bluuebunny/crossref_metadata_2025 huggingface dataset:
The life cycle of Paraquimperia tenerrima: a parasite of the European eel Anguilla anguilla
Authors: Shears J.A. , Kennedy C.R.
Published: June 2005

Previous studies on the life history of the nematode eel specialist Paraquimperia tenerrima (Nematoda: Quimperiidae) have failed to determine whether an intermediate host is required in the life cycle. In the laboratory, eggs failed to hatch below 10°C, hatching occurring only at temperatures between 11 and 30°C. Survival of the free-living second stage larvae (L2) was also temperature dependent, with maximal survival between 10 and 20°C. Total survival of the free-living stages (eggs and L2) is unlikely to exceed a month at normal summer water temperatures, confirming that parasite could not survive the 6 month gap between shedding of eggs in spring and infection of eels in early winter outside of a host. Eels could not be infected directly with L2, nor could a range of common freshwater invertebrate species. Third stage larvae (L3) resembling P. tenerrima were found frequently and abundantly in the swimbladder of minnows Phoxinus phoxinus from several localities throughout the year and were able to survive in this host in the laboratory for at least 6 months. Third stage larvae identical to these larvae were recovered from minnows experimentally fed L2 of P. tenerrima, and eels infected experimentally with naturally and experimentally infected minnows were found to harbour fourth stage larvae (L4) and juvenile P. tenerrima in their intestines. Finally, the whole life cycle from eggs to adult was completed in the laboratory, confirming that minnows are an obligate intermediate host for P. tenerrima.
Parasite populations in the brown rat Rattus norvegicus from Doha, Qatar between years: the effect of host age, sex and density
Authors: Abu-Madi M.A. , Behnke J.M. , Mikhail M. , Lewis J.W. , Al-Kaabi M.L.
Published: June 2005

A total of 179 urban rats were sampled in the city of Doha in Qatar across the winter seasons (February–April) of 2002 and 2003. Only two parasites were identified, with overall prevalences of 35.8% and 41.3% for the cestode Hymenolepis diminuta and the flea Xenopsylla astia respectively. The prevalence of H. diminuta was markedly influenced by both year of study and host age, being higher in 2003 and amongst older rats. The abundance of infection of H. diminuta was influenced by the year of study, host age and sex. Worm burdens in adult rats were almost twice as heavy in males compared with females and adults of both sexes harboured heavier infections than juveniles. The prevalence of X. astia was influenced by both year and host age, being higher in juvenile rats in 2002 and in adults in 2003. The abundance of X. astia was significantly higher in 2003 and both male and female rats showed similar abundances, but in 2003 females were more heavily infested. Reasons for this are discussed in relation to the differing foraging strategies shown by male and female rats. The prevalence and abundance profiles for both H. diminuta and X. astia were higher overall in 2003 due to a significant increase in the rat population density, although this did not reflect in any increase in parasite species richness. Rats that were infected with H. diminuta were almost twice as likely to be infected with X. astia than those without the cestode, but when controlled for the effects of year, host age and sex, no quantitative interactions were detected between the two parasite species.
Helminth communities of the barbel Barbus barbus from large river systems in Austria
Authors: Laimgruber S. , Schludermann C. , Konecny R. , Chovanec A.
Published: June 2005

The composition and diversity of the total and intestinal component endohelminth communities were determined in the cyprinid barbel from three study areas in two large river systems in Austria. Two sample sites in the Danube and one site in the River Drau are the only free flowing stretches of these rivers in Austria. Nine helminth species were identified, with the acanthocephalan Pomphorhynchus laevis being dominant in the Danube, with up to 100% prevalence. In the Drau, where the dominant species was the cestode Bathybothrium rectangulum, species diversity was higher than in the Danube.
Cercarial tail loss in Echinostoma caproni: the influence of in vivo encystment and copper sulphate
Authors: Fried B. , Schneck J.L.
Published: June 2005

Echinostoma caproni tail loss was studied in vitro in the presence of the toxicant copper sulphate (CuSO4) in concentrations ranging from 1 to 10 000 mg l?1 in standardized artificial spring water (pH 7.4, osmolarity 34 mOsm kg?1 H2O, Ca2+ 20 mg l?1) at 23°C. Tail loss was also studied in the absence of toxicants during in vivo encystment of the cercariae in juvenile Biomphalaria glabrata. As the concentration of CuSO4 increased, the percentage of cercarial tail loss increased. By 2 h in 10 000 mg l?1, 1000 mg l?1 and 100 mg l?1 CuSO4, 50%, 23% and 13%, respectively, of the cercariae had lost their tails. In the in vivo studies, by 1 h PI, 59±5% of cercariae had lost their tails and only 4±1% of the cercariae were actively swimming in the multi-well dishes. At 3 h PI, 72±3% of the cercariae began to form cysts within the snails.
Hydatidosis in camels (Camelus dromedarius) and their potential role in the epidemiology of Echinococcus granulosus in Iran
Authors: Ahmadi N.A.
Published: June 2005

