bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in brain‐derived neurotrophic factor and trkB receptor in the adult Rana pipiens retina and optic tectum after optic nerve injury
Authors: Duprey‐Díaz Mildred V. , Soto Ileana , Blagburn Jonathan M. , Blanco Rosa E.
Published: December 2002

In this study we used immunocytochemistry to investigate the distribution of brain‐derived neurotrophic factor (BDNF) and its receptor tyrosine kinase (trkB) in retina and optic tectum of the frog Rana pipiens during regeneration after axotomy. We also measured changes in BDNF mRNA in retina and tectum. Retrograde labeling was used to identify retinal ganglion cells (RGCs) prior to quantification of the BDNF immunoreactivity. In control animals, BDNF was found in the majority of RGCs and displaced amacrine cells and in some cells in the inner nuclear layer (INL). After axotomy, BDNF immunoreactivity was reduced in RGCs but increased in the INL. BDNF mRNA levels in the retina remained high before and after axotomy. Three months after axotomy, after reconnection to the target, the staining intensity of many of the surviving RGCs had partially recovered. In the control tectum, BDNF staining was present in ependymoglial cells and in neurons throughout layers 4, 6, 8, and 9. After axotomy, BDNF staining in tectal neurons became more intense, even though mRNA synthesis was transiently down‐regulated. In control retinas, trkB receptor immunostaining was present in most RGCs; no significant changes were observed after axotomy. In control tectum, trkB was detected only in ependymoglial cells. After axotomy, many neuronal cell bodies were transiently labeled. Our data are consistent with the hypothesis that a considerable fraction of the BDNF normally present in RGCs is acquired from their targets in the tectum. However, there are also intraretinal sources of BDNF that could contribute to the survival of RGCs. J. Comp. Neurol. 454:456–469, 2002. © 2002 Wiley‐Liss, Inc.
Agonist‐stimulated cobalt uptake provides selective visualization of neurons expressing AMPA‐ or kainate‐type glutamate receptors in the retina
Authors: Pourcho Roberta G. , Qin Pu , Goebel Dennis J. , Fyk‐Kolodziej Bozena
Published: December 2002

Fast‐acting excitatory neurotransmission in the retina is mediated primarily by glutamate, acting at α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) ‐selective and kainate‐selective receptors. To localize these sites of action, cat retinas were stimulated with either AMPA or kainate and processed for histochemical visualization of cobalt uptake through calcium‐permeable channels. Treatment with both agonists resulted in staining of A‐ and B‐type horizontal cells and several types of OFF cone bipolar cells; there was no evidence for staining of ON cone bipolar cells or rod bipolar cells. The subpopulations of OFF cone bipolar cells differed in their responses with two distinct types that stained heavily with cobalt after exposure to AMPA and three different types that were preferentially labeled after exposure to kainate. Although many amacrine and ganglion cells appeared to respond to both agonists, AII amacrine cells were stained after stimulation by AMPA but not by kainate. The OFF cone bipolar cells that exhibit AMPA‐stimulated cobalt uptake were found to have a high level of correspondence with cells that show immunocytochemical staining for the AMPA‐selective glutamate receptor subunits GluR1 and GluR2/3. Similarly, the cone bipolar cells exhibiting kainate‐stimulated cobalt uptake resemble those that are immunoreactive for the kainate subunit GluR5. The results indicate that, whereas many retinal neurons express both AMPA and kainate receptors, AII amacrine cells and subpopulations of OFF cone bipolar cells are limited to the expression of either AMPA or kainate receptors. This differential expression may contribute to the unique character of transmission by these cell types. J. Comp. Neurol. 454:341–349, 2002. © 2002 Wiley‐Liss, Inc.
Metabolic and neural activity in the song system nucleus robustus archistriatalis: Effect of age and gender
Authors: Adret Patrice , Margoliash Daniel
Published: December 2002

The sexually dimorphic robust archistriatal nucleus (RA) represents the telencephalic output of the bird song system. Here, we document sex‐dependent changes in both the metabolic and neuronal activity of RA during the sensory and sensorimotor phases of song learning. From posthatching day (PHD) 20–63 in males but not females, RA and its input nucleus HVc showed sharp increases in cytochrome oxidase (CO) activity relative to surrounding archistriatum and the underlying shelf, respectively. In urethane‐anesthetized birds, during the same period, the spontaneous activity of male RA neurons underwent dramatic changes in firing rate, distribution of interspike intervals, and bursting frequency, compared with other archistriatal cells. At PHD 20–21, RA neurons had extremely slow, irregular firing rates in birds of both sexes. In males, from PHD 30–36, RA neurons increased their firing rates and spiking activity became more regular, and at ∼PHD 38, strong bursts followed by inhibition (which in awake animals is associated with singing) began to be observed. Dual recordings from RA and HVc revealed synchronous bursting, with RA spikes lagging ∼10 msec behind HVc. We conclude that changes in relative CO activity correlate with changes in spontaneous firing rates within RA and that patterns of RA spontaneous activity exhibit gradual change as birds enter early song and then again for plastic song. The emergence of strong burst patterns in RA occurs later in life than does input from HVc as established by tracer studies or based on observed HVc bursting in young animals. J. Comp. Neurol. 454:409–423, 2002. © 2002 Wiley‐Liss, Inc.
Structure of the vertical and horizontal system neurons of the lobula plate in Drosophila
Authors: Scott Ethan K. , Raabe Thomas , Luo Liqun
Published: December 2002

