bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of diversity of the north‐eastern Atlantic blenniid fish fauna (Pisces: Blenniidae)
Authors: Almada Vítor C. , Oliveira Rui F. , Gonçalves Emanuel J. , Almeida Armando J. , Santos Ricardo S. , Wirtz Peter
Published: March 2003

This paper presents an analysis of the distributional patterns of blenniids (Pisces: Blenniidae) in the north‐eastern Atlantic. Two peaks of species diversity were found, both in terms of number of species and number of endemics: one in the tropical African coast and another in the Mediterranean Sea. A cluster analysis of similarity values (Jaccard coefficient) among the eastern Atlantic zoogeographical areas, revealed the following groups: a north temperate group, a tropical group formed by the tropical African coast and Mauritania, another group formed by the islands of Cape Verde, a south temperate group (South Africa), and a southern Atlantic group formed by the islands of Ascension and St Helena. Within the north temperate group, the subgroups with higher similarities were: Azores and Madeira, Canary Islands and Morocco, and the Mediterranean and the Atlantic coast of the Iberian Peninsula. Based on affinity indices, the probable directions of faunal flows were inferred. The tropical coast of Africa and the Mediterranean emerged from this analysis as probable speciation centres of the north‐eastern Atlantic blenniid fauna. The Mediterranean may have also acted as a refuge during glacial periods.
Historical biogeography of Iberobathynella (Crustacea, Syncarida, Bathynellacea), an aquatic subterranean genus of Parabathynellids, endemic to the Iberian Peninsula
Authors: Guil Noemí , Camacho Ana I.
Published: March 2003

The origin and distribution of the species of freshwater interstitial (stygobiont) syncarids of the Iberobathynella genus (Crustacea, Parabathynellidae), endemic to the Iberian Peninsula, are considered in the context of evolutionary biogeography.

We established the most likely phylogenetic relationships between the 14 known species of the Iberobathynella genus on the basis of morphological characters. We assumed a common marine ancestor and estimated the possible phylogenetic ages of the 14 inland species from the number of cladogram nodes.

The land ages at the sites where the species are found help to tell us when the landmasses emerged definitively: most species are found in areas that have undergone one or more marine transgressions/regressions since the Triassic and which could therefore have been colonized by the common ancestors.

We assessed the Boutin–Coineau two‐step model of colonization and evolution in an attempt to elucidate the evolutionary history of Iberobathynella and to offer a plausible palaeogeographical scenario. We looked for concordance between the possible chronology of Iberobathynella taxa colonization and their phylogenetic relationships, but found none of significance. Hence, we cannot reject the possibility that evolutionary clade divergence within the genus was independent of sea‐level changes in the Senonian (88.5–65 mya) and Eocene (56.5–35.4 mya) epochs. We can therefore neither confirm nor rule out a correlation.
Biodiversity hotspots: hot for what?
Authors: Jepson Paul , Canney Susan
Published: March 2003

In complex areas of international policy, such as biodiversity conservation, there is a risk that well‐promoted strategies will be received by decision makers as a cure‐all. The U.S.‐based Conservation International is promoting biodiversity hotspots as a ‘silver bullet’ strategy for conserving most species for least cost. We assess the degree to which this goal is compatible with four social values that characterize the conservation movement. We find that biodiversity hotspots provide only a partial response because conservation does not treat all species as equal. We argue that explicit recognition of such values is fundamental to a structured debate contributing to the development of a common strategy for biodiversity conservation.
Equal diversity in disparate species assemblages: a comparison of native and exotic woodlands in California
Authors: Sax Dov F.
Published: March 2003

The species richness of ecosystems can remain stable over time, despite changes in species composition and changes in the dominant plant species. While this pattern of stability is known to occur temporally, it has been examined poorly in a spatial context. To examine this spatially, the species richness, diversity and composition of native woodlands (of oak and bay trees) and exotic woodlands (of eucalypt trees) were compared in California. Species richness was nearly identical for understorey plants, leaf‐litter invertebrates, amphibians and birds; only rodents had significantly fewer species in eucalypt sites. Species diversity patterns (using the Shannon–Wiener Index) were qualitatively identical to those for species richness, except for leaf‐litter invertebrates, which were significantly more diverse in eucalypt sites during the spring. Species composition was different between sites, as evidenced by a principal components analysis, coefficients of similarity, and the relatively few species shared between native and eucalypt sites. Thus, the consistency in richness and diversity observed for most groups, in most seasons, occurred despite significant differences in species composition. These results are consistent with previous demonstrations of temporal stability, suggesting that species richness may often be stable, both temporally and spatially, despite changes in composition and regardless of the dominant vegetation.
Responses of vegetation structure and primary production of a forest transect in eastern China to global change
Authors: Yu Mei , Gao Qiong , Liu Yinghui , Xu Hongmei , Shi Peijun
Published: March 2003

Aim A regional model of vegetation dynamics was enhanced to include biogeochemical cycling of nitrogen and was then applied to a forest transect in east China (FTEC) in order to investigate the responses of the transect to possible global change.

