bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES IN RAPIDITY AND pT-SPECTRA OF PIONS IN HIGH ENERGY NN, NA AND AA COLLISIONS: A COMPREHENSIVE APPROACH
Authors: DE BHASKAR , BHATTACHARYYA S. , GUPTAROY P.
Published: November 2002

The present paper aims at testing a very simple approach to interpret the characteristics of inclusive production of pions in high energy NA and AA collisions by a somewhat in-depth analysis of the same for NN interactions; and also at reporting here thus some interesting observations made on the nature of rapidity and transverse momentum spectra of the produced pions. And this approach is built upon a newly offered master formula holding the key for converting the results of high energy nucleon–nucleon (NN) collision to the corresponding observables on differential and inclusive cross-sections for both nucleon–nucleus and nucleus–nucleus (heavy ion) collisions in a generalized form. The proposed formulae, used in a somewhat phenomenological way, can provide modestly reliable parametrization of data in the broad range of collision energy and the varied range of projectile-target combinations. This opens up the possibility of understanding in a quite unified manner the large amount of data on the rapidity and transverse momentum spectra in a wide range of interactions and energies starting right from ISR, rather Bevelac, to the relativistic heavy ion collisions (RHIC) via the various collider scales of energy. The agreements between the data and calculations, in most cases, are quite satisfactory both qualitatively and quantitatively. While highlighting this success, the limitation of the approach has also been pointed out in the end as clearly and categorically as possible.
CONSTRUCTION FORMULAE FOR SINGULAR VECTORS OF THE TOPOLOGICAL AND OF THE RAMOND N = 2 SUPERCONFORMAL ALGEBRAS
Authors: GATO-RIVERA BEATRIZ
Published: November 2002

We write down one-to-one mappings between the singular vectors of the Neveu–Schwarz N = 2 superconformal algebra and 16 + 16 types of singular vectors of the topological and of the Ramond N = 2 superconformal algebras. As a result one obtains the construction formulae for the latter using Dörrzapf's construction formulae for the Neveu–Schwarz singular vectors. The indecomposable singular vectors of the topological and of the Ramond N = 2 algebras ("no-label" and "no-helicity" singular vectors) cannot be mapped to singular vectors of the Neveu–Schwarz N = 2 algebra, but to subsingular vectors, for which no construction formulae exist.
A MONTE CARLO STUDY ON THE DYNAMICAL FLUCTUATIONS INSIDE QUARK AND ANTIQUARK JETS
Authors: ZHANG KUNSHI , CHEN GANG , LIU LIANSHOU
Published: November 2002

The dynamical fluctuations inside the quark and antiquark jets are studied using Monte Carlo method. Quark and antiquark jets are identified from the two-jet events in e+e- collisions at 91.2 GeV by checking them at parton level. It is found that the transition point exists inside both of these two kinds of jets. At this point the jets are circular in the transverse plane with respect to the property of dynamical fluctuations. The results are consistent with the fact that the third jet (gluon jet) was historically first discovered in e+e- collisions in the energy region 17–30 GeV.
ACCELERATION OF THE UNIVERSE IN TYPE-0 NONCRITICAL STRINGS
Authors: DIAMANDIS G. A. , GEORGALAS B. C. , MAVROMATOS N. E. , PAPANTONOPOULOS E.
Published: November 2002

Presently there is preliminary observational evidence that the cosmological constant might be nonzero, and hence that our universe is eternally accelerating (de Sitter). This poses fundamental problems for string theory, since a scattering matrix is not well defined in such universes. In a previous paper we have presented a model, based on (nonequilibrium) noncritical strings, which is characterized by eventual "graceful" exit from a de Sitter phase. The model is based on a type-0 string theory, involving D3 brane worlds, whose initial quantum fluctuations induce the noncriticality. We argue in this paper that this model is compatible with the current observations. A crucial role for the correct "phenomenology" of the model is played by the relative magnitude of the flux of the five-form of the type 0 string to the size of five of the extra dimensions, transverse to the direction of the flux-field. We do not claim, at this stage at least, that this model is a realistic physical model for the universe, but we find it interesting that the model cannot be ruled out immediately, at least on phenomenological grounds.
EXACT SOLUTIONS OF DIRAC AND SCHRÖDINGER EQUATIONS FOR A LARGE CLASS OF POWER-LAW POTENTIALS AT ZERO ENERGY
Authors: ALHAIDARI A. D.
Published: November 2002

We obtain exact solutions of Dirac equation for radial power-law relativistic potentials at rest mass energies. It turns out that these are the relativistic extension of a subclass of exact solutions of Schrödinger equation at zero energy carrying representations of SO(2,1) Lie algebra. The latter are obtained by point canonical transformations of the exactly solvable problem of the three dimensional oscillator. The wave function solutions are written in terms of the confluent hypergeometric functions and almost always square integrable. For most cases these solutions support bound states at zero energy. Some exceptional unbounded states are normalizable for nonzero angular momentum. Using a generalized definition, degeneracy of the nonrelativistic states is demonstrated and the associated degenerate observable is defined.
EXACT RENORMALIZATION OF MASSLESS QED2
Authors: CASANA RODOLFO , DIAS SEBASTIÃO ALVES
Published: November 2002

We perform the exact renormalization of two-dimensional massless gauge theories. Using these exact results we discuss the cluster property and confinement in both the anomalous and chiral Schwinger models.
WHAT DO TOPOLOGISTS WANT FROM SEIBERG–WITTEN THEORY?
Authors: IGA KEVIN
Published: November 2002

In 1983, Donaldson shocked the topology world by using instantons from physics to prove new theorems about four-dimensional manifolds, and he developed new topological invariants. In 1988, Witten showed how these invariants could be obtained by correlation functions for a twisted N = 2 SUSY gauge theory. In 1994, Seiberg and Witten discovered dualities for such theories, and in particular, developed a new way of looking at four-dimensional manifolds that turns out to be easier, and is conjectured to be equivalent to, Donaldson theory.