The lobula plate in the optic lobe of the fly brain is a high‐order processing center for visual information. Within the lobula plate lie a small number of giant neurons that are responsible for the detection of wide field visual motion. Although the structure and motion sensitivity of these cells have been extensively described in large flies, the system has not been described systematically in Drosophila. Here, we use the mosaic analysis with a repressible cell marker (MARCM) system to analyze a subset of these cells, the horizontal and vertical systems. Our results suggest that the Drosophila horizontal system is similar to those described in larger flies, with three neurons fanning their dendrites over the lobula plate. We found that there are six neurons in the Drosophila vertical system, a figure that compares with 9–11 neurons in large flies. Even so, the Drosophila vertical system closely resembles the systems of larger flies, with each neuron in Drosophila having an approximate counterpart in large flies. This anatomical similarity implies that the inputs to the vertical system are similarly organized in these various fly species, and that it is likely that the Drosophila neurons respond to motions similar to those sensed by their specific structural counterparts in large flies. Additionally, the similar appearance of vertical system cells in multiple cell clones demonstrates that they share a common developmental lineage. Access to these cells in Drosophila should allow for the use of genetic tools in future studies of horizontal and vertical system function. J. Comp. Neurol. 454:470–481, 2002. © 2002 Wiley‐Liss, Inc.
Global well‐posedness and finite‐dimensional global attractor for a 3‐D planetary geostrophic viscous model
Authors: Cao Chongsheng , Titi Edriss S.
Published: December 2002

In this paper we consider a three‐dimensional planetary geostrophic viscous model of the gyre‐scale mid‐latitude ocean. We show the global existence and uniqueness of the weak and strong solutions to this model. Moreover, we establish the existence of a finite‐dimensional global attractor to this dissipative evolution system. © 2002 Wiley Periodicals, Inc.
Clinical utility of cognitive‐behavioural treatment for panic disorder. results obtained in different settings: a research centre and a public mental health care unit
Authors: García‐Palacios A. , Botella C. , Robert C. , Baños R. , Perpiñá C. , Quero S. , Ballester R.
Published: December 2002

Cognitive‐Behavioural programmes have become the treatment of choice for Panic Disorder (PD). However, although its effectiveness has been widely demonstrated, there are still some limitations regarding the possibility of offering this type of treatment to all panic sufferers. Some researchers are studying ways to make these programmes more available. This study deals with the application and testing of treatment programmes for PD in sites where patients usually look for help for their psychological problems, i.e. mental health care centres. Our work follows a strategy of benchmarking, and the results obtained after applying the treatment in habitual clinical contexts are compared with the results obtained after applying it in research contexts. In the present work, we analyse the possibility of ‘transporting’ a group cognitive‐behavioural programme for PD, developed in a research context, to a more natural setting, a public mental health unit. In this work we present data, using a benchmarking strategy, on one hand, on the differential effectiveness of a group cognitive‐behavioural treatment for PD applied in two different settings: a research setting—a clinical unit at the university; and a natural setting—a public mental health unit. On the other hand, we compare our results with those achieved by other studies carried out in research settings in different countries and a study carried out in a natural setting. Results indicated that our treatment was equally effective in both settings and that effectiveness was comparable to that achieved by the other studies in research and natural settings. Copyright © 2002 John Wiley & Sons, Ltd.
Prioritizing access to psychotherapy services: the client priority rating scale
Authors: Walton Carla J. , Grenyer Brin F. S.
Published: December 2002

Determining who gets priority to psychotherapy services within budget‐limited health services remains a dilemma. This study set out to investigate a new method of triage using the Client Priority Rating Scale (CPRS). Clinicians made weighted ratings in the domains of Suicidality, Severity of Presenting Problem, Strength of Internal Coping Resources, Availability of Interim Care Options and Possible Negative Impact of Waiting. The total score was then used to prioritize waiting times for psychotherapeutic services. In order to assess its utility, 68 clients who had been assigned CPRS scores were studied. The CPRS was found to have good inter‐rater reliability and internal consistency. As predicted, those with higher CPRS scores were significantly more likely to commence psychotherapy treatment before those with lower scores. CPRS score was also significantly related to diagnosis and social and psychological functioning. The CPRS method of triage is one approach that determines priority for clients seeking psychotherapy services. Copyright © 2002 John Wiley & Sons, Ltd.
A brief questionnaire of DSM‐IV‐defined anxiety and depression symptoms among children
Authors: Muris Peter , Meesters Cor , Schouten Erik
Published: December 2002

