bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable quantum systems in anti–de Sitter space: Causality, independence, and spectral properties
Authors: Buchholz Detlev , Summers Stephen J.
Published: November 2004

If a state is passive for uniformly accelerated observers in n-dimensional (n⩾2) anti–de Sitter (Ads) space–time (i.e., cannot be used by them to operate a perpetuum mobile), they will (a) register a universal value of the Unruh temperature, (b) discover a PCT symmetry, and (c) find that observables in complementary wedge-shaped regions necessarily commute with each other in this state. The stability properties of such a passive state induce a “geodesic causal structure” on AdS and concommitant locality relations. It is shown that observables in these complementary wedge-shaped regions fulfill strong additional independence conditions. In two-dimensional AdS these even suffice to enable the derivation of a nontrivial, local, covariant net indexed by bounded space–time regions. All these results are model-independent and hold in any theory which is compatible with a weak notion of space–time localization. Examples are provided of models satisfying the hypotheses of these theorems.
The moduli space of three-qutrit states
Authors: Briand Emmanuel , Luque Jean-Gabriel , Thibon Jean-Yves , Verstraete Frank
Published: November 2004

We study the invariant theory of trilinear forms over a three-dimensional complex vector space, and apply it to investigate the behavior of pure entangled three-partite qutrit states and their normal forms under local filtering operations (SLOCC). We describe the orbit space of the SLOCC group SL(3,C)×3 both in its affine and projective versions in terms of a very symmetric normal form parametrized by three complex numbers. The parameters of the possible normal forms of a given state are roots of an algebraic equation, which is proved to be solvable by radicals. The structure of the sets of equivalent normal forms is related to the geometry of certain regular complex polytopes.
Remote preparation of arbitrary ensembles and quantum bit commitment
Authors: Halvorson Hans
Published: November 2004

The Hughston–Jozsa–Wootters theorem shows that any finite ensemble of quantum states can be prepared “at a distance,” and it has been used to demonstrate the insecurity of all bit commitment protocols based on finite quantum systems without superselection rules. In this paper, we prove a generalized HJW theorem for arbitrary ensembles of states on a C*-algebra. We then use this result to demonstrate the insecurity of bit commitment protocols based on infinite quantum systems, and quantum systems with Abelian superselection rules.
Occupation, work environment, and disability pension: A prospective study of construction workers
Authors: Stattin Mikael , Järvholm Bengt
Published: November 2004

Aims: This study investigated the importance of occupation and work environment for the risk of disability pension among construction workers in Sweden. Methods: The data include around 389,000 construction workers who participated in health examinations from 1971 to 1992. During that period 68,000 participants received disability pension in some form. Between 1985 and 1992 questionnaires were used to collect data regarding hazards in the work environment. Some 87,000 participants answered that questionnaire, and almost 6,000 of these were in receipt of a disability pension. To analyse the risk of disability pension in different occupations, incidence rates (SIR) were calculated according to the person-year method. Logistic regression was used to calculate age-controlled odds ratios according to physical and psychosocial work environment factors. Results: The results show considerable variation in risk for disability pension between different occupations within the construction industry. Furthermore, analysis of work environment factors indicated associations with physical, ergonomic, and psychosocial work environment factors. Discussion: A considerable variation between occupations indicates that characteristics in the work situation are important when explaining the risk of disability pension. The results from this study indicate that improvements in working conditions are an important area of intervention in order to facilitate and prolong labour market participation among elderly people.
It is easy to determine whether a given integer is prime
Authors: Granville Andrew
Published: November 2004

“The problem of distinguishing prime numbers from composite numbers, and of resolving the latter into their prime factors is known to be one of the most important and useful in arithmetic. It has engaged the industry and wisdom of ancient and modern geometers to such an extent that it would be superfluous to discuss the problem at length. Nevertheless we must confess that all methods that have been proposed thus far are either restricted to very special cases or are so laborious and difficult that even for numbers that do not exceed the limits of tables constructed by estimable men, they try the patience of even the practiced calculator. And these methods do not apply at all to larger numbers ... It frequently happens that the trained calculator will be sufficiently rewarded by reducing large numbers to their factors so that it will compensate for the time spent. Further, the dignity of the science itself seems to require that every possible means be explored for the solution of a problem so elegant and so celebrated ... It is in the nature of the problem that any method will become more complicated as the numbers get larger. Nevertheless, in the following methods the difficulties increase rather slowly ... The techniques that were previously known would require intolerable labor even for the most indefatigable calculator.” —from article 329 of Disquisitiones Arithmeticae (1801) by C. F. Gauss
The Epidemiology of the Comorbidity of Epilepsy in the General Population
Authors: Gaitatzis Athanasios , Carroll Kevin , Majeed Azeem , Sander Josemir W.
Published: November 2004

Summary: Purpose:To describe the epidemiology of somatic and psychiatric conditions in adults with epilepsy in the community and compare it to that of people without epilepsy.

Methods:A cross‐sectional population‐based study extracting data from the UK General Practice Research Database for the period 1995–1998. Age‐ and sex‐standardized prevalence rates were estimated for selected conditions and groups of conditions (categorized by ICD‐9 chapters) in adults with epilepsy registered with primary care physicians. Results were compared with those in adults without epilepsy in the cohort, and prevalence ratios were calculated according to two broad age groups (16–64 and older than 64 years).

