bluuebunny/crossref_metadata_2025 huggingface dataset:
Richard B. Setlow, a commentary on seminal contributions and scientific controversies
Authors: Cleaver James E.
Published: August 2002

Richard B. Setlow inspired the field of DNA repair. His demonstration that photoproducts could be quantified within cells and their excision examined experimentally pioneered the identification of nucleotide excision repair. His early work was associated with the discovery of many founding phenomena of photobiology and DNA repair: the concept of excision repair itself, correlations between DNA repair, life span and aging, variations in repair among mammalian species, caffeine sensitization to UV damage, and the xeroderma pigmentosum (XP) repair deficiencies. We may now have mapped thoroughly the landscape of DNA repair that Dick helped open to exploration, but questions persist of how comprehensively we have explored all its canyons and mesas. Research into nontraditional species and kingdoms may yet provide unexpected surprises. The signal transduction pathways and mechanisms of DNA replication arrest in damaged mammalian cells remain a challenge. The importance of repair in vivo also provides many difficult research questions. One problem of current interest is the role of endogenous DNA damage and repair in human pathology, especially neurodegeneration exemplified by many XP patients. Cancer and neurodegeneration may represent converse responses of dividing and nondividing cells to mutagenic and lethal effects of DNA damaging agents. Cell death from endogenous oxidative DNA damage (apoptosis) may be antagonistic to malignant transformation in dividing cells but may cause neurodegeneration in nondividing neural tissue. Small reductions in the efficiency of repair, especially transcription‐coupled repair, may overemphasize carcinogenesis in mice, while minimizing neurodegeneration, as compared to human patients. Environ. Mol. Mutagen. 38:122–131, 2001 © 2001 Wiley‐Liss, Inc.
Correction of radioresistant DNA synthesis in ataxia telangiectasia fibroblasts by prostaglandin E2 treatment
Authors: Mirzayans Razmik , Paterson Malcolm C.
Published: August 2002

Cultured cells from patients inheriting the rare cancer‐prone and radiotherapy‐sensitive disorder ataxia telangiectasia (AT) exhibit defects in the activation of cell‐cycle checkpoints after exposure to ionizing radiation. In particular, the failure of AT cells to arrest transiently the DNA de novo replication machinery immediately after irradiation—so‐called radioresistant DNA synthesis (RDS)—is often taken as a molecular hallmark of the disease. Recently we reported that: (i) the radiation‐responsive S‐phase checkpoint operating in normal human cells is mediated by a signal transduction pathway involving Ca2+/calmodulin‐dependent protein kinase II (CaMKII); and (ii) the RDS phenotype of AT cells is associated with failure to mobilize Ca2+ from intracellular stores, which is required for activation of the CaMKII‐dependent S‐phase arrest. In the present study, we demonstrate that the RDS phenotype of AT dermal fibroblasts can be rectified in the absence of ectopic expression of functional ATM, the 350‐kDa protein kinase encoded by the gene mutated in AT. Correction of RDS was observed when AT fibroblasts were coincubated with normal fibroblasts under conditions in which the 2 different cell cultures shared the same medium but were completely separated physically. The RDS trait was also rectified when AT fibroblasts were briefly incubated with prostaglandin E2 in the absence of normal feeder cells, signifying that this ubiquitous eicosanoid can serve as the diffusible “RDS‐correction factor” for AT cells in the aforementioned cocultivation studies. It would therefore appear that prostaglandin E2 can assume the role of an extracellular signaling modulator of the S‐phase checkpoint in AT cells exposed to ionizing radiation, inducing DNA synthesis shutdown via an alternative, ATM‐independent signal transduction pathway. Environ. Mol. Mutagen. 38:191–199, 2001 © 2001 Wiley‐Liss, Inc.
Inelastic buildings with tuned mass dampers under moderate ground motions from distant earthquakes
Authors: Lukkunaprasit P. , Wanitkorkul A.
Published: August 2002

The effectiveness of tuned mass dampers (TMD) in vibration control of buildings was investigated under moderate ground shaking caused by long‐distance earthquakes with frequency contents resembling the 1985 Mexico City (SCT) or the 1995 Bangkok ground motion. The elastic–perfectly plastic material behaviour was assumed for the main structure, with linear TMDs employed by virtue of their simplicity and robustness. The accumulated hysteretic energy dissipation affected by TMD was examined, and the ratio of the hysteretic energy absorption in the structure with TMD to that without it is proposed to be used, in conjunction with the peak displacement ratio, as a supplementary TMD performance index since it gives an indication of the accumulated damage induced in the inelastic structures. For the ground motions considered, TMD would be effective in reducing the hysteretic energy absorption demand in the critical storeys for buildings in the 1.8–2.8 s range. The consequence is reduction in damage of the buildings which would otherwise suffer heavy damage in the absence of TMD, resulting in economical restorability in the damage control limit state. This is of practical significance in view of the current trend toward performance‐based design. Copyright © 2001 John Wiley & Sons, Ltd.
Scattering of elastic waves by a general anisotropic basin. Part 1: a 2D model
Authors: Dravinski Marijan , Wilson Mark S.
Published: August 2002

Scattering of incident plane harmonic pseudo P‐, SH‐, and SV‐waves by a two‐dimensional basin of arbitrary shape is investigated by using an indirect boundary integral equation approach. The basin and surrounding half‐space are assumed to be generally anisotropic, homogeneous, linearly elastic solids. No material symmetries are assumed. The unknown scattered waves are expressed as linear combinations of full‐space time‐harmonic two‐dimensional Green functions. Using the Radon transform, the Green functions are obtained in the form of finite integrals over a unit circle. An algorithm for the accurate and efficient numerical evaluation of the Green functions is discussed. A detailed convergence and parametric analysis of the problem is presented. Excellent agreement is obtained with isotropic results available in the literature.

