bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of prostaglandin D2/CRTH2 pathway on asthma exacerbation induced by Aspergillus fumigatus
Authors: Liu Haixia , Zheng Mingrui , Qiao Jianou , Dang Yajie , Zhang Pengyu , Jin Xianqiao
Published: December 2013

Aspergillus fumigatus is often associated in asthmatic patients with the exacerbation of asthma symptoms. The pathomechanism of this phenomenon has not been fully understood. Here, we evaluated the immunological mechanisms and the role of the prostaglandin D2/ Chemoattractant Receptor‐Homologous Molecule Expressed on Th2 Cells (CRTH2) pathway in the development of Aspergillus‐associated asthma exacerbation. We studied the effects of A. fumigatus on airway inflammation and bronchial hyper‐responsiveness in a rat model of chronic asthma. Inhalation delivery of A. fumigatus conidia increased the airway eosinophilia and bronchial hyper‐responsiveness in ovalbumin‐sensitized, challenged rats. These changes were associated with prostaglandin D2 synthesis and CRTH2 expression in the lungs. Direct inflammation occurred in ovalbumin‐sensitized, challenged animals, whereas pre‐treatment with an antagonist against CRTH2 nearly completely eliminated the A. fumigatus‐induced worsening of airway eosinophilia and bronchial hyper‐responsiveness. Our data demonstrate that production of prostaglandin D2 followed by eosinophil recruitment into the airways via a CRTH2 receptor are the major pathogenic factors responsible for the A. fumigatus‐induced enhancement of airway inflammation and responsiveness.
Commonness patterns and the size of the species pool along a tropical elevational gradient: insights using a new quantitative tool
Authors: Arellano Gabriel , Cayola Leslie , Loza Isabel , Torrez Vania , Macía Manuel J.
Published: December 2013

The goal of this study was a quantitative assessment of two‐dimensional commonness in the lowland, dry, and montane tropical forests of the Madidi region (Bolivia). This region spans a large elevational and environmental gradient, with great diversity differences among sites. We aimed to correlate commonness patterns at different scales with elevation and with the size of the species pool. We also developed 1) a measure of ecological commonness and 2) a criterion to separate common from uncommon species; both based on the h index of academic productivity. With this approach, we calculated the 1) mean commonness of all species of the community; 2) proportion of common species of the community; and 3) mean commonness of the common species. The results showed that the commonness patterns in the Madidi region are strongly linked to the size of the species pool, independently of the environmental heterogeneity involved and the type of forest and spatial scale considered. Although these factors do not affect the general quality of the community, they do influence differences in commonness among species. Overall, we identified strong support for the oligarchy hypothesis, regardless of the strength of the pattern, and conclude that a quantitative approach to commonness could lead to great insights into community structure.
Why are there so many species in the tropics?
Authors: Brown James H.
Published: December 2013

Known for centuries, the geographical pattern of increasing biodiversity from the poles to the equator is one of the most pervasive features of life on Earth. A longstanding goal of biogeographers has been to understand the primary factors that generate and maintain high diversity in the tropics. Many ‘historical’ and ‘ecological’ hypotheses have been proposed and debated, but there is still little consensus. Recent discussions have centred around two main phenomena: phylogenetic niche conservatism and ecological productivity. These two factors play important roles, but accumulating theoretical and empirical studies suggest that the single most important factor is kinetics: the temperature dependence of ecological and evolutionary rates. The relatively high temperatures in the tropics generate and maintain high diversity because ‘the Red Queen runs faster when she is hot’.
The BRICS and Other Emerging Power Alliances and Multilateral Organizations in the Asia‐Pacific and the Global South: Challenges for the European Union and Its View on Multilateralism
Authors: Keukeleire Stephan , Hooijmaaijers Bas
Published: December 2013