Location Eastern China.

Methods Biomass and nitrogen concentration of green and nongreen portions of vegetation, moisture contents of three soil layers, and total and available soil nitrogen are included as state variables in the enhanced model. The model was parameterized and validated against field observations of biomass, productivity, plant and soil nitrogen concentration, nitrogen uptake, a vegetation index derived from satellite remote sensing and digital maps of vegetation and soil distributions along a forest transect in eastern China (FTEC). The model was applied to FTEC in order to investigate the responsive characteristics of the ecosystems to global climatic change. Scenarios of climate change under doubled CO2 produced by seven general circulation models (GCM) were used to drive the model.

Results The simulations indicated that the model is capable of simulating accurately potential vegetation distribution and net primary productivity under contemporary climatic conditions. The simulations for GCM‐projected future climate scenarios with doubled atmospheric CO2 concentration predicted that broadleaf forests would increase, but conifer forests, shrubs and grasses would decrease; and that deciduous forests would have the largest relative increase, but evergreen shrubs would have the largest decrease.

Conclusions The overall effects of doubling CO2 and climatic changes on FTEC were to produce an increased net primary productivity (NPP) at equilibrium for all seven GCM scenarios. The inclusion of nitrogen dynamics in the model imposes more constraint on the responses of FTEC to climatic change than the previous version of the model without nitrogen dynamics. Temperature exerts a stronger control on NPP than precipitation, as indicated by the negative correlations between NPP and temperature. The southern portion of FTEC, at latitudes less than 33 °N, show much larger increases in annual NPP than in the north. However, the predicted range of NPP increases is much larger in the north than in the south.
On the determinants of census area: implications for mammalian macroecological patterns
Authors: Prince Mary Ellen , Silva Marina
Published: March 2003

The aim of this study was to examine the effects of various biological factors such as body mass, trophic level, climate and geography on census area in terrestrial mammals. We also examine the effects of census area on the population density–body mass relationship. The geographic areas covered in this study include most major terrestrial biomes including taïga, desert, savanna, grassland, tropical dry forest, temperate dry forest, tropical rain forest and temperate rain forest. An extensive literature search was conducted and we compiled data on census area and body mass from 377 mammalian populations and 59 communities. Statistical analyses include linear regression, Kruskal–Wallis analysis of variance, LOWESS, and multiple regression. Overall, the regression between log census area (A) and log body mass (M) yielded a slope of 0.710, which did not differ significantly from 0.75, but it was significantly different from 1.0. The analyses also showed that the log A–log M relationship is constrained within a well‐defined space in a similar fashion to the home range–body mass relationship. When mammals were separated into trophic groups, regression lines differed significantly in their intercepts, but not in slopes. At the community level, the census area was particularly affected by the population with the largest body mass within the community. Both the number of species and number of taxa encompassed by the community were found to be correlated positively with log A (r = 0.26, P = 0.0464 and r = 0.27, P = 0.0398, respectively). Sampling of mammalian species is not usually random. Not only is census area significantly associated with the technique used to sample a given species, but it is also influenced by biological factors that have been shown previously to influence population density. Striking similarities were found between the census area–body mass relationship and the home range–body mass relationship, suggesting that investigators may sample mammalian populations over areas that actually reflect the use of space of their focal species.
The relationships between local and regional species richness and spatial turnover
Authors: Koleff Patricia , Gaston Kevin J.
Published: March 2003

Aim To determine the empirical relationships between species richness and spatial turnover in species composition across spatial scales. These have remained little explored despite the fact that such relationships are fundamental to understanding spatial diversity patterns.

Location South‐east Scotland.

Methods Defining local species richness simply as the total number of species at a finer resolution than regional species richness and spatial turnover as turnover in species identity between any two or more areas, we determined the empirical relationships between all three, and the influence of spatial scale upon them, using data on breeding bird distributions. We estimated spatial turnover using a measure independent of species richness gradients, a fundamental feature which has been neglected in theoretical studies.

Results Local species richness and spatial turnover exhibited a negative relationship, which became stronger as larger neighbourhood sizes were considered in estimating the latter. Spatial turnover and regional species richness did not show any significant relationship, suggesting that spatial species replacement occurs independently of the size of the regional species pool. Local and regional species richness only showed the expected positive relationship when the size of the local scale was relatively large in relation to the regional scale.

