bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malignancy through cooperation: an evolutionary game theory approach
Authors: Liu Q. , Liu Z. 
Published: May 2012

AbstractObjectiveTraditional cancer initiation theory propounds evolution of a monoclonal population of fully transformed tumour cells to form a malignant tumour. Cooperation between surrounding stroma and the tumour also often leads to malignancy. This cooperation may exist as a result of sharing of growth signals or growth factors secreted by stromal cells, which can cause those with proliferative phenotypes to switch to motile phenotypes. Mathematical models of sharing of growth factors between cancer stem cells and stromal cells can allow for deeper understanding of tumourigenesis through cooperation. The study presented here describes a novel evolutionary game theoretical approach to investigate emergence of malignancy through interactions among cells of three different phenotypes, one of which produces growth factors.Materials and methodsThree different scenarios have been considered, and types of behaviour of the three phenotypes during interactions, have been modelled in terms of cost and benefit variables. Phenotypic compositions of such a tumour at equilibrium have been analysed, and evolution of the population, with respect to time, has been investigated.ResultsResults suggest the role of cooperation in forming a malignant tumour and show, in all three cases, that emergence of triple polymorphism, two‐strategy polymorphism, and fixation of one phenotype, were possible at equilibrium. The models also suggest that under certain conditions, one phenotype may be completely eliminated from the population, thus leading to new possibilities for potential treatments.ConclusionsThis study explains some current experimental findings from a theoretical viewpoint, and may provide new approaches for future research in oncology.
Eggshell colour is more strongly affected by maternal identity than by dietary antioxidants in a captive poultry system
Authors: Dearborn Donald C. , Hanley Daniel , Ballantine Katherine , Cullum John , Reeder DeeAnn M. 
Published: May 2012

Summary1.Biologists have long puzzled over the apparent conspicuousness of blue‐green eggshell coloration in birds. One candidate explanation is the ‘sexual signalling hypothesis’ that the blue‐green colour of eggshells can reveal an intrinsic aspect of females' physiological quality, with only high‐quality females having sufficient antioxidant capacity to pigment their eggs with large amounts of biliverdin. Subsequent work has argued instead that eggshell colour might signal condition‐dependent traits based on diet.2.Using Araucana chickens that lay blue‐green eggs, we explored (i) whether high levels of dietary antioxidants yield eggshells with greater blue‐green reflectance, (ii) whether females differ from one another in eggshell coloration despite standardized environments, diets and rearing conditions, and (iii) the relative strength with which diet vs. female identity affects eggshell coloration.3.We reared birds to maturity and then placed them on either a high‐ or low‐antioxidant diet, differing fourfold in Vitamin E acetate and Vitamin A retinol. After 8 weeks, the treatments were reversed, such that females laid eggs on both diets in an order‐balanced design. We measured the reflectance spectra of 545 eggs from 25 females.4.Diet had a very limited effect on eggshell spectral reflectance, but individual females differed strongly and consistently from one another, despite having been reared under uniform conditions. However, predictions from avian visual modelling suggest that most of the egg colour differences between females, and nearly all of the differences between diets, are unlikely to be visually discriminable.5.Our data suggest that eggshell reflectance spectra may carry information on intrinsic properties of the female that laid the eggs, but the utility of this coloration as a signal to conspecifics in this species may be limited by the sensitivity of a receiver to detect it.
The consequences of alternative parental care tactics in free‐ranging pythons in tropical Australia
Authors: Stahlschmidt Zachary R. , Shine Richard , DeNardo Dale F. 
Published: May 2012