Hydatid cysts were recovered from 35.2% (233/661) of camels (Camelus dromedarius) slaughtered in five different regions of Iran. The degree of prevalence between males (34.4%) and females (36.6%) was not statistically significant. The highest rate of infection (59.3%) was found in the Isfahan region (in the central part of Iran) while the lowest (25.7%) was found in Kerman province. The organ distribution of cysts was 49.4% in lungs alone, 30.0% in both liver and lungs, 14.6% in liver only and 6.0% in other organs. Therefore, the lungs were the predominant sites of the hydatid cyst. The range in the number of cysts was 1–48 in infected animals. The majority of the camels had 1–5 cysts, with 21.9%, 11.6% and 5.6% of infected camels having 6–10, 11–20 and 21 or more cysts respectively. There was a direct relationship between the rate and intensity of infection and host age. The fertility rate of lung cysts (69.7%) was higher than that of liver cysts (58.7%) and other organs (50.0%) whilst the viability rate of protoscoleces of liver fertile cysts (80.3%) was significantly higher than that of lung cysts (55.8%) and other organs (57.1%). The role of camels in the epidemiology of Echinococcus granulosus in Iran is discussed.
Taenia spp.: 18S rDNA microsatellites for molecular systematic diagnosis
Authors: Foronda P. , Casanova J.C. , Martinez E. , Valladares B. , Feliu C.
Published: June 2005

The 18S rDNA gene of adult worms of Taenia parva found in Genetta genetta in the Iberian Peninsula and larval stages of T. pisiformis from the wild rabbit (Oryctolagus cuniculus) in Tenerife (Canary Islands) were amplified and sequenced. The sequences of the 18S rDNA gene of T. parva (1768 bp) and T. pisiformis (1760 bp) are reported for the first time (GenBank accession nos. AJ555167–AJ555168 and AJ555169–AJ555170, respectively). In 168 alignment positions microsatellites in the 18S rDNA of both taxa were detected for the first time (TGC in T. parva and TGCT in T. pisiformis) and differences in their sequences with different repetition numbers were observed. The use of nucleotide sequences of this gene in the resolution of systematic problems in cestodes is discussed with reference to the systematic status of Taenia spp. and mainly in human taeniids such as T. solium, T. saginata, and Asian human isolates of Taenia.
Dynamics and predicted decline of Anguillicola crassus infection in European eels, Anguilla anguilla, in Neusiedler See, Austria
Authors: Schabuss M. , Kennedy C.R. , Konecny R. , Grillitsch B. , Reckendorfer W. , Schiemer F. , Herzig A.
Published: June 2005

The eel population in Neusiedler See has been maintained by regular massive stocking since 1958. After the establishment of the National Park Neusiedler See-Seewinkel in 1993, eel stocking was prohibited and the population, together with the specific parasites of eels, was predicted to decline to extinction within 10 years. This investigation was undertaken to document the decline and extinction of the Anguillicola crassus population in eels. From 1994 to 2001, 720 eels were collected from two sites in the lake. Prevalence and abundance of A. crassus were lower in spring than in summer and autumn and larger eels harboured more parasites than smaller ones. Neither year of study nor sampling site were correlated with parasite infection levels. No significant trend in the population parameters of A. crassus was detected over the 8 years of the survey. This suggested that there had been no significant decline in the eel population. This suggestion was confirmed by investigations of the fishery, which also found evidence of regular illegal stocking. The stability of the A. crassus population over the past decade seems to reflect the lack of change in eel population density. No mass mortalities of eels occurred over the period despite the many similarities between Neusiedler See and Lake Balaton in Hungary. Differences in eel size, eel diet and the lack of large-scale insecticide use are discussed as possible explanations for the absence of eel mass mortalities in Neusiedler See.
Evaluating the effectiveness of a Mexican strain of Duddingtonia flagrans as a biological control agent against gastrointestinal nematodes in goat faeces
Authors: Ojeda-Robertos N.F. , Mendoza-de Gives P. , Torres-Acosta J.F.J. , Rodríguez-Vivas R.I. , Aguilar-Caballero A.J.
Published: June 2005

The use of Duddingtonia flagrans in the control of goat nematodes was investigated. Initially, the time of passage of chlamydospores through the digestive tract of goats was evaluated. Two groups of seven parasite-free kids were formed. Group A received a single dose of 3.5×106D. flagrans chlamydospores (FTHO-8 strain) per kg of live weight. Group B did not receive any chlamydospores. Faeces were obtained from each kid daily from day 4 prior to inoculation until day 5 post-inoculation (PI) and were placed in Petri dishes containing water agar. Gastrointestinal nematode infective larvae were added to each Petri dish and incubated at 25°C for 7 days. Petri dishes were examined to detect the fungus and trapped nematodes. A second trial evaluated the effect of D. flagrans on the number of gastrointestinal nematode larvae harvested from goat faecal cultures in naturally infected goats. Two groups of seven goats were formed. The treated group received a single dose of 3.5×106D. flagrans chlamydospores per kg of liveweight. The control group did not receive any chlamydospores. Faeces were obtained twice daily from each kid. Two faecal cultures were made for each kid. One was incubated for 7 days and the other for 14 days. Gastrointestinal nematode larvae were recovered from each culture and counted. Percentage of larval development reduction was determined using a ratio of larvae/eggs deposited in the control and treated groups. Duddingtonia flagrans survived the digestive process of goats, and maintained its predatory activity, being observed from 21 to 81 h PI (3 to 4 days). A reduction in the infective larvae population in the treated group compared to the non-treated group was observed in both incubation periods (7 days: 5.3–36.0%; 14 days: 0–52.8%, P>0.05). Although a single inoculation of D. flagrans can induce a reduction of infective larvae collected from faeces, a different scheme of dosing may be needed to enhance the efficacy of D. flagrans in goats.
Relationship between bronchopulmonary nematode larvae and relative abundances of Spanish ibex (Capra pyrenaica hispanica) from Castilla-La Mancha, Spain
Authors: Acevedo P. , Vicente J. , Alzaga V. , Gortazar C.
Published: June 2005

