bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of a sensillum associated with the pharynx of the cockroachPeriplaneta americana
Authors: Chiang R. Gary , Davey K. G.
Published: January 2008

A sensillum associated with the pharynx of the cockroach Periplaneta americana was examined in serial ultrathin sections using electron microscopy. This sensillum consisted of a group of 10–20 similar sensillar subunits. Each sensillar subunit possessed one 60- to 70-μm long dendritic sheath that made direct contact with the cuticle. The dendritic sheath enclosed 3–5 sensory cilia arising from 3–5 sensory cells located in a cluster approximately 30 μm proximal to the base of the sheath. Between the sensory cell body and the base of the sheath the dendrites were wrapped by the sheath-forming cell. Before entering the dendritic sheath itself, the dendrites crossed through an extracellular space, the ciliary sinus. No cuticular specializations, such as a well-defined sensory hair or pore, were observed. The structure of this sensillum suggests that it responds poorly to mechanical distortion of its surroundings. This characteristic supports the hypothesis that this sensillum measures the osmotic concentration of the ingested food.
Seasonal and thermal effects on the emetic responses of ranid frogs
Authors: Suzuki Chiharu , Miyoshi Satoshi , Naitoh Tomio , Wassersug Richard J.
Published: January 2008

We examined the relationship between time of the year and sensitivity to emetics in the frogs Rana rugosa and Rana nigromaculata. In response to apomorphine hydrochloride at a dosage of 50 μg/g body mass (wet mass), both species vomited from the late autumn through the winter, when they naturally hibernate, but not during the spring or summer months, when they are normally active. Exposure to low temperature (7 °C) for 29 days made R. rugosa sensitive to apomorphine even in the summer. Exposure to high temperature (20.0–23.0 °C) for 7–10 days in the winter resulted in loss of the frogs' sensitivity to apomorphine. Based on these results, we conclude that seasonal fluctuation in sensitivity to apomorphine is caused by changes in temperature. Sensitivity to copper sulfate, administered orally at a dosage of 0.4 mg/g, also changed with the time of year. However, in contrast to emesis induced with apomorphine, there was an increase in the latency to emesis induced with copper sulfate in the winter compared with the summer for both species. Thus, the emetic responsiveness of ranid frogs depends on both seasonal changes in temperature and on the agent used to provoke emesis.
Annual life-history variation in the striped plateau lizard, Sceloporus virgatus
Authors: Smith Geoffrey R.
Published: January 2008

I studied temporal variation in life-history and demographic traits of a population of striped plateau lizards, Sceloporus virgatus, over 3 years in the Chiricahua Mountains of southeastern Arizona. The 3 years of the study varied in precipitation and arthropod (prey) abundance, but the 2 years for which data were available did not differ in the amount of time potentially available for lizard activity. Individual growth, gain in body mass, and adult survivorship varied among years, the year of lowest precipitation levels (1994) having the slowest growth rates (0.099 mm/d) and gain in body mass (0.008 g/d) and the lowest adult survivorship (0.28), and the year of highest precipitation levels (1992) having the fastest growth rates (0.117 mm/d) and gain in body mass (0.029 g/d) and the highest adult survivorship (0.40). The proportion of first-year females that reproduced, juvenile survivorship, sex ratio, and age structure of the population did not differ among years. Individuals that grew faster (or slower) than expected from their body size in one year grew faster (or slower) than expected the next year. Survivors (both male and female) did not grow faster than nonsurvivors. Precipitation appears to be the strongest proximate factor influencing annual life-history traits in this population, probably because of its influence on arthropod abundance.
Sponge phylogeny, animal monophyly, and the origin of the nervous system: 18S rRNA evidence
Authors: Cavalier-Smith T. , Allsopp M. T. E. P. , Chao E. E. , Boury-Esnault N. , Vacelet J.
Published: January 2008

We sequenced 18S rRNA genes of a calcareous sponge, Clathrina cerebrum, a demosponge, Axinella polypoides, and a zoanthid cnidarian, Parazoanthus axinellae. Our phylogenetic analysis supports the monophyly of kingdom Animalia and confirms that choanoflagellate protozoans are their closest relatives. Sponges as a whole are monophyletic, but possibly paraphyletic; demosponges and hexactinellids form a monophyletic group of silicious sponges. Our phylogenetic trees support a monophyletic origin of the nervous system in the immediate common ancestor of Cnidaria and Ctenophora. They weakly suggest that animals with a nervous system may be more closely related to calcareous sponges than to silicious sponges; the nervous system might have originated in an early calcareous sponge. Our trees confirm that Myxozoa and Placozoa are animals that arose by secondary loss of the nervous system, but suggest that Myxozoa may be sisters of, rather than derived from, Bilateria. Kingdom Animalia is divided into four subkingdoms: Radiata (Porifera, Cnidaria, Placozoa, Ctenophora), Myxozoa, Mesozoa, and Bilateria. The 18S rRNA genes of Myxozoa evolved over twice as fast as in Radiata. Comparison with the fossil record reveals a brief 10-fold (or greater) acceleration in the rate of rRNA evolution in early Bilateria followed by normal low rates for about 500 million years.
Discrimination of nestmate larvae by the ant Leptothorax longispinosus
Authors: Hare James F.
Published: January 2008

