bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative multilocus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation
Authors: Mayer François , Piel Frédéric B. , Cassel‐Lundhagen Anna , Kirichenko Natalia , Grumiau Laurent , Økland Bjørn , Bertheau Coralie , Grégoire Jean‐Claude , Mardulyn Patrick
Published: February 2015

While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species‐specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree‐killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles’ entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long‐standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced.
Comparative interrogation of the developing xylem transcriptomes of two wood‐forming species: Populus trichocarpa and Eucalyptus grandis
Authors: Hefer Charles A. , Mizrachi Eshchar , Myburg Alexander A. , Douglas Carl J. , Mansfield Shawn D.
Published: February 2015

Wood formation is a complex developmental process governed by genetic and environmental stimuli. Populus and Eucalyptus are fast‐growing, high‐yielding tree genera that represent ecologically and economically important species suitable for generating significant lignocellulosic biomass.

Comparative analysis of the developing xylem and leaf transcriptomes of Populus trichocarpa and Eucalyptus grandis together with phylogenetic analyses identified clusters of homologous genes preferentially expressed during xylem formation in both species.

A conserved set of 336 single gene pairs showed highly similar xylem preferential expression patterns, as well as evidence of high functional constraint. Individual members of multi‐gene orthologous clusters known to be involved in secondary cell wall biosynthesis also showed conserved xylem expression profiles. However, species‐specific expression as well as opposite (xylem versus leaf) expression patterns observed for a subset of genes suggest subtle differences in the transcriptional regulation important for xylem development in each species.

Using sequence similarity and gene expression status, we identified functional homologs likely to be involved in xylem developmental and biosynthetic processes in Populus and Eucalyptus. Our study suggests that, while genes involved in secondary cell wall biosynthesis show high levels of gene expression conservation, differential regulation of some xylem development genes may give rise to unique xylem properties.
Comparative genomics identifies the Magnaporthe oryzae avirulence effector AvrPi9 that triggers Pi9‐mediated blast resistance in rice
Authors: Wu Jun , Kou Yanjun , Bao Jiandong , Li Ya , Tang Mingzhi , Zhu Xiaoli , Ponaya Ariane , Xiao Gui , Li Jinbin , Li Chenyun , Song Min‐Young , Cumagun Christian Joseph R. , Deng Qiyun , Lu Guodong , Jeon Jong‐Seong , Naqvi Naweed I. , Zhou Bo
Published: February 2015

We identified the Magnaporthe oryzae avirulence effector AvrPi9 cognate to rice blast resistance gene Pi9 by comparative genomics of requisite strains derived from a sequential planting method.

AvrPi9 encodes a small secreted protein that appears to localize in the biotrophic interfacial complex and is translocated to the host cell during rice infection. AvrPi9 forms a tandem gene array with its paralogue proximal to centromeric region of chromosome 7. AvrPi9 is expressed highly at early stages during initiation of blast disease.

Virulent isolate strains contain Mg‐SINE within the AvrPi9 coding sequence. Loss of AvrPi9 did not lead to any discernible defects during growth or pathogenesis in M. oryzae. This study reiterates the role of diverse transposable elements as off‐switch agents in acquisition of gain‐of‐virulence in the rice blast fungus.

The prevalence of AvrPi9 correlates well with the avirulence pathotype in diverse blast isolates from the Philippines and China, thus supporting the broad‐spectrum resistance conferred by Pi9 in different rice growing areas. Our results revealed that Pi9 and Piz‐t at the Pi2/9 locus activate race specific resistance by recognizing sequence‐unrelated AvrPi9 and AvrPiz‐t genes, respectively.
Prey diversity and prey identity affect herbivore performance on different time scales in a long term aquatic food‐web experiment
Authors: Behl Stephan , Stibor Herwig
Published: February 2015

The question whether and how diversity‐mediated productivity at the base of food‐webs influences adjacent trophic levels is still unclear. Experiments revealed negative effects on consumers due to the increasing dominance of inedible species under grazing pressure, and positive effects due to a greater variety of prey resources. We experimentally investigate two more hypotheses, which have not been addressed in detail so far: first, more diverse primary producer communities potentially use limiting resources more efficiently, and are, therefore, more productive. This effect can be considered functionally similar to a direct enrichment with limiting resources, potentially resulting in a higher stochastic risk of herbivore extinction (‘paradox of enrichment’). Second, in a stable environment, enclosed primary producer communities should evolve towards a ‘climax state’, eventually dominated by one or few prey species. Therefore, long‐term diversity effects in producer communities should more likely result from the specific traits of the dominating species, than from complementarity. To address these hypotheses, we conducted long‐term laboratory experiments, exposing the freshwater grazer Daphnia magna to a gradient of algal species richness (1, 2, 4 or 8 edible chlorophyte species). The experiments were run in batch cultures, without exchange of growth medium after the start of the experiment. Six parameters related to Daphnia population demography, biomass accrual, and stability were followed and determined over a period of up to 263 days. Producer diversity exhibited strong positive effects on the short‐term performance of grazers (first reproduction, first population peak), and on grazer mean standing stocks. However, herbivore long‐term dynamics (day of extinction and temporal stability) depended on prey species identity, namely the presence of Chlamydomonas reinhardtii. Our experiments suggest that both prey diversity and identity can have positive effects on consumer performance, but act on different time scales.
Long‐term population dynamics of a migrant bird suggests interaction of climate change and competition with resident species
Authors: Wittwer Torben , O'Hara Robert B. , Caplat Paul , Hickler Thomas , Smith Henrik G.
Published: February 2015