The excretion of bronchopulmonary nematode infective larvae was evaluated in 160 faecal samples of Spanish ibex (Capra pyrenaica hispanica) collected from 13 populations in Castilla-La Mancha, south-central Spain in September 2003. Intensities and prevalences were compared with pasture availability, abundances of wild and domestic ungulates at both levels, i.e. for populations and for faeces in a two-step procedure. Protostrongylid larvae showed similar infection rates (mean intensity: 1.56±0.12, n=94; mean prevalence: 25.62±6.86%, n=160) to Dictyocaulus spp. (mean intensity: 1.03±0.11, n=48; mean prevalence: 30.00±7.11%, n=160). At the population level, positive correlations were found between the prevalences of both bronchopulmonary taxa. The prevalence in both groups, but not intensity, also correlated positively with Spanish ibex abundance indexes both for the populations and individual faeces. These findings suggest that: (i) parasite spreading across Spanish ibex populations in Castilla-La Mancha could respond to host density-dependent processes; and (ii) these populations may have similar exposition and/or susceptibility to both bronchopulmonary taxa resulting in similar host–parasite patterns, despite their different life cycles. Bronchopulmonary outputs in the Spanish ibex from Castilla-La Mancha seems not to represent a health risk for this endemic wild ungulate but may be useful in any health surveillance scheme for the increasing populations of Spanish ibex.
Large-Scale Profiling of Rab GTPase Trafficking Networks: The Membrome
Authors: Gurkan Cemal , Lapp Hilmar , Alory Christelle , Su Andrew I. , Hogenesch John B. , Balch William E.
Published: June 2005

Rab GTPases and SNARE fusion proteins direct cargo trafficking through the exocytic and endocytic pathways of eukaryotic cells. We have used steady state mRNA expression profiling and computational hierarchical clustering methods to generate a global overview of the distribution of Rabs, SNAREs, and coat machinery components, as well as their respective adaptors, effectors, and regulators in 79 human and 61 mouse nonredundant tissues. We now show that this systems biology approach can be used to define building blocks for membrane trafficking based on Rab-centric protein activity hubs. These Rab-regulated hubs provide a framework for an integrated coding system, the membrome network, which regulates the dynamics of the specialized membrane architecture of differentiated cells. The distribution of Rab-regulated hubs illustrates a number of facets that guides the overall organization of subcellular compartments of cells and tissues through the activity of dynamic protein interaction networks. An interactive website for exploring datasets comprising components of the Rab-regulated hubs that define the membrome of different cell and organ systems in both human and mouse is available at http://www.membrome.org/ .
A Novel Recombinant Plasma Membrane-targeted Luciferase Reveals a New Pathway for ATP Secretion
Authors: Pellegatti Patrizia , Falzoni Simonetta , Pinton Paolo , Rizzuto Rosario , Di Virgilio Francesco
Published: June 2005

ATP is emerging as an ubiquitous extracellular messenger. However, measurement of ATP concentrations in the pericellular space is problematic. To this aim, we have engineered a firefly luciferase-folate receptor chimeric protein that retains the N-terminal leader sequence and the C-terminal GPI anchor of the folate receptor. This chimeric protein, named plasma membrane luciferase (pmeLUC), is targeted and localized to the outer aspect of the plasma membrane. PmeLUC is sensitive to ATP in the low micromolar to millimolar level and is insensitive to all other nucleotides. To identify pathways for nonlytic ATP release, we transfected pmeLUC into cells expressing the recombinant or native P2X7receptor (P2X7R). Both cell types release large amounts of ATP (100–200 μM) in response to P2X7R activation. This novel approach unveils a hitherto unsuspected nonlytic pathway for the release of large amounts of ATP that might contribute to spreading activation and recruitment of immune cells at inflammatory sites.
Differential In Vivo Binding Dynamics of Somatic and Oocyte-specific Linker Histones in Oocytes and During ES Cell Nuclear Transfer
Authors: Becker Matthias , Becker Antje , Miyara Faiçal , Han Zhiming , Kihara Maki , Brown David T. , Hager Gordon L. , Latham Keith , Adashi Eli Y. , Misteli Tom
Published: June 2005