Laboratory colonies of the ant Leptothorax longispinosus were presented with 10 larvae each from their own nest, conspecific larvae from a nest collected from the same site of origin, and conspecific larvae from a nest collected from another site in the same geographical region. Workers preferentially retrieved larvae from their own nest over those from nests obtained at the same site and other sites. Non-nestmate larvae from the same site were not preferred over those originating from other collection sites. Thus, L. longispinosus workers discriminate among conspecific larvae and preferentially retrieve nestmate larvae. Results of experiments involving CO2-anaesthetized larvae or larva-sized silicone "baits" suggest that the discriminator substances underlying nestmate larva recognition are chemical in nature and are borne on the larval cuticle. Further, those chemical attractants are present on material found within the ant's nest. In a final series of experiments, nestmate larvae were placed in contact with non-nestmate conspecific larvae or with larvae of a congener (Leptothorax ambiguus). Again workers preferred nestmate larvae, and preferred conspecific over allospecific larvae. However, there was no evidence that contact with nestmate larvae enhanced the acceptance of either conspecific or allospecific larvae, nor that contact with non-nestmate larvae diminished the acceptability of actual nestmate larvae. These findings suggest that any cues transferred via contact are insufficient to overwhelm a larva's own underlying recognition signature or that workers selectively attend to familiar cues.
A multivariate analysis of rumen papillary size in red deer (Cervus elaphus)
Authors: Lentle Roger G. , Henderson Ian M. , Stafford Kevin J.
Published: January 2008

We measured the length and width of ruminal papillae from six sites in rumens of farmed and wild red (Cervus elaphus) and wild fallow (Cervus dama) deer. A multivariate (principal components) analysis was used to explore papillary response to habitat. Three axes of papillary variation were defined: overall size, shape, and site (anatomical location within the rumen). These axes responded differently according to age, sex, diet, and species. Overall papillary size increased with age in wild but not in farmed stock, was significantly affected by sex, but showed no interspecies difference. Papillary shape was not influenced by age, sex, or diet but was influenced by species. Site-specific development was influenced by diet and species but not by age or sex. These results corroborate previous descriptive work and offer a technique for quantitative study of the interaction between wild ruminants and their dietary environment.
Feeding of nestling and fledgling brood parasites by individuals other than the foster parents: a review
Authors: Sealy Spencer G. , Lorenzana Janice C.
Published: January 2008

We summarize 67 reports of 13 species of brood-parasitic young, mostly fledglings, being fed by individuals other than the host. We refer to this behavior as auxiliary feeding. The parasite gains extra food resources, whereas the adult that feeds the parasite appears to behave maladaptively. The parasite may present a supernormal stimulus, manipulating unrelated adults into feeding it. Most auxiliary feedings were observed in brood parasites that were raised by small hosts. Host specificity, vocal mimicry, visual mimicry, and nestling competition apparently were not associated with the number of records of auxiliary feedings; however, the trends could not be analyzed statistically because of the anecdotal nature of the observations for each species. Still to be determined is whether obtaining auxiliary feeding is a strategy used by some brood-parasitic species, particularly the pallid cuckoo (Cuculus pallidus).
The Tail of Grand Bank, southeast of Newfoundland, as a geographical boundary for continental slope fishes
Authors: Pinhorn A. T. , Halliday R. G.
Published: January 2008

Fish catches in about 4300 bottom trawl sets made in 1949 – 1991 on the continental slope (365 – 1700 m) between Labrador and the Scotian Shelf in the northwest Atlantic were examined for geographical discontinuities in species distribution and density. Eighteen of 24 taxa that were reliably identified to species showed discontinuities in the vicinity of the Tail of Grand Bank, the remaining 6 having ubiquitous distributions. Bottom temperatures, collected in conjunction with trawl sets, also showed a discontinuity associated with this location, lower temperatures occurring to the east and north than to the south and west at all depths sampled. The species with geographical limits of distribution near the Tail of Grand Bank were those with depth ranges centred on the upper slope (200 – 750 m) and some of those with shelf – upper-slope ranges (the remainder of the latter having ubiquitous geographical distributions). Species with middle- and lower-slope ranges (750 – 2250 m) did not have geographical limits of distribution at this location; nonetheless, they apparently had substantially different levels of density on either side of it.
Prédiction de la composition corporelle post-mortem de cerfs de Virginie (Odocoileus virginianus) à partir de mesures morphologiques et massiques
Authors: Bois Chantal , Crête Michel , Huot Jean , Quellet Jean-Pierre
Published: January 2008

Morphologic and mass measurements were taken on 24 complete white-tailed deer (Odocoileus virginianus) carcasses of varying ages and both sexes in southern Quebec. Each carcass was divided into three parts (skin, viscera, rest) to determine water, protein, fat, and ash content by chemical analyses. Fat content of carcasses varied between 0.8 and 17.4%. Multiple linear regression models were selected to predict carcass composition from morphologic and mass measurements. Two situations were considered: measurements taken at the laboratory on whole animals and measurements taken at field stations on eviscerated carcasses provided by hunters. All selected models can be applied to any deer without taking into account age or sex; they include 1 – 4 independent variables. For whole animals, adjusted R2 of models varied between 0.99 (water) and 0.89 (ash); models developed for field stations were less precise, the lowest R2 values being 0.82 and 0.73 for ash and fat, respectively. These models can be useful for research and management purposes.
Effects of prey size, meal size, meal composition, and daily frequency of feeding on the recovery of rodent remains from carnivore scats
Authors: Kelly Brian T. , Garton Edward O.
Published: January 2008