Conclusions Explanations for the relationships between spatial turnover and local and regional species richness can be found in the spatial patterns of species commonality, gain and loss between areas.
Sib‐TDT analysis of human TGF‐β1 gene single nucleotide polymorphisms in female twins: evidence for linkage and association with blood pressure at the codon 263 polymorphism
Authors: Snieder H. , Van Den Oord Ejcg , Chiano M. , MacGregor Aj , Spector Td
Published: March 2003

We illustrate the use of a quantitative trait locus (QTL) association test with data on blood pressure and six single nucleotide polymorphisms (SNPs) within the transforming growth factor‐β1(TGF‐β1) gene in a large sample of dizygotic (DZ) twins. The test was specified within the framework of structural equation modelling and allows for population stratification and easily incorporates confounders. Results showed linkage in the presence of association between the TGF‐β1 263 polymorphism and blood pressure levels, with carriers showing a clinically significant increase of 6 and 4 mm Hg in systolic and diastolic blood pressure, respectively. The described association test offers an easy and flexible way to analyse QTL data in sib or DZ twin pairs while controlling for population stratification by making use of within‐family controls.
Regression models for association studies of quantitative trait loci in humans
Authors: Cardon Lon R. , Abecasis Gonçalo R.
Published: March 2003

Regression analysis is a simple, computationally efficient and often robust method for assessment of genotype–phenotype relationships in quantitative traits. It has long been used in studies of familiality and selection, and recently has been further extended for linkage and association analysis, linkage disequilibrium mapping and population substructure assessment. We review and compare some of the most commonly used regression models and highlight some useful properties of one model via analysis of angiotensin‐converting enzyme phenotype and marker data.
Adding power to Haseman and Elston’s (1972) method
Authors: Elston Robert C. , Shete Sanjay S.
Published: March 2003

Haseman and Elston1 proposed a model‐free method for testing linkage between a polymorphic marker and a quantitative trait locus from data on a sample of independent sib pairs. In that method the squared sib‐pair trait difference is regressed on the estimated proportion of alleles shared by the sibs at a marker locus, a negative regression coefficient suggesting linkage. It is possible to obtain more power by modelling the sib covariance, as in the variance component method of linkage analysis, and yet retain a method that is computationally fast, involving only linear regression. To do this it is only necessary to change the dependent variable from the squared trait difference to the difference between the squared mean‐corrected sum and the squared trait difference. The method can accommodate sibships of arbitrary size by using generalized least squares and can be made more powerful by weighting the two components. The method is robust in large samples in the presence of any trait distribution, and, in the case of ascertained samples, the mean can be chosen to maximize power.
Distinct differences in a cyclin D1 single nucleotide polymorphism between ethnic groups
Authors: McKay Judith A. , Githang’a Jessie , Indalo Anne , Li Tao , Liu Xiehe , Ameyaw Margaret‐Mary , Ofori‐Adjei David , McLeod Howard L.
Published: March 2003

Introduction  Cyclin D1, encoded by the CCND1 gene, is a key regulator of the cell cycle at the G1/S phase checkpoint. A common A/G single nucleotide polymorphism (SNP) at nt870 of the CCND1 gene has been associated with outcome in patients with lung tumours and head and neck cancer. The aim of this study was to ascertain the genotype and allele frequency of the CCND1 polymorphism in five distinct ethnic populations.

Methods

 Polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis was carried out on genomic DNA from 505 subjects from five distinct ethnic populations (i.e. Caucasian, South‐west Asian, Ghanaian, Kenyan and Chinese subjects).

Results

 Marked differences in genotype were apparent between the ethnic populations, with homozygosity for the G allele ranging from 13.6% in the Chinese subjects to 62.4% amongst Kenyan individuals (P < 0.001). Whereas the East and West African populations demonstrated almost identical allele frequencies, both populations differed significantly from each of the remaining populations. the allele frequencies for the South‐west Asian population fell between that of the Caucasian and Chinese populations but did not differ significantly from either, while the Caucasian and Chinese subjects displayed significant differences in CCND1 alleles (P = 0.003).

Discussion

 These marked variations in SNP frequencies between ethnic groups may have a significant impact on prognosis of cancer in these populations, because the CCND1 genotype appears to influence prognosis in each tumour type examined to date.
The implications of solar UV radiation exposure for fish and fisheries
Authors: Zagarese Horacio E , Williamson Craig E
Published: March 2003

Ultraviolet radiation (UVR) possesses three important properties that combine to make it a potent environmental force. These include the potential to induce damage: UVR carries more energy per photon than any other wavelength reaching the Earth’s surface. Such highly energetic photons are known to damage many biological molecules, such as DNA and proteins. In addition, they can initiate a series of redox reactions to form reactive oxygen species (ROS), which cause oxidative stress to cells and tissues. The second property is ubiquity: owing to their dependence on light, primary producers and most visual predators, such as fish, are also necessarily exposed to damaging levels of UVR. Thirdly, the combined effect of UVR and additional environmental factors may result in synergistic effects, such as the photoactivation of organic pollutants and photosensitisation. In natural environments, the concentration of dissolved organic matter (DOM) and habitat depth are the two main factors controlling the degree of UVR exposure experienced by fish. Additional factors include vegetation coverage, particulate materials in suspension, pH and hydrological characteristics, and site location (latitude, elevation). The range of potential effects on fish includes direct DNA damage resulting in embryo and larval mortality, and adult and juvenile sunburn, as well as indirect oxidative stress, phototoxicity and photosensitisation.
Compensatory density dependence in fish populations: importance, controversy, understanding and prognosis
Authors: Rose Kenneth A , Cowan James H , Winemiller Kirk O , Myers Ransom A , Hilborn Ray
Published: March 2003