This review describes the development of this mathematical subject, and shows how the physics played a pivotal role in the current understanding of this area of topology.
DYNAMICS OF MASSIVE SCALAR FIELDS IN dS SPACE AND THE dS/CFT CORRESPONDENCE
Authors: CHANG ZHE , GUAN CHENG-BO
Published: November 2002

Global geometric properties of dS space are presented explicitly in various coordinates. A Robertson–Walker-like metric is deduced, which is convenient to be used in the study of dynamics in dS space. Singularities of wave functions of massive scalar fields at boundary are demonstrated. A bulk-boundary propagator is constructed by making use of the solutions of equations of motion. The dS/CFT correspondence and the Strominger mass bound is shown.
The Political Economy of Monetary Institutions
Authors: Bernhard William , Broz J. Lawrence , Clark William Roberts
Published: November 2002

In recent decades, countries have experimented with a variety of monetary institutions, including alternative exchange-rate arrangements and different levels of central bank independence. Political economists have analyzed the choice of these institutions, emphasizing their role in resolving both the time-inconsistency problem and dilemmas created by an open economy. This “first-generation” work, however, suffers from a central limitation: it studies exchange-rate regimes and central bank institutions in isolation from one another without investigating how one monetary institution affects the costs and benefits of the other. By contrast, the contributors to this volume analyze the choice of exchange-rate regime and central bank independence together and, in so doing, present a “second generation” of research on the determinants of monetary institutions. The articles incorporate both economic and political factors in explaining the choice of monetary institutions, investigating how political institutions, democratic processes, political party competition, and interest group pressures affect the balance between economic and distributional policy objectives.
Partisan and Electoral Motivations and the Choice of Monetary Institutions Under Fully Mobile Capital
Authors: Clark William Roberts
Published: November 2002

Central bank independence and pegged exchange rates have each been viewed as solutions to the inflationary bias resulting from the time inconsistency of discretionary monetary policy. While it is obvious that a benevolent social planner would opt for such an institutional solution, it is less obvious that a real-world incumbent facing short-term partisan or electoral pressures would do so. In this article, I model the choice of monetary institutions from the standpoint of a survival-maximizing incumbent. It turns out that a wide range of survival-maximizing incumbents do best by forfeiting control over monetary policy. While political pressures do not, in general, discourage monetary commitments, they can influence the choice between fixed exchange rates and central bank independence. I highlight the importance of viewing fiscal policy and monetary policy as substitutes and identify the conditions under which survival-maximizing incumbents will view fixed exchange rates and central bank independence as substitutes. In so doing, I provide a framework for integrating other contributions to this volume.
Real Sources of European Currency Policy: Sectoral Interests and European Monetary Integration
Authors: Frieden Jeffry A.
Published: November 2002

In the thirty years before Economic and Monetary Union was achieved, European currency policies varied widely among countries and over time. In this article, I argue that the sectoral impact of regional exchange-rate arrangements, in particular their expected real effects on European trade and investment, exerted a powerful influence on the course of European monetary integration. The principal benefit of fixing European exchange rates was facilitation of cross-border trade and investment within the European Union (EU); the principal cost of fixed rates was the loss of national governments' ability to use currency policy to improve their producers' competitive position. Empirical results indeed indicate that a stronger and more stable currency was associated with greater importance of manufactured exports to the EU's hard-currency core, while depreciations were associated with an increase in the net import competition faced by the country's producers. This suggests a powerful impact of real factors related to trade and investment, and of private interests concerned about these factors, in determining national currency policies.
Political System Transparency and Monetary Commitment Regimes
Authors: Broz J. Lawrence
Published: November 2002

Central bank independence (CBI) and fixed exchange rates are alternative monetary commitments that differ intransparency. While CBI is opaque and difficult to monitor, a commitment to a fixed exchange rate is easily observed. Political systems also vary in terms of transparency. I argue that the transparency of monetary commitments and the transparency of political systems aresubstitutes. Where political decision making is opaque (autocracies), governments must look to a commitment that is more transparent and constrained (fixed exchange rates) than the government itself. The transparency of the monetary commitment substitutes for the transparency of the political system to engender low inflation. Where the political process is transparent (democracies), a formal commitment to CBI can produce lower inflation because private agents and the political opposition are free to detect and punish government interference with the central bank. Statistical results indicate that (1) autocracies are more likely to adopt exchange-rate pegs than democracies, and (2) CBI is effective in limiting inflation in nations with high levels of political transparency.
Nutritional Success on the Great Plains: Nineteenth-Century Equestrian Nomads
Authors: Prince Joseph M. , Steckel Richard H.
Published: November 2002

