bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of SU11248 on gastrointestinal stromal tumor‐T1 cells: Enhancement of growth inhibition via inhibition of 3‐kinase/Akt/mammalian target of rapamycin signaling
Authors: Ikezoe Takayuki , Yang Yang , Nishioka Chie , Bandobashi Kentaro , Nakatani Hajime , Taguchi Takahiro , Koeffler H. Phillip , Taguchi Hirokuni 
Published: June 2006

SU11248 is an orally available type III and V receptor tyrosine kinase inhibitor. Clinical studies have shown the efficacy of SU11248 in individuals with gastrointestinal stromal tumors (GIST); however, the molecular mechanisms by which SU11248 inhibits the proliferation of these tumor cells remains to be fully elucidated. Taking advantage of GIST‐T1 cells, which possess an activating mutation in exon 11 of the c‐KIT gene, we examined the medicinal action of SU11248 in GIST cells. Clonogenic and MTT assays showed that SU11248 potently inhibited the proliferation of GIST‐T1 cells with IC50 of approximately 1 nM and 40 nM, respectively. SU11248 (10 or 20 nM, 48 h) activated caspase‐3 and induced apoptosis of GIST‐T1 cells as measured by caspase assay, annexin V staining and cleavage of poly (ADP‐ribose) polymerase. Western blot analyses found that SU11248 blocked autophosphorylation of c‐KIT in association with inhibition of its downstream effectors, including Akt and extracellular signal‐regulated kinase, but not signal transducers and activators of transcription. Interestingly, when phosphatidylinositol 3‐kinase/Akt/mammalian target of rapamycin signaling was blocked simultaneously by either LY294002 or rapamycin, growth inhibition mediated by SU11248 was potentiated. Taken together, this study supports clinical studies of SU11248 for individuals with GIST, and the combination of SU11248 and inhibitors of 3‐kinase/Akt/mammalian target of rapamycin signaling represents a promising novel treatment strategy. (Cancer Sci 2006; 97: 945–951)
Trade‐offs within the immune systems of female White‐footed Mice, Peromyscus leucopus
Authors: MARTIN II L. B. , WEIL Z. M. , KUHLMAN J. R. , NELSON R. J. 
Published: June 2006

Summary

In many vertebrates, immune activity is compromised when other expensive activities are concurrent. One explanation for such patterns includes trade‐offs between immune activity and other expensive physiological processes. Trade‐offs among different immune responses themselves may also occur, but thus far few data exist to substantiate them.
We predicted that immune activity in female White‐footed Mice, Peromyscus leucopus, would be weak (relative to sham‐treated controls) if another immune response was already ongoing. To test this hypothesis, we examined (i) the effects of inflicting a cutaneous wound on cell‐mediated immune activity one day after wounding, and (ii) the effects of inducing cell‐mediated immune activity on the cutaneous wound‐healing process when wounds were inflicted one day after the immune challenge.
Prior wounding dampened cell‐mediated immune responses and induction of cell‐mediated immune activity altered progression of wound healing. Immune challenges did not affect reproductive tissue masses, however, as has been detected in males of this species. Also, concentrations of circulating glucocorticoids, which are known modulators of immune activity, were not dramatically different between treatment and sham groups.
In sum, our results provide evidence that some immune responses can negatively influence other recent immunological activity. Further study is warranted, however, to pinpoint the molecular mechanisms underlying these apparent trade‐offs and determine whether induction of immune activity may sometimes prime instead of hinder subsequent immune responses.
Higher stress protein levels are associated with lower humoral and cell‐mediated immune responses in Pied Flycatcher females
Authors: MORALES J. , MORENO J. , LOBATO E. , MERINO S. , TOMÁS G. , MARTÍNEZ DE LA PUENTE J. , MARTÍNEZ J. 
Published: June 2006