Density‐dependent processes such as growth, survival, reproduction and movement are compensatory if their rates change in response to variation in population density (or numbers) such that they result in a slowed population growth rate at high densities and promote a numerical increase of the population at low densities. Compensatory density dependence is important to fisheries management because it operates to offset the losses of individuals. While the concept of compensation is straightforward, it remains one of the most controversial issues in population dynamics. The difficulties arise when going from general concepts to specific populations. Compensation is usually quantified using some combination of spawner–recruit analysis, long‐term field monitoring or manipulative studies, and computer modelling. Problems arise because there are limitations to each of these approaches, and these limitations generally originate from the high uncertainty associated with field measurements. We offer a hierarchical approach to predicting and understanding compensation that ranges from the very general, using basic life‐history theory, to the highly site‐specific, using detailed population models. We analyse a spawner–recruit database to test the predictions about compensation and compensatory reserve that derive from a three‐endpoint life‐history framework designed for fish. We then summarise field examples of density dependence in specific processes. Selected long‐term field monitoring studies, manipulative studies and computer modelling examples are then highlighted that illustrate how density‐dependent processes led to compensatory responses at the population level. Some theoretical and empirical advances that offer hope for progress in the future on the compensation issue are discussed. We advocate an approach to compensation that involves process‐level understanding of the underlying mechanisms, life‐history theory, careful analysis of field data, and matrix and individual‐based modelling. There will always be debate if the quantification of compensation does not include some degree of understanding of the underlying mechanisms.
A dynamic mass‐balance model for marine protected areas
Authors: Watson  , Alder  , Walters
Published: March 2003

A modified Ecosim model was used to investigate the impact of establishing marine protected areas (MPAs) in ecosystems defined by existing
Ecopath models. The impact of MPAs of various sizes was simulated, and changes in biomass and catch over a range of years observed. The response of biomass and catch to MPA size depended on the time period examined. For some ecosystem groups, the initial response was negative, but for all groups there were increases after 10 years. The greater the biomass exchange rate across the MPA boundary, the larger the MPA required to increase biomass levels. Within the range of exchange rates simulated, the maximum increases in catch and overall biomass levels were reached when 20% of the system was protected.
Ecoepidemiology of the effects of pollution on reproduction and survival of early life stages in teleosts
Authors: Murl Rolland Rosalind
Published: March 2003

Evidence from the field and laboratory has shown that reproduction and early life‐stage survival of several species of teleost fishes have been adversely affected following the release of several classes of synthetic, organic chemicals into the environment. Field studies from many geographic areas over several decades have found associations between exposure to synthetic chemicals in the environment and effects on hatchability, embryological success and larval survival. In more recent research, exposure to sewage treatment and bleached kraft mill effluents has been correlated with changes in reproductive system development and alterations in the endocrine physiology of wild teleost fishes. Loss of fecundity and damage during various stages of development and reproduction have been associated with exposure to endocrine disruptors, including many currently used chemicals. The supporting laboratory studies have confirmed that various wild fish species are sensitive to certain synthetic chemicals at levels of exposure of parts per billion and parts per trillion, concentrations that are biochemically, physiologically, and environmentally relevant. This paper reviews the relevant field and laboratory research, and organizes the studies using the ecoepidemiological criteria of time‐order, strength of association, specificity, consistency on replication, coherence and predictive performance. There is sufficient evidence to conclude that ambient concentrations of synthetic chemicals in some regions are at or above concentrations at which certain species could be affected. The viability of fishery resources must be linked not only to the quantity of habitat but also to the quality of habitat.
On ‘variability’ as a sampling artefact: the case of Sardinella in north‐western Africa
Authors: Samb B. , Pauly D.
Published: March 2003

Objective evaluation of the global impact of fisheries on ocean ecosystems may be hampered by various biases suggesting natural variability of exploited species to be stronger and more widespread than is really the case. One of these is reporting biases: papers are usually not published which show that nothing has changed. Another such bias is that much variability is fishery‐induced, i.e. due to the truncation by fishing of the age composition of exploited populations. A third source of bias, emphasized here, is that resulting from sampling a migrating population with a fixed device. This bias is illustrated by contrasting the relatively stable echo‐acoustic estimates of biomass of Sardinella spp. along the north‐west African coast, i.e. from Morocco and Mauritania to Senegal (data from 1992–98), with the more variable estimates of biomass in the waters of each of these countries. We conclude that published reports of ‘variability’ in exploited species should explicitly account for the effect of migrations and other movements, especially when such reports are to be used for contrasting fisheries‐induced with environmental impacts on biomass.
The enhancement of cod stocks
Authors: Svåsand T. , Kristiansen T.S. , Pedersen T. , Salvanes A.G.V. , Engelsen R. , Nævdal G. , Nødtvedt M.
Published: March 2003

Atlantic cod have been a primary target for marine stock enhancement since the 1880s. In the early part of this period, hatched larvae were released in Norway, the USA and Canada. The last larval releases were conducted in Norway in 1971, and a century of cod larvae releases were halted without any clear evidence of benefit. Since the early 1980s, the focus has been on production of larger, more viable juvenile cod. Emphasis has been given to the design of tag–release programmes involving large‐scale releases and ecosystem analysis in selected ecosystems. Most of this research has been carried out in Norway, where more than one million tagged juvenile cod have been released. Smaller stocking experiments have also been performed in Denmark, Sweden, the Faroe Islands and the USA.