The embryonic genome is formed by fusion of a maternal and a paternal genome. To accommodate the resulting diploid genome in the fertilized oocyte dramatic global genome reorganizations must occur. The higher order structure of chromatin in vivo is critically dependent on architectural chromatin proteins, with the family of linker histone proteins among the most critical structural determinants. Although somatic cells contain numerous linker histone variants, only one, H1FOO, is present in mouse oocytes. Upon fertilization H1FOO rapidly populates the introduced paternal genome and replaces sperm-specific histone-like proteins. The same dynamic replacement occurs upon introduction of a nucleus during somatic cell nuclear transfer. To understand the molecular basis of this dynamic histone replacement process, we compared the localization and binding dynamics of somatic H1 and oocyte-specific H1FOO and identified the molecular determinants of binding to either oocyte or somatic chromatin in living cells. We find that although both histones associate readily with chromatin in nuclei of somatic cells, only H1FOO is capable of correct chromatin association in the germinal vesicle stage oocyte nuclei. This specificity is generated by the N-terminal and globular domains of H1FOO. Measurement of in vivo binding properties of the H1 variants suggest that H1FOO binds chromatin more tightly than somatic linker histones. We provide evidence that both the binding properties of linker histones as well as additional, active processes contribute to the replacement of somatic histones with H1FOO during nuclear transfer. These results provide the first mechanistic insights into the crucial step of linker histone replacement as it occurs during fertilization and somatic cell nuclear transfer.
SUBVERSIVE ACTS: FEMALE VOICE AND PERFORMANCE IN THE SONGS OF THE
TROBAIRITZ
Authors: Oliver Sophie
Published: June 2005

THE R.H. GAPPER UNDERGRADUATE ESSAY PRIZE, 2004

The essay which follows is the fifth winner of the R.H. Gapper Undergraduate Essay Prize. The R.H. Gapper prizes were established to promote excellence at all levels of scholarship in French Studies. They commemorate Dick Gapper, the father of a former Treasurer of the Society for French Studies, and they reflect his love of France and his interest in, and direct support of, secondary and tertiary education up to his early death. Entries for the Undergraduate Essay competition this year ranged from Old Provençal to the present day and represented a range of universities. At the end of a rigorous marking process, the runner-up was named as Maria O'Sullivan (University College, Cork) for an essay entitled ‘“We shall cease from exploration […]”’ [Assia Djebar and Kateb Yacine]. The following essay by Sophie Oliver emerged as the undisputed winner.
Comparing Models of Strategic Choice: The Role of Uncertainty and Signaling
Authors: Wand Jonathan
Published: June 2005

Testing the fit of competing equilibrium solutions to extensive form games crucially depends on assumptions about the distribution of player types. To illustrate the importance of these assumptions for differentiating standard statistical models of strategic choice, I draw on a game previously analyzed by Lewis and Schultz (2003). The differences that they highlight between a pair of perfect Bayesian equilibrium and quantal response equilibrium models are not produced by signaling and updating dynamics as claimed, but are instead produced by different assumptions about the distribution of player types. The method of analysis developed and the issues raised are applicable to a broad range of structural models of conflict and bargaining.
Avian collision risk at an offshore wind farm
Authors: Desholm Mark , Kahlert Johnny
Published: June 2005

We have been the first to investigate whether long-lived geese and ducks can detect and avoid a large offshore wind farm by tracking their diurnal migration patterns with radar. We found that the percentage of flocks entering the wind farm area decreased significantly (by a factor 4.5) from pre-construction to initial operation. At night, migrating flocks were more prone to enter the wind farm but counteracted the higher risk of collision in the dark by increasing their distance from individual turbines and flying in the corridors between turbines. Overall, less than 1% of the ducks and geese migrated close enough to the turbines to be at any risk of collision.
A topological analysis of the magnetic breakout model for an eruptive solar flare
Authors: Maclean Rhona , Beveridge Colin , Longcope Dana , Brown Daniel , Priest Eric
Published: June 2005

The magnetic breakout model gives an elegant explanation for the onset of an eruptive solar flare, involving magnetic reconnection at a coronal null point which leads to the initially enclosed flux ‘breaking out’ to large distances. In this paper we take a topological approach to the study of the conditions required for this breakout phenomenon to occur. The evolution of a simple delta sunspot model, up to the point of breakout, is analysed through several sequences of potential and linear force-free quasi-static equilibria. We show that any new class of field lines, such as those connecting to large distances, must be created through a global topological bifurcation and derive rules to predict the topological reconfiguration due to various types of bifurcation.
Eigenfunction expansions on arbitrary domains
Authors: Shankar P.N
Published: June 2005

Consider the boundary-value problem for the field
ψ
(

x

) which satisfies the linear partial differential equation

in an arbitrary domain

with data given on the boundary

. It is generally believed that, unless

is the union of constant coordinate lines in a separable coordinate system for the operator

, the problem cannot be solved by the classical method of eigenfunction expansions. We show how this apparent limitation can be overcome. The key idea is to embed

in a larger embedding domain

, which is endowed with a complete set of eigenfunctions

of the operator

, where the
λ

n

are the eigenvalues. We can now expand
ψ
(

x

) in terms of this set, i.e.

. Although the unknown scalars {
a

n

} can no longer be determined by the use of an inner product, a least-squares procedure which minimizes the error in the boundary data yields the scalars to as high a precision, in principle, as needed. Examples are given of steady heat conduction in two and three dimensions, governed by Laplace's equation, and of Stokes flow in a container, governed by the biharmonic equation, all in non-simple domains. The scope of a powerful classical method has, by this extension, been enlarged very considerably. It is believed that it will be of great use in solving practical, linear boundary-value problems, which until now had to be solved by brute force numerical methods.
An inequality of Simpson type
Authors: Liu Zheng
Published: June 2005

An inequality of the Simpson type for an
n
-times continuously differentiable mapping is given.
Does habitat fragmentation affect temperature-related life-history traits? A laboratory test with a woodland butterfly
Authors: Karlsson Bengt , Van Dyck Hans
Published: June 2005