SummaryThe proper functioning of immune defences may be traded‐off against protecting the organism from physiological stress through the induction of stress protein (HSP) synthesis. Immune function could also be negatively affected by haemoparasite infections.We studied whether two induced immune responses (the humoral response to a tetanus vaccine and the T‐cell‐mediated response to phytohaemaglutinin (PHA) injection) were associated with the levels of two stress proteins (HSP60, HSP70), with haemoparasite infection and with condition in Pied Flycatcher,Ficedula hypoleucaPallas, females. HSP levels, haemoparasite infection and condition were assessed on days 1 and 11 of nestling age, prior to tetanus and PHA challenges, respectively.Females with higher HSP60 levels prior to tetanus challenge mounted lower humoral responses. Females parasitized byHaemoproteusshowed lower humoral responses, when controlling for HSP60 levels. No association was detected for HSP70 levels.Females with higher HSP60 and HSP70 levels prior to PHA challenge, independently ofHaemoproteusinfection, showed lower cell‐mediated responses, when correcting for laying date. Female condition was not associated with immune responses.These results suggest that synthesizing more HSPs to mitigate stress may be traded‐off against mounting humoral and cell‐mediated immune responses, and agree with immune defences being costly.
Immunocompetence and flea parasitism of a desert rodent
Authors: GOÜY DE BELLOCQ J. , KRASNOV B. R. , KHOKHLOVA I. S. , GHAZARYAN L. , PINSHOW B. 
Published: June 2006

SummaryImmunocompetence is the general capacity of an organism to mount an immune response against pathogens and parasites. We studied the relationship between the immunocompetence of a rodent host,Meriones crassus(Sundevall's Jird) and parasitism by the fleaXenopsylla ramesis. We hypothesized that flea parasitism affects physiological and immunological variables of the host, and that the host's level of immunocompetence affects fitness components in the flea parasite. We wanted to find out (a) the effect of flea parasitism on the haematocrit (Hct), leucocyte concentration (LC) and response to phytohaemagglutinin (PHA) of the host; (b) if and how the level of immunocompetence of the host is related to the fitness of fleas exploiting it; and (c) the relationship between the immunological and behavioural defences of the host.We measured Hct and LC and response to PHA before and after 16 days of flea infestation in Sundevall's Jird and compared these variables between jirds subjected to flea parasitism and non‐parasitized (control) animals. We evaluated egg production and hatching success in fleas exploiting hosts with different levels of immunocompetence.The effect of flea parasitism on Hct and LC of rodents was manifested by an increase in among‐host variation in the temporal changes of these variables. Response to PHA injection was significantly lower in parasitized than in control animals.Flea egg production and hatching success were not related to either LC, prior to experimental treatments, or to the PHA response of rodents. However, both of these flea fitness traits were negatively correlated with changes in LC between the 1st and the 16th days of infestation.At the end of the experiment, blood consumption of fleas was measured in jirds of both treatment groups. Fleas consumed significantly more blood when they fed on previously parasitized than on non‐parasitized animals. Among fleas that fed on previously parasitized animals, blood consumption was positively correlated with the initial LC of the hosts, and negatively correlated with differences in LC between the 1st and the 16th days of flea infestation. We found no correlation between blood consumption in fleas that fed on control animals and either immunological variable of the hosts.No trade‐off was found between behavioural and immune defences of the rodent hosts.
Caching as a strategy for surviving periods of resource scarcity; a comparative study of two species of Neotoma
Authors: POST D. M. , SNYDER M. V. , FINCK E. J. , SAUNDERS D. K. 
Published: June 2006

Summary

Energy management has been studied in migrators and hibernators but little is know about energy management in cachers.
We investigated the energy management behaviour of two species of cachers, Neotoma floridana and Neotoma micropus. We also investigated differences in energy management of these two species that experience different environmental conditions during the period of food scarcity.
Results show that both species decrease body mass from autumn to winter and increase mass from winter to spring. Both species decrease body fat from autumn to winter but only N. floridana increases body fat from winter to spring. Plasma protein follows the same pattern as body mass in N. floridana. Plasma lipids decrease from autumn to winter but do not increase from winter to spring.
Results indicate that cachers, unlike hibernators or migrators, are able to use the food cache to increase body mass and body fat when new resources are not being produced in the environment.
Results suggest that environmental conditions alter resource management and the species that experiences more severe conditions stores more energy as fat.
Assessing larval food quality for phytophagous insects: are the facts as simple as they appear?
Authors: MOREAU J. , BENREY B. , THIERY D. 
Published: June 2006