The present study examined the psychometric properties of the Revised Child Anxiety and Depression Scale (Chorpita, Yim, Moffitt, Umemoto, & Francis, 2000), a self‐report questionnaire for assessing symptoms of DSM‐defined anxiety disorders and major depression, in a large sample of school children (N = 1748). Exploratory and confirmatory factor analysis revealed that the structure of the RCADS was not fully in agreement with that reported by Chorpita et al. (2000). After removing conceptually inconsistent items, the questionnaire was reduced to 25 items representing five scales, namely, generalized anxiety disorder, separation anxiety disorder, social phobia, panic disorder, and major depressive disorder. A confirmatory factor analysis showed that a correlated 5‐factor structure of the shortened version of the RCADS (i.e. the RCADS‐25) indeed provided a good fit for the data. Second, the psychometric properties of the RCADS‐25 were comparable to those obtained with the full‐length version. That is, the questionnaire was reliable in terms of internal consistency and test–retest stability, displayed reasonable parent–child agreement, and good convergent and divergent validity. Altogether, the RCADS and its shortened version, the RCADS‐25, seem to be useful questionnaires for clinical and research purposes. Copyright © 2002 John Wiley & Sons, Ltd.
Single‐cell image analysis to assess ABC‐transporter–mediated efflux in highly purified hematopoietic progenitors
Authors: Raaijmakers H.G.P. , van den Bosch G. , Boezeman J. , de Witte T. , Raymakers R.A.P.
Published: December 2002

Background

Normal and malignant hematopoietic stem cells are characterized by their capacity to actively extrude fluorescent dyes. The contribution of different ATP‐binding cassette (ABC) transporters to this phenomenon is largely unknown due to the small stem cell numbers limiting the use of standard methods to assess functional efflux.

Methods

We used epifluorescence microscopy (EFM) in combination with single‐cell image analysis to study ABC‐transporter–mediated efflux in highly purified, viable, CD34+CD38‐ cells sorted on an adhesive biolayer. P‐glycoprotein and multidrug‐resistant protein (MRP)‐mediated efflux were quantitated using fluorescent substrates (rhodamine‐123 and calcein acetoxymethyl ester [calcein‐AM]) and specific inhibitors (verapamil and probenecid, respectively).

Results

The feasibility, sensitivity, and reproducibility of rhodamine‐123 efflux quantitation using single‐cell EFM was shown in cell lines and compared with standard flow cytometric assessment. P‐glycoprotein–mediated transport was higher in CD34+CD38‐ cells than in more differentiated progenitors (mean efflux index = 2.24 ± 0.35 and 1.14 ± 0.11, respectively; P = 0.01). P‐glycoprotein–mediated transport was the main determinant of the rhodamine “dull” phenotype of these cells. In addition, significant MRP‐mediated efflux was demonstrated in CD34+CD38‐ and CD38+ cells (mean efflux index = 1.42 ± 0.19 and 1.28 ± 0.18, respectively).

Conclusion

The described method is a valuable tool for assessing ABC‐transporter–mediated efflux in highly purified single cells. Both P‐glycoprotein and MRP‐mediated efflux are present in human CD34+CD38‐ hematopoietic stem cells. Cytometry 49:135–142, 2002. © 2002 Wiley‐Liss, Inc.
Xenopus, the next generation: X. Tropicalis genetics and genomics
Authors: Hirsch Nicolas , Zimmerman Lyle B. , Grainger Robert M.
Published: December 2002

A small, fast‐breeding, diploid relative of the frog Xenopus laevis, Xenopus tropicalis, has recently been adopted for research in developmental genetics and functional genomics. X. tropicalis shares advantages of X. laevis as a classic embryologic system, but its simpler genome and shorter generation time make it more convenient for multigenerational genetic, genomic, and transgenic approaches. Its embryos closely resemble those of X. laevis, except for their smaller size, and assays and molecular probes developed in X. laevis can be readily adapted for use in X. tropicalis. Genomic manipulation techniques such as gynogenesis facilitate genetic screens, because they permit the identification of recessive phenotypes after only one generation. Stable transgenic lines can be used both as in vivo reporters to streamline a variety of embryologic and molecular assays, or to experimentally manipulate gene expression through the use of binary constructs such as the GAL4/UAS system. Several mutations have been identified in wild‐caught animals and during the course of generating inbred lines. A variety of strategies are discussed for conducting and managing genetic screens, obtaining mutations in specific sequences, achieving homologous recombination, and in developing and taking advantage of the genomic resources for Xenopus tropicalis. © 2002 Wiley‐Liss, Inc.
Thyroid hormone promotes neurogenesis in the Xenopus spinal cord
Authors: Schlosser Gerhard , Koyano‐Nakagawa Naoko , Kintner Chris
Published: December 2002

Three phases of neurogenesis can be recognized during Xenopus spinal cord development. An early peak during gastrulation/neurulation is followed by a phase of low level neurogenesis throughout the remaining embryonic stages and a later peak at early larval stages. We show here that several genes known to be essential for early neurogenesis (X‐NGNR‐1, XNeuroD, XMyT1, X‐Delta‐1) are also expressed during later phases of neurogenesis in the spinal cord, suggesting that they are involved in regulating spinal neurogenesis at later stages. However, additional neuronal determination genes may be important during larval stages, because X‐NGNR‐1 shows only scant expression in the spinal cord during larval stages. Thyroid hormone treatment of early larvae promotes neurogenesis in the spinal cord, where thyroid hormone receptor xTRα is expressed from early larval stages onward and results in precocious up‐regulation of XNeuroD, XMyT1, and N‐Tubulin expression. Similarly, thyroid hormone treatments of Xenopus embryos, which were coinjected with xTRα and the retinoid X receptor xRXRα, repeatedly resulted in increased numbers of neurons, whereas unliganded receptors repressed neurogenesis. Our findings show that thyroid hormones are sufficient to up‐regulate neurogenesis in the Xenopus spinal cord. © 2002 Wiley‐Liss, Inc.
Techniques and probes for the study ofXenopus tropicalisdevelopment
Authors: Khokha Mustafa K. , Chung Christina , Bustamante Erika L. , Gaw Lisa W.K. , Trott Kristin A. , Yeh Joanna , Lim Nancy , Lin Jennifer C.Y. , Taverner Nicola , Amaya Enrique , Papalopulu Nancy , Smith James C. , Zorn Aaron M. , Harland Richard M. , Grammer Timothy C.
Published: December 2002