Native Americans have often been portrayed as merely unfortunate victims of European disease and aggression, but data on human stature show—and travelers' accounts and skeletal records confirm—that the equestrian Plains nomads were ingenious, adaptive, and nutritionally successful in the face of exceptional demographic stress. Much of their extraordinary achievement can be attributed to a rich and varied diet, a modest disease load other than epidemics, a remarkable facility at reorganization following demographic disasters, and egalitarian principles of operation.
Property Devolution in Tuscany
Authors: Emigh Rebecca Jean
Published: November 2002

Much of the historical demographic literature focuses on inheritance, and, in particular, how parents' transmission of land to their offspring facilitated their economic survival. Thus, inheritance practices are often linked to age of marriage and household structure. Analyses of the fifteenth-century notarial documents and tax declarations of smallholders in a region of Tuscany called the Val di Cecina illustrate the many forms of property devolution that these smallholders used and the different ways that they gained access to land through local markets. Given the high mortality rates that prevented a predictable transmission of property between the generations, the local markets, and the varieties of property devolution, inheritance may have been less important for economic survival and age of marriage in the Val di Cecina than in other regions, indicating the variability of inheritance in preindustrial settings.
Did Montaigne Love His Children? Demography and the Hypothesis of Parental Indifference
Authors: Woods Robert
Published: November 2002

Philippe Aries' hypothesis that parental indifference is inversely related to infant and child survival has proved to be particularly influential during the last four decades. Aries uses Montaigne's apparent indifference to the deaths of his own infant children as an example to support his case. But it can be argued on the basis of firmer supporting evidence not only that Montaigne was a caring father but also that infant and childhood mortality were not universally high in modern Europe.
Broken Homes: The “Missing” Children of the 1910 Census
Authors: Moehling Carolyn M.
Published: November 2002

Progressive-era activists claimed that poverty led to broken homes: Impoverished parents—particularly single mothers—were compelled to place children in the care of relatives or institutions. The 1910 census asked all ever-married women how many of their children were alive on the census date. Many women had “missing” children; they reported having more than were living with them. Nearly 25 percent of white single mothers and more than 30 percent of African-American single mothers under age thirty-five had missing children, many of them likely in substitute care. Sizable fractions of young African-American married mothers and remarried mothers of both races also had missing children. The data indicate that placing children in substitute care was associated with limited household resources but was also related to the migration patterns of the period.
Intramucosal–arterial PCO
2 gap fails to reflect intestinal dysoxia in hypoxic hypoxia
Authors: Dubin Arnaldo , Murias Gastón , Estenssoro Elisa , Canales Héctor , Badie Julio , Pozo Mario , Sottile Juan P , Barán Marcelo , Pálizas Fernando , Laporte Mercedes
Published: November 2002

Introduction

An elevation in intramucosal–arterial PCO2 gradient (ΔPCO2) could be determined either by tissue hypoxia or by reduced blood flow. Our hypothesis was that in hypoxic hypoxia with preserved blood flow, ΔPCO2 should not be altered.

Methods

In 17 anesthetized and mechanically ventilated sheep, oxygen delivery was reduced by decreasing flow (ischemic hypoxia, IH) or arterial oxygen saturation (hypoxic hypoxia, HH), or no intervention was made (sham). In the IH group (n = 6), blood flow was lowered by stepwise hemorrhage; in the HH group (n = 6), hydrochloric acid was instilled intratracheally. We measured cardiac output, superior mesenteric blood flow, gases, hemoglobin, and oxygen saturations in arterial blood, mixed venous blood, and mesenteric venous blood, and ileal intramucosal PCO2 by tonometry. Systemic and intestinal oxygen transport and consumption were calculated, as was ΔPCO2. After basal measurements, measurements were repeated at 30, 60, and 90 minutes.

Results

Both progressive bleeding and hydrochloric acid aspiration provoked critical reductions in systemic and intestinal oxygen delivery and consumption. No changes occurred in the sham group. ΔPCO2 increased in the IH group (12 ± 10 [mean ± SD] versus 40 ± 13 mmHg; P < 0.001), but remained unchanged in HH and in the sham group (13 ± 6 versus 10 ± 13 mmHg and 8 ± 5 versus 9 ± 6 mmHg; not significant).

Discussion

In this experimental model of hypoxic hypoxia with preserved blood flow, ΔPCO2 was not modified during dependence of oxygen uptake on oxygen transport. These results suggest that ΔPCO2 might be determined primarily by blood flow.
Cricothyroidotomy for elective airway management in critically ill trauma patients with technically challenging neck anatomy
Authors: Rehm Christina G , Wanek Sandra M , Gagnon Eliot B , Pearson Slone K , Mullins Richard J
Published: November 2002

Introduction

To assess the value of elective cricothyroidotomy for airway management in critically ill trauma patients with technically challenging neck anatomy.

Materials and methods

A retrospective chart review of patients admitted to the Trauma Service at a Level I Trauma Center who underwent cricothyroidotomy for elective airway management over a 40-month period from January 1997 to April 2000. Comparison was made with a cohort of Trauma Service patients who received a tracheostomy.