Over the past decade the BRICS (Brazil, Russia, India, China and South Africa) and other emerging power alliances (such as BASIC [Brazil, South Africa, India and China] and IBSA [India, Brazil, South Africa]), as well as multilateral organizations in the Asia‐Pacific and the global south, have become increasingly important players on the world stage. None of the variations on Asian regionalism and emerging power alliances is in itself very influential. Taken together, however, they are not inconsequential for the European Union (EU) and its position on multilateralism. Their views on multilateralism differ from the EU's vision with regard to contents and methodology. Problematic for the EU is that their views not only structure the relations between the emerging powers themselves, but that these powers also increasingly try to promote them as the basic principles for structuring international relations and regimes on a global level.
Cyclooxygenase 2 expression and apoptosis in normal and psoriatic epidermis models exposed to salt water soaks and narrowband ultraviolet B radiation
Authors: Gambichler T. , Terras S. , Skrygan M.
Published: December 2013

Background

Combined treatment using salt water baths and artificial ultraviolet (UV) radiation (balneophototherapy, BPT) is a common therapeutic option for conditions such as psoriasis. However, it remains unknown whether pre‐treatment with salt water soaks alter inflammatory and/or carcinogenic effects of UVB phototherapy.

Objectives

We aimed to investigate the impact of BPT on COX‐2 gene expression and apoptosis in normal and psoriatic keratinocytes.

Methods

Normal epidermis models (NEM) and psoriatic epidermis models (PEM) were treated using different salt water soaks (3% NaCl, 30% NaCl, 30% Dead Sea salt; DSS) and subsequent narrowband ultraviolet B (NB‐UVB) for three consecutive days. RT‐PCR was performed for cyclooxygenase 2 (COX‐2), survivin, and caspase‐3.

Results

Compared with untreated controls COX‐2 mRNA was significantly increased in NB‐UVB irradiated NEM and PEM. NB‐UVB‐exposed and non‐exposed 30% NaCl and 30% DSS‐treated NEM and PEM (except for NB‐UVB‐exposed and non‐irradiated 30% DSS) showed significantly higher COX‐2 mRNA when compared with controls and 3% NaCl. In NB‐UVB‐exposed 30% NaCl and 30% DSS‐treated NEM and PEM survivin mRNA was significantly decreased when compared with controls and 3% NaCl. Compared with NB‐UVB‐exposed controls mRNA of caspase‐3 was significantly increased in NB‐UVB‐exposed 30% NaCl and 30% DSS‐treated PEM.

Conclusion

Although BPT using high‐concentrated salt water solutions is associated with increased epidermal COX‐2 mRNA expression, apoptosis of keratinocytes is enhanced possibly due to the down‐regulation of survivin mRNA expression. If confirmed in larger studies these observations have important implications for BPT efficacy as well as safety, particularly with regard to the risk of early carcinogenesis.
Inferring the mode of colonization of the rapid range expansion of a solitary bee from multilocusDNAsequence variation
Authors: Dellicour S. , Mardulyn P. , Hardy O. J. , Hardy C. , Roberts S. P. M. , Vereecken N. J.
Published: December 2013

Rapid geographic range expansions can have dramatic effects on the distribution of genetic diversity, both within and among populations. Based on field records collected over the past two decades in Western Europe, we report on the rapid geographic range expansion inColletes hederae, a solitary bee species. To characterize how this expansion shaped the distribution of genetic diversity within and among populations, we performed a genetic analysis based on the sequencing of three nuclear loci (RNAp,CADand WgL). We then simulated the evolution ofDNAsequences under a spatially explicit model of coalescence to compare different hypotheses regarding the mode of colonization associated with this rapid expansion and to identify those that are most consistent with the observed molecular data. Our genetic analyses indicate that the range expansion was not associated with an important reduction in genetic diversity, even in the most recently colonized area in the United Kingdom. Moreover, little genetic differentiation was observed among populations. Our comparative analysis of simulated data sets indicates that the observed genetic data are more consistent with a demographic scenario involving relatively high migration rates than with a scenario based on a high reproduction rate associated with few migrants. In the light of these results, we discuss the factors that might have contributed to the rapid geographic range expansion of this pollen‐specialist solitary bee species acrossWesternEurope.
The effect of population bottlenecks on mutation rate evolution in asexual populations
Authors: Raynes Y. , Halstead A. L. , Sniegowski P. D.
Published: December 2013