The frogXenopus laevishas provided significant insights into developmental and cellular processes. However,X. laevishas an allotetraploid genome precluding its use in forward genetic analysis. Genetic analysis may be applicable toXenopus (Silurana) tropicalis, which has a diploid genome and a shorter generation time. Here, we show that many tools for the study ofX. laevisdevelopment can be applied toX. tropicalis. By using the developmental staging system of Nieuwkoop and Faber, we find thatX. tropicalisembryos develop at similar rates toX. laevis, although they tolerate a narrower range of temperatures. We also show that many of the analytical reagents available forX. laeviscan be effectively transferred toX. tropicalis. TheX. laevisprotocol for whole‐mount in situ hybridization to mRNA transcripts can be successfully applied toX. tropicaliswithout alteration. Additionally,X. laevisprobes often work inX. tropicalis—alleviating the immediate need to clone theX. tropicalisorthologs before initiating developmental studies. Antibodies that react againstX. laevisproteins can effectively detect theX. tropicalisprotein by using established immunohistochemistry procedures. Antisense morpholino oligonucleotides (MOs) offer a new alternative to study loss of gene activity during development. We show that MOs function inX. tropicalis. Finally,X. tropicalisoffers the possibility for forward genetics and genomic analysis. © 2002 Wiley‐Liss, Inc.
Survivin mRNA is down‐regulated during early Xenopus laevis embryogenesis
Authors: Murphy Cary R. , Sabel Jaime L. , Sandler Anthony D. , Dagle John M.
Published: December 2002

One of the hallmarks of early development is the rapid proliferation of cells immediately after fertilization. Many of the rules that govern cell division in normal somatic cells, such as contact inhibition and apoptosis, seem temporarily suspended in the early embryo. A similar suspension of mechanisms normally regulating cell division occurs in the development of cancer. Survivin, an inhibitor of apoptosis and a positive regulator of progression through the cell cycle, localizes to the mitotic spindle and interacts with several proapoptotic caspases. Survivin protein expression has been studied during the development of the salivary gland in mouse. However, the regulation of survivin during the critical transitions defining oocyte maturation and the early restriction of developmental potential are not easily examined in the mouse. We therefore studied survivin mRNA expression during oogenesis and early embryogenesis in Xenopus laevis. We found that survivin mRNA is present in the earliest stages of Xenopus oocytes and that it accumulates during oogenesis. Progesterone‐induced maturation of Xenopus oocytes leads to polyadenylation of the survivin transcript. Survivin mRNA is also present in early Xenopus embryos. After the onset of zygotic transcription, however, the amount of survivin mRNA declines rapidly to undetectable levels. This decrease in survivin mRNA correlates temporally with both the slowing of the cell cycle and the onset of endogenous embryonic apoptosis. With the exception of the ovary, survivin mRNA was undetectable in all adult Xenopus tissues examined. © 2002 Wiley‐Liss, Inc.
Metamorphosis‐dependent transcriptional regulation of xak‐c, a novel Xenopus type I keratin gene
Authors: Watanabe Yusuke , Tanaka Rumi , Kobayashi Hisao , Utoh Rie , Suzuki Ken‐Ichi , Obara Masanobu , Yoshizato Katsutoshi
Published: December 2002

Anuran larvae transform their epidermis to the adult counterpart during metamorphosis. The major event of this process is the proliferation of larval epidermal basal cells and their differentiation into adult ones. The present study isolated novel type I keratin cDNA dubbed xak‐c (Xenopus adult keratin‐c) that was exclusively expressed in adult epidermal basal cells. The gene started its expression in the larval epidermis at the onset of metamorphosis. Thyroid hormone (TH) induced the precocious expression of the gene in the epidermis of premetamorphic tadpoles. To study the transcriptional regulation of this gene in relation to epidermal metamorphosis, a 2.8 kb 5′‐flanking region of xak‐c was cloned and its promoter activity was investigated. Gene constructs were made so as to contain the xak‐c promoter region and gene of EGFP or luciferase as a reporter gene and were transfected into various types of cells, which revealed that the 5′‐flanking region had an epidermal cell‐specific transcriptional activity in both anurans and mammals. Larval skin tissues of Xenopus were transfected with the constructs and cultured in the presence and absence of TH, which showed that the promoter region is responsive to TH, although the region did not contain the consensus TH response element‐like sequence. In sharp contrast, the promoter region did not respond to TH in the adult skin, clearly indicating that the cloned region contains specific sequences that respond to metamorphosis‐dependent transcription factor(s). © 2002 Wiley‐Liss, Inc.
Neural network pruning applied to real exchange rate analysis
Authors: Kaashoek Johan F. , van Dijk Herman K.
Published: December 2002