The separation of abiotic and biotic factors affecting populations and communities is an important step in understanding how climate change can influence ecological processes, but quantifying their relative contribution to community changes is a challenge. We assessed the effect of temperature and species interactions on the population dynamics of a forest bird community with a hierarchical dynamic population model in a Bayesian framework. We used a long‐term time‐series (1956–2012) of four secondary cavity‐nesting birds with similar food and nesting requirements but different migration habits, to analyse the effects of the four species population size and the local weather fluctuations on each species’ population dynamics. We found clear evidence of a negative effect of two resident species (blue tit and great tit) on a long‐distance migrant (pied flycatcher). Among the residents we only found a competition effect of the great tit on the marsh tit. The birds showed opposite responses to weather: the pied flycatcher favoured colder springs whereas the blue tit and great tit favoured warmer springs. Although alternative mechanisms cannot be ruled out, our results suggest that the resident species (blue tit and great tit) could adjust to increasing spring temperature while the migrant species (pied flycatcher) could not, leading progressively to the exclusion of the pied flycatcher from the area. These results point out the potential role of competitive interactions by providing insightful clues, call for refined research, and support recent efforts to include population dynamics in species distribution models.
Rapid evolution of dispersal‐related traits during range expansion of an invasive vine Mikania micrantha
Authors: Huang Fangfang , Peng Shaolin , Chen Baoming , Liao Huixuan , Huang Qiaoqiao , Lin Zhenguang , Liu Gang
Published: February 2015

Rapid range expansion of invasive plants provides a unique opportunity to explore evolutionary changes of dispersal‐related traits during the invasion process. Increasing evidence now suggests that a higher dispersal rate is favored at the invasion front. However, little is known about the role of genetic differentiation and phenotypic plasticity on patterns of dispersal ability during the invasion process. In this study, we combined a field survey and a common garden transplant experiment to test for evidence of genetically based dispersal ability in Mikania micrantha, a highly invasive vine, across its invaded range in southern China. Three dispersal‐related traits, plume loading, seed mass and pappus radius, were measured in both natural and common garden populations. We found that in natural conditions, plume loading and seed mass significantly decreased with expanding distance from the source population, but in controlled conditions, these two traits exhibited a significant humped trend against percent field cover, indicating that dispersal ability of M. micrantha was selected for during range expansion and that the related traits were likely to be under genetic control. Furthermore, rebounding dispersal ability was detected in highly competitive sites in the range core, which suggested that this evolutionary process was likely partially driven by intraspecific competition. Because more and more plant species are under spatial nonequilibirum due to climate change, this study can serve to provide hints at the fate of spatially fluctuant populations.
Using habitat selection theories to predict the spatiotemporal distribution of migratory birds during stopover – a case study of pink‐footed geeseAnser brachyrhynchus
Authors: Chudzińska Magda E. , van Beest Floris M. , Madsen Jesper , Nabe‐Nielsen Jacob
Published: February 2015

Understanding how animals select for habitat and foraging resources therein is a crucial component of basic and applied ecology. The selection process is typically influenced by a variety of environmental conditions including the spatial and temporal variation in the quantity and quality of food resources, predation or disturbance risks, and inter‐ and intraspecific competition. Indeed, some of the most commonly employed ecological theories used to describe how animals choose foraging sites are: nutrient intake maximisation, density‐dependent habitat selection, central‐place foraging, and predation risk effects. Even though these theories are not mutually exclusive, rarely are multiple theoretical models considered concomitantly to assess which theory, or combination thereof, best predicts observed changes in habitat selection over space and time. Here, we tested which of the above theories best‐predicted habitat selection of Svalbard‐breeding pink‐footed geese at their main spring migration stopover site in mid‐Norway by computing a series of resource selection functions (RSFs) and their predictive ability (k‐fold cross validation scores). At this stopover site geese fuel intensively as a preparation for breeding and further migration. We found that the predation risk model and a combination of the density‐dependent and central‐place foraging models best‐predicted habitat selection during stopover as geese selected for larger fields where predation risk is typically lower and selection for foraging sites changed as a function of both distance to the roost site (i.e. central‐place) and changes in local density. In contrast to many other studies, the nutritional value of the available food resources did not appear to be a major limiting factor as geese used different food resources proportional to their availability. Our study shows that in an agricultural landscape where nutritional value of food resources is homogeneously high and resource availability changes rapidly; foraging behaviour of geese is largely a tradeoff between fast refuelling and disturbance/predator avoidance.
Functional dissimilarity across trophic levels as a driver of soil processes in a Mediterranean decomposer system exposed to two moisture levels
Authors: Coulis Mathieu , Fromin Nathalie , David Jean‐François , Gavinet Jordane , Clet Alexandre , Devidal Sébastien , Roy Jacques , Hättenschwiler Stephan
Published: February 2015