Results:Conditions common in the general population also were common in adults with epilepsy. Psychiatric disorders occurred twice as often, and the risk of somatic disorders was increased in people with epilepsy, with the exception of musculoskeletal and connective tissue disorders in older adults. The prevalence ratio of neoplasia, excluding intracranial tumors, was not increased in epilepsy. The prevalence ratio of brain tumors was particularly increased in young adults [prevalence ratio (PR), 70.7] and of meningiomas in older adults (PR, 91.9). Neurodegenerative conditions, particularly dementias and Alzheimer' disease (PR, 6.3 and 8, respectively) and Parkinson' disease (PR, 3.2), appeared more frequently in people with epilepsy. Upper gastrointestinal bleed occurred more frequently in epilepsy (PR, 4.3), as did cardio‐ and cerebrovascular disorders, fractures, pneumonia and chronic lung diseases, and diabetes. Eczema, osteoarthritis, and rheumatoid arthritis did not occur more frequently in epilepsy.

Conclusions:The prevalence ratio of many common psychiatric and somatic conditions is increased in adults with epilepsy who consult a primary care physician in the U.K. These findings may have implications in the diagnosis and management of epilepsy and coexisting conditions, as well as in health care provision.
Are “Generalized” Seizures Truly Generalized? Evidence of Localized Mesial Frontal and Frontopolar Discharges in Absence
Authors: Holmes Mark D. , Brown Micah , Tucker Don M.
Published: November 2004

Summary:  Purpose: To determine whether specific regions of cerebral cortex are activated at the onset and during the propagation of absence seizures.

Methods: Twenty‐five absence seizures were recorded in five subjects (all women; age 19–58 years) with primary generalized epilepsy. To improve spatial resolution, all studies were performed with dense‐array, 256‐channel scalp EEG. Source analysis was conducted with equivalent dipole (BESA) and smoothed linear inverse (LORETA) methods. Analyses were applied to the spike components of each spike–wave burst in each seizure, with sources visualized with standard brain models.

Results: For each patient, the major findings were apparent on inspection of the scalp EEG maps and waveforms, and the two methods of source analysis gave generally convergent results. The onset of seizures was typically associated with activation of discrete, often unilateral areas of dorsolateral frontal or orbital frontal lobe. Consistently across all seizures, the negative slow wave was maximal over frontal cortex, and the spike that appeared to follow the slow wave was highly localized over frontopolar regions of orbital frontal lobe. In addition, sources in dorsomedial frontal cortex were engaged for each spike–wave cycle. Although each patient showed unique features, the absence seizures of all patients showed rapid, stereotyped evolution to engage both mesial frontal and orbital frontal cortex sources during the repeating cycles of spike–wave activity.

Conclusions: These data suggest that absence seizures are not truly “generalized,” with immediate global cortical involvement, but rather involve selective cortical networks, including orbital frontal and mesial frontal regions, in the propagation of ictal discharges.
Expression and Cellular Distribution of Major Vault Protein: A Putative Marker for Pharmacoresistance in a Rat Model for Temporal Lobe Epilepsy
Authors: Van Vliet Erwin A. , Aronica Eleonora , Redeker Sandra , Gorter Jan A.
Published: November 2004

Summary:  Purpose: Because drug transporters might play a role in the development of multidrug resistance (MDR), we investigated the expression of a vesicular drug transporter, the major vault protein (MVP), in a rat model for temporal lobe epilepsy.

Methods: By using real‐time polymerase chain reaction (PCR) analysis and immunocytochemistry, we quantified MVP mRNA and protein from the dentate gyrus (DG) and parahippocampal cortex (PHC) taken from EEG‐monitored rats at 1 week after electrically induced status epilepticus (SE) and at 5–9 months after SE, when rats exhibit spontaneous seizures.

Results: Within 1 week after SE, MVP mRNA levels increased in both DG and PHC compared with those in controls. In chronic epileptic rats, MVP mRNA was still significantly upregulated in the PHC, whereas in the DG, the expression returned to control levels. MVP protein increased within 1 day after SE in reactive microglial cells within most limbic regions; the hippocampus showed the highest expression at 1 week after SE. In chronic epileptic rats, MVP protein expression was largely decreased in most brain regions, but it was still high, especially in the piriform cortex. The occurrence of SE was a prerequisite for increased MVP expression, because no increase was found in electrically stimulated rats that did not exhibit SE.

Conclusions: MVP expression is upregulated in chronic epileptic rats and may contribute to the development of pharmacoresistance.
Seizures in the Developing Brain Cause Adverse Long‐term Effects on Spatial Learning and Anxiety
Authors: Sayin Umit , Sutula Thomas P. , Stafstrom Carl E.
Published: November 2004

Summary: Purpose: Seizures in the developing brain cause less macroscopic structural damage than do seizures in adulthood, but accumulating evidence shows that seizures early in life can be associated with persistent behavioral and cognitive impairments. We previously showed that long‐term spatial memory in the eight‐arm radial‐arm maze was impaired in rats that experienced a single episode of kainic acid (KA)‐induced status epilepticus during early development (postnatal days (P) 1–14). Here we extend those findings by using a set of behavioral paradigms that are sensitive to additional aspects of learning and behavior.