Results

Eighteen patients met study criteria, and an unpaired t test revealed significance (P < 0.05) for age only. There was no difference with Injury Severity Score, number of days in the intensive care unit, number of days requiring ventilation post procedure or number of days intubated prior to procedure. The major difference was the more technically challenging neck anatomy in the patients undergoing cricothyroidotomy. Five out of 18 patients undergoing cricothyroidotomy died prior to discharge and two out of 18 died after discharge from complications unrelated to their airway. Two out of 18 patients undergoing tracheostomy died prior to discharge from complications unrelated to their airway. For a period of 1 week–15 months (average, 5.5 months), notes in subsequent clinic appointments were reviewed for subjective assessment of wound healing, breathing and swallowing difficulties, and voice changes. One patient with a cricothyroidotomy required silver nitrate to treat some granulation tissue. Otherwise, no complications were identified. Telephone interviews were conducted with eight of the 11 surviving cricothyroidotomy patients and nine of the 16 surviving tracheostomy patients. One tracheostomy patient required surgical closure 3 months after discharge; otherwise, the only noted change was minor voice changes in three patients in each group. All six of these patients denied that this compromised them in any way.

Conclusion

Elective cricothyroidotomy has a low complication rate and is a reasonable, technically less demanding option in critically ill patients with challenging neck anatomy requiring a surgical airway.
Fast principal component analysis of large data sets based on information extraction
Authors: Vogt F. , Tacke M.
Published: November 2002

Principal component analysis (PCA) and principal component regression (PCR) are routinely used for calibration of measurement devices and for data evaluation. However, their use is hindered in some applications, e.g. hyperspectral imaging, by excessive data sets that imply unacceptable calculation time. This paper discusses a fast PCA achieved by a combination of data compression based on a wavelet transformation and a spectrum selection method prior to the PCA itself. The spectrum selection step can also be applied without previous data compression. The calculation speed increase is investigated based on original and compressed data sets, both simulated and measured. Two different data sets are used for assessment of the new approach. One set contains 65 536 synthetically generated spectra at four different noise levels with 256 measurement points each. Compared with the conventional PCA approach, these examples can be accelerated 20 times. Evaluation errors of the fast method were calculated and found to be comparable with those of the conventional approach. Four experimental spectra sets of similar size are also investigated. The novel method outperforms PCA in speed by factors of up to 12, depending on the data set. The principal components obtained by the novel algorithm show the same ability to model the measured spectra as the conventional time‐consuming method. The acceleration factors also depend on the possible compression; in particular, if only a small compression is feasible, the acceleration lies purely with the novel spectrum selection step proposed in this paper. Copyright © 2002 John Wiley & Sons, Ltd.
Degenerate solutions obtained from several variants of factor analysis
Authors: Zijlstra Bonne J. H. , Kiers Henk A. L.
Published: November 2002

Considerable research has been performed concerning degenerate solutions from the Parafac model. However, degenerate solutions have also been reported to occur with the shifted multiplicative model and a model for component analysis of multitrait multimethod matrices. Furthermore, we obtained similarly degenerate solutions for the directly fitted Parafac‐2 model, the indirectly fitted Parafac‐2 model and a constrained variant of the Tucker‐3 model. Comparing degenerate solutions reported in the literature with the degenerate solutions we obtained ourselves, we learned that for all the above‐mentioned models there are two‐factor degenerate solutions sharing the same properties. We distinguish three common features. Furthermore, the above‐mentioned models have in common that they are all variants of factor analysis producing component matrices with components that are rotationally unique. Underscoring the significance of this property, we show that all models for two‐way and three‐way factor analysis not resulting in solutions with rotationally unique components cannot produce degenerate solutions. Copyright © 2002 John Wiley & Sons, Ltd.
Distribution of brain‐derived neurotrophic factor and TrkB receptor proteins in the fetal and postnatal hippocampus and cerebellum of the guinea pig
Authors: Dieni Sandra , Rees Sandra
Published: November 2002

This study investigates the distribution of brain‐derived neurotrophic factor protein (BDNF) and its receptor, TrkB, during the development of hippocampus and cerebellum in a long‐gestation species, the guinea pig. In the granule cell populations of both structures, BDNF immunoreactivity (‐IR) was exclusive to postmigratory, mature neurons. In dentate granule cells, TrkB‐IR was coexpressed with BDNF‐IR, suggesting that the ligand‐receptor interaction could occur by means of an autocrine/paracrine mechanism. In cerebellar granule cells, TrkB‐IR was detected in both pre‐ and postmigratory cells, indicating that immature neurons are also BDNF‐responsive. With advancing gestational age an increase in the intensity of BDNF‐IR in granule cells was accompanied by concomitant increases in the staining and areal growth of the associated mossy fiber layer in the hippocampus, and the molecular layer in the cerebellum. The developmental increase in BDNF‐ and TrkB‐IR in the neuropil of both structures coincided with periods of significant growth in all strata, indicating a role for BDNF and TrkB in process outgrowth. In the hippocampus, CA2, CA3, and hilar, neurons demonstrated both BDNF‐ and TrkB‐IR during development and maturation, whereas CA1 neurons showed TrkB‐IR throughout this period but only transient BDNF‐IR in early gestation. In the fetal cerebellum, Purkinje cell bodies coexpressed BDNF‐IR and TrkB‐IR. In the postnatal period, BDNF‐IR was down‐regulated but TrkB‐IR persisted, indicating that mature Purkinje cells might retain their responsiveness to BDNF. Thus, we have demonstrated in both the hippocampus and cerebellum that the spatiotemporal distribution of BDNF‐IR and TrkB‐IR coincides with the maturation of granule cells prenatally and with significant periods of neuropil growth, both prenatally and in the immediate postnatal period. J. Comp. Neurol. 454:229–240, 2002. © 2002 Wiley‐Liss, Inc.
Morphology and differentiation of radial glia in the developing rat spinal cord
Authors: McMahon Siobhan S. , McDermott Kieran W.
Published: November 2002