Steady‐state surface ground motion is presented for semi‐circular basins with generally anisotropic material properties. The results show that surface motion strongly depends upon the material properties of the basin as well as the angle of incidence and frequency of the incident wave. Significant mode conversion can be observed for general triclinic materials which are not present in isotropic models. Comparison with an isotropic basin response demonstrates that anisotropy is very important for assessing the nature of surface motion atop basins. Copyright © 2001 John Wiley & Sons, Ltd.
Correction factors for estimating suspended sediment export from loess catchments
Authors: Steegen A. , Govers G.
Published: August 2002

This study focuses on problems related to estimating the exact exported suspended sediment quantity and quality from flow‐proportional samples taken at a fixed height at the outlet of a small, agricultural catchment in central Belgium. First, a correction factor is introduced to estimate the real suspended sediment concentration. This factor depends on the stream depth and the grain size distribution of the sediment and is necessary because of the presence of a concentration gradient in the stream. Secondly, water depth is corrected for the sediment volume, and thirdly, the grain size distribution of the exported sediment is corrected.
 The application of these correction factors leads to a reduction of the estimated total sediment export by 18 per cent (from 4810 Mg over a period of three years to 3930 Mg). Furthermore, the importance of small grain size fractions increases, leading to higher enrichment ratios for the clay fraction and lower ratios for the sand fraction. Suspended sediment export is thus more selective than was previously thought. Due to the overestimation of the sediment export, total phosphorus losses from the catchment are also overestimated by 17 per cent. This paper therefore emphasizes that point sampling of suspended sediment is biased and that a method should be incorporated to correct the sediment export in terms of quantity and quality. Copyright © 2001 John Wiley & Sons, Ltd.
Twenty‐year weathering remeasurements at St Paul's Cathedral, London
Authors: Trudgill S. T. , Viles H. A. , Inkpen R. , Moses C. , Gosling W. , Yates T. , Collier P. , Smith D. I. , Cooke R. U.
Published: August 2002

Microerosion meter (MEM) measurements of the surface height of the balustrade of St Paul's Cathedral, London, have been repeated in the year 2000 following earlier measurements in 1980, 1981, 1985 and 1990. Methodological sources of error mean that while the measurements were made to 0·0001 mm, the data are reliable to two decimal places. There was a reduction in the mean erosion rate on horizontal sites from 0·045 mm a−1 in the period 1980–1990 to 0·025 mm a−1 in 1990–2000. Decreases in atmospheric SO2 levels from 20–25 ppb in 1980–1982 to around 10 ppb in 1990–2000, offer a causal explanation. The surface topography evolved more erratically in 1990–2000 than before, with much, but not all, of the more microelevated areas showing greater, and often more variable erosion. There are also indications of less erosion and more surface rises in low‐lying microareas on horizontal sites which is interpreted as possible deposition and/or microfloral growth in wetter depressions, the pattern being largely absent on a well drained vertical site. Copyright © 2001 John Wiley & Sons, Ltd.
The aeolian dust accumulation curve
Authors: Goossens Dirk
Published: August 2002

This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. The concept is tested in an aeolian dust wind tunnel. The agreement between the accumulation curve predicted by the model and the accumulation curve obtained in the experiments is close to perfect and shows that it is necessary to discriminate between the processes of aeolian dust deposition and aeolian dust accumulation. Two important thresholds determine the accumulation process. For wind speeds below the deflation threshold, the aeolian accumulation of dust increases linearly with the wind speed. For wind velocities between the deflation threshold and the accumulation limit, the sedimentation balance is above unity and there is still accumulation, though it rapidly drops once the deflation threshold has been exceeded. At wind speeds beyond the accumulation limit, the sedimentation balance is below unity and there will no longer be an accumulation of dust. The thresholds have been determined in a wind tunnel test at friction velocity u* = 0·34 m s−1 (deflation threshold) and u* = 0·43 m s−1 (accumulation limit), but these values are only indicative since they depend heavily on the characteristics of the accumulation surface and of the airborne grains. Copyright © 2001 John Wiley & Sons, Ltd.
Toxic cloud imaging by infrared spectrometry: A scanning FTIR system for identification and visualization
Authors: Harig Roland , Matz Gerhard
Published: August 2002