Methods: On P1, P7, P14, or P24, rats underwent status epilepticus induced by intraperitoneal injections of age‐specific doses of KA. In adulthood (P90–P100), the behavioral performance of these rats was compared with that of control rats that did not receive KA. A modified version of the radial‐arm maze was used to assess short‐term spatial memory; the Morris water maze was used to evaluate long‐term spatial memory and retrieval; and the elevated plus maze was used to determine anxiety.

Results: Compared with controls, rats with KA seizures at each tested age had impairedshort‐termspatial memory in the radial‐arm maze (longer latency to criterion and more reference errors), deficientlong‐termspatial learning and retrieval in the water maze (longer escape latencies and memory for platform location), and a greater degree of anxiety in the elevated plus maze (greater time spent in open arms).

Conclusions: These findings provide additional support for the concept that seizures early in life may be followed by life‐long impairment of certain cognitive and behavioral functions. These results may have clinical implications, favoring early and aggressive control of seizures during development.
Application of Fourier transform and autocorrelation to cluster identification in the three‐dimensional atom probe
Authors: VURPILLOT F. , DE GEUSER F. , DA COSTA G. , BLAVETTE D.
Published: November 2004

Because of the increasing number of collected atoms (up to millions) in the three‐dimensional atom probe, derivation of chemical or structural information from the direct observation of three‐dimensional images is becoming more and more difficult. New data analysis tools are thus required. Application of a discrete Fourier transform algorithm to three‐dimensional atom probe datasets provides information that is not easily accessible in real space. Derivation of mean particle size from Fourier intensities or from three‐dimensional autocorrelation is an example. These powerful methods can be used to detect and image nano‐segregations. Using three‐dimensional ‘bright‐field’ imaging, single nano‐segregations were isolated from the surrounding matrix of an iron–copper alloy. Measurement of the inner concentration within clusters is, therefore, straightforward. Theoretical aspects related to filtering in reciprocal space are developed.
Investigation of quantitative secondary electron imaging of semiconducting polymer materials using environmental scanning electron microscopy
Authors: WILLIAMS S. J. , DONALD A. M.
Published: November 2004

The development of environmental scanning electron microscopy has opened the way for the examination of a wide variety of new sample types that were previously inaccessible to conventional scanning electron microscope techniques. With the advent of such a new methodology comes also the potential for new contrast mechanisms. We investigated the use of environmental scanning electron microscopy on semiconducting organic polymer materials. We observed contrast from these materials in secondary electron images, this contrast being attributed to differences in electron yield due to the polymer's electronic structure. Further study of these materials, and specifically the influence of film thickness on signal, has indicated a significant effect as the secondary electrons move through the sample. Systematic studies such as these are needed for a full understanding of the relationship between electronic properties and signal and, hence, the ability to probe structure–property relationships in greater depth.
A BROAD SPECTRUM ARTIFICIAL SEA WATER MEDIUM FOR COASTAL AND OPEN OCEAN PHYTOPLANKTON1
Authors: Harrison Paul J. , Waters Rosemary E. , Taylor F. J. R.
Published: November 2004

A new artificial seawater medium has been tested with 83 strains of coastal and open ocean phytoplankton from 11 different algal classes. The cultures were carried through four transfers, representing a period of eight weeks for most species. Only three species could not be maintained in the enriched artificial seawater, and 16 species, mainly from the Prymnesiophyceae and Dinophyceae, had reduced final cell yields compared to those grown in enriched natural seawater. Since 77% of the species tested grew equally well in enriched artificial or natural seawater and more than 95% could be maintained in the artificial medium, this recipe is useful over a broad spectrum of species. The artificial seawater base was enriched with a modified ES enrichment solution; the primary modifications were the omission of Tris and the addition of Si. Enriched medium was autoclaved without precipitation by lowering the pH before autoclaving. This was accomplished by adding equimolar amounts of Na‐HCO3 and HCl which produced NaCl and CO2 during the heating process. When no pH buffer was used, precipitation could only be avoided by autoclaving the artificial seawater base as two separate salt solutions (with Ca and Sr separated from CO3−2 and SO4−2), cooling, mixing and aseptically adding the sterilized enrichment solution.
To what extent can management variables explain species assemblages? A study of carabid beetles in forests
Authors: Warnaffe Gaëtan du Bus de , Dufrêne Marc
Published: November 2004

Studies concerning the influence of forest management on invertebrate communities often focus on a limited set of chosen variables and rarely quantify the importance of management as opposed to other influences. We aimed at: 1) comparing the importance for species assemblages of habitat variables defined by management with those independent of it; 2) understanding the ecological significance of the variation remaining when both management and non‐management variables are used. We caught carabid beetles according to a stratified pitfall sampling based on forest structure, tree composition and stand age. Forty‐nine habitat variables were measured using three spatial scales. We decomposed the variation of species assemblages with successive constrained ordinations based on sets of variables, and studied the life traits of the species least and best explained by the model including all of the variables. Forest structure, composition and stand age showed important effects but explained a relatively small part of the overall variation in species assemblages. Management accounted for ca 30% of the variation, but non‐management variables had a significant impact and the interaction between management and non‐management sets resulted in significant influences. Most species for which the variation was highly explained by the model were generally large and with inefficient wings, while the least explained species were small. Our study suggests that: 1) even with highly controlled samples, the influence of management on species assemblages should not be studied by a limited set of categorical variables; 2) management variables may interact with factors outside of the manager's control; 3) a significant part of the variation cannot be explained by habitat variables and needs taking ecological processes into account; 4) rules to optimise constrained ordination techniques applied to species‐habitat studies can be proposed.
Forest classification in an Amazonian rainforest landscape using pteridophytes as indicator species
Authors: Salovaara Kati J. , Cárdenas Glenda G. , Tuomisto Hanna
Published: November 2004