Recovery of rodent bone and teeth from coyote (Canis latrans) scats (feces) varied with prey size, meal size, energy content of the meal, and the frequency with which prey were consumed. Mean percentages of mouse and rat teeth recovered ranged from 1% (SE = 0.5%, n = 5) to 24.4% (SE = 3.6%, n = 4) and from 13.8% (SE = 3.8%, n = 5) to 52.5% (SE = 16.6%, n = 5), respectively. A significant portion of this variation resulted from physiological mechanisms affecting how long prey were retained in the digestive acids of the stomach. Recovery of hair did not vary and thus it was considered to be nondigestible. Owing to the variation in the recovery of bone and teeth and the lack of variation in the recovery of hair, we recommend the use of teeth or bone to identify the small rodents present in carnivore scats, and then the use of a visual estimate of hair, or sample of hair, to apportion the scat to the prey items present. We caution against using the numbers of teeth or diagnostic bones to determine the number or amount of a prey item represented by a scat without addressing the variability in their recovery. The effects of gastrointestinal physiology should be considered when planning feeding trials to derive correction factors for scat analysis.
Diurnal time budget of the mouflon (Ovis musimon) on the Kerguelen archipelago: influence of food resources, age, and sex
Authors: Moncorps Sébastien , Boussès Patrick , Réale Denis , Chapuis Jean-Louis
Published: January 2008

The population of introduced mouflons on the Kerguelen subantarctic archipelago (Indian Ocean) is characterized by a demographic cycle marked by rapid variations in density. The diurnal time budgets of the different age–sex classes were compared between two consecutive summers separated by a winter with a massive die-off. Following the drastic reduction in population density between 1994 (100–110 individuals/km2) and 1995 (40–50 individuals/km2), mouflons spent less time foraging, while the time devoted to rest did not differ significantly. This difference is explained by an increase in food availability that allowed the animals to become satiated more rapidly. Although the time spent resting did not differ between the two summers, shorter foraging phases may explain the occurrence of a more polymodal rhythm for these two activities when range conditions improved. Our results indicate that even during the summer period of relative food abundance, the diurnal time budget of mouflons is strongly affected by population density. At high population densities, animals may find it more difficult to restore their body condition and reserves, even in summer. This could have contributed to the high mortality rate observed the following winter.
The importance of using the proper methodology and spatial scale in the study of habitat selection by birds
Authors: Pribil Stanislav , Picman Jaroslav
Published: January 2008

Nest-site preferences of birds have traditionally been inferred from correlations between reproductive success and various habitat attributes. Because there are several problems associated with this method, we examined preferences by comparing characteristics of actual nest sites with those of sites available to females at the time of their settlement. We examined these preferences on two spatial scales using the marsh-nesting Red-winged Blackbird (Agelaius phoeniceus). On the broad spatial scale, univariate analyses established that female settlement was nonrandom with respect to four of five habitat characteristics. However, a multivariate analysis revealed that females settled nonrandomly only with respect to water depth (they preferred areas located in deep water). The other characteristics, including cattail density, were not important. On the narrow spatial scale, females preferred sites located in dense cattail clumps that were surrounded by unusually sparse cattail vegetation. The preference of female redwings for deep-water areas was not detected in an earlier study conducted in the same marsh using the traditional method. In addition, if we were to have examined female preferences on the broad scale only, we would have failed to recognize the importance of cattail density in nest-site selection. The results of this study demonstrate the importance of examining nest-site selection using an appropriate method and multiple spatial scales.
Male sexual behaviour elicited by a hybrid pheromone: a comparative study on Lycosa thorelli, L. carbonelli, and their hybrid progeny (Araneae, Lycosidae)
Authors: Costa Fernando G. , Viera Carmen , Francescoli Gabriel
Published: January 2008

Three groups of spiders were raised from birth in the laboratory: Lycosa thorelli, L. carbonelli, and their experimentally obtained hybrid progeny. We analyzed the behaviour of the three male groups in the presence of a hybrid sexual pheromone. From the tests, 22 behaviour units were identified; 11 were simple and 11 were complex, the latter resulting from temporal overlapping of two or three simple units. Hybrid males showed behaviours similar to those of each of the parental species, but their characteristics were mainly intermediate between the two species. Variability in sexual behaviour of the hybrids was similar to that of parental males. Parental males exposed to a hybrid stimulus showed an activity level intermediate to previous descriptions of sexual behaviour elicited by conspecific and heterospecific stimuli. The importance of certain visual and acoustic displays for reproductive isolation, and their possible inheritance mechanisms, are a particular focus of discussion.
Body mass and first-time reproduction in female chipmunks (Tamias striatus)
Authors: Svendsen G. E. , White M. M.
Published: January 2008