Passive remote sensing by Fourier‐transform infrared (FTIR) spectrometry allows detection and identification of toxic clouds in the atmosphere. However, the probability of detection is dependent upon the background of the field of view of the spectrometer because the signal is a function of the difference between the temperature of the cloud and the brightness temperature of the background. For small temperature differences the signal is proportional to this difference. Thus, it is possible to enhance the probability of detection by aiming the spectrometer in a direction that yields a high temperature difference between the cloud and the background. If this alignment is performed manually, the probability of detection is strongly influenced by the operator. By scanning all fields of view within the area in which a cloud is expected the probability of detection is maximized. Moreover, it is possible to visualize the cloud. An imaging passive remote‐sensing system comprised of an FTIR spectrometer, an azimuth‐elevation–scanning mirror, a data‐acquisition and control system with a digital signal processor (DSP), and a personal computer has been developed. The DSP system controls the scanning mirror, collects the interferograms of the FTIR spectrometer, and performs the Fourier transformation. The spectra are transferred to the personal computer and analyzed by a real‐time identification algorithm that does not require background spectra for the analysis. The results of the identification algorithm are visualized in false color images. The system has a high selectivity and low noise‐equivalent spectral radiance, and it allows localization of clouds and their sources. The automatic identification algorithm, the scanner system, the software for real‐time identification and imaging, and the results of field measurements are presented. © 2001 Field Analyt Chem Technol 5: 75–90, 2001
Assessment of Potential Environmental Health Risks of Residue of High‐Explosive Munitions on Military Test Ranges—Comparison in a Humid and Arid Climate
Authors: Phillips Loren , Perry Bernard
Published: August 2002

The U.S. Army Developmental Test Command (DTC) manages active ranges in a wide variety of
environmental settings where personnel fire munitions of all calibers. Over time, physical, chemical, and
biological processes may distribute munition fragments and residue on the range. Estimating the human health and
ecological risks of these residues is a challenge because little information exists for evaluating the health
effects of military‐unique releases. A human health and ecological risk assessment at two DTC munition
ranges (one in a humid, temperate climate (Aberdeen Proving Ground, Maryland), and one in a hot,
arid climate (Yuma Proving Ground, Arizona) has been completed. The objective was to estimate health
risks associated with exposure to munition residues. The scope included identifying the nature and extent of
munition residue at firing points and in impact areas from firing munitions, analyzing exposure pathways,
estimating the dose to living organisms and the response to the dose, and estimating risk from exposure. Where
appropriate, water, soil, sediment, air, and biota samples were collected from the range area and reference areas.
Samples were tested for explosives and metals. Risk to humans and ecosystem species was modeled. Results show that
munition residue is not getting into the food chain or being transmitted by direct or indirect exposure in either
climate despite low‐level detections in some media. © 2002 Wiley Periodicals, Inc.*
The essential oil composition of Salvia argentea L.
Authors: Couladis M. , Tzakou O. , Stojanovic D. , Mimica‐Dukic N. , Jancic R.
Published: August 2002

The essential oil of Salvia argentea L., collected from south‐eastern Serbia, was analysed by GC–MS. Forty‐seven constituents were identified. The oil was characterized by a high content of sesquiterpenes. The major constituents were viridiflorol (32.4%), manool (14.6%) and α‐humulene (10.7%). Copyright © 2001 John Wiley & Sons, Ltd.
Complements or substitutes? Equivalent futures contract markets—the case of corn and soybean futures on U.S. and Japanese exchanges
Authors: Holder Mark E. , Pace R. Daniel , Tomas Michael J.
Published: August 2002

This article examines the relationship between corn and soybean futures volumes for contracts traded in the
United States and Japan. Because the contract specifications for corn and soybeans futures traded on the Chicago
Board of Trade (CBOT), the Tokyo Grain Exchange (TGE), and the Kanmon Commodity Exchange
(KCE) are highly similar, the existence of interactions might be expected. Previous research has
identified price relationships between these similar contracts. With the advent of agricultural trading on the
CBOT's Project A overnight electronic trading system, an overlap of trading times of the U.S. and Japanese
exchanges for these commodity contracts resulted. An analysis of TGE and KCE corn and soybean futures volumes
indicates that these contracts, rather than acting as substitutes, exhibit a complementary
relationship. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:355–370, 2002
Asymmetric information and corporate derivatives use
Authors: Dadalt Peter , Gay Gerald D. , Nam Jouahn
Published: August 2002

We investigate the relationship between derivatives use and the extent of asymmetric information faced by the
firm. Using alternative analyst forecast proxies for asymmetric information, we find evidence that both the use of
derivatives and the extent of derivatives usage is associated with lower asymmetric information. Specifically, for
firms using derivatives (notably currency derivatives) we find that analysts' earnings forecasts
have significantly greater accuracy and lower dispersion. These findings support the conjectures of DeMarzo and
Duffie (1995) and Breeden and Viswanathan (1998) who argue that hedging reduces noise related
to exogenous factors and hence decreases the level of asymmetric information regarding a firm's earnings.
© 2002 John Wiley & Sons, Inc. Jrl Fut Mark 22: 241–267, 2002
Direct correlation between FRA3B expression and cigarette smoking
Authors: Stein Constance K. , Glover Thomas W. , Palmer J. Lynn , Glisson Bonnie S.
Published: August 2002