Habitat classification systems are poorly developed for tropical rainforests, where extremely high plant species richness causes numerous methodological difficulties. We used an indicator species approach to classify primary rainforest vegetation for purposes of comparative wildlife habitat studies. We documented species composition of pteridophytes (ferns and fern allies) in 635 plots (2×100 m) along 8 transects within a continuous rainforest landscape in northeastern Peruvian Amazonia. Considerable floristic variation was found when the data were analyzed using multivariate methods. The obtained forest classification was interpreted with the help of indicator value analysis and known soil preferences of the pteridophyte species. The final classification included four forest types: 1) inundated forests, 2) terrace forests, 3) intermediate tierra firme forests and 4) Pebas Formation forests. This rapid and relatively simple vegetation classification technique offers a practical, quantitative method for large‐scale vegetation inventory in complex rainforest landscapes.
Estimation of the spatial autocorrelation function: consequences of sampling dynamic populations in space and time
Authors: Tobin Patrick C.
Published: November 2004

The estimation of spatial autocorrelation in spatially‐ and temporally‐referenced data is fundamental to understanding an organism's population biology. I used four sets of census field data, and developed an idealized space‐time dynamic system, to study the behavior of spatial autocorrelation estimates when a practical method of sampling is employed. Estimates were made using both a classical geostatistical approach and a recently developed non‐parametric approach. In field data, the estimate of the local spatial autocorrelation (i.e. autocorrelation as the distance between pairs of sampling points approaches 0), was greatly affected by sample size, while the range of spatial dependence (i.e. the distance at which the autocorrelation becomes negligible) was fairly stable. Similar patterns were seen in the theoretical system, as well as greater variability in local spatial autocorrelation during the invasion stage of colonization. When sampling for the purposes of quantifying spatial patterns, improved estimates of spatial autocorrelation may be obtained by increasing the number of pairs of points that are close in space at the expense of attempting to cover the entire region of interest with equidistant sampling points. Also, results from the theoretical space‐time system suggested that greater resolution in sampling may be required in newly establishing populations relative to those already established.
Distribution pattern of the epiphyteNeckera pennataon three spatial scales – importance of past landscape structure, connectivity and local conditions
Authors: Snäll Tord , Hagström Anna , Rudolphi Jörgen , Rydin Håkan
Published: November 2004

We tested which factors explain the distribution pattern of the epiphytic mossNeckera pennataon three spatial scales using the framework of generalized linear models. First, we tested which factors explained its occurrence in forest stands in a 2500 ha landscape. At this scale, we also tested the effect of the historic landscape structure. We recorded its occurrence in all suitable stands. The occurrence probability increased with increasing present quantity ofAcer platanoides, and with increasing present and past quantity ofFraxinus excelsior. The probability also increased with increasing connectivity to occupied stands. However, the connectivity to stands present in 1977 (recorded from infra‐red aerial photographs) explained more of the variation. This suggests that the regional metapopulation size ofN. pennatahas decreased during the past decades, and that its present distribution pattern reflects the age of the remaining stands, and the distribution of past dispersal sources in the landscape. Second, we tested which factors explained the occurrence and abundance on individual trees in three forest stands.Neckera pennatamainly occurred onAcerandFraxinusstems. The most important variable in explaining occurrence probability was connectivity to surrounding occupied trees, which probably reflects the restricted dispersal range in this species. The abundance on occupied trees was also explained by this variable. The occurrence probability and abundance also increased with increasing tree diameter, probably reflecting the time that a tree has been available for colonization and the time since colonization, respectively. The occurrence probability and abundance furthermore decreased on strongly leaning (and deteriorating) trees. The occurrence probability increased with increasing bark roughness, probably reflecting increasing suitability regarding bark chemistry and moisture. Third, we tested its vertical distribution on occupied trees. The main distribution was below 1.6 m.
Soil phytoliths as evidence for species replacement in grazed rangelands of central Argentina
Authors: Gallego Lucrecia , Distel Roberto A. , Camina Ricardo , Rodríguez Iglesias Ricardo M.
Published: November 2004