In the absence of recombination, a mutator allele can spread through a population by hitchhiking with beneficial mutations that appear in its genetic background. Theoretical studies over the past decade have shown that the survival and fixation probability of beneficial mutations can be severely reduced by population size bottlenecks. Here, we use computational modelling and evolution experiments with the yeast S. cerevisiae to examine whether population bottlenecks can affect mutator dynamics in adapting asexual populations. In simulation, we show that population bottlenecks can inhibit mutator hitchhiking with beneficial mutations and are most effective at lower beneficial mutation supply rates. We then subjected experimental populations of yeast propagated at the same effective population size to three different bottleneck regimes and observed that the speed of mutator hitchhiking was significantly slower at smaller bottlenecks, consistent with our theoretical expectations. Our results, thus, suggest that bottlenecks can be an important factor in mutation rate evolution and can in certain circumstances act to stabilize or, at least, delay the progressive elevation of mutation rates in asexual populations. Additionally, our findings provide the first experimental support for the theoretically postulated effect of population bottlenecks on beneficial mutations and demonstrate the usefulness of studying mutator frequency dynamics for understanding the underlying dynamics of fitness‐affecting mutations.
Socially flexible female choice and premating isolation in field crickets (Teleogryllus spp.)
Authors: Bailey N. W. , Macleod E.
Published: December 2013

Social influences on mate choice are predicted to influence evolutionary divergence of closely related taxa, because of the key role mate choice plays in reproductive isolation. However, it is unclear whether females choosing between heterospecific and conspecific male signals use previously experienced social information in the same manner or to the same extent that they do when discriminating among conspecific mates only. We tested this using two field cricket sister species (Teleogryllus oceanicus and Teleogryllus commodus), in which considerable information is known about the role of male calling song in premating isolation, in addition to the influence of acoustic experience on the development of reproductive traits. We manipulated the acoustic experience of replicate populations of both species and found, unexpectedly, that experience of male calling song during rearing did not change how accurate females were in choosing a conspecific over a heterospecific male song during playback trials. However, females with acoustic experience were considerably less responsive to male song compared with naïve females. Our results suggest that variation in the acoustic environment affects mate choice in both species, but that it may have a limited impact on premating isolation. The fact that social flexibility during interspecific mate discrimination does not appear to operate identically to that which occurs during conspecific mate discrimination highlights the importance of considering the context in which animals exercise socially flexible mating behaviours. We suggest an explanation for why social flexibility might be context dependent and discuss the consequences of such flexibility for the evolution of reproductive isolation.
The role of phylogeny and ecology in shaping morphology in 21 genera and 127 species of Australo‐Papuan myobatrachid frogs
Authors: Vidal‐García M. , Byrne P. G. , Roberts J. D. , Keogh J. S.
Published: December 2013

Body shape is predicted to differ among species for functional reasons and in relation to environmental niche and phylogenetic history. We quantified morphological differences in shape and size among 98.5% of the 129 species and all 21 genera of the Australo‐Papuan endemic myobatrachid frogs to test the hypothesis that habitat type predicts body shape in this radiation. We tested this hypothesis in a phylogenetic context at two taxonomic levels: across the entire radiation and within the four largest genera. Thirty‐four external measurements were taken on 623 museum specimens representing 127 species. Data for seven key environmental variables relevant to anurans were assembled for all Australian‐distributed species based on species' distributions and 131,306 locality records. The Australo‐Papuan myobatrachid radiation showed high diversity in adult body size, ranging from minute (15 mm snout–vent length) to very large species (92 mm), and shape, particularly sin relative limb length. Five main morphological and environmental summary variables displayed strong phylogenetic signal. There was no clear relationship between body size and environmental niche, and this result persisted following phylogenetic correction. For most species, there was a better match between environment/habitat and body shape, but this relationship did not persist following phylogenetic correction. At a broad level, species fell into three broad groups based on environmental niche and body shape: 1) species in wet habitats with relatively long limbs, 2) species in arid environments with relatively short limbs (many of which are forward or backward burrowers) and 3) habitat generalist species with a conservative body shape. However, these patterns were not repeated within the four largest genera − Crinia, Limnodynastes, Pseudophryne and Uperoleia. Each of these genera displayed a highly conservative anuran body shape, yet individual species were distributed across the full spectrum of Australian environments. Our results suggest that phylogenetic legacy is important in the evolution of body size and shape in Australian anurans, but also that the conservative body plan of many frogs works well in a wide variety of habitats.
Cultural transmission and the evolution of human behaviour: a general approach based on the Price equation
Authors: El Mouden C. , André J.‐B. , Morin O. , Nettle D.
Published: December 2013