Habitat fragmentation may change local climatic conditions leading to altered selection regimes for life-history traits in small ectotherms, including several insects. We investigated temperature-related performance in terms of fitness among populations of the woodland butterflyPararge aegeria(L.) originating from populations of a closed, continuous woodland landscape versus populations of an open, highly fragmented agricultural landscape in central Belgium. Female fecundity and longevity were evaluated in a temperature-gradient experiment. As predicted, females of woodland landscape origin reached higher maximum daily fecundity and lifetime number of eggs than did agricultural landscape females at low ambient temperatures, but this reversed at high ambient temperature. Egg weight decreased with temperature, and eggs of woodland butterflies were smaller. Contrary to what is generally assumed, remaining thorax mass was a better predictor of lifetime reproductive output than was abdomen mass. Since we used the F2 generation from wild-caught females reared under common garden conditions, the observed effects are likely to rely on intrinsic, heritable variation. Our results suggest that differential selection regimes associated with different landscapes intervene by intraspecific variation in the response of a butterfly to variation in ambient temperature, and may thus be helpful when making predictions of future impacts on how wild populations respond to environmental conditions under a global change scenario, with increasing temperatures and fragmented landscapes.
Probabilistic anatomical connectivity derived from the microscopic persistent angular structure of cerebral tissue
Authors: Parker Geoffrey J.M , Alexander Daniel C
Published: June 2005

Recently developed methods to extract the persistent angular structure (PAS) of axonal fibre bundles from diffusion-weighted magnetic resonance imaging (MRI) data are applied to drive probabilistic fibre tracking, designed to provide estimates of anatomical cerebral connectivity. The behaviour of the PAS function in the presence of realistic data noise is modelled for a range of single and multiple fibre configurations. This allows probability density functions (PDFs) to be generated that are parametrized according to the anisotropy of individual fibre populations. The PDFs are incorporated in a probabilistic fibre-tracking method to allow the estimation of whole-brain maps of anatomical connection probability. These methods are applied in two exemplar experiments in the corticospinal tract to show that it is possible to connect the entire primary motor cortex (M1) when tracing from the cerebral peduncles, and that the reverse experiment of tracking from M1 successfully identifies high probability connection via the pyramidal tracts. Using the extracted PAS in probabilistic fibre tracking allows higher specificity and sensitivity than previously reported fibre tracking using diffusion-weighted MRI in the corticospinal tract.
Stochastic models of neuronal dynamics
Authors: Harrison L.M , David O , Friston K.J
Published: June 2005

Cortical activity is the product of interactions among neuronal populations. Macroscopic electrophysiological phenomena are generated by these interactions. In principle, the mechanisms of these interactions afford constraints on biologically plausible models of electrophysiological responses. In other words, the macroscopic features of cortical activity can be modelled in terms of the microscopic behaviour of neurons. An evoked response potential (ERP) is the mean electrical potential measured from an electrode on the scalp, in response to some event. The purpose of this paper is to outline a population density approach to modelling ERPs.

We propose a biologically plausible model of neuronal activity that enables the estimation of physiologically meaningful parameters from electrophysiological data. The model encompasses four basic characteristics of neuronal activity and organization: (i) neurons are dynamic units, (ii) driven by stochastic forces, (iii) organized into populations with similar biophysical properties and response characteristics and (iv) multiple populations interact to form functional networks. This leads to a formulation of population dynamics in terms of the Fokker–Planck equation. The solution of this equation is the temporal evolution of a probability density over state-space, representing the distribution of an ensemble of trajectories. Each trajectory corresponds to the changing state of a neuron. Measurements can be modelled by taking expectations over this density, e.g. mean membrane potential, firing rate or energy consumption per neuron. The key motivation behind our approach is that ERPs represent an average response over many neurons. This means it is sufficient to model the probability density over neurons, because this implicitly models their average state. Although the dynamics of each neuron can be highly stochastic, the dynamics of the density is not. This means we can use Bayesian inference and estimation tools that have already been established for deterministic systems. The potential importance of modelling density dynamics (as opposed to more conventional neural mass models) is that they include interactions among the moments of neuronal states (e.g. the mean depolarization may depend on the variance of synaptic currents through nonlinear mechanisms).

Here, we formulate a population model, based on biologically informed model-neurons with spike-rate adaptation and synaptic dynamics. Neuronal sub-populations are coupled to form an observation model, with the aim of estimating and making inferences about coupling among sub-populations using real data. We approximate the time-dependent solution of the system using a bi-orthogonal set and first-order perturbation expansion. For didactic purposes, the model is developed first in the context of deterministic input, and then extended to include stochastic effects. The approach is demonstrated using synthetic data, where model parameters are identified using a Bayesian estimation scheme we have described previously.
Inferring causality in brain images: a perturbation approach
Authors: Paus Tomáš
Published: June 2005

When engaged by a stimulus, different nodes of a neural circuit respond in a coordinated fashion. We often ask whether there is a cause and effect in such interregional interactions. This paper proposes that we can infer causality in functional connectivity by employing a ‘perturb and measure’ approach. In the human brain, this has been achieved by combining transcranial magnetic stimulation (TMS) with positron emission tomography (PET), functional magnetic resonance imaging or electroencephalography. Here, I will illustrate this approach by reviewing some of our TMS/PET work, and will conclude by discussing a few methodological and theoretical challenges facing those studying neural connectivity using a perturbation.
Discovery of an ancient lineage of Cyprinus carpio from Lake Biwa, central Japan, based on mtDNA sequence data, with reference to possible multiple origins of koi
Authors: Mabuchi K. , Senou H. , Suzuki T. , Nishida M.
Published: June 2005