Neural networks are fitted to real exchange rates of several industrialized countries. The size and topology of the networks is found through the use of multiple correlation coefficients, principal component analysis of residuals and graphical analysis of network output per hidden layer cell and input layer cell. These pruned neural networks are good approximations to varying non‐linear trends in real exchange rates. Non‐linear dynamic analysis shows that the long‐term equilibrium values of several European currencies correspond to the actual values within the European Monetary System. Based on its long‐term equilibrium value, the Euro appears to be undervalued vis‐à‐vis the US dollar at the introduction of the Euro on 1 January 1999. Copyright © 2002 John Wiley & Sons, Ltd.
Selection of the relevant information set for predictive relationships analysis between time series
Authors: Triacca Umberto
Published: December 2002

In time series analysis, a vector Y is often called causal for another vector X if the former helps to improve the k‐step‐ahead forecast of the latter. If this holds for k=1, vector Y is commonly called Granger‐causal for X. It has been shown in several studies that the finding of causality between two (vectors of) variables is not robust to changes of the information set. In this paper, using the concept of Hilbert spaces, we derive a condition under which the predictive relationships between two vectors are invariant to the selection of a bivariate or trivariate framework. In more detail, we provide a condition under which the finding of causality (improved predictability at forecast horizon 1) respectively non‐causality of Y for X is unaffected if the information set is either enlarged or reduced by the information in a third vector Z. This result has a practical usefulness since it provides a guidance to validate the choice of the bivariate system {X, Y} in place of {X, Y, Z}. In fact, to test the ‘goodness’ of {X, Y} we should test whether Z Granger cause X not requiring the joint analysis of all variables in {X, Y, Z}. Copyright © 2002 John Wiley & Sons, Ltd.
Multivariate Bayesian regression applied to the problem of network security
Authors: Triantafyllopoulos Kostas , Pikoulas John
Published: December 2002

An Erratum has been published for this article inJournal of Forecasting 23(6): 461 (2004).

This paper examines the problem of intrusion in computer systems that causes major breaches or allows unauthorized information manipulation. A new intrusion‐detection system using Bayesian multivariate regression is proposed to predict such unauthorized invasions before they occur and to take further action. We develop and use a multivariate dynamic linear model based on a unique approach leaving the unknown observational variance matrix distribution unspecified. The result is simultaneous forecasting free of the Wishart limitations that is proved faster and more reliable. Our proposed system uses software agent technology. The distributed software agent environment places an agent in each of the computer system workstations. The agent environment creates a user profile for each user. Every user has his or her profile monitored by the agent system and according to our statistical model prediction is possible. Implementation aspects are discussed using real data and an assessment of the model is provided. Copyright © 2002 John Wiley & Sons, Ltd.
Forecasting trend output in the Euro area
Authors: Schumacher Christian
Published: December 2002

This paper is an applied study about forecasting trend output and the output gap in the Euro area. The need for trend output forecasts is justified by an analysis of the monetary strategy of the European Central Bank. Trend output serves as a direct inflation indicator and helps to determine the reference value for money. For both purposes, trend output has to be forecasted. A permanent–transitory decomposition based on cointegration restrictions gives an estimate of trend output in the Euro area. Ex‐ante point forecasts of trend output are computed and bootstrap simulation is employed to construct prediction intervals that take estimation uncertainty into consideration. The uncertainty of trend output and the output gap is quite large and raises questions about their usefulness as indicators for monetary policy. Copyright © 2002 John Wiley & Sons, Ltd.
An electron microprobe study of P645/T390: Evidence for an Early Helladic III Lerna–Aegina connection
Authors: Dorais Michael J. , Shriner Christine M.
Published: December 2002

Middle Helladic Aeginetan Ware is widely distributed throughout the Aegean. It is characterized by a “gold mica or volcanic ash” fabric and is abundant at Lerna on the Argive plain, Greece, in the Middle Helladic and Late Helladic I periods. A group of Early Helladic III ceramics at Lerna includes P645/T390, which also has a volcanic fabric. We have sampled all the major rock types of the separate volcanic episodes on Aegina, Methana, and Poros and analyzed the constituent minerals with the electron microprobe. These analyses provide a reference standard against which the mineralogy of P645/T390 and other potential Aeginetan wares can be compared. The compositions of amphibole, clinopyroxene, plagioclase, and biotite in P645/T390 are identical to the same minerals in dacites on Aegina, suggesting an origin on that island. Compositional mismatches with the minerals of Methana and Poros indicated the ceramic was not manufactured at these locations. This narrow‐necked jar represents the earliest occurrence of Aeginetan Ware on mainland Greece that has been confirmed by a quantitative method. © 2002 Wiley Periodicals, Inc.
The source of raw materials for Roman pottery from Leptiminus, Tunisia
Authors: Sherriff Barbara L. , Court Patricia , Johnston Shannon , Stirling Lea
Published: December 2002