Body mass has been proposed as a factor that contributes to the onset of puberty in some species of mammals. In this study we examined the relationship between body mass and primiparity in the eastern chipmunk (Tamias striatus) by comparing females that reproduced and those that did not during any given breeding opportunity. We also investigated whether season of birth influenced the season of first reproduction. No differences in season of first reproduction were observed between spring-born and fall-born females. Females that produced a litter had significantly greater body mass than did females that did not. Significant differences in body mass were also observed, based on season of birth. Food availability and timing of hibernation may be important contributors to the observed pattern.
The genusEctemnia(Diptera: Simuliidae): taxonomy, polytene chromosomes, new species, and phylogeny
Authors: Moulton J. K. , Adler P. H.
Published: January 2008

The genus Ectemnia Enderlein consists of four North American species, two of which are described as new. The two previously described species, E. invenusta and E. taeniatifrons, are primarily northern in distribution and their immature stages occupy rocky rivers. The two new species, E. primaeva and E. reclusa, occur in the southeastern Coastal Plain; their immature stages inhabit blackwater swamp streams and sandy rivers. Keys are provided for larvae, pupae, and adults. The polytene chromosomes of all species are analyzed in detail. Seven fixed inversions, 10 unshared autosomal polymorphisms, two centromere-band expressions, and five sex-chromosome systems are recognized among the four species. At least 10 synapomorphies indicate that the genus is monophyletic. Phylogenetically, Ectemnia is in a clade with Metacnephia and Simulium.
Conspecific skin extracts elicit antipredator responses in juvenile rainbow trout (Oncorhynchus mykiss)
Authors: Brown Grant E. , Smith R. Jan F.
Published: January 2008

We investigated, under laboratory conditions, the presence of chemical alarm signals in juvenile rainbow trout (Oncorhynchus mykiss). In an initial experiment, we exposed trout to a whole-body extract from conspecifics or a distilled-water control. When exposed to whole-body extract, trout significantly (i) decreased time spent swimming, (ii) increased time taken to resume foraging, and (iii) decreased the number of food items eaten. These data indicate a significant chemically mediated antipredator response. A second experiment was conducted to determine (i) if this is a generalized response to injured fish or a specific response to injured conspecifics, and (ii) if the chemical signal is localized in the skin. We exposed juvenile trout to one of three chemical stimuli: (1) trout skin extract, (2) trout body extract, or (3) swordtail (Xiphophorus helleri) skin extract. Significant antipredator responses were observed in trout exposed to conspecific skin extract, but responses of those exposed to conspecific body extract or swordtail skin extract did not differ from those of distilled-water controls. These data strongly suggest that juvenile rainbow trout possess a chemical alarm signal, localized in the skin, that elicits antipredator behaviour when detected.by conspecifics.
Is wolf predation ratio-dependent?
Authors: Eberhardt L. L.
Published: January 2008

The controversy over whether wolves (Canis lupus) can regulate ungulate numbers is difficult to assess, owing to data limitations, relaxation of predator control, and the fact that current predator – prey theory was developed from the study of invertebrate populations. A ratio-dependent predator – prey model appears to be supported by data on predation on ungulates, and the data indicate that wolves have a significant impact on numbers of moose (Alces alces), and thus can exert a regulatory effect on that species.
Twinning and fetal sex ratio in moose: effects of maternal age and mass
Authors: Nygrén T. , Kojola I.
Published: January 2008

To evaluate hypotheses concerning the effects of maternal characteristics on litter size and offspring sex ratio in a polygynous mammal, we examined how female age and mass affected the number and sex ratio of fetuses in moose (Alces alces). We analysed 420 fetuses collected from 297 females killed in Finland. Females that carried two fetuses were older than females with one fetus, while mass did not affect litter size. Sex ratio was not conclusively linked with maternal quality. The overall lack of difference in the sex ratio (no male bias among fetuses carried by the heaviest females) can be explained by the rather low degree of polygyny and the lack of intense female – female competition for a limited food supply (no female bias among fetuses carried by the heaviest females).
REFINING THE CLASSIFICATION OF THE IRREPS OF THE 1D N-EXTENDED SUPERSYMMETRY
Authors: KUZNETSOVA ZHANNA , TOPPAN FRANCESCO
Published: January 2008

The linear finite irreducible representations of the algebra of the 1D N-Extended Supersymmetric Quantum Mechanics are discussed in terms of their "connectivity" (a symbol encoding information on the graphs associated to the irreps). The classification of the irreducible representations with the same fields content and different connectivity is presented up to N ≤ 8.
HIERARCHY PROBLEMS IN STRING THEORY AND LARGE VOLUME MODELS
Authors: CONLON JOSEPH P.
Published: January 2008

Nature generates many hierarchically different scales. It is necessary to explain where these scales come from and how they are related. Three such scales are the weak scale, the scale associated with axion physics, and the scale associated with neutrino masses. I review the large volume models that arise in flux compactifications of type IIB string theory and explain how an intermediate string scale can quantitatively explain the above three scales. The models also predict a new physical scale at 1 MeV, associated to a gravitationally coupled scalar.
EXTENDED SCHOUTEN CLASSIFICATION FOR NON-RIEMANNIAN GEOMETRIES
Authors: CASANOVA SABRINA , LECIAN ORCHIDEA MARIA , MONTANI GIOVANNI , RUFFINI REMO , ZALALETDINOV ROUSTAM
Published: January 2008