Summary1.Life‐history theory attributes the evolution of parental care to the benefits to offspring viability outweighing any costs to parental viability. However, the consequences of parental care tactics to parent(s) and the developmental environment have seldom been measured under field conditions.2.Laboratory research on pythons shows that maternal nest‐site selection and egg brooding benefit embryos, but prolonged nest attendance may impose fitness costs to free‐ranging females. A population of water pythons (Liasis fuscus) in tropical Australia provides an excellent opportunity to examine this parent–offspring trade‐off because females exhibit parental care polymorphism wherein some individuals brood their eggs only briefly (<10 days) post‐oviposition (‘short brooders’) while others remain with their eggs throughout the incubation period (>50 days; ‘long brooders’).3.We used radiotelemetry, temperature and humidity data loggers, ultrasonography, haematological techniques, and habitat analyses to examine the correlates and consequences of maternal nesting decisions in 14 free‐ranging female pythons over the 4‐month reproductive season.4.Nest‐site selection and maternal attendance enhanced thermal and hydric regimes within the nest. Egg production by reproducing female pythons resulted in high energetic costs (loss of 60% of maternal body mass) and increased parasite load. However, the estimated mass loss because of brooding was (i) low (<5%), (ii) inversely related to fecundity (females that produced relatively large clutches tended to select lower temperatures and thus lost less mass during brooding) and (iii) surprisingly unrelated to brooding duration. Phenotypic traits of short and long brooders were similar, but long brooders had higher haemoparasite burdens prior to oviposition. Clutches of long brooders were laid in more open sites (less canopy cover) and experienced warmer and more humid conditions than did those of short brooders.5.Together with previous research, we suggest several explanations for the maintenance of maternal care polymorphism within this population, such as a trade‐off between offspring number and quality (long brooders may produce fewer clutches during their lifespan but enhance offspring quality). Our study provides detailed measurements of the correlates and consequences of parental care in a free‐ranging reptile, and it clarifies the trade‐offs mediated by taxonomically widespread maternal decisions (e.g. nest‐ or oviposition‐site selection and nest attendance).
Below‐ground plant species richness: new insights from DNA‐based methods
Authors: Pärtel Meelis , Hiiesalu Inga , Öpik Maarja , Wilson Scott D. 
Published: May 2012

Summary1.Ideas about mechanisms controlling plant species richness are founded on empirical studies of above‐ground vegetation. In many ecosystems, however, the majority of vegetation (e.g. 50–90% in temperate grasslands) occurs below‐ground as roots, rhizomes and shoot bases. Whether the richness patterns described for above‐ground vegetation also hold for the large below‐ground component is still unknown.2.Here, we provide a concise overview how the use of DNA‐based techniques might alter our perception of richness patterns in plant communities. We focus mainly on temperate grasslands, but new patterns should also arise in other community types (except epiphyte‐rich ecosystems).3.We hypothesise that DNA‐based measurements of below‐ground plant richness will reveal that richness is greater below‐ than above‐ground because many perennial plants persist below‐ground even in the temporary absence of above‐ground shoots, and because the roots and rhizomes of plant individuals occupy larger areas than do shoots. Consequently, the species–area relationship may show steeper slopes for below‐ground than above‐ground richness. Further, above‐ground richness may not be a constant proportion of below‐ground richness, so the ratio of below/above‐ground richness may vary along environmental gradients of productivity, disturbance and heterogeneity.4.We also hypothesize that the often‐observed decrease in above‐ground richness with increasing productivity may not occur for below‐ground richness, partly for the reasons noted above, and partly because of differences between above‐ and below‐ground resources. Light is supplied largely in one dimension and does not persist in the environment for later uptake, whereas nutrients and water are supplied in three dimensions and can persist in the soil. Together, these differences should allow more niche differentiation and greater species richness below‐ground.5.Current DNA‐based methods that allow measurement of below‐ground richness in the field are likely to reveal patterns different from those well‐documented for above‐ground richness and may also produce new insights about plant community structure and function.
Effects of climate change on an emperor penguin population: analysis of coupled demographic and climate models
Authors: Jenouvrier Stéphanie , Holland Marika , Stroeve Julienne , Barbraud Christophe , Weimerskirch Henri , Serreze Mark , Caswell Hal 
Published: May 2012