The role of biodiversity for soil processes remains poorly understood. Existing evidence suggests that functional diversity rather than species richness is relevant for soil functioning. However, the importance of functional diversity has rarely been assessed simultaneously at more than one trophic level, critically limiting the prediction of consequences of biodiversity loss for soil functioning. In a laboratory microcosm experiment, we tested the hypothesis that increasing functional dissimilarity of both litter‐feeding soil fauna and litter mixtures interactively affects the rates of five different soil processes related to litter decomposition. We created trait‐based functional dissimilarity gradients using five assemblages of two detritivore species and five mixtures of two plant litter species commonly found in Mediterranean shrubland ecosystems of southern France. With increasing drought periods predicted for Mediterranean ecosystems in the future, we additionally included two different watering frequencies to evaluate the impact of drought on soil processes and how drought interacts with functional dissimilarity. The different fauna assemblages and litter mixtures showed strong effects on litter mass loss, soil organic carbon and nitrogen leaching, as well as on soil microbial activities. Up to 20% of the variation in response variables was explained by functional dissimilarity, suggesting an ecologically relevant impact of functional diversity on soil process rates. Detritivore functional dissimilarity tended to have stronger effects when combined with increasingly dissimilar litter mixtures, suggesting that trait dissimilarity interacts across trophic levels. Drought affected several soil processes but did not modify the relationships between functional dissimilarity and process rates. Our results indicate that trait diversity of detritivore assemblages and litter mixtures is an important predictor of soil process rates. The common and easily measurable traits used in our study suggest straightforward application across different types of ecosystems and environmental conditions.
Beyond food: a foundation species facilitates its own predator
Authors: Agüera Antonio , van de Koppel Johan , Jansen Jeroen M. , Smaal Aad C. , Bouma Tjeerd J.
Published: February 2015

Facilitation by foundation species can play a critical role in structuring ecological communities. As environmental stress increases, generally more organisms become dependent on the stress buffering provided by foundation species. As such, foundation species may even facilitate their own predators, an interaction that can influence the functioning and structure of the foundation species population and thereby the facilitated organisms. This work presents a case study on the blue mussels and sea stars, where we tested to what extent a foundation species (i.e. blue mussels) may facilitate its own predator (sea star) when exposed to a gradient of environmental stress (hydrodynamic forces). Amelioration of hydrodynamic stress by mussels facilitated sea stars, allowing them to persist on a soft bottom in highly dynamic environment, which would not be possible in the absence of mussels. Moreover, sea stars continue preying on mussels when environmental stress increases. The results suggest that a foundation species may interact with its own predator beyond the role of food source, by ameliorating environmental stress, creating an additional dependence link between the foundation species and the predator, which potentially has major implications for ecosystem structure and stability.
Consumer–plant interaction strength: importance of body size, density and metabolic biomass
Authors: Atkins Rebecca L. , Griffin John N. , Angelini Christine , O'Connor Mary I. , Silliman Brian R.
Published: February 2015

Explaining variability in the strength and sign of trophic interactions between primary consumers and plants is a long‐standing research challenge. Consumer density and body size vary widely in space and time and are predicted to have interactive effects on consumer–plant interactions. In a southern US salt marsh, we used replicate field enclosures to orthogonally manipulate the body size (mass) and density of a dominant consumer (a snail). We investigated impacts (leaf damage and biomass) on monocultures of cordgrass, the foundation species, over three months. Increasing consumer density and body size increased leaf damage additively and, as predicted, multiplicatively reduced plant biomass. Notably, size and density determined the sign of consumer impact on plants: low to medium densities of small consumers enhanced, while high densities of large consumers strongly suppressed, plant biomass. Finally, total consumer metabolic biomass (mass0.75) within an enclosure parsimoniously explained plant biomass response, supporting theoretical predictions and suggesting that multiplicative effects of density and body size resulted from their effects on total metabolic biomass. The consequences of changes in consumer density and body size resulting from anthropogenic perturbations may therefore be predicted based on metabolic biomass.