Cytogenetic deletions and/or loss of heterozygosity (LOH) of the short arm of chromosome 3, often with a break at 3p14, are well documented in lung tumors. The coincidence of a chromosomal fragile site, FRA3B, at a common chromosomal breakpoint in lung cancer has suggested that fragility at this site may predispose to breakage that could contribute to multistep carcinogenesis. This idea is supported by the more recent finding that FRA3B maps within the FHIT (fragile histadine triad) gene, and that aberrant transcripts and genomic deletions of FHIT/FRA3B occur in a variety of tumors including lung tumors. To determine whether some individuals have increased fragility of FRA3B that might increase the risk for breakage or deletion in 3p14.2, fragile site expression was examined in smokers, nonsmokers, and small cell lung cancer (SCLC) patients. The data clearly show that active smokers exhibit a significantly higher frequency of fragile site expression, including FRA3B, compared to that of nonsmokers and patients diagnosed with SCLC who have stopped smoking. These results suggest that active tobacco exposure increases chromosome fragile site expression, and that this fragility is transient and reversible. The data support the hypothesis that exposure to tobacco carcinogens increases the potential for chromosome breakage at fragile sites. © 2002 Wiley‐Liss, Inc.
Drosophila synaptotagmin I null mutants survive to early adulthood
Authors: Loewen Carin A. , Mackler Jennifer M. , Reist Noreen E.
Published: August 2002

Summary: Synaptotagmin is a synaptic vesicle protein required for efficient neurotransmitter release, yet its exact role in the synaptic vesicle cycle is unclear. Drosophila presents an ideal organism for studies aimed at determining the in vivo functions of proteins. However, synaptotagmin studies have been limited by the early (embryonic or first instar) lethality previously reported for Drosophila synaptotagmin I null (sytnull) mutants. Here we report a new culturing technique that enhances survival of severely uncoordinated mutants thereby permitting Drosophila sytnull mutants to survive through early adulthood. We examined synapses in sytnull third instar larvae by electrophysiology and found that they exhibit severely decreased and asynchronous evoked neurotransmitter release, as well as an increased rate of spontaneous neurotransmitter release, as previously seen in first instar sytnull larvae. The ability to examine severe synaptotagmin mutants as third instar larvae, a stage where electrophysiological and morphological analyses are more easily accomplished, will facilitate structure/function studies. genesis 31:30–36, 2001. © 2001 Wiley‐Liss, Inc.
Properties of the transmission‐disequilibrium test in the presence of inbreeding
Authors: Génin Emmanuelle , Todorov Alexandre A. , Clerget‐Darpoux Françoise
Published: August 2002

Family‐based association tests such as the transmission‐disequilibrium test (TDT), which compare alleles transmitted and non‐transmitted from parents to affected offspring, are widely used to detect the role of genetic risk factors in diseases. These methods have the advantage of being robust to population stratification and are thus believed to be valid whatever the population context. In different studies of the statistical properties of the TDT, parents of affected offspring are typically assumed to be neither inbred nor related. In many human populations, however, this assumption is false and parental alleles are then no longer independent. It is thus of interest to determine whether the TDT is a valid test of linkage and association in the presence of inbreeding. We present a method to derive the expected value of the TDT statistic under different disease models and for any relationship between the parents of affected offspring. Using this method, we show that in the presence of inbreeding, the TDT is still a valid test for linkage but not for association. The power of the test to detect linkage may, however, be increased in the presence of inbreeding under different modes of inheritance. Genet. Epidemiol. 22:116–127, 2002. © 2002 Wiley‐Liss, Inc.
Power of multipoint identity‐by‐descent methods to detect linkage using variance component models
Authors: Ekstrøm Claus Thorn
Published: August 2002

Multipoint linkage analysis gives increased power over single‐point analysis to detect linkage for quantitative trait loci (QTL). Besides increased power, the use of multipoint methods makes it possible to estimate not only the location but also the magnitude of the QTL. Currently, two methods are commonly used for calculating multipoint identity‐by‐descent (IBD) allele‐sharing estimates for pedigrees of moderate sizes. The method of Fulker et al. is based on multiple regression of the IBD status at the observed marker loci, whereas the hidden Markov model approach of Kruglyak and Lander estimates the true inheritance distribution at each chromosomal location. Simulation studies of full sibs and nuclear pedigrees show that the two methods for estimating multipoint IBD scores may give very different estimates for a pair of relatives and that a small increase in power to detect linkage can be obtained by using the hidden Markov model compared with the regression method. Genet. Epidemiol. 21:285–298, 2001. © 2001 Wiley‐Liss, Inc.
Glial expression of tumor necrosis factor in transgenic animals: How do these models reflect the “normal situation”?
Authors: Probert Lesley , Akassoglou Katerina
Published: August 2002