Important events underlying the proper functioning of the central nervous system (CNS) include the production, assembly, and differentiation of appropriate types and numbers of cells during development. The mechanisms that control these events are difficult to unravel because of displacement of cells from their sites of origin to their permanent locations and because of the diverse cellular composition of the CNS. As in other regions of the mammalian CNS, the two major classes of neuroglial cells in the rat spinal cord are oligodendrocytes and astrocytes. In the developing spinal cord, radial glia are prominent. In this study, radial glia in the cervical region of the spinal cord were analysed. 1,1′Dioctadecyl‐3,3,3′‐tetramethylindocarbocyanine perchlorate (DiI) was used to determine the morphology and distribution of radial glia during spinal cord development. The DiI labelling technique enabled locating glial precursor cells during spinal cord development. Radial fibres that extended from the central canal to the pial surface were present at embryonic days 14, 16, and 18 in the developing spinal cord. Their distribution was restricted with increasing development, and by embryonic day 20 the only remaining evidence of radial glia were short radial processes in the white matter. J. Comp. Neurol. 454:263–271, 2002. © 2002 Wiley‐Liss, Inc.
Few intrinsic connections cross the hand‐face border of area 3b of New World monkeys
Authors: Fang Pei‐Chun , Jain Neeraj , Kaas Jon H.
Published: November 2002

After long‐standing loss of afferents from the hand, the hand representation in area 3b of the somatosensory cortex of monkeys becomes responsive to touch on the face. Because the reactivation of deprived hand cortex by the face inputs could depend on axonal connections across the hand‐face border, we determined the extent of such connections in New World marmosets, owl monkeys, and squirrel monkeys. Small injections of anatomic tracers were placed in the hand or the face representations after these representations were identified by microelectrode recordings. The positions of retrogradely labeled neurons were plotted in processed brain sections cut parallel to the brain surface, and their locations were related to anatomic isomorphs of the hand and face representations revealed in adjacent brain sections stained for myelin. In these sections, the hand‐face border was clearly visualized as a myelin‐poor septum. The intrinsic connections of area 3b labeled by injections in either the hand or face representations were almost completely confined to their respective representation, and very few neurons projected across the border. In addition, neurons in the somatosensory thalamus labeled by injections in either face or hand representations were confined to either VPM, representing the face, or the hand subnucleus of VPL. Thus the reactivation of hand cortex by face stimulation does not depend on a previously existing network of intrinsic cortical connections across the hand‐face border, or mismatched thalamocortical projections. J. Comp. Neurol. 454:310–319, 2002. © 2002 Wiley‐Liss, Inc.
Localization of the Slack potassium channel in the rat central nervous system
Authors: Bhattacharjee Arin , Gan Li , Kaczmarek Leonard K.
Published: November 2002

The Slack gene encodes a voltage‐dependent K+ channel that has a unitary conductance of ∼60 pS. Evidence from heterologous expression studies suggests that Slack channel subunits can also combine with the Slo subunit to generate Ca2+‐activated K+ channels of larger conductances. Nonetheless, the function of Slack in the brain remains to be identified. We have now generated an affinity‐purified antibody against the N‐terminal of rat Slack, for biochemical and immunohistochemical studies. The antibody recognized Slack in transiently transfected CHO cells both by immunocytochemistry and by Western blot analysis. The antibody also detected a single band in rat brain membranes. The localization of Slack in rat brain slices was then determined using the antibody. Most prominent Slack immunoreactivity occurs in the brainstem, in particular the trigeminal system and reticular formation, where very intense staining was found in both cell bodies and axonal fibers of associated nuclei. Labeling was also very strong in the vestibular and oculomotor nuclei. Within the auditory system, the medial nucleus of the trapezoid had a robust signal consistent with staining of the giant presynaptic terminals. Strong Slack immunoreactivity was present in the olfactory bulb, red nucleus, and deep cerebellar nuclei. There was labeling also in the thalamus, substantia nigra, and amygdala. The only cortical region in which Slack immunoreactivity was detected was the frontal cortex. The subcellular and regional distribution of Slack differs from that previously reported for the Slo channel subunit and suggests that Slack may also have an autonomous role in regulating the firing properties of neurons. J. Comp. Neurol. 454:241–254, 2002. © 2002 Wiley‐Liss, Inc.
Odor‐stimulated glutamatergic neurotransmission in the zebrafish olfactory bulb
Authors: Edwards Jeffrey G. , Michel William C.
Published: November 2002