Synthesis

Consumer size, density and biomass can all strongly affect consumer–plant interactions. Though density and body size have been extensively studied as drivers of variation in interaction strength, the role of biomass as the ultimate driver has been less appreciated. We manipulated body size and density of a single consumer species and, based on metabolic theory, integrated these into a single variable: total metabolic biomass. Our results suggest that changes in interaction strength attributed to size or density may in fact be due to changes in metabolic biomass. This metric could thus serve as a useful tool in further understanding species interactions.
Multi‐temporal factors influence predation for polar bears in a changing climate
Authors: Pilfold Nicholas W. , Derocher Andrew E. , Stirling Ian , Richardson Evan
Published: February 2015

Predation is an ecological interaction influenced by abiotic and biotic factors acting on multiple temporal scales, yet multi‐temporal comparisons are rare in empirical studies. For polar bears Ursus maritimus, the physical configuration of the habitat and conditions in which seals are hunted may change on intra‐ and inter‐seasonal scales. Additionally, while the effects of climate change on polar bears have focused on linking reductions in sea ice to body condition and survival, the potential changes to on‐ice hunting conditions have not been examined. Employing observational counts of seals killed by polar bears between early‐April and late‐May 1985–2011 (n = 650), we modelled the likelihood of predation events in the Beaufort Sea, Canada at multi‐temporal scales. We used the top model to estimate the expected kill rate of seals in the springs of 1985–1986 and 2005–2006 and integrated the result with fasting rates derived from physiological markers in blood samples. A log‐likelihood ratio test suggested a multi‐temporal approach fit the seal kill data better than any single scale alone. Predation events were influenced by ringed seal Pusa hispida reproduction and haul‐out behaviour, regional sea ice concentration and the phase of climatic indices. The expected kill rate from the top predation model and the estimated mean biomass of seal kills were significant predictors of polar bear fasting rates. Results suggest that 50% less seal biomass was killed in 2005–2006 than in 1985–1986, which correlates with a significant increase in the frequency of polar bears in a fasting state. We propose that the documented changes in polar bear fasting rates between 1985–1986 and 2005–2006 are due to a complex set of abiotic and biotic factors including underlying prey dynamics, rather than a single‐scale environmental correlation.
An experimental test of the relationship between seed size and competitive ability in annual plants
Authors: Ben‐Hur Eyal , Kadmon Ronen
Published: February 2015

Competition–colonization tradeoff models explain the coexistence of competing species in terms of a tradeoff between competitive ability and colonization ability. One class of such models is based on the idea that seed size determines competitive ability, seed number determines colonization ability, and the two traits are negatively correlated such that higher competitive ability of large‐seeded species compensates for their smaller seed number. According to such models, species inhabiting the same community should show a distinct ranking of competitive ability and this ranking should be correlated with seed size. We tested these predictions using a greenhouse competition experiment focusing on 25 annual species that coexist in sandy habitats of the Mediterranean region in Israel. Rankings of species based on their competitive effects on two independent phytometers were positively correlated. Corresponding rankings based on competitive responses were also correlated. Rankings based on competitive effects were correlated with those based on competitive responses. Yet, in spite of the clear hierarchy in all measures of competitive ability, none of the measures was correlated with seed size. While lack of correlation between seed size and competitive ability has been documented in some systems, our study is the first time that absence of such correlation is documented in a system where the existence of competition is well established and the component species show a clear hierarchy of competitive ability.
Enhanced waterlogging tolerance in barley by manipulation of expression of the N‐end rule pathway E3 ligase PROTEOLYSIS6
Authors: Mendiondo Guillermina M. , Gibbs Daniel J. , Szurman‐Zubrzycka Miriam , Korn Arnd , Marquez Julietta , Szarejko Iwona , Maluszynski Miroslaw , King John , Axcell Barry , Smart Katherine , Corbineau Francoise , Holdsworth Michael J.
Published: February 2015

Increased tolerance of crops to low oxygen (hypoxia) during flooding is a key target for food security. In Arabidopsis thaliana (L.) Heynh., the N‐end rule pathway of targeted proteolysis controls plant responses to hypoxia by regulating the stability of group VII ethylene response factor (ERFVII) transcription factors, controlled by the oxidation status of amino terminal (Nt)‐cysteine (Cys). Here, we show that the barley (Hordeum vulgare L.) ERFVII BERF1 is a substrate of the N‐end rule pathway in vitro. Furthermore, we show that Nt‐Cys acts as a sensor for hypoxia in vivo, as the stability of the oxygen‐sensor reporter protein MCGGAIL‐GUS increased in waterlogged transgenic plants. Transgenic RNAi barley plants, with reduced expression of the N‐end rule pathway N‐recognin E3 ligase PROTEOLYSIS6 (HvPRT6), showed increased expression of hypoxia‐associated genes and altered seed germination phenotypes. In addition, in response to waterlogging, transgenic plants showed sustained biomass, enhanced yield, retention of chlorophyll, and enhanced induction of hypoxia‐related genes. HvPRT6 RNAi plants also showed reduced chlorophyll degradation in response to continued darkness, often associated with waterlogged conditions. Barley Targeting Induced Local Lesions IN Genomes (TILLING) lines, containing mutant alleles of HvPRT6, also showed increased expression of hypoxia‐related genes and phenotypes similar to RNAi lines. We conclude that the N‐end rule pathway represents an important target for plant breeding to enhance tolerance to waterlogging in barley and other cereals.
Protein accumulation and rumen stability of wheat γ‐gliadin fusion proteins in tobacco and alfalfa
Authors: Sun Xiaodong , Chi‐Ham Cecilia L. , Cohen‐Davidyan Tamar , DeBen Christopher , Getachow Girma , DePeters Edward , Putnam Daniel , Bennett Alan
Published: February 2015