Recent progress in the field of experimental genetics, which enables the selective and conditional ablation or dysregulation in the expression of specific genes in mice, and its application to the study of experimentally inducible models for human disease, have contributed enormously to our understanding of the molecules and mechanisms that underlie autoimmunity and inflammation in the CNS. This article describes the lessons learned from the application of such technology to the study of the tumor necrosis factor‐α (TNF) ligand/receptor system in the CNS. Important roles for TNF and its two membrane‐bound receptors in the initiation and support of CNS inflammation, the development of CNS autoimmunity, and possibly in the resolution of T‐cell‐mediated disease, as well as their implications for our understanding of the “normal” cellular and molecular mechanisms that underlie CNS pathology, are discussed. GLIA 36:212–219, 2001. © 2001 Wiley‐Liss, Inc.
Cognitive function in UK community‐dwelling African Caribbean elders: normative data for a test battery
Authors: Stewart Robert , Richards Marcus , Brayne Carol , Mann Anthony
Published: August 2002

Many ‘first generation’ African Caribbean residents in the UK have now reached ages where risk of cognitive impairment and dementia starts to increase. In addition, conditions which may impair cognitive function, such as hypertension, diabetes and stroke, have high prevalence rates in African Caribbean populations. However, there is a lack of normative data for cognitive tests in this ethnic group. Cognitive assessment was carried out in a south London community population of 285 African Caribbean participants aged 55–75 years. Tests were drawn principally from the consortium to establish a registry for Alzheimer's disease (CERAD) battery (Boston Naming Test, verbal fluency, word list recall, and Trailmaking Tests A and B) and also included orientation items from the Mini‐Mental State Examination (MMSE) and the Clock Drawing Test. Independent effects of age, sex, education and occupation were identified on scores for most but not all cognitive tests. Compared with normative data for African American populations, lower scores on verbal fluency and the Boston Naming Test were observed but scores on memory tests were comparable. Normative data for the tests are presented, stratified by level of education. Copyright © 2001 John Wiley & Sons, Ltd
The clock drawing test in primary care: sensitivity in dementia detection and specificity against normal and depressed elderly
Authors: Kirby Michael , Denihan Aisling , Bruce Irene , Coakley David , Lawlor Brian A.
Published: August 2002

Objectives

The aim of this study was to examine the sensitivities and specificities of the clock drawing test (CDT) in the detection of dementia among older people in primary care, with particular emphasis on the effect of depression on CDT specificity. Most previous studies have been sited in specialist settings and few have addressed the issue of specificity aginst depression.

Methods

Comparison of cohorts identified from community‐based screening with GMS‐AGECAT. The CDT and the Mini‐Mental State Examination (MMSE) were administered to 41 elderly subjects with organic disorder (dementia), 84 elderly subjects with case level depression and 523 normal elderly subjects. Sensitivities and specificities of the CDT were calculated.

Results

The sensitivity of the CDT in the detection of dementia in the general community was 76%. The specificities of the CDT against normal elderly and depressed elderly was 81% and 77% respectively. Higher sensitivity and specificity were achieved by the MMSE.

Conclusions

The use of the CDT in the detection of dementia syndromes is likely to be more relevant in the primary care context than in specialist settings. The CDT provides good sensitivity and specificity but may not be as sensitive or specific in the general community as previous studies have suggested, particularly in mild dementia. Community‐based late life depression does not appear to alter the specificity of the CDT. Copyright © 2001 John Wiley & Sons, Ltd.
Discontinuation of lithium augmentation in an elderly cohort
Authors: Fahy Sabina , Lawlor Brian A.
Published: August 2002

Objectives

To observe the effects of gradual discontinuation of lithium augmentation therapy in a group of patients over the age of 65 years and to measure the rate of relapse and to identify any factors which would predict relapse.

Methods

This was a naturalistic study involving 21 patients who were on lithium augmentation and whose lithium was discontinued for a variety of clinical reasons. In most cases lithium was tapered and discontinued over a period of 2–12 weeks. Demographic and other variables were collected at baseline and compared between those who remained well and those that subsequently relapsed.

Results

Eleven patients (52.4%) relapsed following discontinuation of lithium augmentation. Those who relapsed had been on lithium for significantly longer than those who remained well off lithium (p = 0.007). There was a trend towards more hospital admissions in the relapse group (p = 0.062).

Conclusions

When lithium augmentation therapy is discontinued in elderly depressives over half of these patients relapse. A longer duration of prediscontinuation lithium treatment and more hospital admissions appear to be associated with increased risk of relapse. Copyright © 2001 John Wiley & Sons, Ltd.
High‐risk management guidelines for elderly suicidal patients in primary care settings
Authors: Brown Gregory K. , Bruce Martha L. , Pearson Jane L. ,   the PROSPECT Study Group
Published: August 2002

Older adults, especially older white men, are more likely to commit suicide than other age‐groups. The assessment and management of suicide ideation and behavior for the elderly is especially relevant for primary care physicians because many patients visit their physician shortly before committing suicide. In 1993, the Agency for Health Care Policy and Research (AHCPR) released clinical practice guidelines for the treatment of depression in primary care settings. The AHCPR guidelines offered some assistance with respect to detecting and treating patients who are suicidal. However, these guidelines lacked detailed and specific instructions for managing high‐risk patients within the context of intervention research. The current set of guidelines builds upon this previous work by describing (1) a general approach for interacting with suicidal patients; (2) structured assessments for determining the degree of risk for suicide; (3) crisis intervention strategies; and (4) ongoing management procedures for working with suicidal patients in primary care settings. Copyright © 2001 John Wiley & Sons, Ltd.
Prefrontal cortex involvement in processing incorrect arithmetic equations: Evidence from event‐related fMRI
Authors: Menon Vinod , Mackenzie Katherine , Rivera Susan Michelle , Reiss Allan Leonard
Published: August 2002