Leptiminus, a Roman port city on the west coast of Tunisia, North Africa, exported olive oil and a garum fish paste to Rome. Excavations have uncovered many facilities including kilns and a potter's workshop, indicating an extensive ceramic industry. The vessels, manufactured at Leptiminus, included African red‐slip fineware, coarseware, and amphorae. A petrographic study of pottery sherds showed them to contain very similar temper, rounded aeolian sand grains and limestone, but varying in proportions to produce different textures. An investigation of the source of raw materials for the pottery found three distinct types of clay within a 50 km radius of Leptiminus: grey Miocene, brown Pliocene, and green Late Pliocene clay. Statistical analysis of trace element compositions, using induced neutron activation, of clays and sherds showed that the Pliocene brown clay was used to create all types of pottery. The specific clay horizon, used in Roman times, has apparently been removed by quarrying. However, a lateral continuation of this bed was found 7 m beneath the Leptiminus site 290. © 2002 Wiley Periodicals, Inc.
Eolian processes, ground cover, and the archaeology of coastal dunes: A taphonomic case study from San Miguel Island, California, U.S.A.
Authors: Rick Torben C.
Published: December 2002

Geomorphological evidence and historical wind records indicate that eolian processes have heavily influenced San Miguel Island environments for much of the Late Quaternary. The island is almost constantly bombarded by prevailing northwesterly winds, with peak velocities exceeding 75 km/h and wind gusts reaching over 100 km/h. These strong winds played an important role in the location, formation, and preservation of the island's more than 600 archaeological sites. Excavation and surface collection at a stratified Middle and Late Holocene archaeological site on the island's north coast suggest that wind related disturbances result in significant displacement of light fish bones, produce concentrations of shellfish and heavy mammal bones, and cause significant abrasion, etching, and polishing of bones, shells, and artifacts. These data illustrate that wind not only alters surface materials but can significantly disturb subsurface deposits to a depth of at least 20 cm. Working in concert with a variety of taphonomic processes, wind can play a fundamental role in the preservation of archaeological sites and careful scrutiny during excavation and laboratory analysis is required to delineate its effects. © 2002 Wiley Periodicals, Inc.
Statistical flattening of MEG beamformer images
Authors: Barnes Gareth R. , Hillebrand Arjan
Published: December 2002

We propose a method of correction for multiple comparisons in MEG beamformer based Statistical Parametric Maps (SPMs). We introduce a modification to the minimum‐variance beamformer, in which beamformer weights and SPMs of source‐power change are computed in distinct steps. This approach allows the calculation of image smoothness based on the computed weights alone. In the first instance we estimate image smoothness by looking at local spatial correlations in residual images generated using random data; we then go on to show how the smoothness of the SPM can be obtained analytically by measuring the correlations between the adjacent weight vectors. In simulations we show that the smoothness of the SPM is highly inhomogeneous and depends on the source strength. We show that, for the minimum variance beamformer, knowledge of image smoothness is sufficient to allow for correction of the multiple comparison problem. Per‐voxel threshold estimates, based on the voxels extent (or cluster size) in flattened space, provide accurate corrected false positive error rates for these highly inhomogeneously smooth images. Hum. Brain Mapping 18:1–12, 2003. © 2002 Wiley‐Liss, Inc.
Reproducibility of the hemodynamic response to auditory oddball stimuli: A six‐week test–retest study
Authors: Kiehl Kent A. , Liddle Peter F.
Published: December 2002

Determining the reliability and reproducibility of the hemodynamic response is important for the interpretation and understanding of the results of functional magnetic resonance imaging (fMRI) experiments. We describe a whole brain fMRI study designed to examine the reproducibility of the event‐related hemodynamic response elicited by low‐probability task‐relevant target stimuli and low‐probability task‐irrelevant novel stimuli assessed 6 weeks apart. Reliable activation was observed during test and retest for processing of target stimuli in multiple frontal, temporal, parietal, cerebellar, and subcortical sites. Novel stimuli elicited reliable activation during test and retest in lateral frontal cortex, inferior parietal lobule, and lateral temporal cortex, though there was evidence of habituation at some cortical sites. The patterns of activation associated with target detection and novelty processing are consistent with the intracranial distribution of the neural sources generated during similar tasks and replicate the results of previous event‐related fMRI studies. The observed pattern of results supports the hypothesis that the hemodynamic response to target and novel stimuli is highly reproducible over the 6‐week test–retest period. Hum. Brain Mapping 18:42–52, 2003. © 2002 Wiley‐Liss, Inc.
Posterior cingulate cortex activation by emotional words: fMRI evidence from a valence decision task
Authors: Maddock Richard J. , Garrett Amy S. , Buonocore Michael H.
Published: December 2002

Functional imaging studies consistently find that emotional stimuli activate the posterior cingulate cortex, a region that appears to have memory‐related functions. However, prior imaging studies have not controlled for non‐emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the posterior cingulate cortex when these potentially confounding factors were controlled. Sixty‐four pleasant and 64 unpleasant words were matched with neutral words on non‐emotional features known to influence memory. Eight subjects underwent block‐designed functional magnetic resonance imaging scans while evaluating the valence of these words. The posterior cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the posterior cingulate cortex by emotional stimuli cannot be attributed to the memory‐enhancing effects of non‐emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory‐related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual cingulate cortex, and suggest a means of probing this region in patients with mood disorders. Hum. Brain Mapping 18:30–41, 2003. © 2002 Wiley‐Liss, Inc.
Efficient acquisition of human retinotopic maps
Authors: Slotnick Scott D. , Yantis Steven
Published: December 2002