The nutritional value of various crops can be improved by engineering plants to produce high levels of proteins. For example, because methionine deficiency limits the protein quality of Medicago Sativa (alfalfa) forage, producing alfalfa plants that accumulate high levels of a methionine‐rich protein could increase the nutritional value of that crop. We used three strategies in designing methionine‐rich recombinant proteins that could accumulate to high levels in plants and thereby serve as candidates for improving the protein quality of alfalfa forage. In tobacco, two fusion proteins, γ‐gliadin‐δ‐zein and γ‐δ‐zein, as well as δ‐zein co‐expressed with β‐zein, all formed protein bodies. However, the γ‐gliadin‐δ‐zein fusion protein accumulated to the highest level, representing up to 1.5% of total soluble protein (TSP) in one transformant. In alfalfa, γ‐gliadin‐δ‐zein accumulated to 0.2% of TSP, and in an in vitro rumen digestion assay, γ‐gliadin‐δ‐zein was more resistant to microbial degradation than Rubisco. Additionally, although it did not form protein bodies, a γ‐gliadin‐GFP fusion protein accumulated to much higher levels, 7% of TSP, than a recombinant protein comprised of an ER localization signal fused to GFP in tobacco. Based on our results, we conclude that γ‐gliadin‐δ‐zein is a potential candidate protein to use for enhancing methionine levels in plants and for improving rumen stability of forage protein. γ‐gliadin fusion proteins may provide a general platform for increasing the accumulation of recombinant proteins in transgenic plants.
How do country‐level governance characteristics impact the relationship between R&D and firm value?
Authors: Pindado Julio , de Queiroz Valdoceu , de la Torre Chabela
Published: February 2015

This article addresses the question of how country‐level governance characteristics moderate the market valuation of research and development (R&D). Using a valuation model and panel data from companies in the European Union, United States, and Japan, we find that effective corporate governance allows the market to better assess a firm's R&D investments. This finding is the conjunction with the effect of the legal system, the financial system, and mechanisms of control. First, as effectiveness of investor protection increases, the market valuation of R&D projects also increases. Second, more developed financial systems do a better job assessing R&D. Third, effective control mechanisms reinforce the positive effect of R&D on a firm's market value. In sum, our findings shed light on how policymakers can increase the benefits from firms' R&D spending and thus foster economic growth and social welfare using these country‐level governance characteristics.
Experiences of working as an advanced practice nurse in Finland – the substance of advanced nursing practice and promoting and inhibiting factors
Authors: Wisur‐Hokkanen Carola , Glasberg Ann‐Louise , Mäkelä Carita , Fagerström Lisbeth
Published: February 2015

Background

Evaluation of new advanced practice nursing roles, from different angles, is strongly recommended in the literature. New nurses' experiences of working in an advanced role may highlight problems and/or factors that promote or inhibit a successful implementation of new advanced nursing roles.

Aim

To explore advanced practice nurses' experiences of the content of their nursing care and to describe promoting or inhibiting factors for working with a full scope of advanced nursing practice.

Methods

The study design was explorative and descriptive. A total of 24 advanced practice nurses participated in focus group interviews (two were interviewed individually) about the processes, structure and outcome of working as advanced practice nurses. Qualitative manifest content analysis was used for data analysis.

Findings

The substance of advanced practice nursing can be described with three main themes: a broader and deeper holistic view of patients' state of health, an independent and responsible manner of working and knowing own limits. Promoting factors were an identity as a nurse with advanced competency, feedback from satisfied patients and fruitful teamwork is a necessity. Inhibiting factors were a lack of organisational understanding for advanced nursing practice, poor planning leads to unsatisfactory advanced practice nursing models and advanced practice nurses' lack of courage in adopting new advanced roles.