The main aim of this study was to investigate the differential processing of correct and incorrect equations to gain further insight into the neural processes involved in arithmetic reasoning. Electrophysiological studies in humans have demonstrated that processing incorrect arithmetic equations (e.g., 2 + 2 = 5) elicits a prominent event‐related potential (ERP) compared to processing correct equations (e.g., 2 + 2 = 4). In the present study, we investigated the neural substrates of this process using event‐related functional magnetic resonance imaging (fMRI). Subjects were presented with arithmetic equations and asked to indicate whether the solution displayed was correct or incorrect. We found greater activation to incorrect, compared to correct equations, in the left dorsolateral prefrontal cortex (DLPFC, BA 46) and the left ventrolateral prefrontal cortex (VLPFC, BA 47). Our results provide the first brain imaging evidence for differential processing of incorrect vs. correct equations. The prefrontal cortex activation observed in processing incorrect equations overlaps with brain areas known to be involved in working memory and interference processing. The DLPFC region differentially activated by incorrect equations was also involved in overall arithmetic processing, whereas the VLPFC was activated only during the differential processing of incorrect equations. Differential response to correct and incorrect arithmetic equations was not observed in parietal cortex regions such as the angular gyrus and intra‐parietal sulcus, which are known to play a specific role in performing arithmetic computations. The pattern of brain response observed is consistent with the hypothesis that processing incorrect equations involves detection of an incorrect answer and resolution of the interference between the internally computed and externally presented incorrect answer. More specifically, greater activation during processing of incorrect equations appears to reflect additional operations involved in maintaining the results in working memory, while subjects attempt to resolve the conflict and select a response. These findings allow us to further delineate and dissociate the contributions of prefrontal and parietal cortices to arithmetic reasoning. Hum. Brain Mapping 16:119–130, 2002. © 2002 Wiley‐Liss, Inc.
The semantic interference effect in the picture‐word paradigm: An event‐related fMRI study employing overt responses
Authors: de Zubicaray Greig I. , Wilson Stephen J. , McMahon Katie L. , Muthiah Santhi
Published: August 2002

We used event‐related functional magnetic resonance imaging (fMRI) to investigate neural responses associated with the semantic interference (SI) effect in the picture‐word task. Independent stage models of word production assume that the locus of the SI effect is at the conceptual processing level (Levelt et al. [1999]: Behav Brain Sci 22:1–75), whereas interactive models postulate that it occurs at phonological retrieval (Starreveld and La Heij [1996]: J Exp Psychol Learn Mem Cogn 22:896–918). In both types of model resolution of the SI effect occurs as a result of competitive, spreading activation without the involvement of inhibitory links. These assumptions were tested by randomly presenting participants with trials from semantically‐related and lexical control distractor conditions and acquiring image volumes coincident with the estimated peak hemodynamic response for each trial. Overt vocalization of picture names occurred in the absence of scanner noise, allowing reaction time (RT) data to be collected. Analysis of the RT data confirmed the SI effect. Regions showing differential hemodynamic responses during the SI effect included the left mid section of the middle temporal gyrus, left posterior superior temporal gyrus, left anterior cingulate cortex, and bilateral orbitomedial prefrontal cortex. Additional responses were observed in the frontal eye fields, left inferior parietal lobule, and right anterior temporal and occipital cortex. The results are interpreted as indirectly supporting interactive models that allow spreading activation between both conceptual processing and phonological retrieval levels of word production. In addition, the data confirm that selective attention/response suppression has a role in resolving the SI effect similar to the way in which Stroop interference is resolved. We conclude that neuroimaging studies can provide information about the neuroanatomical organization of the lexical system that may prove useful for constraining theoretical models of word production. Hum. Brain Mapping 14:218–227, 2001. © 2001 Wiley‐Liss, Inc.
Benchmarking distance education
Authors: Novak Richard J.
Published: August 2002

This chapter explores benchmarks of quality for distance education and considers the unique perspectives of the various stakeholders promoting these benchmarks.
The role of permanent income and family structure in the determination of child health in Canada
Authors: Curtis Lori J. , Dooley Martin D. , Lipman Ellen L. , Feeny David H.
Published: August 2002