A bifield stimulation method for rapidly obtaining retinotopic maps in human occipital cortex using functional MRI was compared to conventional unifield stimulation. While maintaining central fixation, each participant viewed the conventional display, consisting of a single rotating checkerboard wedge and, in a separate run, the bifield display, consisting of two symmetrically placed rotating checkerboard wedges (a ‘propeller’ configuration). Both stimulus configurations used wedges with 30 degree polar angle width, 6.8 degrees visual angle extension from fixation, and 8.3 Hz contrast polarity reversal rate. Retinotopic maps in each condition were projected onto a distortion corrected computationally flattened cortical surface representation obtained from a high‐resolution structural MRI. An automated procedure to localize borders between early visual areas revealed, as expected, that map precision increased with duration of data acquisition for both conditions. Bifield stimulation required 40% less time to yield maps with similar precision to those obtained using conventional unifield stimulation. Hum. Brain Mapping 18:22–29, 2003. © 2002 Wiley‐Liss, Inc.
Reducing avoidable inequalities in health: a new criterion for setting health care capitation payments
Authors: Hauck Katharina , Shaw Rebecca , Smith Peter C.
Published: December 2002

Traditionally, most health care systems which pretend to any sort of rationality and cost control have sought to allocate their limited funds in order to secure equal opportunity of access for equal need. The UK government is implementing a fundamental change of resource allocation philosophy towards ‘contributing to the reduction of avoidable health inequalities’. The purpose of this essay is to explore some of the economic issues that arise when seeking to allocate health care resources according to the new criterion. It indicates that health inequalities might arise because of variations in the quality of health services, variations in access to those services, or variations in the way people produce health, and that the resource allocation consequences differ depending on which source is being addressed. The paper shows that an objective of reducing health inequalities is not necessarily compatible with an objective of equity of access, nor with the objective of maximising health gain. The results have profound consequences for approaches towards economic evaluation, the role of clinical guidelines and performance management, as well as for resource allocation methods. Copyright © 2002 John Wiley & Sons, Ltd.
Desmoplastic neurotropic melanoma of the head and neck: The role of radiation therapy
Authors: Anderson Timothy D. , Weber Randal S. , Guerry Dupont , Elder David , Schuchter Lynn , Loevner Laurie A. , Rosenthal David I.
Published: December 2002

Background

Desmoplastic neurotropic melanoma (DNM) is an uncommon cutaneous melanoma variant with pronounced neurotropism. In contrast to ordinary melanomas, locoregional recurrences are common and distant metastasis are uncommon in patients with DNM. Local control with surgery and radiation therapy may assume a more important role in this variant of melanoma. We present a case of an unresectable skull base recurrence of DNM that was controlled using radiation therapy alone and review the literature.

Methods

Case report with 36‐month follow‐up.

Results

The patient is a 68‐year‐old with multiple recurrences of a DNM that originated on the forehead. After extensive surgery, including total parotidectomy and temporal bone resection, the patient had an unresectable recurrence of the skull base develop. This was treated with definitive radiation therapy, resulting in a complete response. The patient has had no evidence of recurrence at 3 years.

Conclusions

DNM is a locally aggressive type of melanoma with a high risk of local recurrence that can be radioresponsive. The incidence of distant metastasis is low, so aggressive treatment to control local disease is warranted. This may include surgery plus adjuvant radiation therapy or definitive radiotherapy for unresectable recurrences. © 2002 Wiley Periodicals, Inc.
Direct coaptation of extensive facial nerve defects after removal of the superficial part of the parotid gland: An anatomic study
Authors: Gardetto Alexander , Kovacs Peter , Piegger Johannes , Rainer Christian , Meirer Romed , Piza‐Katzer Hildegunde
Published: December 2002

Background.

In the surgical repair of facial nerve paralysis, a tension‐free end‐to‐end coaptation of the trunk or its branches with or without rerouting is functionally superior to grafting. Assuming that a lengthening of all branches of the parotid plexus can be attained by removal of the superficial part of the parotid gland and mobilization of the branches, we performed an anatomic study.

Methods.

The parotid regions of 10 cadavers were dissected to investigate the length gained for the branches of the parotid plexus by this technique. Every branch at the upper and ventral border of the gland was marked by a surgical suture. After removing the superficial part of the parotid gland, the branches were cut at the suture, and the proximal stump was drawn toward the distal stump. The distance of the overlapping stumps was measured by means of an electronic gliding caliper. In addition, in five specimens only the trunk of the facial nerve was dissected by the same method, and the distance of the overlapping stumps was measured.

Results and Conclusions.