Conclusion

The participants experienced both a personal inner transition and a role transition that were either supported or opposed. Vague or nonexistent definitions and concepts, insufficient knowledge, insufficient support and undefined roles hindered participants' role transition. Two main strategies should be employed. The first is the realisation of more strategic leadership and support from organisations on all management levels, including nursing organisations/unions, while the second is to more realistically prepare future advanced practice nurses for the challenges they will face, through mentorship programmes and continuous further training.
Perceived positive and negative consequences after surviving cancer and their relation to quality of life
Authors: Castellano‐Tejedor Carmina , Eiroa‐Orosa Francisco‐José , Pérez‐Campdepadrós Marta , Capdevila Lluís , Sánchez de Toledo José , Blasco‐Blasco Tomás
Published: February 2015

Surviving childhood cancer has multiple implications on both physical and psychological domains of the individual. However, its study and possible effects on health‐related quality of life (HRQoL) outcomes of adolescent survivors has been understudied. The objective of this study was twofold; to assess positive and negative cancer‐related consequences (psychosocial and physical) in a sample of adolescent cancer survivors and to explore their relationship with HRQoL outcomes. Forty‐one participants answered two questions about positive and negative consequences in the aftermath of cancer and filled in the KIDSCREEN‐52 self‐reported version. Data were analysed using mixed methods approach. Overall, 87.8% of the studied sample identified positive consequences and 63.4% negative consequences in survivorship. Four positive categories and five negative categories with regard to cancer‐related consequences were found. Changed perspectives in life narratives seem to be the positive consequence more related to HRQoL (physical well‐being, mood & emotions, autonomy, social support & peers), followed by useful life experience (physical well‐being, autonomy, social support & peers). Psychological impact was the most referred negative consequence with a significant detrimental effect on social support and peers HRQoL dimension. Even if the majority of survivors reported benefit finding in the aftermath of cancer, concomitant positive and negative consequences have been found. However, findings only reveal a significant relationship between positive narratives and HRQoL, and negative consequences do not seem to have a significant influence on overall HRQoL in survivorship.
Prospective Associations between Peer Aggression and Victimization: The Moderating Roles of Physiological Stress Reactivity and Gender
Authors: Pitula Clio E. , Murray‐Close Dianna , Banny Adrienne M. , Crick Nicki R.
Published: February 2015

The present investigation examined whether heightened skin conductance reactivity (SCLR) to peer stress strengthened the prospective associations between physical and relational aggression and victimization, and whether associations were stronger for physical forms of aggression and victimization among boys and relational forms of aggression and victimization among girls. A total of 91 children [M age = 10.18 years, standard deviation (SD) = .68] were assessed twice over 1 year. At the first assessment, SCLR in response to recounting a relational stressor (e.g., exclusion; SCLR‐R) and an instrumental stressor (e.g., property theft; SCLR‐I), and teacher‐reported aggression were measured. Parents reported on child victimization at both time points. Among youth with heightened SCLR‐I, physical aggression was associated with increases in physical victimization for boys and decreases in physical victimization for girls. Among youth with heightened SCLR‐R, relational aggression was associated with increases in physical victimization for girls only. Results were largely consistent with the hypothesis that aggressors with a propensity to exhibit negative displays of emotion, as indexed by heightened sympathetic nervous system (SNS) reactivity to peer stress, may be especially likely to suffer peer victimization. Gender‐specific effects highlight the importance of including both physical and relational forms of aggression and victimization to capture victimization risk among aggressive boys and girls.
Three weeks with strangers: Photography and the production of social identity during the 1935 Board of Anthropological Research expedition to the Warburton Range, Western Australia
Authors: McGrath Pamela Faye
Published: February 2015

Using a range of archival and published sources including field notes, photographs and drawings, this paper investigates the social relationships formed between Ngaanyatjarra families and a small group of scientists in the presence of cameras during a 3‐week ethnographic research expedition to the Warburton Range in 1935. The impression left by the ethno‐historical record is that, despite disparate norms around looking behaviours, a degree of familiarity was quickly established that enabled intimate acts of filming and photography. And yet the inter‐subjectivity that facilitated such photography was deliberately obscured when the images produced were subsequently disseminated to outside audiences, in effect reinstating social distance and turning Aboriginal familiars back into strangers. Recent reconsiderations of the figure of ‘the stranger’ (Simmel 1999; Marotta 2012) and an extensive literature on the relationship between anthropological knowledge and photography (Edwards 1992, 2001) help to unpack what this sociality reveals about belonging, identity and the representative reach of photographic mediums. A series of crayon drawings by the expedition's young Aboriginal guide points to the limits of the social categories assumed for Ngaanyatjarra people by these scientists. In their place is found complex contemporary Aboriginal identities that were simultaneously modern and traditional, embedded in evolving intergenerational social frameworks that have endured until today.
Genetic polymorphisms of serum amyloid A1 and coronary artery disease risk
Authors: Xie X. , Ma Y‐T. , Yang Y‐N. , Li X‐M. , Zheng Y‐Y. , Liu F. , Ma X. , Fu Z‐Y. , Yu Z‐X. , Chen Y. , Chen B‐D. , Huang Y.
Published: February 2015