Summary

We argue here that host plant quality affects many life‐history traits of herbivorous insects and these traits often interact. Studies that look only at a limited number of traits often fail to determine the overall effect of plant quality on larval performance and adult fitness. Parameters such as mating success and adult longevity are frequently neglected even though they are affected by larval feeding and are crucial to overall fitness.
To illustrate this, we examined a whole suite of life‐history traits of the moth Lobesia botrana after rearing larvae of this grape pest on three different grape cultivars.
Development time, mating success, fecundity, egg size and fertility were differentially affected by the cultivar on which the larvae were reared. Our results highlight that decreased fecundity can be balanced by an increase in egg size and fertility.
Throughout this study, we emphasize that drawing conclusions about larval food quality can be spurious when based on too few life‐history traits. Therefore, it is essential to study all fitness related life‐history traits to fully understand the effects of larval food quality on herbivore fitness.
Several components of global change alter nitrifying and denitrifying activities in an annual grassland
Authors: BARNARD R. , LE ROUX X. , HUNGATE B. A. , CLELAND E. E. , BLANKINSHIP J. C. , BARTHES L. , LEADLEY P. W. 
Published: June 2006

Summary

The effects of global change on below‐ground processes of the nitrogen (N) cycle have repercussions for plant communities, productivity and trace gas effluxes. However, the interacting effects of different components of global change on nitrification or denitrification have rarely been studied in situ.
We measured responses of nitrifying enzyme activity (NEA) and denitrifying enzyme activity (DEA) to over 4 years of exposure to several components of global change and their interaction (increased atmospheric CO2 concentration, temperature, precipitation and N addition) at peak biomass period in an annual grassland ecosystem. In order to provide insight into the mechanisms controlling the response of NEA and DEA to global change, we examined the relationships between these activities and soil moisture, microbial biomass C and N, and soil extractable N.
Across all treatment combinations, NEA was decreased by elevated CO2 and increased by N addition. While elevated CO2 had no effect on NEA when not combined with other treatments, it suppressed the positive effect of N addition on NEA in all the treatments that included N addition. We found a significant CO2–N interaction for DEA, with a positive effect of elevated CO2 on DEA only in the treatments that included N addition, suggesting that N limitation of denitrifiers may have occurred in our system. Soil water content, extractable N concentrations and their interaction explained 74% of the variation in DEA.
Our results show that the potentially large and interacting effects of different components of global change should be considered in predicting below‐ground N responses of Mediterranean grasslands to future climate changes.
Sexual selection, growth compensation and fast‐start swimming performance in Green Swordtails, Xiphophorus helleri
Authors: ROYLE N. J. , METCALFE N. B. , LINDSTRÖM J. 
Published: June 2006

Summary

Fast‐start swimming provides an integrated physiological index of performance and a measure of ability to escape predators, so may be expected to covary with other important composite life‐history traits such as growth rate.
Variation in resource availability during growth and development is common, and organisms may show compensatory responses (such as catch‐up growth) to periods of low food availability. However, such responses usually carry costs.
We examined fast‐start performance in adult Green Swordtails in relation to growth regime experienced as a juvenile. In contrast to previous studies we found that conditions experienced early in life did not significantly affect fast‐start swimming performance, indicating that escape ability is at a premium in green swordtails.
Fish raised on ad libitum food had similar performance to fish raised on a restricted diet and fish experiencing compensatory growth, controlling for body size.
Body depth was positively related to fast‐start performance in both males and females, with males having faster escape responses than females for a given body depth.
Remarkably, males with the relatively longest sexual ornaments (‘swords’) had the greatest escape ability, suggesting that sword length may be a good indicator of quality among males of similar age.
Nuptial feeding is reflected in tissue nitrogen isotope ratios of female katydids
Authors: VOIGT C. C. , LEHMANN G. U. C. , MICHENER R. H. , JOACHIMSKI M. M. 
Published: June 2006