MtDNA sequence data (c. 2100 bp of complete D‐loop + cytochrome b gene regions) showed a principal phylogenetic split within common carp Cyprinus carpio between the Lake Biwa wild form (n = 3) and ‘Eurasian’ wild (n = 18) and domesticated (n = 35) forms. This supports the idea of the ancient origin of the Lake Biwa wild form, as well as the East Asian origin of wild common carp, previously proposed on the basis of fossil data. In addition, a possible multiple origin of koi carp was indicated by the polyphyletic distribution of five mtDNA haplotypes of koi carp within the ‘Eurasian’ clade.
Dietary analysis of the herbivorous hemiramphid Hyporhamphus regularis ardelio: an isotopic approach
Authors: Carseldine L. , Tibbetts I. R.
Published: June 2005

The stable isotope values for a range of size classes of Hyporhamphus regularis ardelio from Moreton Bay, south‐east Australia were determined. There was a positive linear relationship between δ13C and standard length (LS)(δ13C = 0·034 LS − 16·23; r2 = 0·78). δ13C ranged from −8·48 to −17·29‰ with the smallest size class (50 mm LS) being on average 1·04‰ enriched with respect to that of zooplankton (Temora turbinata) and 7·97‰ depleted compared to Zostera capricorni. δ13C was positively correlated with LS(P < 0·01)(more enriched with increasing LS) with those fish of the largest size class (225 mm LS) being 9·86 and 0·84‰ enriched than T. turbinata and Z. capricorni, respectively. There was no detectable trend in δ15N values with LS(P > 0·01) with δ15N, ranging from 9·18 to 11·00‰. Fish of all size classes were on average 2·32 and 7·63‰ more enriched than zooplankton and seagrass, respectively. Carbon isotope data indicate that H. r. ardelio commence life as carnivores and change to a diet in which seagrass is the primary carbon source. The dependence on animal matter, however, is always present. Due to the low percentage of nitrogen in Z. capricorni(2·5%) compared to zooplankton (9·1%) it appears that nitrogen from zooplankton is necessary throughout their life history with the carbon requirements for these fish coming chiefly from Z. capricorni.
Genetic isolation between Atlantic and Mediterranean albacore populations inferred from mitochondrial and nuclear DNA markers
Authors: Nakadate M. , Viñas J. , Corriero A. , Clarke S. , Suzuki N. , Chow S.
Published: June 2005

Genetic population structure of Atlantic and Mediterranean albacore Thunnus alalunga was investigated using nucleotide sequence variations of the glucose‐6‐phosphate dehydrogenase gene intron (G6PD) and the mitochondrial DNA (mtDNA) D‐loop region (Dloop). Restriction analysis using Ase I digestion detected two major restriction types (A and B) at the Dloop locus with strong frequency differences between Atlantic and Mediterranean samples. Thirty‐six individuals of 100 Mediterranean albacore were of the B type whereas no B type individuals were found in the Atlantic samples (n = 102). Phylogenetic analysis using nucleotide sequence data of the Dloop locus indicated that the B type lineage recently arose from the ancestral A lineage in the Mediterranean Sea and has not dispersed into the Atlantic Ocean. The frequencies of two alleles (L and S) at the G6PD locus were significantly different between the samples from the Atlantic (L = 0·495) and the Mediterranean (L = 0·725), but no significant heterogeneity was observed between mtDNA‐A and ‐B types of the Mediterranean sample. These molecular data indicate that gene flow between the Atlantic and Mediterranean albacore populations have been considerably restricted and strongly suggest these populations should continue to be treated as two distinct management units.
Explaining the so‐called “price premium” in oil markets
Authors: Merino Antonio , Ortiz Álvaro
Published: June 2005

This paper explores the information content of several variables on the so‐called “oil price premium over fundamentals”. We define this premium as the difference between the market oil price and the estimated price consistent with the OECD's relative industry stock level. By using Granger causality tests and extended regressions we test the systematic ability of a broad set of variables to explain the premium. We find that speculation in the oil market — measured by non‐commercial long positions — can improve the traditional model, reducing the premium significantly during some parts of the sample.
Hypertext atlas of dermatopathology with expert system for epithelial tumors of the skin
Authors: Feit Josef , Kempf Werner , Jedličková Hana , Burg Günter
Published: June 2005

Background:  Image resolution required for reference histological images is high. Obtaining high‐resolution images requires a system, composing large image from individual smaller components. Such systems must thus be capable of automatically taking individual image parts, performing shading compensation and fusion of the image parts into one large image. Distribution of such images over the Internet requires developing a suitable user's interface with access to the image details.

Methods:  The ways of creating high‐resolution images (virtual slides) and the interface enabling access to image details using Internet browser are described.