A generalized connection, including Christoffel coefficients, torsion, non-metricity tensor and metric-asymmetricity object, is analyzed according to the Schouten classification. The inverse structure matrix is found in the linearized regime, autoparallel trajectories are defined and the contribution of the components of the connection are clarified at first-order approximation.
MOLECULAR DYNAMICS SIMULATIONS OF SINGLESiADATOM DIFFUSION ON THESi(001)SURFACE AND ACROSS SINGLE-LAYERSi(001)STEPS
Authors: WANG CHANGQING , JIA YU , WANG XUEQING , LI XINJIAN , HU XING , WANG SONGYOU
Published: January 2008

By using the Stillinger–Weber atomic interactional potential, we have carried out molecular dynamics simulations of single Si adatom diffusing on the Si(001) surface and single-layer Si(001) steps at temperatures ranging from 1000 K to 1300 K. We have presented one new diffusion pathway of a single Si adatom diffusing on the Si(001) along the direction perpendicular to dimer rows, that can weaken the diffusion anisotropy. We have investigated the process of the single Si adatom diffusing across single-layer Si(001) steps as well and given adatom diffusion pathways of step-flow and transformation of single-layer into double-layer steps. Our results show that the exchange between an adatom and a surface atom plays an important role in the adatom diffusion process above 1000 K.
ENGINEERING MACROSCOPIC QUANTUM STATES OF A SINGLE TRAPPED ION: HIGHER-ORDER LAMB–DICKE APPROXIMATIONS
Authors: CHEN H. Y. , LAN H. J. , JIA H. Y.
Published: January 2008

The effects of higher-order Lamb–Dicke approximations (LDAs), on engineering motional quantum states of a single trapped cold ion, are discussed. By measuring the internally electronic states of a single trapped cold ion, which is driven by two classical laser beams tuning respectively to the first upper and lower sidebands, we show that the externally macroscopic vibrational states superposed by either even or odd number states are generated. Under the LDA (i.e., only the first order effect of LD parameter η is considered), these states just are the usual even and odd coherent states. For relative large values of η, we showed that the effects of higher-order LDAs, i.e., terms relating to ηk, k ≥ 2, are not negligible. They might significantly enhance certain nonclassical properties, e.g., squeezing and antibunching effects of the generated macroscopic quantum states.
SIMULATING SEDIMENT TRANSPORT ON RIVER NETWORKS
Authors: HAO RUI , WANG XU-MING , HUO JIE , ZHANG JIN-FENG
Published: January 2008

The simulation of the variation of the erosion or sedimentation and the sediment-carrying capability of the water on the river segments, as it changes from the lower-water season to the higher-water season, is performed by a dynamical model of the sediment transport on a river network. The model is constructed by considering that the sediment-carrying capability of the water in one segment is modulated by the undergone state of it and that of its neighbor segments. The calculated results can simulate the relative variations occuring in the natural river when the water seasons alternate.
ROBUSTNESS OF THE REGRESSION MODELS FOR UNCERTAIN CATEGORIES
Authors: BOLOTIN ARKADY
Published: January 2008

Dichotomization of the outcome by a single cut-off point is an important part of medical studies. Usually the relationship between the resulted dichotomized dependent variable and explanatory variables is analyzed with linear regression, probit or logistic regression. However, in many real-life situations, a certain cut-off point is unknown and can be specified only approximately, i.e. surrounded by some (small) uncertainty. It means that in order to have any practical meaning the regression model must be robust to this uncertainty. In this paper, we test the robustness of the linear regression model and get that neither the beta in the model, nor its significance level is robust to the small variations in the dichotomization cut-off point.

As an alternative robust approach to the problem of uncertain categories, we propose to make use of the linear regression model with the fuzzy membership function as a dependent variable. In the paper, we test the robustness of the linear regression model of such fuzzy dependent variable and get that this model can be insensitive against the uncertainty in the cut-off point location.

To demonstrate theoretical conclusions, in the paper we present the modelling results from the real study of low haemoglobin levels in infants.
FUSING FUZZY ASSOCIATION RULE-BASED CLASSIFIERS USING SUGENO INTEGRAL WITH ORDERED WEIGHTED AVERAGING OPERATORS
Authors: HU YI-CHUNG , TSAI JUNG-FA
Published: January 2008

The time or space complexity may considerably increase for a single classifier if all features are taken into account. Thus, it is reasonable to train a single classifier by partial features. Then, a set of multiple classifiers can be generated, and an aggregation of outputs from different classifiers is subsequently performed. The aim of this paper is to propose a classification system with a heuristic fusion scheme in which multiple fuzzy association rule-based classifiers with partial features are combined, and show the feasibility and effectiveness of fusing multiple classifiers through the Sugeno integral extended by ordered weighted averaging operators. In comparison with the Sugeno integral by computer simulations on the iris data and the appendicitis data show that the overall classification accuracy rate could be improved by the Sugeno integral with ordered weighted averaging operators. The experimental results further demonstrate that the proposed method performs well in comparison with other fuzzy or non-fuzzy classification methods.
INTERVAL METHODS IN KNOWLEDGE REPRESENTATION
Authors: Kreinovich Vladik
Published: January 2008

This section is maintained by Vladik Kreinovich. Please send your abstracts (or copies of papers that you want to see reviewed here) to vladik@utep.edu, or by regular mail to: V. Kreinovich, Department of Computer Science, University of Texas, El Paso, TX 79968, USA.
Function of Heparanase in Prostate Tumorigenesis: Potential for Therapy
Authors: Lerner Immanuel , Baraz Leah , Pikarsky Eli , Meirovitz Amichay , Edovitsky Evgeny , Peretz Tamar , Vlodavsky Israel , Elkin Michael
Published: January 2008

Purpose: Heparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. Whereas the role of heparanase in sustaining the pathology of human cancer is well documented, its association with prostate carcinoma remains uncertain. Our research was undertaken to elucidate the significance of heparanase in prostate tumorigenesis and bone metastasis.