The role of glutamate as a neurotransmitter in the zebrafish olfactory bulb (OB) was established by examining neuronal activation following 1) glutamate receptor agonist stimulation of isolated olfactory bulbs and 2) odorant stimulation of intact fish. Four groups of neurons (mitral cells, projection neurons; granule cells, juxtaglomerular cells, and tyrosine hydroxylase‐containing cells; interneurons) were identified on the basis of cell size, cell location, ionotropic glutamate receptor (iGluR) agonist/odorant sensitivity, and glutamate, γ‐aminobutyric acid (GABA), and tyrosine hydroxylase immunoreactivity. Immunoreactive glutamate levels were highest in olfactory sensory neurons (OSNs) and mitral cells, the putative glutamatergic neurons. The sensitivity of bulbar neurons to iGluR agonists and odorants was established using a cationic channel permeant probe, agmatine (AGB). Agmatine that permeated agonist‐ or odor‐activated iGluRs was fixed in place with glutaraldehyde and detected immunohistochemically. N‐methyl‐D‐aspartic acid (NMDA) and α‐amino‐3‐hydroxyl‐5‐methylisoxazole‐4‐propionic acid (AMPA)/kainic acid (KA) iGluR agonists and odorants (glutamine, taurocholic acid) stimulated activity‐dependent labeling of bulbar neurons, which was blocked with a mixture of the iGluR antagonists, D‐2‐amino‐5‐phosphono‐valeric acid (APV) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX). The AMPA/KA antagonist CNQX completely blocked glutamine‐stimulated AGB labeling of granule cells and tyrosine hydroxylase‐containing cells, suggesting that, in these cell types, AMPA/KA receptor activation is essential for NMDA receptor activation. However, blocking AMPA/KA receptor activity failed to eliminate AGB labeling of mitral cells or juxtaglomerular cells. Collectively, these findings indicate that glutamate is the primary excitatory neurotransmitter in the zebrafish OB and that iGluR subtypes function heterogeneously in the bulbar neurons. J. Comp. Neurol. 454:294–309, 2002. © 2002 Wiley‐Liss, Inc.
Identification of cells expressing somatostatin receptor 2 in the gastrointestinal tract of Sstr2 knockout/lacZ knockin mice
Authors: Allen Jeremy P. , Canty Alison J. , Schulz Stefan , Humphrey Patrick P.A. , Emson Piers C. , Young Heather M.
Published: November 2002

Somatostatin is found in neurons and endocrine cells in the gastrointestinal tract. The actions of somatostatin are mediated by a family of G‐protein–coupled receptors that compose five subtypes (SSTR1–5), each of which is encoded by a separate gene. lacZ “knockin” mice, in which the reporter gene lacZ was engineered into the genomic locus of Sstr2 by gene targeting, were used to examine the expression pattern of Sstr2 and identify potential targets for neurally released and hormonal somatostatin in the gastrointestinal tract. In the body of the stomach, a large proportion of epithelial cells and subpopulations of myenteric neurons expressed Sstr2. Double‐ or triple‐labeling with antisera to H+K+ATPase (to identify parietal cells) and/or histidine decarboxylase (to identify enterochromaffin‐like [ECL] cells) combined with β‐galactosidase staining revealed that both parietal cells and ECL cells expressed Sstr2, and these two cell types accounted for almost all of the Sstr2‐expressing epithelial cells. Somatostatin inhibits gastric acid secretion. The presence of SSTR2 on both parietal and ECL cells suggests that somatostatin acting on SSTR2 may reduce acid secretion by both acting directly on parietal cells and by reducing histamine release from ECL cells. In the small and large intestine, subpopulations of neurons in the myenteric and submucosal plexuses expressed Sstr2, and many of the Sstr2‐expressing myenteric neurons also showed SSTR2(a) immunostaining. Most of Sstr2‐expressing neurons in the myenteric plexus showed nitric oxide synthase (NOS) immunoreactivity. Previous studies have shown that NOS neurons are descending interneurons and anally projecting, inhibitory motor neurons. Thus, somatostatin acting at SSTR2 receptors on NOS neurons might modulate descending relaxation. J. Comp. Neurol. 454:329–340, 2002. © 2002 Wiley‐Liss, Inc.
Stakeholder excellence? Framing the evolution and complexity of a stakeholder perspective of the firm
Authors: Jonker Jan , Foster David
Published: November 2002

Analysing and dealing with the needs and demands of stakeholders is a major concern of modern business. This paper attempts to frame, systematize and conceptualize a number of the underlying issues related to the phenomenon. As a result, a vast array of unaddressed and unanswered questions emerges. What unites these is the implicit acceptance of an emerging (contemporary) stakeholder theory of the firm. This largely normative theory provides some understanding of what constitutes a stakeholder, what stakes they seek to protect and the way in which transactions between the stakeholder and the organizations are handled. While the brevity of the contribution necessitates a somewhat superficial treatment of the issues, the paper leads inevitably to the conclusion that the demonstrated complexity of really engaging with stakeholders means that both theory‐development and practice still have a long way to go. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment.
Merocyanine 540 as a fluorescent probe of altered membrane phospholipid asymmetry in activated whole blood platelets
Authors: Watala Cezary , Waczulikova Iveta , Wieclawska Boguslawa , Rozalski Marcin , Gresner Peter , Gwoździński Krzysztof , Mateasik Anton , Śikurova Libuśa
Published: November 2002

Background

Platelet activation leads to the loss of a natural asymmetry of membrane phospholipids (PL) and the subsequent exposure of negatively charged PL in platelets with procoagulant activity that can be monitored routinely with annexin V (AN‐V).

Methods

Flow cytometric analysis of merocyanine 540 (MC540) binding may be the alternate choice for the monitoring of platelet procoagulant activity. Due to the increased partition of negatively charged phosphatidylserine (PS) in the membrane outer leaflet of activated platelets, the interaction with MC540 is reduced.