Results:  A collection of about 3200 dermatopathological, mostly histologic images is available at http://www.muni.cz/atlases: Hypertext atlas of dermatopathology. Methods of high‐resolution image acquisition were used in digitizing the collection of skin lymphomas (Dermatology Institute, University Hospital, Zurich), which is a part of the atlas. The atlas is continuously maintained and upgraded; the number of contributors is growing.
Juvenile hyaline fibromatosis: a case report
Authors: Karaçal Naci , Gülçelik Nevzat , Yildiz Kadriye , Mungan Sevdegül , Kutlu Necmettin
Published: June 2005

Juvenile hyaline fibromatosis ( JHF ) is a rare autosomal recessive disease characterized by papulonodular skin lesions, gingival hyperplasia, joint contractures, and bone lesions. The skin lesions may consist of multiple large tumors, commonly on the scalp and around the neck, and small pearly, pink papules and plaques on the trunk, chin, ears, and around the nostrils. Here, we report a 2‐year‐old boy with characteristic stiffness of the knees and elbows and pink confluent papules on the paranasal folds, and periauricular and perianal regions. He also had hard nodules all over the scalp and around the mouth, and severe gingival hyperplasia. The lesions were totally excised and clinicopathological diagnosis was JHF.
Clear cell ‘sugar’ tumor (PEComa) of the skin: a case report
Authors: De Saint Aubain Somerhausen N. , Gomez Galdon M. , Bouffioux B. , Courtin C. , Theunis A. , Vogeleer M. N. , Myant N.
Published: June 2005

Abstract:  The so‐called perivascular epithelioid cell neoplasm (PEComa) family includes angiomyolipoma, clear cell ‘sugar’ tumor (CCST), lymphangioleiomyomatosis, and clear cell myomelanocytic tumor (CCMMT). These rare tumors are characterized by the co‐expression of melanocytic and muscle markers. They have been recognized in an increasing number of sites but currently only one case of PEComa, of the CCMMT subtype, has been reported in the skin in abstract form.

We provide the clinicopathologic description of a case of extrapulmonary CCST located in the dermis and superficial subcutis of the thigh of a 60‐year‐old female. The lesion was composed of nests of epithelioid and spindle cells with abundant clear to granular cytoplasm and distinct cell borders. The tumor showed strong and diffuse immunoreactivity with HMB‐45. Scattered cells expressed desmin and h‐caldesmon. Antibodies to S‐100 protein, melan‐A, cytokeratins, and smooth muscle actin were negative. This first case of cutaneous PEComa of the CCST type expands the differential diagnosis of clear cell/granular cell tumors of the skin.
Basal cell carcinoma with matrical differentiation in a transplant patient: A case report and review of the literature
Authors: Ali Faizi , Brown Allison , Gottwald Lorie , Thomas Jean
Published: June 2005

Background: Shadow cells, characterized by basaloid squamous cells with a distinct well‐defined border and a central unstained area as a shadow of lost nuclei, are characteristic of pilomatricoma, a distinct neoplasm of hair matrix differentiation. The presence of shadow cells within tumor islands composed of follicular germinative cells of an otherwise classic basal cell carcinoma (BCC) has been considered as a distinct diagnostic category of BCC with matrical differentiation. We present a case of BCC with matrical differentiation in a transplant patient. To our knowledge, only 10 cases [Aloi et al. Am J Dermatopathol 1988; 10: 509; Ambrojo et al. Am J Dermatopathol 1992; 14: 293; Sagol et al. East J Med 1999; 4: 37; Kwittken J. Cutis 2002; 69: 57; Kim et al. Yonsei Med J 2003; 44: 523] of BCC showing matrical differentiation have been reported. None have been reported arising on the background of immunosuppression.

Methods: A 58‐year‐old male cardiac transplant patient with a nodule on the dorsum of left hand was studied. It arose and enlarged rapidly within a few months, causing irritation and bleeding. The nodule was surgically excised and submitted for histopathologic evaluation. The sections were prepared by hematoxylin and eosin (H&E) method.

Results: The H&E‐stained sections of the hand lesion revealed multiple nodular masses of basaloid follicular germinative cells. In some areas, there was peripheral palisading and stromal retraction artifact typical of classic BCC. In these areas, the tumor nodules were connected to the epidermis, whereas in others, it extended deep into the reticular dermis to the subcutaneous fat junction. Elsewhere, the majority of the tumor contained a population of shadow cells, similar to those in pilomatricoma, with basaloid‐appearing matrical cells in the periphery. Trichohyaline granules were identified in the cytoplasm of many of the peripheral basaloid cells. These granules are one of the characteristic features of follicular matrix differentiation. Mitoses were rare. Areas of cystic degeneration were present throughout the tumor. There was no evidence of an infiltrating growth pattern, lymphovascular invasion, or sarcomatoid growth pattern.

Conclusion: BCC with matrical differentiation is a distinct pathologic entity and a rare subtype of BCC featuring shadow and matrical cells, typically seen in pilomatricoma, a benign hair matrix neoplasm. This tumor has not yet been reported in an immunosuppressed transplant patient.
Solitary glomeruloid haemangioma without POEMS syndrome
Authors: Vélez D. , Delgado‐Jiménez Y. , Fraga J.
Published: June 2005

Background:  The term ‘glomeruloid haemangioma’ was coined by Chan et al. for a histologically distinctive cutaneous haemangioma, which they considered a specific cutaneous marker for POEMS syndrome. Glomeruloid haemangiomas appear to be specific to POEMS syndrome, because they have not been reported in patients without this syndrome.