Serum amyloid A (SAA) protein is not only an inflammatory factor but also an apolipoprotein that can replace apolipoprotein A1 (apoA1) as the major apolipoprotein of high‐density lipoprotein cholesterol (HDL‐C). However, the relationship between genetic polymorphisms of SAA and coronary artery disease (CAD) remains unclear. A total of four single nucleotide polymorphisms (rs12218, rs4638289, rs7131332, and rs11603089) of the SAA gene were genotyped using the polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) method in two independent case–control studies, one of the Han population (1416 CAD patients and 1373 control subjects) and the other of the Uygur population (588 CAD patients and 529 control subjects). We found that the rs12218 CC genotype was more frequent among the CAD patients than among the controls in both the Han (8.3% vs. 4.8%, P < 0.001) and Uygur populations (15.5% vs. 11.3%, P < 0.05). After adjustments for confounding factors, such as sex, age, smoking, drinking, hypertension, diabetes, and serum levels of triglycerides, total cholesterol, HDL, and plasma SAA, the differences remained significant in the Han (CC vs. CT+TT, P < 0.001, OR = 3.863, 95% CI: 1.755–12.477) and Uygur groups (CC vs. CT+TT, P = 0.031, OR = 3.022, 95% CI: 1.033–8.840). Genetic polymorphisms in SAA1 are associated with CAD in the Han and Uygur populations in western China.
Area‐preservation Simplification of Polygonal Boundaries by the Use of the Structured Total Least Squares Method with Constraints
Authors: Tong Xiaohua , Jin Yanmin , Li Lingyun , Ai Tinghua
Published: February 2015

This article presents an area‐preservation approach for polygonal boundary simplification by the use of structured total least squares adjustment with constraints (STLSC), with the aim being to maintain the area of the original polygons after the simplification. Traditionally, a simplified line is represented by critical points selected from the original one. However, this study focuses on maintaining the areas of the polygons in the process of simplification of polygonal boundaries. Therefore, the proposed method in this article is a supplement to the existing line simplification methods, and it improves the quality of the simplification of polygonal boundaries in terms of positional and area errors. Based on the sub‐divisions of the original polyline, using the critical points detected from the polyline by the use of line simplification methods, the framework of the proposed method includes three main components, as follows: (1) establishment of the straight‐line‐segment fitting model based on both the critical and intermediate points on the sub‐polyline; (2) introduction of both area and end‐point constraints to reduce the geometric distortions due to the line simplification; and (3) derivation of the solution of boundary simplification by the use of STLSC.

An empirical example was conducted to test the applicability of the proposed method. The results showed that: (1) by imposing the linear fitting model on both the critical and intermediate points on the sub‐polylines in the proposed STLSC method, the positional differences between the original points and the simplified line are approximately in a normal distribution; and (2) by introducing both end‐point and area constraints in the proposed STLSC method, the areas of the simplified polygons are the same as those of the original ones at different scales, and the two neighboring fitted lines are connected to each other at the optimized position.
Voriconazole exposure and the risk of cutaneous squamous cell carcinoma in allogeneic hematopoietic stem cell transplant patients
Authors: Wojenski D.J. , Bartoo G.T. , Merten J.A. , Dierkhising R.A. , Barajas M.R. , el‐Azhary R.A. , Wilson J.W. , Plevak M.F. , Hogan W.J. , Litzow M.R. , Patnaik M.M. , Wolf R.C. , Hashmi S.K.
Published: February 2015

Background

Voriconazole is a commonly used antifungal medication in allogeneic hematopoietic stem cell transplantation (allo‐HSCT) patients. In solid organ transplantation, voriconazole use has been associated with the development of cutaneous squamous cell carcinoma (SCC). We sought to determine if voriconazole use was associated with SCC in patients undergoing allo‐HSCT.

Methods

We retrospectively reviewed consecutive adult patients who underwent allo‐HSCT at Mayo Clinic from January 2007 through July 2012. Multivariable Cox models were created to assess the relationship of SCC with two time‐dependent voriconazole exposure variables: (i) history of voriconazole exposure (yes/no), and (ii) cumulative days of voriconazole use.

Results

In our cohort of 381 allo‐HSCT patients, SCC developed in 26 of 312 patients exposed to voriconazole (25 post‐voriconazole) and in 1 of 69 patients who received alternative antifungal agent(s). Cumulative incidence of SCC was estimated to be 19% at 5 years post allo‐transplant. Cumulative days of voriconazole use was found to be a risk factor for SCC, and this relationship persisted in a multivariable model using previously identified risk factors as covariates (hazard ratio 1.859 for each 180 days of use, P < 0.001).