Results

Collagen, which facilitated platelet PL bilayer symmetrization, vastly reduced MC540 fluorescence and augmented AN‐V binding to platelets. Such a collagen‐induced symmetrization was further augmented in the presence of thrombin receptor‐activating peptide (TRAP, SFLLRNPNDKYEPF). In the presence of VO4(−3) (the inhibitor of aminophospholipid translocase), the rebuilt of membrane asymmetry was attenuated, which resulted in further reduced MC540 fluorescence and enhanced AN‐V binding in activated cells. In platelets incubated with thapsigargin, the inhibitor of platelet tubular system Ca2+ ATP‐ase, which elevates intraplatelet Ca2+ concentration, TRAP increased AN‐V and reduced MC540 binding. The chelating of Ca2+ with EGTA outside of activated platelets reduced AN‐V binding, but did not affect MC540‐positive platelets. The fluctuations in reduced staining with MC540 paralleled enhanced AN‐V binding (r = −0.481, P < 0.01), especially for strong “procoagulant” activating agents.

Conclusions

(1) MC540 may be used in whole blood flow cytometry for the monitoring of platelet membrane symmetrization as an alternate or compounding method to AN‐V. (2) Platelet staining with MC540 is sensitive to the fluctuations in the intraplatelet [Ca2+] during platelet activation. (3) Use of MC540 is characterized by improved diagnostic precision and reliability compared with AN‐V. Cytometry 49:119–133, 2002. © 2002 Wiley‐Liss, Inc.
Antimycin A‐induced apoptosis of HL‐60 cells
Authors: King Malcolm A. , Radicchi‐Mastroianni Monica A.
Published: November 2002

Background

Previous experiments in our laboratory investigating apoptosis induced in HL‐60 cells by camptothecin (CAM) have revealed that the sequence and rapidity of the apoptotic phenomena in an individual cell depend on the proliferative state of that cell when it encounters CAM. The role of mitochondria in HL‐60 apoptosis was explored using an inhibitor of oxidative phosphorylation, antimycin A (AMA).

Methods

Changes in cell light scatter, binding of annexin V‐fluorescein isothiocyanate (FITC), uptake of propidium iodide (PI), and DNA content after membrane fixation/permeabilization were monitored by flow cytometry. Z‐VAD‐FMK was used to inhibit caspases. Fluorescence microscopy was used to examine cell morphology.

Results

Cells in the G1 phase of the cell cycle were the first to exhibit signs of apoptosis in response to 100 μM AMA and some of these cells disintegrated without exposing to phosphatidylserine (PS). Caspase inhibition prevented fragmentation of DNA, the nucleus, and the cell, but only delayed PS exposure and loss of plasma membrane integrity.

Conclusions

The highly active mitochondria of G1‐phase HL‐60 cells make them particularly sensitive to AMA. PS exposure and plasma membrane damage are mediated by noncaspase molecules released from mitochondria. We hypothesize that if mitochondria are subjected to a sufficiently severe insult, whether indirectly as a result of extensive CAM‐induced DNA damage or directly by the effect of AMA on electron transport, the nature and quantities of the proapoptotic molecules released are such that apoptosis proceeds to the point of cell disintegration before the PS exposure pathway is complete. Cytometry 49:106–112, 2002. © 2002 Wiley‐Liss, Inc.
Exposure of cells to static magnetic field accelerates loss of integrity of plasma membrane during apoptosis
Authors: Teodori Laura , Grabarek Jerzy , Smolewski Piotr , Ghibelli Lina , Bergamaschi Antonio , De Nicola Milena , Darzynkiewicz Zbigniew
Published: November 2002

Background

Much attention is being paid to the biologic effects of magnetic fields (MFs). Although MFs enhance tumorigenesis, they are neither mutagenic nor tumorigenic. The mechanism of their tumorigenic effect has not been elucidated.

Methods

To investigate the effect of MFs on apoptosis in HL‐60 cells, we exposed the cells to static MFs of 6 mT generated by a magnetic disk of known intensity. Apoptosis was triggered by the DNA topoisomerase I inhibitor, camptothecin (CPT). Activation of caspases in situ using the fluorochrome‐labeled inhibitor (FLICA) method and determination of plasma membrane integrity by excluding propidium iodide (PI) were measured by both laser scanning cytometry (LSC) and flow cytometry (FC). LSC and FC identified cells at three sequential stages of their demise: early apoptosis (cells with activated caspases and PI negative); late apoptosis (cells with activated caspases but unable to exclude PI); secondary necrosis (cells with apoptotic morphology no longer stained with FLICA, not excluding PI).

Results

MF alone did not induce any apoptogenic or necrogenic effect. CPT exposure led to the sequential appearance of apoptotic cells. In the presence of CPT and MF, the overall proportion of cells undergoing apoptosis was not significantly changed. However, we consistently observed a significant increase in the frequency of late apoptotic/necrotic cells when compared with samples treated with CPT alone (P < 0.001), as well as a decrease in the percentage of early apoptotic cells (P = 0.013). The data obtained by FC and LSC were consistent with each other, showing a similar phenomenon.