Summary

During copulation male katydids transfer a protein‐rich nuptial gift to females, which is ingested by the female. We hypothesized that female katydids are built at least partly from proteins assimilated from nuptial gifts.
We measured the ratio of nitrogen isotopes (δ15N) in the diet and tissue of sexually reproducing Isophya kraussii and obligate parthenogenetically reproducing Poecilimon intermedius. We used the δ15N of muscles as an indicator of the most recent diet and the δ15N of the cuticula as an indicator of the larval diet.
In free‐ranging I. kraussi, muscular and cuticular δ15N of adult males was low, suggesting a plant diet. Cuticular δ15N did not differ between sexes, indicating that immatures of both sexes fed on similar diets. Female muscles were significantly more enriched in nitrogen‐15 than female cuticula and also than male muscles, suggesting that adult females incorporated animal proteins and immature females plant material.
Female I. kraussii that were kept with males in captivity had higher δ15N in muscular tissue than in cuticula. Muscular δ15N of these females was also higher than that of muscle and cuticula of females held isolated from males, suggesting that incorporated nitrogen originated from nuptial gifts.
In parthenogenetically reproducing P. intermedius muscular and cuticular δ15N was almost identical, suggesting no additional uptake of insect proteins in the absence of nuptial gifts.
We therefore conclude that female I. kraussii substantially assimilate spermatophylax compounds for both egg production and body homeostasis.
Moving towards acceleration for estimates of activity‐specific metabolic rate in free‐living animals: the case of the cormorant
Authors: WILSON RORY P. , WHITE CRAIG R. , QUINTANA FLAVIO , HALSEY LEWIS G. , LIEBSCH NIKOLAI , MARTIN GRAHAM R. , BUTLER PATRICK J. 
Published: June 2006

Summary

Time and energy are key currencies in animal ecology, and judicious management of these is a primary focus for natural selection. At present, however, there are only two main methods for estimation of rate of energy expenditure in the field, heart rate and doubly labelled water, both of which have been used with success; but both also have their limitations.
The deployment of data loggers that measure acceleration is emerging as a powerful tool for quantifying the behaviour of free‐living animals. Given that animal movement requires the use of energy, the accelerometry technique potentially has application in the quantification of rate of energy expenditure during activity.
In the present study, we test the hypothesis that acceleration can serve as a proxy for rate of energy expenditure in free‐living animals. We measured rate of energy expenditure as rates of O2 consumption () and CO2 production () in great cormorants (Phalacrocorax carbo) at rest and during pedestrian exercise. and were then related to overall dynamic body acceleration (ODBA) measured with an externally attached three‐axis accelerometer.
Both and were significantly positively associated with ODBA in great cormorants. This suggests that accelerometric measurements of ODBA can be used to estimate and and, with some additional assumptions regarding metabolic substrate use and the energy equivalence of O2 and CO2, that ODBA can be used to estimate the activity specific rate of energy expenditure of free‐living cormorants.
To verify that the approach identifies expected trends in from situations with variable power requirements, we measured ODBA in free‐living imperial cormorants (Phalacrocorax atriceps) during foraging trips. We compared ODBA during return and outward foraging flights, when birds are expected to be laden and not laden with captured fish, respectively. We also examined changes in ODBA during the descent phase of diving, when power requirements are predicted to decrease with depth due to changes in buoyancy associated with compression of plumage and respiratory air.
In free‐living imperial cormorants, ODBA, and hence estimated , was higher during the return flight of a foraging bout, and decreased with depth during the descent phase of a dive, supporting the use of accelerometry for the determination of activity‐specific rate of energy expenditure.
Effects of parental effort on blood stress protein HSP60 and immunoglobulins in female blue tits: a brood size manipulation experiment
Authors: MERINO SANTIAGO , MORENO JUAN , TOMÁS GUSTAVO , MARTÍNEZ JAVIER , MORALES JUDITH , MARTÍNEZ‐DE LA PUENTE JOSUÉ , OSORNO JOSÉ LUIS 
Published: June 2006