This paper reviews the major findings from these programmes. We include summaries and evaluations of rearing techniques for juvenile cod, methods of tagging and recapture, experimental fishing, migration, mortality and growth rates in the different habitats, genetic analysis, and ecosystem studies that have tried to describe the variation in the cod carrying capacity of selected release areas.

Despite relatively large variation in environmental conditions, in cod production and in fishing mortality along the Norwegian coast, results indicate that, under the conditions experienced during the 1980s and 1990s, releases of juvenile cod did not significantly increase cod production and catches. The biological limitations and future prospects of Atlantic cod stock enhancement are addressed.
Aerobic muscle function during steady swimming in fish
Authors: Coughlin David J
Published: March 2003

Axial swimming in fish varies across a range of body forms and swimming modes. Swimming by eels, tunas, mackerels, scup, rainbow trout and bass span this range from high curvature anguilliform swimmers to rigid body thunniform swimmers. Recent work on these and other species has elucidated an impressive array of solutions to the problem of how to use the red (aerobic, slow‐twitch) muscle to power steady or sustained swimming. This review will use a comparative approach to understand the generalities of aerobic muscle function during steady swimming in fish and determine possible rules for the relationships between muscle contractile kinetics, in vivo muscle activity and power output during swimming. Beyond an exploration of the diversity in muscle activity and swimming kinematics, I suggest that analysis of the molecular basis for longitudinal variations in muscle function is needed to complement morphological and physiological research on fish muscle. This will permit both a general understanding of the integrative function of the fish myotome and, perhaps, predictive tools for muscle activity and swimming performance in fish.
Species concepts: the basis for controversy and reconciliation
Authors: Ghiselin Michael T
Published: March 2003

Some of the disputes about species concepts can be resolved through clarification of the conceptual issues. Others are intractable because incompatible preferences are being optimized. According to the current biological consensus species (taxa) are populations rendered cohesive by sex. The philosophical consensus has it that the species and other categories are (abstract) classes, whereas particular species and other taxa are (concrete) individuals (in the ontological sense). Natural kinds are classes that have the properties they do because of laws of nature. Individuals such as species and clades owe their properties to history, not laws of nature; they are not kinds at all and calling them natural kinds is, therefore, grossly misleading. Having the species of taxonomy be equivalent to the species of evolutionary theory facilitates the integration of history and laws of nature within biology. Efforts to define the species category on the basis of similarity create misleading impressions about the laws and mechanisms of speciation processes. A diversity of incompatible species concepts (pluralism) is undesirable because the various kinds of units that are called ‘species’ differ with respect to the underlying laws of nature that make them natural kinds.
Reconciling traditional inland fisheries management and sustainability in industrialized countries, with emphasis on Europe
Authors: Arlinghaus Robert , Mehner Thomas , Cowx Ian G
Published: March 2003

In northern industrialized countries, the inland fisheries sector has long been dominated by recreational fisheries, which normally exploit fish for leisure or subsistence and provide many (poorly investigated) benefits to society. Various factors constrain the development and existence of inland fisheries, such as local user conflicts, low social priority and inadequate research and funding. In many cases, however, degradation of the environment and loss of aquatic habitat are the predominant concerns for the sustainability of inland fisheries. The need for concerted effort to prevent and reduce environmental degradation, as well as conservation of freshwater fish and fisheries as renewable common pool resources or entities in their own right is the greatest challenge facing sustainable development of inland waters. In inland fisheries management, the declining quality of the aquatic environment coupled with long‐term inadequate and often inappropriate fisheries management has led to an emphasis on enhancement practices, such as stocking, to mitigate anthropogenic stress. However, this is not always the most appropriate management approach. Therefore, there is an urgent need to alter many traditional inland fisheries management practices and systems to focus on sustainable development.