Experimental Design: We applied immunohistochemical analysis of tissue microarray, in vitro adhesion and invasion assays, as well as mouse models of intraosseous growth and spontaneous metastasis of prostate cancer, monitored by whole-body bioluminescent imaging. Electroporation-assisted administration of anti-heparanase small interfering RNA in vivo was applied as a therapeutic approach.

Results: We report a highly statistically significant (P < 0.0001) prevalence of heparanase overexpression in prostate carcinomas versus noncancerous tissue, as well as strong correlation between tumor grade and the extent of heparanase expression. We observed >5-fold increase in the metastatic potential of PC-3 prostate carcinoma cells engineered to overexpress heparanase. Notably, overexpression of a secreted form of the enzyme also led to a dramatic increase in intraosseous prostate tumor growth. Local in vivo silencing of heparanase resulted in a 4-fold inhibition of prostate tumor growth, representing the first successful application of anticancer therapy based on heparanase small interfering RNA and validating the potential of heparanase as a target for prostate cancer treatment.

Conclusions: Heparanase directly contributes to prostate tumor growth in bone and its ability to metastasize to distant organs. Thus, anti-heparanase strategy may become an important modality in the treatment of prostate cancer patients, particularly those with bone metastases.
Cell Therapy for Modification of the Myocardial Electrophysiological Substrate
Authors: Yankelson Lior , Feld Yair , Bressler-Stramer Tal , Itzhaki Ilanit , Huber Irit , Gepstein Amira , Aronson Doron , Marom Shimon , Gepstein Lior
Published: January 2008

Background—

Traditional antiarrhythmic pharmacological therapies are limited by their global cardiac action, low efficacy, and significant proarrhythmic effects. We present a novel approach for the modification of the myocardial electrophysiological substrate using cell grafts genetically engineered to express specific ionic channels.

Methods and Results—

To test the aforementioned concept, we performed ex vivo, in vivo, and computer simulation studies to determine the ability of fibroblasts transfected to express the voltage-sensitive potassium channel Kv1.3 to modify the local myocardial excitable properties. Coculturing of the transfected fibroblasts with neonatal rat ventricular myocyte cultures resulted in a significant reduction (68%) in the spontaneous beating frequency of the cultures compared with baseline values and cocultures seeded with naive fibroblasts. In vivo grafting of the transfected fibroblasts in the rat ventricular myocardium significantly prolonged the local effective refractory period from an initial value of 84±8 ms (cycle length, 200 ms) to 154±13 ms (
P
<0.01). Margatoxin partially reversed this effect (effective refractory period, 117±8 ms;
P
<0.01). In contrast, effective refractory period did not change in nontransplanted sites (86±7 ms) and was only mildly increased in the animals injected with wild-type fibroblasts (73±5 to 88±4 ms;
P
<0.05). Similar effective refractory period prolongation also was found during slower pacing drives (cycle length, 350 to 500 ms) after transplantation of the potassium channels expressing fibroblasts (Kv1.3 and Kir2.1) in pigs. Computer modeling studies confirmed the in vivo results.

Conclusions—

Genetically engineered cell grafts, transfected to express potassium channels, can couple with host cardiomyocytes and alter the local myocardial electrophysiological properties by reducing cardiac automaticity and prolonging refractoriness.
How Much of the Recent Decline in the Incidence of Myocardial Infarction in British Men Can Be Explained by Changes in Cardiovascular Risk Factors?
Authors: Hardoon Sarah L. , Whincup Peter H. , Lennon Lucy T. , Wannamethee S. Goya , Capewell Simon , Morris Richard W.
Published: January 2008

Background—

The incidence of myocardial infarction (MI) in Britain has fallen markedly in recent years. Few studies have investigated the extent to which this decline can be explained by concurrent changes in major cardiovascular risk factors.

Methods and Results—

The British Regional Heart Study examined changes in cardiovascular risk factors and MI incidence over 25 years from 1978 in a cohort of 7735 men. During this time, the age-adjusted hazard of MI decreased by 3.8% (95% confidence interval 2.6% to 5.0%) per annum, which corresponds to a 62% decline over the 25 years. At the same time, after adjustment for age, cigarette smoking prevalence, mean systolic blood pressure, and mean non–high-density lipoprotein (HDL) cholesterol decreased, whereas mean HDL cholesterol, mean body mass index, and physical activity levels rose. No significant change occurred in alcohol consumption. The fall in cigarette smoking explained the greatest part of the decline in MI incidence (23%), followed by changes in blood pressure (13%), HDL cholesterol (12%), and non-HDL cholesterol (10%). In combination, 46% (approximate 95% confidence interval 23% to 164%) of the decline in MI could be explained by these risk factor changes. Physical activity and alcohol consumption had little influence, whereas the increase in body mass index would have produced a rise in MI risk.