AbstractSea ice conditions in the Antarctic affect the life cycle of the emperor penguin (Aptenodytes forsteri). We present a population projection for the emperor penguin population of Terre Adélie, Antarctica, by linking demographic models (stage‐structured, seasonal, nonlinear, two‐sex matrix population models) to sea ice forecasts from an ensemble of IPCC climate models. Based on maximum likelihood capture‐mark‐recapture analysis, we find that seasonal sea ice concentration anomalies (SICa) affect adult survival and breeding success. Demographic models show that both deterministic and stochastic population growth rates are maximized at intermediate values of annual SICa, because neither the complete absence of sea ice, nor heavy and persistent sea ice, would provide satisfactory conditions for the emperor penguin. We show that under some conditions the stochastic growth rate is positively affected by the variance in SICa. We identify an ensemble of five general circulation climate models whose output closely matches the historical record of sea ice concentration in Terre Adélie. The output of this ensemble is used to produce stochastic forecasts of SICa, which in turn drive the population model. Uncertainty is included by incorporating multiple climate models and by a parametric bootstrap procedure that includes parameter uncertainty due to both model selection and estimation error. The median of these simulations predicts a decline of the Terre Adélie emperor penguin population of 81% by the year 2100. We find a 43% chance of an even greater decline, of 90% or more. The uncertainty in population projections reflects large differences among climate models in their forecasts of future sea ice conditions. One such model predicts population increases over much of the century, but overall, the ensemble of models predicts that population declines are far more likely than population increases. We conclude that climate change is a significant risk for the emperor penguin. Our analytical approach, in which demographic models are linked to IPCC climate models, is powerful and generally applicable to other species and systems.
Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature
Authors: Dieleman Wouter I. J. , Vicca Sara , Dijkstra Feike A. , Hagedorn Frank , Hovenden Mark J. , Larsen Klaus S. , Morgan Jack A. , Volder Astrid , Beier Claus , Dukes Jeffrey S. , King John , Leuzinger Sebastian , Linder Sune , Luo Yiqi , Oren Ram , De Angelis Paolo , Tingey David , Hoosbeek Marcel R. , Janssens Ivan A. 
Published: May 2012

AbstractIn recent years, increased awareness of the potential interactions between rising atmospheric
CO2

concentrations ([
CO2

]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [
CO2

] manipulation, and compares it with those obtained in single factor [
CO2

] and temperature manipulation experiments. Across all combined elevated [
CO2

] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [
CO2

]‐only treatment than to those in the warming‐only treatment. In contrast to warming‐only experiments, both the combined and the [
CO2

]‐only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [
CO2

]‐only treatment, possibly due to the warming‐induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [
CO2

] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [
CO2

] and warming, i.e. the response to the combined treatment was usually less‐than‐additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long‐term) multifactor manipulation experiments. Because single factor
CO2

responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
Influence of anti‐asthmatic medications on dental caries in children in Slovenia
Authors: SAMEC TOMI , AMAECHI BENNETT TOCHUKWU , BATTELINO TADEJ , KRIVEC UROŠ , JAN JANJA 
Published: May 2012

International Journal of Paediatric Dentistry 2013; 23: 188–196
Objective.  The study investigated the influence of exposure to anti‐asthmatic medications and of various factors on the caries prevalence in children in Slovenia.Methods.  The study population consisted of children aged 2‐ to 17 years (n = 220) under treatment for asthma, who had used anti‐asthmatic medications for at least 1 year; 220 controls were matched for age. Caries status was determined by the number of decayed, missing, and filled surfaces through clinical examination by two calibrated dentists using the International Caries Detection and Assessment System‐II scoring criteria. Questionnaires completed by parents and data from the patients’ medical records provided information on various confounding factors.Results.  Asthmatic children had significantly higher (P ≤ 0.01) prevalence of caries on primary and permanent teeth in all age groups, and the proportion of caries‐free children was significantly smaller (P ≤ 0.05). In multivariate regression analysis, asthma diagnosis, child’s age, daily use of inhaled glucocorticoids, length and frequency of medicine application, spacer use, mouth rinsing with water after medicine application, parents’ education, frequent food and drink consumption, and frequency of toothbrushing were associated with caries experience of asthmatic children.Conclusion.  Children with asthma who had used anti‐asthmatic medications had higher caries experience in primary and permanent teeth.
Home site advantage in two long‐lived arctic plant species: results from two 30‐year reciprocal transplant studies
Authors: Bennington Cynthia C. , Fetcher Ned , Vavrek Milan C. , Shaver Gaius R. , Cummings Kelli J. , McGraw James B. 
Published: May 2012