We use data from the Ontario Child Health Study (OCHS) to provide the first Canadian estimates of how the empirical association between child health and both low‐income and family status (lone‐mother versus two‐parent) changes when we re‐estimate the model with pooled data. Two waves of data provide a better indication of the family's long‐run level of economic resources than does one wave. Our measures of health status include categorical indicators and the health utility score derived from the Health Utilities Index Mark 2 (HUI2) system. Consistent with findings from other countries, we find that most outcomes are more strongly related to low‐average income (in 1982 and 1986) than to low‐current income in either year. Unlike some previous research, we find the quantitative impact of low‐income on child health to be modest to large. Lone‐mother status is negatively associated with most outcomes, but the lone‐mother coefficients did not change significantly when we switched from low‐current income to low‐average income. This implies that the lone‐mother coefficient in single cross‐sections is not just a proxy for low‐permanent income. Copyright © 2001 John Wiley & Sons, Ltd.
The physician–patient relationship as a game of strategic information transmission
Authors: De Jaegher Kris , Jegers Marc
Published: August 2002

We show that the intuition underlying the supplier‐induced demand (SID) hypothesis is reflected in the cheap‐talk literature from game theory, and in the credence‐good literature from the economics of information. Applying these theories, we conclude that a neoclassical version of the SID hypothesis is only relevant for treatment decisions involving an expensive treatment that is equally effective in curing several states, but efficient in curing only some of these states (in that a cheaper treatment is efficient otherwise). For a simple game involving such a treatment decision, we show that a Nash equilibrium exists where the patient is able to constrain the physician in inducing demand, without the market for the potentially induced treatment failing. This equilibrium allows us to derive comparative statistics and welfare results. Copyright © 2001 John Wiley & Sons, Ltd.
Atypical fibroxanthoma of the scalp
Authors: Anderson Peter J. , McPhaden Allan R. , Ratcliffe Robert J.
Published: August 2002

Background

Atypical fibroxanthoma occurs most frequently in the head and neck region of the elderly. Previous reports have identified that the condition usually arises at the following sites: the nose, cheeks, forehead, and the ears; its development at other sites is unusual.

Method

We report a series of 10 cases with lesions all occurring at an apparently unusual site, the scalp, over a 10‐year period. We compared the clinical and histologic appearances and behavior of this series with the existing reports of these lesions elsewhere in the head and neck region to investigate whether there were differences with those occurring at a conventional site.

Results

Despite the identification of a range of clinical and histologic findings in our cases, we were unable to find any significant differences with those arising at a conventional site.

Conclusion

This clustering of cases at an apparently unusual site leads us to propose that this condition occurs more commonly on the scalp than current literature suggests. The possibility of its development at this site should be remembered by head and neck surgeons in their differential diagnosis of exophytic lesions of the scalp. © 2001 John Wiley & Sons, Inc. Head Neck 23: 399–403, 2001.
Further experience with botox injection for tracheoesophageal speech failure
Authors: Lewin Jan S. , Bishop‐Leone Julie K. , Forman Arthur D. , Diaz Eduardo M.
Published: August 2002

Background

Some patients fail to acquire tracheoesophageal (TE) speech after laryngectomy because of pharyngeal constrictor hypertonicity. Botox injection relieves hypertonicity, but there are little objective data regarding outcomes, duration of effect, and reinjection rates.

Methods

Hypertonicity was identified by means of insufflation testing and confirmed videofluoroscopically in 23 unsuccessful TE speakers. Each patient received an EMG‐guided Botox injection. Additional injections were offered if the first injection failed to produce fluent speech.

Results

Overall, 20 of 23 patients (87%) achieved fluent TE speech production after Botox injections; 5 after additional injections. Two patients declined further intervention, and 1 failed to achieve fluent TE speech production even after 3 Botox injections. The longest sustained effect was 37 months, the shortest was 5 months for 1 patient who required reinjection of Botox to maintain her TE speech production.

Conclusions

Botox injection relieves constrictor hypertonicity in selected cases of TE speech failure with little need for reinjection to maintain long‐term speech success. © 2001 John Wiley & Sons, Inc. Head Neck 23: 456–460 2001.
Surgical treatment of squamous cell carcinoma of the base of tongue
Authors: Gourin Christine G. , Johnson Jonas T.
Published: August 2002

Introduction

Squamous cell carcinoma (SSC) of the tongue base has historically been shown to be associated with a poor prognosis. We reviewed our experience with primary surgery followed by postoperative radiation therapy (XRT) to determine the impact of our treatment protocols on outcome.

Methods

We retrospectively reviewed the records of all patients presenting to the University of Pittsburgh with previously untreated SSC of the tongue base between 1980–1997. Patients who were treated nonoperatively were excluded from analysis. Surgical excision of the primary was performed with ipsilateral neck dissection. The contralateral neck was dissected when the primary lesion was located in the midline or for clinically positive contralateral neck nodes. Postoperatively, most patients (93%) received XRT to the primary site and neck. Adjuvant chemotherapy was offered if histologic signs of aggressive behavior were identified (multiple nodes or extracapsular spread).

Results

Of 87 patients identified, 39 (45%) were initially seen with T1 or T2 tumors. Seventy‐nine patients (91%) were initially seen with stage III or IV disease. Contralateral neck dissection was performed in 36 patients (41%). Metastatic disease was demonstrated in 84% of ipsilateral neck nodes and in 47% of contralateral neck nodes. Occult metastases were found in 61% of clinically N0 necks. Local recurrence occurred in 5 patients, regional recurrence occurred in 12 patients, and distant metastases developed in 22 patients. Overall and disease‐specific survival rates at 5 years for all patients were 49% and 56%, respectively. The 5 year disease‐specific survival rates for stage I, stage II, stage III, and stage IV disease were 100%, 86%, 62%, and 48%. The 5‐year disease‐specific survival rate was 88% for T1 lesions, 64% for T2 lesions, 58% for T3 lesions, and 30% for T4 lesions (p < .05, log‐rank test).