Rangeland utilization for livestock production in central Argentina has apparently resulted in the replacement of preferred mid‐grasses (Poa ligularis and Stipa clarazii) by preferred short‐grasses (Piptochaetium napostaense and Stipa tenuis) and avoided grasses (Stipa tenuissima and Stipa eriostachya). However, the botanical composition in the pristine condition is unknown due to the lack of historical data and relict areas. The objective of this study was to analyze soil phytolith assemblages from a representative site of central Argentina rangelands to test the presumed floristic changes. Soil phytolith assemblages (SPAs) were compared with three plant phytolith assemblages (PPAs), each of it made up of two species. One PPA was integrated by the preferred mid‐grasses P. ligularis and S. clarazii, another by the preferred short‐grasses P. napostaense and S. tenuis, and a third one by the avoided grasses S. eriostachya and S. tenuissima. For each PPA, the proportion of species representing the best fit with SPAs was estimated by considering all possible lineal combinations between the phytolith assemblage of the two integrating species, and selecting that representing the minimum distance to SPA. The highest degree of similarity between SPAs and PPAs corresponded to the PPA integrated by P. ligularis and S. clarazii. Our results support the hypothesis of the dominance of preferred mid‐grasses in the pristine condition in rangelands of central Argentina, and that a shift towards the dominance of preferred short‐grasses and avoided grasses has occurred in its present disturbed condition.
Grasshopper populations across 2000 m of altitude: is there life history adaptation?
Authors: Berner Daniel , Körner Christian , Blanckenhorn Wolf U.
Published: November 2004

Life history differentiation along climatic gradients may have allowed a species to extend its geographic range. To explore this hypothesis, we compared eleven Omocestus viridulus (Orthoptera: Acrididae) populations along an altitudinal gradient from 410 to 2440 m in Switzerland, both in the field and laboratory. In situ temperature records indicated a striking decline in available heat sums along the gradient, and field populations at high altitudes reached egg hatching and adulthood much later in the year than at low elevation. The reproductive period at high altitude is thus severely limited by season length, especially during a cool year. However, controlled environment experiments revealed that intrinsic rates of embryonic and juvenile development increased with the populations’ altitude of origin. This countergradient variation is largely genetic and conforms to predictions of life history theory. No corresponding differentiation in the overwintering egg stage, a pivotal determinant of phenology, was found. This trait seems conserved within the gomphocerine grasshopper subfamily. Although we found evidence for altitudinal adaptation in development, the potential of O. viridulus to adapt to cool alpine climates appears restricted by a phylogenetic constraint.
Role of neuronal nitric oxide synthase in response to hypertonic saline loading in rats
Authors: Wangensteen R. , Rodríguez‐Gomez I. , Moreno J. M. , Chamorro V. , Osuna A. , Vargas F.
Published: November 2004

Aims:  This study analyses the influence of neuronal nitric oxide synthase (nNOS) blockade with 7‐nitroindazole (7NI) on the haemodynamic and renal response to a hypertonic saline load (HSL). We also evaluated the effects of non‐specific NOS inhibitor Nω‐nitro‐l‐arginine methyl ester (l‐NAME).

Methods:  The following groups were used: controls, rats treated with 7NI at 0.5 or 5 mg kg−1, and rats treated with l‐NAME at 0.5 or 5 mg kg−1. A further five groups received an isotonic saline load (ISL).

Results:  Mean arterial pressure (MAP) was significantly increased in control rats after HSL. MAP was further increased in both 7NI‐treated groups, and the l‐NAME groups showed marked dose‐related pressor responses. During ISL, MAP was only significantly increased in the group treated with 5 mg kg−1 of l‐NAME. The pressure–natriuresis relationship during the experimental period after the HSL was reduced in the 7NI group treated with 5 mg kg−1 and severely attenuated in both l‐NAME groups. The increase in plasma sodium was significantly greater after the HSL in both 7NI groups and both l‐NAME groups compared with controls.

Conclusions:  The present results suggest that nNOS and other NOS isozymes play a counter‐regulatory role in the pressor response to HSL. Moreover, the blockade of nNOS with the higher dose of 7NI produces a blunted pressure–natriuresis relationship in response to the HSL. Finally, it is concluded that nNOS participates in the homeostatic cardiovascular and renal response to hypertonic saline loading by attenuating the blood pressure increase and hypernatremia, and facilitating natriuresis.
The behaviour of the flow‐mediated brachial artery vasodilatation during orthostatic stress in normal man
Authors: Guazzi M. , Lenatti L. , Tumminello G. , Puppa S. , Fiorentini C. , Guazzi M. D.
Published: November 2004

Aims:  Flow‐mediated brachial artery vasodilatation is an index of endothelial function. Published literature describes only supine data and no study has been performed during vertical displacement. This subject deserves investigation for two main reasons: humans spend the larger part of their life in the upright position; this position has significant effects on neural vascular regulation.

Methods:  In 21 healthy men (25 ± 2 years) the flow‐dependent brachial artery vasodilating response to distal circulatory arrest was assessed by Doppler ultrasound imaging, while supine and during 20° and 60° head‐up tilting (HUT). In 11 of these subjects the vasodilating response to nitroglycerine was also explored.

Results:  Absolute and percentage increments in brachial calibre during hyperaemia after deflation of the occluding cuff became increasingly greater at 20° (+0.44 mm) and 60° (+0.92 mm) HUT (P < 0.01), compared with the horizontal position (+0.27 mm), and the arterial dilatation for an increase in flow (0.98 ± 0.08 and 1.68 ± 0.06 mm mL−1 min−1 × 1000, respectively) was larger (P < 0.01) than occurred while supine (0.41 ± 0.05 mm mL−1 min−1 × 1000). Nitroglycerine‐mediated vasodilatation at 60° HUT was similar to that in the supine position.