This paper reviews the literature regarding the inputs needed for sustainability of inland fisheries in industrialized countries. To understand better the problems facing sustainable inland fisheries management, the inland fisheries environment, its benefits, negative impacts and constraints, as well as historical management, paradigms, trends and current practices are described. Major philosophical shifts, challenges and promising integrated management approaches are envisaged in a holistic framework. The following are considered key elements for sustainable development of inland fisheries: communication, information dissemination, education, institutional restructuring, marketing outreach, management plans, decision analysis, socioeconomic evaluation and research into the human dimension, in addition to traditional biological and ecological sciences. If these inputs are integrated with traditional fisheries management practices, the prospects for sustainability in the inland fisheries will be enhanced.
A randomized, double‐blind, placebo‐controlled study of methylphenidate in patients with organic amnesia
Authors: Tiberti C. , Sabe L. , Jason L. , Leiguarda R. , Starkstein S.
Published: March 2003

We examined the usefulness of methylphenidate (MPH) in the treatment of organic amnesia in a randomized, double‐blind, placebo‐controlled design. Twenty patients with amnesia due to closed head injuries (n= 10), viral encephalitis (n= 2), stroke lesions (n= 4), or surgical brain resections (n= 4) were assessed with a neuropsychological battery after the intake of MPH (10, 20, 30 or 40 mg), or placebo. We found no significant benefit of MPH for any of the cognitive tests.
An example of lack of frontal inhibition: the ‘utilization behaviour’
Authors: Brazzelli Miriam , Spinnler Hans
Published: March 2003

The focus of this report is utilization behaviour (UB) conceived as part of the Environmental Dependency Syndrome following frontal damage. An historical sketch is provided on the many conceptualizations of the frontal lobe functions relevant to the understanding of UB. The detailed study of the neuropsychological picture presented by a patient (PG) with massive herpetic damage is then outlined. Emphasis is put on PG's prominent UB as well as on her several dissociations between impaired (as expected) and spared (non expected) cognitive abilities. Such dissociations are discussed with reference to the historical conceptualizations outlined above.

The question is raised of whether a great inter‐subjects variability of the top‐functional arrangements in the healthy frontal lobes could be the main cause of the variability of symptoms observed in patients with frontal lesions.
Activities in the Danish Year of the Brain 1997
Authors: Olesen Jes , Öberg Gunilla , Vestergaard Per
Published: March 2003

In this paper we report about the Danish Year of the brain 1997 because it may serve as a model for other countries. It was possible in Denmark to organize a very large scale effort which has been well received by the general public and which has significantly improved the image of the neurological disciplines. The resources spent on nationwide initiatives in the Danish Year of the Brain are more than 2 million ECU in country with 5 million inhabitants. In addition however considerably amounts were spent in each country of Denmark. Since all professionals have worked for free innumerable hours of work have not been budgeted. In fact the Danish Year of the Brain has been the largest privately organized health campaign ever held in Denmark and it has been so successful that the Danish Heart Association. Which is old well organized and extremely strong financially has been worried about the shift of attention from the heart to the brain.
Serum levels of β‐carotene, α‐carotene and vitamin A in patients with Alzheimer's disease
Authors: Jiménez‐Jiménez Félix Javier , Molina José Antonio , de Bustos Fernando , Ortí‐Pareja Miguel , Benito‐León Julián , Tallón‐Barranco Antonio , Gasalla Teresa , Porta Jesús , Arenas Joaquín
Published: March 2003

To elucidate the possible role of carotenoids and vitamin A as risk factors for Alzheimer's disease (AD), we compared serum levels of β‐carotene and α‐carotene, and vitamin A, measured by isocratic high performance liquid chromatography, of 38 AD patients and 42 controls. The serum levels of α‐carotene did not differ significantly between AD patients and control groups. However, the serum levels of β‐carotene and vitamin A were significantly lower in the AD‐patient group. These values did not correlate to age, age at onset or score on the MiniMental State Examination. Weight and body mass index were significantly lower in AD patients than in controls. These results suggest that low serum β‐carotene concentrations in AD patients could be related to a deficiency in dietary intake of this provitamin, although its possible relationship with risk for AD could not be excluded.
EMG evidence of myopathy and the occurrence of titin autoantibodies in patients with myasthenia gravis
Authors: Somnier Finn E. , Skeie Geir O. , Aarli Johan A. , Trojaborg Werner
Published: March 2003

We studied 65 patients with myasthenia gravis (MG). Clinical, neurophysiological, immunological, and histological findings suggested the coexistence of a presumed autoimmune myopathy. The clinical features were persistent pyridostigmine‐resistant weakness and atrophy of striated muscles. The myopathy was found more often in patients with late‐onset MG than in those with early‐onset (37% vs 13%). Patients with myopathy were also prone to have other immune disorders (47% vs 13%). Elevated titres of antibodies against titin were detected more often in patients with electromyography (EMG) evidence of myopathy than in the sera of those without, and only in late‐onset MG cases.
Trichloroethylene and parkinsonism: a human and experimental observation
Authors: Guehl Dominique , Bezard Erwan , Dovero Sandra , Boraud Thomas , Bioulac Bernard , Gross Christian
Published: March 2003

This report describes the case of a 47‐year‐old woman who developed Parkinson's disease after seven years of professional exposure to trichloroethylene. In the light of this clinical report, mice were intoxicated with trichloroethylene and tyrosine hydroxylase immunoreactivity was used to measure neuronal death in the substantia nigra pars compacta. Treated mice presented significant dopaminergic neuronal death in comparison with control mice (50%). The environmental trichlorethylene pollution, as well as other unspecific neurotoxic solvents, could potentially contribute to the genesis of some cases of Parkinson's disease.
Manganese‐containing superoxide dismutase signal sequence polymorphism associated with sporadic motor neuron disease
Authors: Van Landeghem Glen Fernand , Tabatabaie Pedram , Beckman Gunhild , Beckman Lars , Andersen Peter Munch
Published: March 2003

