preferred, and the order of potency was p‐tolyl, p‐methoxyphenyl, phenyl > α‐naphthyl, β‐naphthyl. A benzoyl ester was of intermediate potency. Aliphatic esters and carbonate derivatives at the tyrosyl phenol were inactive, while a tyrosyl O‐benzyl ether was relatively potent. The most potent P2X7 receptor antagonists identified in this study contained Cbz at the R1 position, an aryl sulfonate at the R2 position, and various acyl groups at the R3 position. At R3, t‐butyloxycarbonyl‐ and benzoyl groups were preferred. The opening of the piperazinyl ring to an ethylene diamine moiety abolished antagonism. In concentration–response studies, a di‐isoquinolinyl, Boc derivative, 4 (MRS2306), displayed an IC50 value of 40 nM as an antagonist of P2X7 receptor‐mediated ion flux and was more potent than the reference compound 1. Nα‐Cbz, Boc‐piperazinyl derivatives, 11 (MRS2317), 22 (MRS2326), and 41 (MRS2409) were less potent than 1, with IC50 values of 200–300 nM. Drug Dev. Res. 54:75–87, 2001. © 2001 Wiley‐Liss, Inc.
Prenatal ethanol exposure and spatial navigation: Effects of postnatal handling and aging
Authors: Gabriel Kara I. , Johnston Sarah , Weinberg Joanne
Published: August 2002

Prenatal ethanol exposure results in spatial navigation deficits in young and mid‐aged animals. In contrast, postnatal handling attenuates spatial deficits that emerge with age in animals that are not handled. Therefore, we investigated the ability of handling to attenuate spatial deficits in animals prenatally exposed to ethanol (E). Sprague‐Dawley male offspring from E, pair‐fed (PF), and control (C) groups were handled (H) or nonhandled (NH) from 1 to 15 days of age and tested on the Morris water maze at 2 or 13 to 14 months of age. In young animals, H‐E males had longer latencies to locate the submerged platform, and E animals, across handling conditions, showed altered search patterns compared to their PF and C counterparts. Mid‐aged animals had longer latencies than young animals, with no differences among E, PF, and C animals. However, corticosterone levels were higher in mid‐aged E than in C males. Handling did not attenuate impairments associated with either prenatal ethanol exposure or aging. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 345–357, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10023
Cholecystokinin receptor antagonists increase the rat pup's preference toward maternal‐odor and rug texture
Authors: Shayit Michal , Weller Aron
Published: August 2002

The role of the cholecystokinin (CCK) system in mediating the infant's natural preferences toward maternal‐related stimuli was examined by peripheral administration of selective CCKA and CCKB receptor antagonists (Devazepide and L‐365,260, respectively) to 11–12‐day‐old rats and presenting them with a 3‐minute preference test. In Experiment 1, the choice was between two floor textures, rug and plywood; the time spent on the relatively preferred side (rug) was measured. In Experiment 2, the odor of maternal faces emanated from one end of the test arena; time spent near that end was measured. These sensory stimuli were chosen as they represent olfactory and tactile aspects of the dam and nest. Compared to controls, both CCK receptor antagonists selectively increased the time spent on the preferred side, in both experiments, without affecting axillary temperature or locomotor activity. The results suggest that CCK may mediate and attenuate the infant's attraction toward naturally preferred stimuli. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 38: 164–173, 2001
Cardiovascular indices of physiological arousal in boys with fragile X syndrome
Authors: Roberts Jane E. , Boccia Maria L. , Bailey Donald B. , Hatton Deborah D. , Skinner Martie
Published: August 2002

In this study, the relationship between physiological arousal, as indexed by heart rate variability, was examined in boys with fragile X syndrome (FXS) and typically developing boys matched on chronological age. In addition, the relationship of heart activity to clinical and molecular factors in the group of boys with FXS was examined. Results suggest that boys with FXS have higher levels of heart activity during the passive phases, as reflected in shorter heart periods. This high level of heart activity appears to be due to increased sympathetic activity and reduced parasympathetic activity. Boys with FXS did not display the expected patterns of heart activity in response to phases of increasing challenge, and sympathetic and parasympathetic systems did not appear coordinated in these boys with FXS. Clinical factors may be related to neural regulation of heart activity while molecular factors do not appear to be. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 107–123, 2001
Identification of the components of taste mixtures by adults and children
Authors: Watson W. L. , Laing D. G. , Hutchinson I. , Jinks A. L.
Published: August 2002

Recently, it was reported that cognitive factors may have impeded the analysis of binary taste mixtures by 8‐ to 9‐year‐old children, resulting in them identifying only the strongest component in each mixture compared to adults who identified both components (Oram, Laing, Freeman, & Hutchinson, 2001). The current study aimed to overcome this limitation by employing different training procedures and different instructions when conducting the task. In particular, the training involved familiarization with the two stimuli at several levels of perceived intensity to facilitate identification of the varying levels of each stimulus in mixtures. Using a selective attention procedure, adults and children were required to identify the components of stimuli that contained water, sucrose (sweet), sodium chloride (salty), or were binary mixtures of these two tastants. Both groups were successful in identifying the component(s) in each stimulus, demonstrating the importance of appropriate training and test procedures when studying the sensory responses of children. Together with data from the earlier study by Oram et al. (2001) it is concluded that 8‐ to 9‐year‐olds have the cognitive skills to analyze taste mixtures in terms of the identity of the components and their perceived strengths. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 137–145, 2001