Conclusion:  The orthostatic stimulus is associated with an increase of the flow‐mediated brachial artery vasodilatation, which is proportional to the degree of displacement. The mechanism of this effect does not consist of changes in nitric oxide sensitivity.
Ageing, oxidative stress, and mitochondrial uncoupling
Authors: Harper M.‐E. , Bevilacqua L. , Hagopian K. , Weindruch R. , Ramsey J. J.
Published: November 2004

Mitochondria are a cell's single greatest source of reactive oxygen species. Reactive oxygen species are important for many life sustaining processes of cells and tissues, but they can also induce cell damage and death. If their production and levels within cells is not effectively controlled, then the detrimental effects of oxidative stress can accumulate. Oxidative stress is widely thought to underpin many ageing processes, and the oxidative stress theory of ageing is one of the most widely acknowledged theories of ageing. As well as being the major source of reactive oxygen species, mitochondria are also a major site of oxidative damage. The purpose of this review is a concise and current review of the effects of oxidative stress and ageing on mitochondrial function. Emphasis is placed upon the roles of mitochondrial proton leak, the uncoupling proteins, and the anti‐ageing effects of caloric restriction.
Mitochondrial dysfunction measured in vivo
Authors: Marcinek D. J.
Published: November 2004

Aims:  Mitochondria are responsible for meeting the majority of the energetic demand of most tissues. They also play a major role in regulating cell survival. These dual roles of mitochondria place them at the centre of many pathologies leading to tissue degeneration and disruption of energy balance. The prominent role of mitochondria in ageing and disease has led to a tremendous growth in mitochondrial research at the cellular and molecular level. We describe below a new non‐invasive approach to measure mitochondrial function that will bridge the gap between our understanding of mitochondrial function in vitro and that in the intact organism.

Methods and Results:  This approach uses optical and magnetic resonance spectroscopy to measure in vivo O2 consumption and ATP synthesis rates, respectively, from skeletal muscle. These values lead to a quantitative assessment of the mitochondrial ATP/O2 or P/O. The P/O represents the efficiency of coupling between phosphorylation and oxygen consumption in the mitochondria, which is a measure of mitochondrial dysfunction.

Conclusions:  This work represents a significant advance in research on the role of mitochondria in degenerative disease and ageing because it allows a quantitative measure of mitochondrial pathology in vivo. The non‐invasive nature of this approach also enables repeated measures of mitochondrial function on the same individual, thereby making this a potentially useful diagnostic technique. The results from this work have led to insights into the coupling of ATP synthesis to oxidation and the regulation of oxidative phosphorylation by intracellular PO2.
Comparative analysis and development of microsatellite markers on swine (Sus scrofa) chromosome 1qter
Authors: Mikawa S. , Shimanuki S. , Morozumi T. , Domukai M. , Shinkai H. , Uchida Y. , Mikawa A. , Miyake M. , Miyake Y. , Hayashi N. , Kusumoto H. , Uenishi H. , Hayashi T. , Awata T.
Published: November 2004

Several quantitative trait loci (QTL) have been detected on SSC1qter (Sus scrofa chromosome 1qter), including QTL for the number of vertebrae, as reported in our previous study. To provide the tools for analysis of QTLs on SSC1qter, we constructed a comparative map of swine and human. In addition, we identified 26 swine STSs and mapped 16 of them on SSC1qter using the INRA – University of Minnesota porcine radiation hybrid (IMpRH) panel. We screened a BAC library using these swine STSs and developed 35 new polymorphic microsatellite markers from the BAC clones, of which 26 were informative in our reference family. We also mapped nine microsatellite markers we had isolated previously. Consequently a total of 44 new polymorphic microsatellite markers were located within a 60‐cM region of SSC1qter, spanning from SW1092 to the telomere.
Altered patterns of the interferon‐inducible gene IFI16 expression in head and neck squamous cell carcinoma: immunohistochemical study including correlation with retinoblastoma protein, human papillomavirus infection and proliferation index
Authors: Azzimonti B , Pagano M , Mondini M , De Andrea M , Valente G , Monga G , Tommasino M , Aluffi P , Landolfo S , Gariglio M
Published: November 2004

Aims:  To investigate whether the expression of interferon (IFN)‐inducible gene IFI16 is inversely related to proliferative activity in vivo, we compared immunohistochemical reactivity of IFI16 in a series of head and neck squamous cell carcinomas (HNSCCs) with their proliferation index and the cell cycle regulator pRb. As human papillomavirus (HPV) infection is manifested by changes in the function or expression level of host genes such as IFN‐inducible genes, we also investigated the presence of HPV DNA to determine whether head and neck cancers associated with HPV DNA can be distinguished from tumours that are presumably transformed by other mechanisms.

Methods:  Thirty‐six HNSCCs were evaluated for IFI16, pRb and Ki67 expression by immunohistochemistry. The presence of HPV was also detected by polymerase chain reaction. Nine tumours were located in the oropharynx (tonsillar area) and 27 in the larynx.