Conclusion

This is the first study, to our knowledge, to identify cumulative days of voriconazole use as a risk factor for SCC development following allo‐HSCT, and may help guide appropriate antifungal use in this patient population.
Changes in mitochondrial perilipin 3 and perilipin 5 protein content in rat skeletal muscle following endurance training and acute stimulated contraction
Authors: Ramos S. V. , Turnbull P. C. , MacPherson R. E. K. , LeBlanc P. J. , Ward W. E. , Peters S. J.
Published: February 2015

New Findings

What is the central question of this study?

The aim was to determine whether mitochondrial protein content of perilipin 3 (PLIN3) and perilipin 5 (PLIN5) is increased following endurance training and whether mitochondrial PLIN5 protein is increased to a greater extent in endurance‐trained rats when compared with sedentary rats following acute contraction.

What is the main finding and its importance?

Mitochondrial PLIN3 but not PLIN5 protein was increased in endurance‐trained compared with sedentary rats, suggesting a mitochondrial role for PLIN3 due to chronic exercise. Contrary to our hypothesis, acute mitochondrial PLIN5 protein was similar in both sedentary and endurance‐trained rats.

Endurance training results in an increased association between skeletal muscle lipid droplets and mitochondria. This association is likely to be important for the expected increase in intramuscular fatty acid oxidation that occurs with endurance training. The perilipin family of lipid droplet proteins, PLIN(2–5), are thought to play a role in skeletal muscle lipolysis. Recently, results from our laboratory demonstrated that skeletal muscle mitochondria contain PLIN3 and PLIN5 protein. Furthermore, 30 min of stimulated contraction induces an increased mitochondrial PLIN5 content. To determine whether mitochondrial content of PLIN3 and PLIN5 is altered with endurance training, Sprague–Dawley rats were randomized into sedentary or endurance‐trained groups for 8 weeks of treadmill running followed by an acute (30 min) sciatic nerve stimulation to induce lipolysis. Mitochondrial PLIN3 protein was ∼1.5‐fold higher in red gastrocnemius of endurance‐trained rats compared with sedentary animals, with no change in mitochondrial PLIN5 protein. In addition, there was an increase in plantaris intramuscular lipid storage. Acute electrically stimulated contraction in red gastrocnemius from sedentary and endurance‐trained rats resulted in a similar increase of mitochondrial PLIN5 between these two groups, with no net change in PLIN3 in either group. Plantaris intramuscular lipid content decreased to a similar extent in sedentary and endurance‐trained rats. These results suggest that while total mitochondrial PLIN5 content is not altered by endurance training, PLIN5 does have an acute role in the mitochondrial fraction during muscle contraction. Conversely, mitochondrial PLIN3 does not change acutely with muscle contraction, but PLIN3 content was increased following endurance training, indicating a role in chronic adaptations of skeletal muscle.
Three-Dimensional Flow in a Driven Cavity Subjected to an External Magnetic Field
Authors: Jin K. , Vanka S. P. , Thomas B. G.
Published: February 2015

In this paper, we study the three-dimensional (3D) flow of an electrically conducting fluid in a cubic cavity with the top wall moving and subjected to an external magnetic field. The governing flow and electromagnetic field equations are integrated by a second-order space and time accurate numerical scheme, implemented on a graphics processing unit (GPU) with high parallel efficiency. Solutions for several Reynolds and Stuart numbers have been obtained on sufficiently fine grids to achieve grid independent solutions. As expected, the magnetic field significantly influences the circulation in the cavity and modifies the shape and locations of the primary and secondary eddies. The observed flow patterns are illustrated graphically as well as through selected line plots and tabulated data. With increasing magnetic field strength, the center of the primary eddy is seen to shift to the top right corner. Further, situations where the flow is unsteady in the absence of the magnetic field have become steady after a certain value of the magnetic interaction parameter.
Measurements of Laminar Flame Speeds of Alternative Gaseous Fuel Mixtures
Authors: Ibrahim Ahmed S. , Ahmed Samer F.
Published: February 2015

Global warming and the ever increasing emission levels of combustion engines have forced the engine manufacturers to look for alternative fuels for high engine performance and low emissions. Gaseous fuel mixtures such as biogas, syngas, and liquefied petroleum gas (LPG) are new alternative fuels that have great potential to be used with combustion engines. In the present work, laminar flame speeds (SL) of alternative fuel mixtures, mainly LPG (60% butane, 20% isobutane, and 20% propane) and methane have been studies using the tube method at ambient conditions. In addition, the effect of adding other fuels and gases such as hydrogen, oxygen, carbon dioxide, and nitrogen on SL has also been investigated. The results show that any change in the fuel mixture composition directly affects SL. Measurements of SL of CH4/LPG–air mixtures have found to be about 56 cm/s at ø = 1.1 with 60% LPG in the mixture, which is higher than SL of both pure fuels at the same ø. Moreover, the addition of H2 and O2 to the fuel mixtures increases SL notably, while the addition of CO2/N2 mixture to the fuel mixture, to simulate the EGR effect, decreases SL of CH4/LPG–air mixtures.