An alanin‐9valin (Ala‐Val) polymorphism in the mitochondrial targeting sequence of managanese‐containing superoxide dismutase (Mn‐SOD) has recently been described. We studied this polymorphism in 72 Swedish paients with sporadic motor neuron diseases (MND) and controls unsing an oligonucleotide ligation assay. There were significant differences in genotype between MND patients and controls (P= 0.025), and between male and female MND patients (P= 0.009). Individuals homozygous for the Ala allele had a higher risk for MND [odds ratio, 2.9; 95% confidence interval (CI), 1.3–6.6], which was increased when including only females in the analysis (odds ratio, 5.0; 95% CI, 1.8–14.0). In classical amyotrophic lateral sclerosis, the odds ratio was 3.8 (95% CI, 1.3–10.0), and 5.5 (95% CI, 1.5–19.9) when including only females. The results suggest that mutations influencing the allocation of Mn‐SOD may be a risk factor in MND, especially in females, and that MND may be a disease of misdistribution of the superoxide dismutase enzymes.
Heterogeneity of congnitive profiles in aging: successful aging, normal aging, and individuals at risks for cognitive decline
Authors: Ylikoski Raija , Ylikoski Ari , Keskivaara Pertti , Tilvis Reijo , Sulkava Raimo , Erkinjuntti Timo
Published: March 2003

Neuropsychological clinical decision‐making is complicated by the fact that variability in test performance increases with advancing age. The research explores the presences of homogeneous subgroups in 120 neurologically healthy individuals, from 55 to 85 years of age. Subjects at risk for dementing diseases were diagnosed as Aging‐Associated Cognitive Decline (AACD) and Mild Cognitive Impairment (MCI). Cluster analysis was applied on 11 neuropsychological variables assessing logical memory immediate recall and retention percentage, visual memory immediate recall and retention, conceptual thinking, naming verbal fluency, constructional functions, motor speed, flexibility and finger tapping. Five clusters were extracted, one representing cognitively successfully aged, and two consisting of individuals with normal or average level performance. One cluster was characterized by older subjects with difficulties in visual memory, visuoconstructional functions, and speed and attention, most of the younger subjects in the same cluster had a diagnosis of AACD or MCI. The fifth cluster represented individuals at risk for dementing diseases; most of them were diagnosed having AACD and more than half had a diagnosis of MCI. Age, activity and intellectual levels, and to a lesser degree education, were significantly related to the cluster solution. The present findings caution against treating samples of elderly individuals as homogeneous.
Bilateral symmetrical enhancing brainstem lesions: an unusual presentation of primary CNS lymphoma
Authors: Larner Andrew J , D'Arrigo Corrado , Scaravilli Francesco , Howard Robin S
Published: March 2003

We report a patient with a progressive brainstem syndrome, who on magnetic resonance imaging had large bilateral, symmetrical, contrast‐enhancing, infratentorial space‐occupying lesons. Biopsy of one of the lesions revealed this unusual appearance to be due to a primary central nervous system (CNS) lymphoma of B‐cell type. Symmetry of lesions may be a clue to the diagnosis, perhaps reflecting the mechanism by which CNS lymphomas spread.
Syringomyelia complicating syphilitic spinal meningitis: a case report
Authors: Bulundwe K. K. , Myburgh C. J. , Gledhill R. F.
Published: March 2003

An association between syringomyelia and spinal syphilis was described in the early literature but has not been the subject of reports subsequently. We give details of a contemporary case, affirmed by magnetic resonance imaging. The patient showed significant clinical recovery following penicillin treatment, while the imaging appearances became less pronounced.
The apolipoprotein E ε4 allele and the response to tacrine therapy in Alzheimer’s disease
Authors: Rigaud A.‐S. , Traykov L. , Caputo L. , Guelfi M.‐C. , Latour F. , Couderc R. , Moulin F. , De Rotrou J. , Forette F. , Boller F.
Published: March 2003

The objective of our study was to evaluate the effects of the apolipoprotein E (ApoE) phenotype and gender on the response to tacrine treatment in Alzheimer’s disease (AD). ApoE phenotyping was performed on 76 patients treated with tacrine for AD. This group comprised 33 ApoE ε4 allele carriers (ε4+) and 43 non‐ε4 carriers (ε4–). Patients were treated blindly in relation to the ApoE phenotype, with incremental tacrine dosages ranging from 40 mg/day up to the highest dosage (160 mg) tolerated without side‐effects. At least 6 weeks elapsed between each increase. Changes in the scores for the Alzheimer Disease Assessment Scale‐Cognitive Component (ADAS‐Cog) between baseline and each increment in dosage were assessed in the ε4– and ε4+ groups. The cut‐off point for being considered as responsive to tacrine treatment was a 4‐point decrease in the ADAS‐Cog score.