Conclusions

Surgical treatment of SCC of the tongue base is highly effective in achieving local disease control and disease‐free survival for early lesions. Because both functional outcome and survival are poor after surgical treatment of advanced lesions, we now offer brachytherapy with XRT or participation in a combined chemoradiation protocol rather than primary surgical therapy to patients with advanced disease. Prospective studies are needed to compare the effect of these organ‐preserving therapies with traditional combined surgery and XRT to determine the effect on functional outcome and quality of life. © 2001 Wiley & Sons, Inc. Head Neck 23: 653–660, 2001.
Comparative analysis of cholinergic innervation in the dorsal hippocampus of adult mouse and rat: A quantitative immunocytochemical study
Authors: Aznavour Nicolas , Mechawar Naguib , Descarries Laurent
Published: August 2002

To obtain quantitative data on the distribution of the acetylcholine (ACh) innervation in the dorsal hippocampus of adult mouse (C57/B6) and rat (Sprague‐Dawley), a semicomputerized method was used to measure the length of immunostained axons in hippocampal sections processed for light microscopic immunocytochemistry with a highly sensitive antibody against choline acetyltransferase (ChAT). The results could be expressed in density of axons (meters per mm3) for the different layers and regions of dorsal hippocampus (CA1, CA3, DG), and also in density of axon varicosities (millions per mm3), after having determined the average number of varicosities per unit length of ChAT‐immunostained axon (4 varicosities/10 μm). In mouse, the mean regional densities of ACh innervation were thus measured at 13.9, 16.1, and 15.8 m of axons, for 5.6, 6.4, and 6.3 million varicosities per mm3 of tissue, in CA1, CA3, and DG, respectively. The values were comparable in rat, except for CA1, in which the densities were lower than in mouse by 40% in the stratum lacunosum, and 20% in the stratum radiatum. Otherwise, the laminar patterns of innervation were similar in the two species, the highest densities being found in the stratum lacunosum moleculare of CA3, pyramidale of both CA1 and CA3, and moleculare of DG. These quantitative data will be of particular interest to evaluate changes in mutant mice, or mice and rats subjected to experimental conditions affecting the cholinergic phenotype. Hippocampus 2002;12:206–217. © 2002 Wiley‐Liss, Inc.
Lufthansa's Transformation Marathon: Process of Liberating and Focusing Change Energy
Authors: Bruch Heike , Sattelberger Thomas
Published: August 2002

Transformations often fail to activate the energy of those whose creativity and action are needed to realize
fundamental change. In 1991 Lufthansa was almost bankrupt. Today it has become one of the world's most
profitable airline companies and a founding member of the STAR ALLIANCE, aspiring to become the world's leading
aviation group. Lufthansa has undergone a fundamental ongoing change—its approach relies on people. Core
elements of this strategy involve providing space for reflection and dialogue despite the crisis pressure, building
networks of change actors and creating durable platforms for emotional mobilization and reflection on action. ©
2001 John Wiley & Sons, Inc.
Evidence for seasonal subglacial outburst events at a polythermal glacier, Finsterwalderbreen, Svalbard
Authors: Wadham J. L. , Hodgkins R. , Cooper R. J. , Tranter M.
Published: August 2002

Bulk runoff and meteorological data suggest the occurrence of two meltwater outburst events at Finsterwalderbreen, Svalbard, during the 1995 and 1999 melt seasons. Increased bulk meltwater concentrations of Cl− during the outbursts indicate the release of snowmelt from storage. Bulk meltwater hydrochemical data and suspended sediment concentrations suggest that this snowmelt accessed a chemical weathering environment characterized by high rock:water ratios and long rock–water contact times. This is consistent with a subglacial origin. The trigger for both the 1995 and 1999 outbursts is believed to be high rates of surface meltwater production and the oversupply of meltwater to areas of the glacier bed that were at the pressure melting point, but which were unconnected to the main subglacial drainage network. An increase in subglacial water pressure to above the overburden pressure lead to the forcing of a hydrological connection between the expanding subglacial reservoir and the ice‐marginal channelized system. The purging of ice blocks from the glacier during the outbursts may indicate the breach of an ice dam during connection. Although subglacial meltwater issued continually from the glacier terminus via a subglacial upwelling during both melt seasons, field observations showed outburst meltwaters were released solely via an ice‐marginal channel. It is possible that outburst events are a seasonal phenomenon at this glacier and reflect the periodic drainage of meltwaters from the same subglacial reservoir from year to year. However, the location of this reservoir is uncertain. A 100 m high bedrock ridge traverses the glacier 6·5 km from its terminus. The overdeepened area up‐glacier from this is the most probable site for subglacial meltwater accumulation. Copyright © 2001 John Wiley & Sons, Ltd.