Conclusion

Whereas MF alone or with CPT did not affect overall cell viability, it accelerated the rate of cell transition from apoptosis to secondary necrosis after induction of apoptosis by the DNA‐damaging agent, CPT. Modulation of the kinetics of the transition from apoptosis to secondary necrosis by MF in vivo may play a role in inflammation and tumorigenesis. Cytometry 49:113–118, 2002. © 2002 Wiley‐Liss, Inc.
Detection of underlying characteristics of nuclear chromatin patterns of thyroid tumor cells using texture and factor analyses
Authors: Murata Shin‐ichi , Mochizuki Kunio , Nakazawa Tadao , Kondo Tetsuo , Nakamura Nobuki , Yamashita Hiroto , Urata Yoji , Ashihara Tsukasa , Katoh Ryohei
Published: November 2002

Background

Aspiration biopsy cytology of thyroid tumors has been used more frequently in recent times to differentiate between malignant and benign lesions. Chromatin patterns of the tumor cell nuclei are one of most important factors for cytologic diagnosis. The interpretation of nuclear chromatin patterns is subjective and more difficult than that of nuclear size or shape. In the present report, we investigated how to detect underlying chromatin characteristics of benign and malignant thyroid tumor cells by means of texture and factor analyses.

Methods

We employed a computer‐aided system in which light microscopy was combined with an image processor and monochrome camera. Using this system, 100 randomly selected cells in a Papanicolaou stained, aspiration biopsy cytologic smear in each case of 39 benign and malignant thyroid tumor cases were digitized. We applied two‐dimensional and higher texture analyses with the use of co‐occurrence and run‐length matrices to analyze the chromatin patterns. Factor analysis was used to determine whether a large number of independent variables actually measured one or more underlying common variables.

Results

According to parameters with high factor‐loading values, the morphologic chromatin characters were classified into three categories according to heterogeneity, contrast, and homogeneity of chromatin patterns. On the basis of analyses with these morphologic categories, nuclei of papillary carcinoma showed higher contrast of chromatin patterns than did those of the benign group. Moreover, there was a variety of contrasting chromatin patterns among cells in each papillary carcinoma case in comparison with the benign group. In contrast, follicular carcinomas showed a significant difference in the standard deviation of factor 3, which indicated more monotonous chromatin patterns among cells in each follicular carcinoma case than in each benign case.

Conclusion

We believe that this technique, using texture and factor analyses, is useful in the detection of underlying characteristics of nuclear chromatin patterns in aspiration biopsy cytology. Cytometry 49:91–95, 2002. © 2002 Wiley‐Liss, Inc.
Simultaneous flow cytometric analysis of two cell surface markers, telomere length, and DNA content
Authors: Schmid Ingrid , Dagarag Mirabelle D. , Hausner Mary Ann , Matud Jose L. , Just Tom , Effros Rita B. , Jamieson Beth D.
Published: November 2002

Background

Various protocols for estimation of telomere length in individual cells by flow cytometry using fluorescence in situ hybridization of fluorescently labeled peptide nucleic acid (PNA) probes (Flow‐FISH) have been described. Combined analysis of telomere length and cell phenotype, however, remains difficult because few fluorochromes with suitable emission spectra tolerate the harsh conditions needed for DNA denaturation during hybridization of the telomere‐specific PNA probe. We overcame these problems and developed a method for measuring telomere length in cell subsets characterized by the expression of two surface antigens.

Methods

Alexa Fluor 488 and Alexa Fluor 546 were used for cell surface staining. Antigen–antibody complexes were covalently cross‐linked onto the cell membrane before Flow‐FISH. Cells were hybridized with a PNA probe conjugated to cyanine 5 (Cy5). Hoechst 33342 (HO342) was added for determination of cellular DNA content. For assay standardization, we added an aliquot of a single batch of 1301 cells to each sample as an internal control before hybridization with the PNA probe. Samples were prepared in duplicate and analyzed on a standard three‐laser BD LSR flow cytometer. For assay validation, the same samples were analyzed in parallel to correlate the percentage of telomere length of the sample versus 1301 control cells to the mean size of terminal restriction fragments (TRFs) of DNA as determined by Southern gel analysis.

Results

The method permitted clear identification of lymphocyte subsets in samples hybridized for Flow‐FISH, with subset frequencies comparable to those of untreated samples. At a concentration of 10 nM, the Cy5‐labeled telomere‐specific PNA probe produced a bright fluorescence signal well separated from background. Addition of HO342 in low concentration did not interfere with Cy5 telomere fluorescence, produced adequate DNA histograms, and permitted clear identification of cell phenotype. The probe concentration of 10 nM also proved optimal for inclusion of 1301 control cells for assay standardization. Telomere length estimations by the current method correlated highly with TRF calculations by Southern gel hybridization (r2= 0.9, P = 0.0003). Application of our protocol to the analysis of human CD8CD28 lymphocyte subsets showed that CD8+brightCD28− lymphocytes generally exhibit shorter telomeres than CD8+brightCD28+ cells. These data concurred with previous results of telomere shortening in CD8+CD28− T cells that were obtained by using different techniques.

Conclusions

The multiparameter Flow‐FISH protocol permitted rapid determination of differences in telomere length in subpopulations characterized by two surface markers without prior cell separation. Cytometry 49:96–105, 2002. © 2002 Wiley‐Liss, Inc.
Stochastic seismic analysis of hydrodynamic pressure in dam reservoir systems
Authors: Di Paola M. , Zingales M.
Published: November 2002

Hydrodynamic seismic‐induced pressure requires careful consideration in the aseismic design of dams. Effects induced by earthquake excitation may cause many‐fold increments of hydrostatic pressure. In this study earthquake excitation has been modelled by means of random process theory obtaining the response statistics of a dam‐reservoir dynamical system. The analysis has been conducted assuming a rigid retaining wall of the reservoir and dissipative fluid. Copyright © 2002 John Wiley & Sons, Ltd.