Methods:  We report on an 86‐year‐old man without POEMS syndrome and with a solitary red papule on the face.

Results:  A cutaneous biopsy showed histological findings consistent with a glomeruloid haemangioma. Physical examination of the skin did not show any other cutaneous lesion and laboratory and radiological studies ruled out the presence of POEMS syndrome.

Conclusions:  Glomeruloid haemangiomas could exceptionally be present as solitary vascular tumours and out of the context of POEMS syndrome. To our knowledge, this is the first case reported of glomeruloid haemangioma without POEMS syndrome. Moreover, the presentation on the face is also highly unusual.
Transforming growth factor‐β and malignant melanoma: molecular mechanisms
Authors: Hussein Mahmoud R.
Published: June 2005

Abstract:  Transforming growth factor family members (TGF‐β) are secretory polypeptides that have dual tumor‐suppressor and oncogenic effects. They signal through kinase receptor complexes on the cell surface, which phosphorylate cytoplasmic mediators (SMADs). Upon phosphorylation, SMADs march to the nucleus and interact with coactivators or corepressors to mediate the transcriptional regulation of several genes resulting in diverse effects. In tumorigenesis, malignant cells escape from the tumor‐suppressive effects of TGF‐β by mutational inactivation or dysregulated expression of the molecular components in TGF‐β signaling pathway. Although melanoma cells are resistant to the tumor‐suppressive effects of TGF‐β, there are no detectable defects at the receptor/SMAD level. Therefore, in these lesions, it is possible that TGF‐β effects occur independently of TGF‐β receptor/SMAD pathway. This review seeks to examine the present knowledge about TGF‐β receptor/SMAD signaling pathway and its related genes (SMADs, SKI, Filamin, endoglin, Follistatin, and other molecules) in melanomas.
Cellular digital fibromas: distinctive CD34‐positive lesions that may mimic dermatofibrosarcoma protuberans
Authors: McNiff Jennifer M. , Subtil Antonio , Cowper Shawn E. , Lazova Rossitza , Glusac Earl J.
Published: June 2005

Background:  Digital fibromas are common benign acral tumors typically reported as angiofibromas (AFs) or acquired digital fibrokeratomas (ADFs). Cellular variants are not well recognized.

Methods:  We collected 14 acral fibrocytic lesions showing a spindle cell morphology from our files, and evaluated CD34, Factor XIIIa, epithelial membrane antigen (EMA), and S100 protein staining of these lesions. We compared the histologic and immunohistochemical features of these cellular fibromas with five digital AFs, five ADFs, and five digital dermatofibromas.

Results:  The 14 cellular digital fibromas showed intersecting fascicles of thin delicate bland spindle cells in the superficial reticular dermis with a fibrotic‐to‐slight myxoid stroma. The spindle cells in all cases stained strongly for CD34, and only scattered stromal cells stained for Factor XIIIa. Five tested cases were negative for EMA and S100 protein. The digital AFs, fibrokeratomas, and dermatofibromas stained predominately for Factor XIIIa, with no or minimal staining for CD34.

Conclusions:  These findings suggest that a subset of digital fibromas is characterized by a dense cellular proliferation of CD34‐positive spindle cells. Awareness of this variant of digital fibroma and its staining pattern is critical in preventing misdiagnosis as dermatofibrosarcoma protuberans, particularly in superficial biopsies.
The Impact on UK Acquirers of Domestic, Cross‐border, Public and Private Acquisitions
Authors: Conn Robert L. , Cosh Andy , Guest Paul M. , Hughes Alan
Published: June 2005

Abstract:  We examine the announcement and post‐acquisition share returns of UK acquirers in over 4,000 acquisitions of domestic, cross‐border, public and private targets. Domestic public acquisitions result in negative announcement and post‐acquisition returns, whilst cross‐border public acquisitions result in zero announcement returns and negative post‐acquisition returns. In contrast, both domestic and cross‐border private acquisitions result in positive announcement returns and zero post‐acquisition returns. The main differences between private and public acquisitions are that glamour acquirers underperform in public acquisitions but not in private acquisitions, and that acquirers using noncash methods of payment underperform in domestic public acquisitions but not in domestic private acquisitions. Overall, cross‐border acquisitions result in lower announcement and long run returns than domestic acquisitions. In cross‐border acquisitions, those involving high‐tech firms perform relatively well, as do those with low national cultural differences.
The Wealth Effects of Capital Investment Decisions: An Empirical Comparison of Korean Chaebol and Non‐Chaebol Firms
Authors: Kim Wi Saeng , Lyn Esmeralda , Park Tae‐Jun , Zychowicz Edward
Published: June 2005

Abstract:  This paper investigates the capital investment decisions of Korean firms and their impact on shareholder wealth. Overall, we find positive abnormal returns surrounding the announcements of 697 cases of investment projects during the period 1992–1999. This paper also finds that the investment decisions of business group (chaebol‐affiliated) firms do not increase shareholder wealth, while the capital investment decisions of non‐chaebol firms generate significantly positive abnormal returns. The multivariate tests provide consistent evidence that the announcement effects for chaebol firms are lower than for non‐chaebol firms, after growth opportunities, investment size and firm size are controlled for. The findings support the view that the organizational structure of Korean chaebols creates an incentive for managers to make non‐value maximizing capital investment decisions.