SummaryPhysiological stress in animals may impose a limit for investment in current reproduction in the wild. A brood manipulation experiment was conducted in a population of blue titsCyanistes caeruleusto study the effect of parental effort on changes in two types of proteins related with stress: the blood stress protein HSP60 and the plasma immunoglobulins.Levels of HSP60 were reduced across the experiment for females attending reduced broods, and females attending enlarged broods experienced a reduction of immunoglobulin levels. Moreover, the overall changes in the levels of both proteins were positively related.By controlling for the change in immunoglobulin levels we found an increase in HSP60 for females in the enlarged treatment, presumably to offset deleterious effects derived from increased effort.Maternal effort was able to partially compensate for the effect of treatment as nestlings did not differ in mass and levels of immunoglobulins and HSP60 among treatments.Physiological stress as reflected in stress and immunoglobulin proteins may limit maternal effort in breeding blue tits.
Species resistance and community response to wind disturbance regimes in northern temperate forests
Authors: PAPAIK M. J. , CANHAM C. D. 
Published: June 2006

Summary

Severe winds are the predominant cause of natural disturbance in temperate forests of north‐eastern and north‐central North America. Conceptual models of the effects of wind disturbance have traditionally focused on the impacts of catastrophic disturbances and have painted a simple picture of how disturbance acts to maintain tree species diversity. These models ignore variation among species characteristics that could have important consequences for both resistance to and recovery from disturbance.
We integrated an empirically parameterized, mechanistic model of windstorm mortality (WINDSTORM) and a seed‐mass‐based dispersal and recruitment model into a spatially explicit, individual tree model of forest dynamics (SORTIE) in order to create simulated long‐term ‘experiments’ designed to explore the sensitivity of forest composition and structure to species‐specific resistance to and recovery from disturbance.
We found that species‐specific variation in resistance to wind mortality interacted strongly with: (i) shade tolerance characteristics, (ii) the medium‐term history of disturbances, (iii) the long‐term average severity of the disturbance regime and (iv) seedbed substrate dynamics to influence tree population dynamics and successional trajectories.
We also examined how local and long‐distance dispersal affect response to wind disturbance. Ignoring differences among local dispersal characteristics overestimates the importance of dispersal‐limited species. Our results show that long‐distance immigration maintains species coexistence only if the immigration rate is very high relative to local dispersal. Despite this, stand‐scale models that ignore long‐distance dispersal can underestimate population dynamics of dispersal‐limited species.
Our results indicate that landscape‐scale heterogeneity in structure and species composition in these forests is facilitated by synergisms between the stochastic nature of wind disturbance and complex interactions between species traits that govern: (i) resistance to disturbance, (ii) local dispersal and seedling establishment and (iii) competitive (i.e. growth/survival) traits that do not adhere to strict tradeoffs.
We conclude that wind disturbance has much more complex and variable effects on long‐term dynamics of forest structure and composition than suggested by previous models. In particular, non‐catastrophic disturbances can generate important variation in forest dynamics that can either lead to dominance by a single or small number of species, or facilitate species coexistence.
Bayesian identification of admixture events using multilocus molecular markers
Authors: CORANDER JUKKA , MARTTINEN PEKKA 
Published: June 2006

AbstractBayesian statistical methods for the estimation of hidden genetic structure of populations have gained considerable popularity in the recent years. Utilizing molecular marker data, Bayesian mixture models attempt to identify a hidden population structure by clustering individuals into genetically divergent groups, whereas admixture models target at separating the ancestral sources of the alleles observed in different individuals. We discuss the difficulties involved in the simultaneous estimation of the number of ancestral populations and the levels of admixture in studied individuals’ genomes. To resolve this issue, we introduce a computationally efficient method for the identification of admixture events in the population history. Our approach is illustrated by analyses of several challenging real and simulated data sets. The software (baps), implementing the methods introduced here, is freely available at http://www.rni.helsinki.fi/~jic/bapspage.html.