Conclusions—

Modest favorable changes in the major cardiovascular risk factors appear to have contributed to considerable reductions in MI incidence. This highlights the potential value of population-wide measures to reduce exposure to these risk factors in the prevention of coronary heart disease.
Fetal Hemodynamic Adaptive Changes Related to Intrauterine Growth
Authors: Verburg Bero O. , Jaddoe Vincent W.V. , Wladimiroff Juriy W. , Hofman Albert , Witteman Jacqueline C.M. , Steegers Eric A.P.
Published: January 2008

Background—

It has been suggested that an adverse fetal environment increases susceptibility to hypertension and cardiovascular disease in adult life. This increased risk may result from suboptimal development of the heart and main arteries in utero and from adaptive cardiovascular changes in conditions of reduced fetal growth. The aim of the present study was to evaluate whether reduced fetal growth is associated with fetal circulatory changes and cardiac dysfunction.

Methods and Results—

This study was embedded in a population-based, prospective cohort study starting in early fetal life. Fetal growth characteristics and fetal circulation variables were assessed with ultrasound and Doppler examinations in 1215 healthy women. The fetal circulation was examined in relation to estimated fetal weight. Higher placental resistance indices were strongly associated with decreased fetal growth. Cerebral resistance showed a gradual decline with reduced fetal growth. Cardiac output, peak systolic velocity of the outflow tracts, and cardiac compliance showed a gradual reduction with diminished fetal growth, whereas intraventricular pressure gradually increased.

Conclusions—

Decreased fetal growth is associated with adaptive fetal cardiovascular changes. Cardiac remodeling and cardiac output changes are consistent with a gradual increase in afterload and compromised arterial compliance in conditions of decreased fetal growth. These changes have already begun to occur before the stage of clinically apparent fetal growth restriction and may contribute to the increased risk of cardiovascular disease in later life.
Dietary Intake and the Development of the Metabolic Syndrome
Authors: Lutsey Pamela L. , Steffen Lyn M. , Stevens June
Published: January 2008

Background—

The role of diet in the origin of metabolic syndrome (MetSyn) is not well understood; thus, we sought to evaluate the relationship between incident MetSyn and dietary intake using prospective data from 9514 participants (age, 45 to 64 years) enrolled in the Atherosclerosis Risk in Communities (ARIC) study.

Methods and Results—

Dietary intake was assessed at baseline via a 66-item food frequency questionnaire. We used principal-components analysis to derive “Western” and “prudent” dietary patterns from 32 food groups and evaluated 10 food groups used in previous studies of the ARIC cohort. MetSyn was defined by American Heart Association guidelines. Proportional-hazards regression was used. Over 9 years of follow-up, 3782 incident cases of MetSyn were identified. After adjustment for demographic factors, smoking, physical activity, and energy intake, consumption of a Western dietary pattern (
P
trend
=0.03) was adversely associated with incident MetSyn. After further adjustment for intake of meat, dairy, fruits and vegetables, refined grains, and whole grains, analysis of individual food groups revealed that meat (
P
trend
<0.001), fried foods (
P
trend
=0.02), and diet soda (
P
trend
=< 0.001) also were adversely associated with incident MetSyn, whereas dairy consumption (
P
trend
=0.006) was beneficial. No associations were observed between incident MetSyn and a prudent dietary pattern or intakes of whole grains, refined grains, fruits and vegetables, nuts, coffee, or sweetened beverages.

Conclusions—

These prospective findings suggest that consumption of a Western dietary pattern, meat, and fried foods promotes the incidence of MetSyn, whereas dairy consumption provides some protection. The diet soda association was not hypothesized and deserves further study.
Hypoxic Modulation of Exogenous Nitrite-Induced Vasodilation in Humans
Authors: Maher Abdul R. , Milsom Alexandra B. , Gunaruwan Prasad , Abozguia Khalid , Ahmed Ibrar , Weaver Rebekah A. , Thomas Philip , Ashrafian Houman , Born Gustav V.R. , James Philip E. , Frenneaux Michael P.
Published: January 2008

Background—

It has been proposed that under hypoxic conditions, nitrite may release nitric oxide, which causes potent vasodilation. We hypothesized that nitrite would have a greater dilator effect in capacitance than in resistance vessels because of lower oxygen tension and that resistance-vessel dilation should become more pronounced during hypoxemia. The effect of intra-arterial infusion of nitrite on forearm blood flow and forearm venous volumes was assessed during normoxia and hypoxia.

Methods and Results—

Forty healthy volunteers were studied. After baseline infusion of 0.9% saline, sodium nitrite was infused at incremental doses from 40 nmol/min to 7.84 μmol/min. At each stage, forearm blood flow was measured by strain-gauge plethysmography. Forearm venous volume was assessed by radionuclide plethysmography. Changes in forearm blood flow and forearm venous volume in the infused arm were corrected for those in the control arm. The peak percentage of venodilation during normoxia was 35.8±3.4% (mean±SEM) at 7.84 μmol/min (
P
<0.001) and was similar during hypoxia. In normoxia, arterial blood flow, assessed by the forearm blood flow ratio, increased from 1.04±0.09 (baseline) to 1.62±0.18 (nitrite;
P
<0.05) versus 1.07±0.09 (baseline) to 2.37±0.15 (nitrite;
P
<0.005) during hypoxia. This result was recapitulated in vitro in vascular rings.