The results demonstrate that removing the superficial part of the parotid gland may be sufficient to enable direct coaptation without nerve grafting. Cut temporal or zygomatic branches with a gap of up to 15 mm and cut buccal or marginal mandibular branches with a gap of up to 23 mm can be bridged by mobilization of just the proximal stumps. This technique may also be used to bridge a 17‐mm gap of the trunk of the facial nerve. © 2002 Wiley Periodicals, Inc. Head Neck 24: 1047–1053, 2002
Clinical usefulness of telomerase activation and telomere length in head and neck cancer
Authors: Patel Mintoo M. , Parekh Lalit J. , Jha Franky P. , Sainger Rachana N. , Patel Jayendra B. , Patel Devendra D. , Shah Pankaj M. , Patel Prabhudas S.
Published: December 2002

Background.

Telomere shortening at every replication cycle is postulated to limit the life span of human somatic cells. In contrast, activation of telomerase is proposed to be an essential step for cancer cell immortalization. Head and neck cancer is the most common malignancy in the Indian population compared with Western countries. However, there are very few reports on telomerase activity and telomere length in head and neck cancer.

Methods.

Telomerase activation and telomere length alterations were studied in tumor and adjacent normal tissues in 110 patients with head and neck cancer and 40 patients with precancerous/benign conditions. Telomerase activity and telomere lengths were determined by Telomeric Repeat Amplification Protocol (TRAP assay) and Southern blot analysis, respectively.

Results.

Telomerase activation was observed in 78.2% of the malignant tissues, 85% of the precancerous tissues, and 53.1% of the adjacent normal tissues. Peak terminal restriction fragment length (TRF) was observed to be significantly lower in malignant tissues compared with the adjacent normal tissues. No significant correlation could be observed between telomerase activation and clinicopathologic characteristics of the patients. Two‐year disease‐free survival analysis showed that patients showing telomerase activation in the adjacent normal tissues and patients showing higher telomere length in malignant tissues had poor disease‐free survival.

Conclusions.

Our results demonstrate the significant clinical usefulness of telomerase activation and telomere length for head and neck cancer patients. These markers may be helpful in predicting the clinical course of the disease and thus in identifying the patients in need of a close follow‐up and vigorous adjuvant treatment. © 2002 Wiley Periodicals, Inc. Head Neck 24: 1060–1067, 2002
Platelet 5‐HT2A‐receptor‐mediated induction of aggregation is not altered in major depression
Authors: Gómez‐Gil Esther , Gastó Cristóbal , Díaz‐Ricart Maribel , Carretero Marta , Salamero Manel , Catalán Rosa , Escolar Ginés
Published: December 2002

Background

Studies of the 5‐HT2A receptor subtype in major depression have focused on the density of these receptors in neuronal cells and platelets, showing an up‐regulation secondary to a deficit in serotonergic activity in major depression. However, their functional state has often been disregarded. The aim of the study was to investigate whether depressed patients show abnormalities in the function of the 5‐HT2A receptor pathway in platelets.

Method

The percentage of serotonin‐amplified platelet aggregation to adenosine diphosphate (ADP) was assessed in 30 untreated patients with major depressive disorder and in 15 controls. Since 5‐HT2A platelet receptors mediate the serotonin‐induced platelet aggregation response, this index was used as a measure of the functional status of the platelet 5‐HT2A receptor pathway.

Results

There was no significant difference in the percentage of serotonin‐amplified platelet aggregation to ADP between depressed patients and controls. No correlation with the severity of depression, as assessed by the Hamilton scale, was found.

Conclusion

The results showed no consistent changes in the platelet aggregating responses to serotonin in the depressed patients. Therefore this study does not support the hypothesis of an alteration of the functional status of platelet 5‐HT2A receptors in major depression. Copyright © 2002 John Wiley & Sons, Ltd.
Decomposition of litter in a dry sclerophyll eucalypt forest and a Pinus radiata plantation in southeastern Australia
Authors: Crockford R. H. , Richardson D. P.
Published: December 2002

This study of litter decomposition was part of an extensive project examining the partitioning of rainfall, the associated chemistry, and litterfall in a dry sclerophyll eucalypt forest and a Pinus radiata plantation in southeastern Australia. The eucalypt species studied were Eucalyptus rossii, E. mannifera and E. dives. The components tested were Pinus radiata needles, leaves of the three eucalypt species, and the bark of E. rossii and E. mannifera.

During the first 16 weeks of the decomposition experiment there was a rapid decrease in the concentrations of potassium, magnesium, sodium and phosphorus; this was attributed to leaching. During this period, concentrations of nitrogen and calcium increased for most components. After this period, decomposition became the dominant process, during which the concentrations of most elements increased. By the end of the experiment there was, compared with the initial values, a marked reduction in concentrations of sodium, magnesium and potassium for all eucalypt and pine litter. Calcium concentrations increased through time, with eucalypt bark showing a mid‐period decline. Phosphorus concentrations decreased for the eucalypt leaves but increased substantially for the pine needles and the eucalypt bark. For all components of both the eucalypts and pines, total nitrogen concentrations rose consistently throughout the decomposition period. This was attributed to the formation of nitrogen‐substituted lignin, which was more resistant to decomposition than the other nitrogen‐containing compounds, as well as some nitrogen being stored in the micro‐organisms responsible for decomposition. Because of loss of fragmented litter from the litter bags after 16 weeks, the weight changes could not be confidently measured after this period. Copyright © 2002 John Wiley & Sons, Ltd.