Transmitted culture can be viewed as an inheritance system somewhat independent of genes that is subject to processes of descent with modification in its own right. Although many authors have conceptualized cultural change as a Darwinian process, there is no generally agreed formal framework for defining key concepts such as natural selection, fitness, relatedness and altruism for the cultural case. Here, we present and explore such a framework using the Price equation. Assuming an isolated, independently measurable culturally transmitted trait, we show that cultural natural selection maximizes cultural fitness, a distinct quantity from genetic fitness, and also that cultural relatedness and cultural altruism are not reducible to or necessarily related to their genetic counterparts. We show that antagonistic coevolution will occur between genes and culture whenever cultural fitness is not perfectly aligned with genetic fitness, as genetic selection will shape psychological mechanisms to avoid susceptibility to cultural traits that bear a genetic fitness cost. We discuss the difficulties with conceptualizing cultural change using the framework of evolutionary theory, the degree to which cultural evolution is autonomous from genetic evolution, and the extent to which cultural change should be seen as a Darwinian process. We argue that the nonselection components of evolutionary change are much more important for culture than for genes, and that this and other important differences from the genetic case mean that different approaches and emphases are needed for cultural than genetic processes.
Relationship between the epithelial expression of hMLH1, MDM2, and p63 and lower lip carcinogenesis
Authors: de Oliveira Denise Hélen Imaculada Pereira , de Sousa Lopes Maria Luiza Diniz , de Santana Sarmento Dmitry José , Queiroz Lélia Maria Guedes , da Costa Miguel Márcia Cristina , da Silveira Éricka Janine Dantas
Published: December 2013

Objectives

To evaluate the relationship between the epithelial expression of hMLH1, MDM2, and p63 in lower lip carcinogenesis, comparing the immunostaining of these proteins in cases of actinic cheilitis (AC) and lower lip squamous cell carcinoma (SCC).

Study Design

Forty cases of AC and 40 cases of SCC were studied, both lesions were of lower lip. Histological sections of 3 μm were submitted to immunoperoxidase method, and 1000 cells were counted for immunohistochemical analysis of lesions. The results were analyzed quantitatively, and expression was compared by the Mann–Whitney, Student t‐test, or one‐way ANOVA, adopting a level of significance of 5%.

Results

A higher percentage of epithelial cells expressing hMLH1 was observed in cases of AC without dysplasia or mild dysplasia (721.23 ± 88.116), whereas fewer positive cells were observed in lower lip SSCs (255.03 ± 199.47) when compared to the AC group (P < 0.001). Immunoexpression of MDM2 was higher in SCCs of the lower lip compared with AC (P = 0.019). For p63 protein, the expression was higher in AC than in SCC (P = 0.045).

Conclusion

The present results showed changes in the immunoexpression of hMLH1, MDM2, and p63 in epithelial cells from premalignant and malignant lip disease, supporting the hypothesis that these alterations are related to the process of lower lip carcinogenesis.
Cross-Sex Hormonal Treatment and Body Uneasiness in Individuals with Gender Dysphoria
Authors: Fisher Alessandra D. , Castellini Giovanni , Bandini Elisa , Casale Helen , Fanni Egidia , Benni Laura , Ferruccio Naika , Meriggiola Maria Cristina , Manieri Chiara , Gualerzi Anna , Jannini Emmanuele , Oppo Alessandro , Ricca Valdo , Maggi Mario , Rellini Alessandra H.
Published: December 2013

Introduction

Cross-sex hormonal treatment (CHT) used for gender dysphoria (GD) could by itself affect well-being without the use of genital surgery; however, to date, there is a paucity of studies investigating the effects of CHT alone.