Conclusions—

Nitrite is a potent venodilator in normoxia and hypoxia. Arteries are modestly affected in normoxia but potently dilated in hypoxia, which suggests the important phenomenon of hypoxic augmentation of nitrite-mediated vasodilation in vivo. The use of nitrite as a selective arterial vasodilator in ischemic territories and as a potent venodilator in heart failure has therapeutic implications.
Performance of Delayed-Enhancement Magnetic Resonance Imaging With Gadoversetamide Contrast for the Detection and Assessment of Myocardial Infarction
Authors: Kim Raymond J. , Albert Timothy S.E. , Wible James H. , Elliott Michael D. , Allen John C. , Lee Jennifer C. , Parker Michele , Napoli Alicia , Judd Robert M.
Published: January 2008

Background—

The identification and assessment of myocardial infarction (MI) are important for therapeutic and prognostic purposes, yet current recommended diagnostic strategies have significant limitations. We prospectively tested the performance of delayed-enhancement magnetic resonance imaging (MRI) with gadolinium-based contrast for the detection of MI in an international, multicenter trial.

Methods and Results—

Patients with their first MI were enrolled in an acute (≤16 days after MI; n=282) or chronic (17 days to 6 months; n=284) arm and then randomized to 1 of 4 doses of gadoversetamide: 0.05, 0.1, 0.2, or 0.3 mmol/kg. Standard delayed-enhancement MRI was performed before contrast (control) and 10 and 30 minutes after gadoversetamide. For blinded analysis, precontrast and postcontrast MRIs were randomized and then scored for enhanced regions by 3 independent readers not associated with the study. The infarct-related artery perfusion territory was scored from x-ray angiograms separately. In total, 566 scans were performed in 26 centers using commercially available scanners from all major US/European vendors. All scans were included in the analysis. The sensitivity of MRI for detecting MI increased with rising dose of gadoversetamide (
P
<0.0001), reaching 99% (acute) and 94% (chronic) after contrast compared with 11% before contrast. Likewise, the accuracy of MRI for identifying MI location (compared with infarct-related artery perfusion territory) increased with rising dose of gadoversetamide (
P
<0.0001), reaching 99% (acute) and 91% (chronic) after contrast compared with 9% before contrast. For gadoversetamide doses ≥0.2 mmol/kg, 10- and 30-minute images provided equal performance, and peak creatine kinase-MB levels correlated with MRI infarct size (
P
<0.0001).

Conclusions—

Gadoversetamide-enhanced MRI using doses of ≥0.2 mmol/kg is effective in the detection and assessment of both acute and chronic MI. This study represents the first multicenter trial designed to evaluate an imaging approach for detecting MI.
Pericardial Fat, Visceral Abdominal Fat, Cardiovascular Disease Risk Factors, and Vascular Calcification in a Community-Based Sample
Authors: Rosito Guido A. , Massaro Joseph M. , Hoffmann Udo , Ruberg Frederick L. , Mahabadi Amir A. , Vasan Ramachandran S. , O’Donnell Christopher J. , Fox Caroline S.
Published: January 2008

Background—

Pericardial fat may be an important mediator of metabolic risk. Correlations with cardiovascular disease risk factors and vascular calcification in a community-based sample are lacking. We sought to examine associations between pericardial fat, metabolic risk factors, and vascular calcification.

Methods and Results—

Participants free of cardiovascular disease from the Framingham Heart Study (n=1155, mean age 63 years, 54.8% women) who were part of a multidetector computed tomography study underwent quantification of intrathoracic fat, pericardial fat, visceral abdominal fat (VAT), coronary artery calcification, and aortic artery calcification. Intrathoracic and pericardial fat volumes were examined in relation to body mass index, waist circumference, VAT, metabolic risk factors, coronary artery calcification, and abdominal aortic calcification. Intrathoracic and pericardial fat were directly correlated with body mass index (
r
=0.41 to 0.51,
P
<0.001), waist circumference (
r
=0.43 to 0.53,
P
<0.001), and VAT (
r
=0.62 to 0.76,
P
<0.001). Both intrathoracic and pericardial fat were associated with higher triglycerides (
P
<0.0001), lower high-density lipoprotein (
P
<0.0001), hypertension (
P
<0.0001 to 0.01), impaired fasting glucose (
P
<0.0001 to 0.001), diabetes mellitus (
P
=0.0005 to 0.009), and metabolic syndrome (
P
<0.0001) after multivariable adjustment. Associations generally persisted after additional adjustment for body mass index and waist circumference but not after adjustment for VAT (all
P
>0.05). Pericardial fat, but not intrathoracic fat, was associated with coronary artery calcification after multivariable and VAT adjustment (odds ratio 1.21, 95% confidence interval 1.005 to 1.46,
P
=0.04), whereas intrathoracic fat, but not pericardial fat, was associated with abdominal aortic calcification (odds ratio 1.32, 95% confidence interval 1.03 to 1.67,
P
=0.03).

Conclusions—

Pericardial fat is correlated with multiple measures of adiposity and cardiovascular disease risk factors, but VAT is a stronger correlate of most metabolic risk factors. However, intrathoracic and pericardial fat are associated with vascular calcification, which suggests that these fat depots may exert local toxic effects on the vasculature.