Results:  HPV DNA was found in 14 of 25 (56%) laryngeal SCCs and in five of nine (56%) tonsillar SCC specimens examined; 17 out of the 19 HPV‐DNA‐positive cases showed high‐grade IFI16 expression. Overall, proliferative activity was significantly related to tumour differentiation and histological grading. IFI16 protein expression was significantly inversely correlated with Ki67 (P = 0.039). Low‐proliferating tumours positive for IFI16 staining showed a marked expression of pRb and a better prognosis than those whose tumours had low IFI16, pRb levels and a high proliferation index.

Conclusions:  To our knowledge, this is the first expression analysis of the IFN‐inducible IFI16 gene in HNSCC. Low‐proliferating tumours positive for IFI16 staining showed a marked expression of pRb and a better prognosis than those whose tumours had low IFI16, pRb levels and a high proliferation index.
Comparative analysis of COX‐2, vascular endothelial growth factor and microvessel density in human renal cell carcinomas
Authors: Hemmerlein B , Galuschka L , Putzer N , Zischkau S , Heuser M
Published: November 2004

Aims:  Cyclooxygenase‐2 (COX‐2) and vascular endothelial growth factor (VEGF) are frequently up‐regulated in malignant tumours and play a role in proliferation, apoptosis, angiogenesis and tumour invasion. In the present study, the expression of COX‐2 and VEGF in renal cell carcinoma (RCC) was analysed and correlated with the microvessel density (MVD).

Methods and results:  COX‐2 and VEGF were analysed by realtime reverse transcriptase‐polymerase chain reaction and immunohistochemistry. The MVD was assessed by CD31 immunohistochemistry. The expression of COX‐2 and VEGF was determined in the RCC cell lines A498 and Caki‐1 under short‐term hypoxia and in multicellular tumour cell aggregates. COX‐2 was expressed in RCC by tumour epithelia, endothelia and macrophages in areas of cystic tumour regression and tumour necrosis. COX‐2 protein in RCC was not altered in comparison with normal renal tissue. VEGF mRNA was up‐regulated in RCC and positively correlated with MVD. RCC with high up‐regulation of VEGF mRNA showed weak intracytoplasmic expression of VEGF in tumour cells. Intracytoplasmic VEGF protein expression was negatively correlated with MVD. In RCC with necrosis the MVD was reduced in comparison with RCC without necrosis. A498 RCC cells down‐regulated COX‐2 and up‐regulated VEGF under conditions of hypoxia. In Caki‐1 cells COX‐2 expression remained stable, whereas VEGF was significantly up‐regulated. In multicellular A498 cell aggregates COX‐2 and VEGF were up‐regulated centrally, whereas no gradient was found in Caki‐1 cells.

Conclusions:  COX‐2 and VEGF are potential therapeutic targets because COX‐2 and VEGF are expressed in RCC and associated cell populations such as endothelia and monocytes/macrophages.
Polymerized α1‐antitrypsin is present on lung vascular endothelium. New insights into the biological significance of α1‐antitrypsin polymerization
Authors: Aldonyte R , Jansson L , Ljungberg O , Larsson S , Janciauskiene S
Published: November 2004

Aims:  The damage to lung tissue in chronic obstructive pulmonary disease (COPD) may involve the progressive loss of pulmonary vascular endothelial cells. Endothelial binding of α1‐antitrypsin (α1‐AT) derived from plasma has been identified, and α1‐AT deficiency is a known genetic risk factor associated with α1‐AT polymerization and COPD development. Therefore, in the present study we aimed to investigate if α1‐AT is present on the lung vascular endothelium, and if it is in a polymeric form.

Methods and results:  Postmortem paraffin‐embedded tissue specimens from 15 COPD (chronic bronchitis and emphysema) cases with and without Z α1‐AT (Glu342Lys) deficiency and from 10 cases without signs of COPD were studied. Immunohistochemistry was performed using the streptavidin–biotin method with a monoclonal ATZ11 antibody specific for polymeric α1‐AT, and polyclonal antibodies against human α1‐AT and neutrophil elastase. Vascular endothelium showed intense staining for α1‐AT with the ATZ11 antibody in all cases; however, intensity of staining in patients with α1‐AT deficiency was greater. No endothelial staining was observed with the anti‐elastase antibody.

Conclusions:  This is the first demonstration that α1‐AT bound to the vascular endothelium of lungs is in a polymeric form, which also suggests a possible previously unknown role for polymeric α1‐AT in vivo.
Presence of nanobacteria in psammoma bodies of ovarian cancer: evidence for pathogenetic role in intratumoral biomineralization
Authors: Hudelist G , Singer C F , Kubista E , Manavi M , Mueller R , Pischinger K , Czerwenka K
Published: November 2004

Aims:  The presence of laminated, calcified extracellular debris known as psammoma bodies is a well‐known histomorphological feature of ovarian adenocarcinomas and other human malignancies. Biomineralization has recently been found to be associated with a group of extremely small Gram‐negative bacteria capable of precipitating calcium salts. The aim of the present study was to evaluate a possible pathogenic link between the development of psammoma bodies and nanobacteria infection.