Aims

This study aimed to assess differences in body uneasiness and psychiatric symptoms between GD clients taking CHT and those not taking hormones (no CHT). A second aim was to assess whether length of CHT treatment and daily dose provided an explanation for levels of body uneasiness and psychiatric symptoms.

Methods

A consecutive series of 125 subjects meeting the criteria for GD who not had genital reassignment surgery were considered.

Main Outcome Measures

Subjects were asked to complete the Body Uneasiness Test (BUT) to explore different areas of body-related psychopathology and the Symptom Checklist-90 Revised (SCL-90-R) to measure psychological state. In addition, data on daily hormone dose and length of hormonal treatment (androgens, estrogens, and/or antiandrogens) were collected through an analysis of medical records.

Results

Among the male-to-female (MtF) individuals, those using CHT reported less body uneasiness compared with individuals in the no-CHT group. No significant differences were observed between CHT and no-CHT groups in the female-to-male (FtM) sample. Also, no significant differences in SCL score were observed with regard to gender (MtF vs. FtM), hormone treatment (CHT vs. no-CHT), or the interaction of these two variables. Moreover, a two-step hierarchical regression showed that cumulative dose of estradiol (daily dose of estradiol times days of treatment) and cumulative dose of androgen blockers (daily dose of androgen blockers times days of treatment) predicted BUT score even after controlling for age, gender role, cosmetic surgery, and BMI.

Conclusions

The differences observed between MtF and FtM individuals suggest that body-related uneasiness associated with GD may be effectively diminished with the administration of CHT even without the use of genital surgery for MtF clients. A discussion is provided on the importance of controlling both length and daily dose of treatment for the most effective impact on body uneasiness.
Sleep enhances memory consolidation in children
Authors: Ashworth Anna , Hill Catherine M. , Karmiloff‐Smith Annette , Dimitriou Dagmara
Published: December 2013

Sleep is an active state that plays an important role in the consolidation of memory. It has been found to enhance explicit memories in both adults and children. However, in contrast to adults, children do not always show a sleep‐related improvement in implicit learning. The majority of research on sleep‐dependent memory consolidation focuses on adults; hence, the current study examined sleep‐related effects on two tasks in children. Thirty‐three typically developing children aged 6–12 years took part in the study. Actigraphy was used to monitor sleep. Sleep‐dependent memory consolidation was assessed using a novel non‐word learning task and the Tower of Hanoi cognitive puzzle, which involves discovering an underlying rule to aid completion. Children were trained on the two tasks and retested following approximately equal retention intervals of both wake and sleep. After sleep, children showed significant improvements in performance of 14% on the non‐word learning task and 25% on the Tower of Hanoi task, but no significant change in score following the wake retention interval. Improved performance on the Tower of Hanoi may have been due to children consolidating explicit aspects of the task, for example rule‐learning or memory of previous sequences; thus, we propose that sleep is necessary for consolidation of explicit memory in children. Sleep quality and duration were not related to children's task performance. If such experimental sleep‐related learning enhancement is generalizable to everyday life, then it is clear that sleep plays a vital role in children's educational attainment.
Identification of PDE5A:E90K: A Polymorphism in the Canine Phosphodiesterase 5A Gene Affecting Basal cGMP Concentrations of Healthy Dogs
Authors: Stern J. A. , Reina‐Doreste Y. , Chdid L. , Meurs K. M.
Published: December 2013

Background

Cyclic guanosine monophosphate (cGMP)‐specific phosphodiesterase (PDE5A) is the target of phosphodiesterase inhibitors such as sildenafil. Polymorphisms in the PDE5A gene that may predict response to therapy with sildenafil and nitric oxide, be linked to disease progression, and aid in risk assessment have been identified in human beings. Identification of polymorphisms in PDE5A could affect the physiologic actions of PDE5A and the effects of phosphodiestrase type 5 inhibitor drugs.