Summary1. Reciprocal transplant experiments designed to quantify genetic and environmental effects on phenotype are powerful tools for the study of local adaptation. For long‐lived species, especially those in habitats with short growing seasons, however, the cumulative effects of many years in novel environments may be required for fitness differences and phenotypic changes to accrue.2. We returned to two separate reciprocal transplant experiments thirty years after their initial establishment in interior Alaska to ask whether patterns of differentiation observed in the years immediately following transplant have persisted. We also asked whether earlier hypotheses about the role of plasticity in buffering against the effects of selection on foreign genotypes were supported. We censused survival and flowering in three transplant gardens created along a snowbank gradient for a dwarf shrub (Dryas octopetala) and six gardens created along a latitudinal gradient for a tussock‐forming sedge (Eriophorum vaginatum). For both species, we used an analysis of variance to detect fitness advantages for plants transplanted back into their home site relative to those transplanted into foreign sites.3. ForD. octopetala, the original patterns of local adaptation observed in the decade following transplant appeared even stronger after three decades, with the complete elimination of foreign ecotypes in both fellfield and snowbed environments. ForE. vaginatum, differential survival of populations was not evident 13 years after transplant, but was clearly evident 17 years later. There was no evidence that plasticity was associated with increased survival of foreign populations in novel sites for eitherD. octopetalaorE. vaginatum.4. Synthesis. We conclude that local adaptation can be strong, but nevertheless remain undetected or underestimated in short‐term experiments. Such genetically based population differences limit the ability of plant populations to respond to a changing climate.
Development of a novel PCR assay based on the 16S–23S rRNA internal transcribed spacer region for the detection of Lactococcus garvieae
Authors: Dang H T , Park H K , Myung S C , Kim W 
Published: May 2012

AbstractLactococcus garvieae is recognized as an emerging pathogen in fish. Several PCR‐based methods have been developed for the detection and identification of L. garvieae; however, the sensitivity of these methods is still in question regarding the discrimination of this organism from other closely related species. Two primers, ITSLg30F and ITSLg319R, were designed from the sequence in the 16S–23S internal transcribed spacer (ITS) region and used for the specific detection of L. garvieae. L. garvieae strains including fish isolates were positive by this method. In contrast, previously developed PCR methods showed false‐positive results with non‐L. garvieae species. Our results indicate that a PCR method using the newly designed ITS primer set provides a sensitive and efficient tool for the detection of L. garvieae in fish and aquaculture environments.
WebDASC: a web‐based dietary assessment software for 8–11‐year‐old Danish children
Authors: Biltoft‐Jensen A. , Trolle E. , Christensen T. , Islam N. , Andersen L. F. , Egenfeldt‐Nielsen S. , Tetens I. 
Published: May 2012

AbstractBackground:  The present study describes the development and formative evaluation of the Web‐based Dietary Assessment Software for Children (WebDASC). WebDASC is part of the OPUS project (‘Optimal well‐being, development and health for Danish children through a healthy New Nordic Diet’) and was intended to measure dietary change resulting from a school‐based intervention.Methods:  WebDASC was developed as a self‐administered tool that could be used by 8–11‐year‐old children with or without parent’s aid. The development of WebDASC followed a prototyping approach: focus groups, informal interviews, literature review, and usability tests preceded its release. Special consideration was given to age‐appropriate design issues.Results:  In WebDASC an animated armadillo guides respondents through six daily eating occasions and helps them report foods and beverages previously consumed. A database of 1300 food items is available either through category browse or free text search, aided by a spell check application. A type‐in format is available for foods not otherwise found through category browse or text search. Amount consumed is estimated by selecting the closest portion size among four different digital images. WebDASC includes internal checks for frequently forgotten foods, and the following features to create motivation: a food‐meter displaying cumulative weight of foods reported, a most popular food ranking, and a computer game with a high score list.Conclusions:  WebDASC was developed as an intuitive, cost‐effective, and engaging method to collect detailed dietary data from 8‐ to 11‐year‐old children. Preliminary testing demonstrated that it was well accepted among children.
How to engage children in self‐administered dietary assessment programmes
Authors: Lu A. S. , Baranowski J. , Islam N. , Baranowski T. 
Published: May 2012

AbstractEffectively assessing children’s dietary intake is essential for understanding the complex relationships among dietary behaviours and obesity. Dietary assessment accuracy decreases when children are unable or unmotivated to complete accurate self‐reports. Technology‐based assessment instruments for children’s self‐report of diet can be enhanced in light of developments in media psychology and communication science. To motivate children to complete a dietary assessment, researchers could use animated, customisable agents; embed the assessment process into a video game; or add narratives to encourage self‐reporting behaviour. To improve accuracy, the intake environment could be recreated virtually; training sessions could be interspersed to improve portion estimation; and implicit attitudinal measures could be incorporated as a control or to increase validity. Research is needed to evaluate possible methods of enhancing children’s self‐reporting motivation and accuracy. The main challenge remains how to engage children without biasing their reporting.