Material and results:  Immunohistochemical staining and reverse transcriptase‐polymerase chain reaction (RT‐PCR) were used to analyse nanobacterial protein and gene expression in eight psammona body‐containing adenocarcinomas and in 10 malignant ovarian tumours without signs of biomineralization. Nanobacterial proteins were detected in eight out of eight (100%) psammoma‐positive tumour samples. Conversely, none of the 10 psammoma‐negative tissues (0%) was positive for nanobacterial antigens. Furthermore, nanobacterial mRNA was detectable in all of the four tissues (100%) that contained psammoma bodies, but was absent in all 10 ovarian cystadenocarcinomas (0%) that were psammoma negative.

Conclusions:  We found a 100% concordance between the expression of nanobacteria and the presence of psammoma bodies in malignant ovarian tumours. Several lines of evidence suggest the involvement of these organisms in the process of biomineralization. We therefore conclude that nanobacterial infection of malignant ovarian tissue contributes to mechanisms leading to the formation of calcified deposits known as psammoma bodies.
From transaction to transformation: information and communication technology, professional development and the formation of communities of practice
Authors: Triggs P. , John P.
Published: November 2004

AbstractUsing the concept of ‘layers of community’, this paper describes and explains the ways in which teams of teachers, teacher educators and researchers worked together on the research project InterActive Education: teaching and learning in the information age. The focus is on the development and dissemination of professional knowledge as it relates to teaching and learning that incorporates information and communications technology (ICT) as a tool. Drawing on a range of data, we illustrate how ‘micro‐’, ‘meso‐’ and ‘macro’‐communities inter‐connect to create the settings for improved professional growth. The purpose is to challenge the linearity embedded in much of the professional development processes associated with ICT and to re‐model the relationship between practice and research.
Transforming teaching and learning: embedding ICT into everyday classroom practices
Authors: Sutherland R. , Armstrong V. , Barnes S. , Brawn R. , Breeze N. , Gall M. , Matthewman S. , Olivero F. , Taylor A. , Triggs P. , Wishart J. , John P.
Published: November 2004

Drawing on socio‐cultural theory, this paper describes how teams of teachers and researchers have developed ways of embedding information and communications technology (ICT) into everyday classroom practices to enhance learning. The focus is on teaching and learning across a range of subjects: English, history, geography, mathematics, modern foreign languages, music and science. The influence of young people's out‐of‐school uses of ICT on in‐school learning is discussed. The creative tension between idiosyncratic and institutional knowledge construction is emphasised and we argue that this is exacerbated by the use of ICT in the classroom.
The natural history of maternal immunization against foetal platelet alloantigens
Authors: Ohto H. , Miura S. , Ariga H. , Ishii T. , Fujimori K. , Morita S.
Published: November 2004

Summary.  Foetomaternal alloimmune thrombocytopenia (FMAIT) occurs when maternal antibodies of an antigen‐negative mother cause destruction of sensitized foetal platelets. In Caucasian populations, 6–12% of human platelet antigen (HPA)‐1a‐negative women develop anti‐HPA‐1a, and the incidence of clinically affected cases is estimated to be 10–20% of immunized women. This study was performed in order to elucidate the rate of maternal immunization, incidence of FMAIT and the likely outcome of the condition in Asians. Excluding two or more pregnancies during the period, serum samples from 24 630 pregnant women, mainly Japanese, were screened for antibodies against platelet alloantigens by means of mixed passive haemagglutination (MPHA) (Anti‐HPA‐MPHA, Olympus, Tokyo). Antibodies were detected in 0·91% (223/24 630) of the women's samples and the immunization rate was correlated with the number of pregnancies. Antibody specificity included anti‐HPA‐4b (49), anti‐HPA‐5a (three), anti‐HPA‐5b (168), anti‐HPA‐4b + 5b (one) and anti‐Naka (CD36) (two). No alloimmunization was observed within the HPA‐1, HPA‐2, HPA‐3 or HPA‐6 systems. Among HPA‐4b‐ or HPA‐5b‐negative women, 24% or 14% estimated, respectively, had antibodies and 26% (10/38) or 10% (12/125) of neonates, respectively, born to these mothers developed thrombocytopenia. Two neonates born to mothers having anti‐HPA‐4b developed generalized purpura. No cases of intracranial bleeding or death due to FMAIT were recorded. Generalized purpura due to FMAIT occurs in one in 9359 (95% CI: 1 in 77 519–1 in 2591) pregnancies solely because of HPA‐4b incompatibility.
Neonatal alloimmune thrombocytopenia due to an antibody against a labile component of human platelet antigen‐3b (Bakb)
Authors: Kataoka S. , Kobayashi H. , Chiba K. , Nakamura M. , Shinada S. , Morita S. , Lin M. , Shibata Y.
Published: November 2004

Summary.  We report the second case of neonatal alloimmune thrombocytopenia due to anti‐human platelet antigen (HPA)‐3b (Bakb) antibody. The infant was severely affected with intracranial haemorrhage. Most importantly, we were able to detect this antibody only by using fresh, unfixed platelets as antigen. This antibody was detectable neither by conventional mixed passive haemagglutination, platelet immunofluorescence test using fixed platelets, nor by monoclonal antigen immobilization of platelet antigen assay using solubilized platelets. We assume that this antibody reacts only with fresh platelets and that the antigen is a labile component of HPA‐3b (Bakb).