There was no tendency for the ε4– carriers to respond better than the ε4+ carriers. When patients were stratified by gender, no differences were found between the effects of the treatment on men and women. Consequently, these results do not support the hypothesis that the ApoE phenotype and gender are predictors of the response to tacrine in AD patients.
Mitral papillary fibroelastoma as a cause of cardiogenic embolic stroke: report of two cases and review of the literature
Authors: Sastre‐Garriga J. , Molina C. , Montaner J. , Mauleón A. , Pujadas F. , Codina A. , Álvarez‐Sabín J.
Published: March 2003

Papillary fibroelastoma (PFE) is a rare benign tumour that attaches to the endocardial surface, mostly on cardiac valves. Though usually asymptomatic, it can be the source of several complications. To date, 49 cases have been reported of embolic stroke with a PFE as the probable origin. Case reports: (i) a 39‐year‐old male presented with ischemic embolic stroke; the presence of a PFE was assessed by means of transoesophageal echocardiography and confirmed by pathological findings; (ii) a 32‐year‐old woman presented with sudden onset of left hemiparesis; a cardiogenic embolic stroke was suspected, and a diagnosis of PFE was made based on echocardiographic and pathological findings. In both cases, surgical excision of the tumours was performed with no recurrences at follow‐up. Two mechanisms can explain the formation of emboli in PFE: dislodgement of the tumour leaves or fibrin‐platelet aggregation on the endocardial surface of these leaves. Transthoracic echocardiography may lead to the suspicion of a PFE, but transoesophageal echocardiography is required for confirmation. Prompt surgical excision is indicated in most cases. Anticoagulation is only recommended in situations of high surgical risk and during the wait for surgery.
A valine to methionine polymorphism at codon 83 in the 8‐oxo‐dGTPase gene MTH1 is not associated with sporadic Parkinson’s disease
Authors: Satoh J. , Kuroda Y.
Published: March 2003

Recently, 8‐oxo‐7,8‐dihydrodeoxyguanosine triphosphatase (8‐oxo‐dGTPase; MTH1), a key enzyme for preventing oxidative stress‐induced DNA damage, has been found to be expressed aberrantly in the nigrostriatal dopaminergic neurones in the brains of those with Parkinson’s disease (PD). A valine (Val) to methionine (Met) polymorphism at codon 83 in exon 4 of the MTH1 gene was studied in 73 patients with sporadic PD and 151 age‐matched non‐PD controls by PCR‐RFLP analysis, to determine a possible association of this polymorphism with development of PD. The frequency of either 83Val or 83Met allele was not statistically different between PD patients (92.5% or 7.5%) and the controls (88.7% or 11.3%) (χ2 = 1.511, P = 0.2190). The 83Met/Met homozygotes consisting of an infrequent genotype in the control population (1.3%) were not found in the PD group. The frequency of both 83Val/Met heterozygotes and 83Met/Met homozygotes combined was not statistically different between PD patients (15.1%) and the controls (21.2%), compared with that of the 83Val/Val homozygotes (χ2 = 1.190, P = 0.2754). These results indicate that the 83Val/Met polymorphism in the MTH1 gene is not associated with an increased risk for development of sporadic PD.
Medium‐term functional benefits in children with cerebral palsy treated with botulinum toxin type A: 1‐year follow‐up using gross motor function measure
Authors: Linder M. , Schindler G. , Michaelis U. , Stein S. , Kirschner J. , Mall V. , Berweck S. , Korinthenberg R. , Heinen F.
Published: March 2003

One of the main goals when treating spasticity is to relieve pain and improve function. Intramuscular injection of botulinum toxin type A (BTX‐A) has gained widespread acceptance in the treatment of spastic cerebral palsy. Several studies have clearly shown the short‐term functional benefit of BTX‐A treatment. Information is limited, however, on the efficacy of medium and long‐term regimens, using repeated injection of BTX‐A. The aim of the present open‐label, prospective study was to evaluate functional outcome in children with spastic cerebral palsy after 1 year of treatment with BTX‐A, using the Gross Motor Function Measure (GMFM) as a validated outcome measure. Patients (n=25, age 1.5–15.5 years) were treated with BTX‐A for adductor spasm (n=12) or pes equinus (n=13). The local effect was evaluated using passive range of motion and modified Ashworth Scale. Apart from a significant improvement in joint mobility and reduction of spasticity compared to pretreatment values (P < 0.01), we demonstrated a significant improvement of gross motor function after 12 months of treatment, with a median gain of 6% in total and goal scores (P < 0.001). An increase in GMFM scores was particularly evident in younger and moderately impaired children (Gross Motor Function Classification System level III). Whether the observed improvement in gross motor function in children with cerebral palsy is specifically related to therapy with BTX‐A or represents at least in part the natural course of motor development still needs clarification.