Hypothesis/Objective

Functional polymorphisms exist in the canine PDE5A gene. Specific objectives were to identify PDE5A polymorphisms and evaluate their functional relevance.

Animals

Seventy healthy dogs.

Methods

The exonic, splice‐site, 3′ and 5′ untranslated regions of the canine PDE5A gene were sequenced in 15 dogs and aligned with the canine reference sequence. Identified polymorphisms were evaluated in 55 additional, healthy, unrelated dogs of 20 breeds. Plasma was collected from 51 of these dogs and cGMP was measured. An unpaired t‐test and one‐way ANOVA with Dunnett's test of multiple comparisons were used to evaluate the effect of genotype on cGMP.

Results

A common exonic polymorphism was identified that changed glutamic acid to lysine and resulted in significantly lower cGMP concentrations in the group with polymorphism versus the wild type group (P = .014). Additionally, 6 linked single nucleotide polymorphisms in the 3′ untranslated region were identified that did not alter cGMP concentrations.

Conclusions and Clinical Importance

A polymorphism exists in the canine PDE5A gene that is associated with variable circulating cGMP concentrations in healthy dogs and warrants investigation in diseases such as pulmonary hypertension.
Pharmacokinetic–pharmacodynamic integration and modelling of florfenicol in calves
Authors: Sidhu P. , Rassouli A. , Illambas J. , Potter T. , Pelligand L. , Rycroft A. , Lees P.
Published: December 2013

Florfenicol was administered subcutaneously to 10 calves at a dose of 40 mg/kg. Pharmacokinetic–pharmacodynamic (PK‐PD) integration and modelling of the data were undertaken using a tissue cage model, which allowed comparison of microbial growth inhibition profiles in three fluids, serum, exudate and transudate. Terminal half‐lives were relatively long, so that florfenicol concentrations were well maintained in all three fluids. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined in vitro for six strains each of the calf pneumonia pathogens, Mannhemia haemolytica and Pasteurella multocida. An PK‐PD integration for three serum indices provided mean values for P. multocida and M. haemolytica, respectively, of 12.6 and 10.4 for Cmax/MIC, 183 and 152 h for AUC0–24 h/MIC and 78 and 76 h for T>MIC. Average florfenicol concentrations in serum exceeded 4 × MIC and 1.5 × MIC for the periods 0–24 and 48–72 h, respectively. Ex vivo growth inhibition curves for M. haemolytica and P. multocida demonstrated a rapid (with 8 h of exposure) and marked (6 log10 reduction in bacterial count or greater) killing response, suggesting a concentration‐dependent killing action. During 24‐h incubation periods, inhibition of growth to a bacteriostatic level or greater was maintained in serum samples collected up to 96 h and in transudate and exudate samples harvested up to 120 h. Based on the sigmoidal Emax relationship, PK‐PD modelling of the ex vivo time–kill data provided AUC0–24 h/MIC serum values for three levels of growth inhibition, bacteriostatic, bactericidal and 4 log10 decrease in bacterial count; mean values were, respectively, 8.2, 26.6 and 39.0 h for M. haemolytica and 7.6, 18.1 and 25.0 h for P. multocida. Similar values were obtained for transudate and exudate. Based on pharmacokinetic and PK‐PD modelled data obtained in this study and scientific literature values for MIC distributions, Monte Carlo simulations over 100 000 trials were undertaken to predict once daily dosages of florfenicol required to provide 50% and 90% target attainment rates for three levels of growth inhibition, namely, bacteriostasis, bactericidal action and 4 log10 reduction in bacterial count.
Topography and edge effects are more important than elevation as drivers of vegetation patterns in a neotropical montane forest
Authors: Lippok Denis , Beck Stephan G. , Renison Daniel , Hensen Isabell , Apaza Amira E. , Schleuning Matthias
Published: December 2013

Aims

The high plant species diversity of tropical mountain forests is coupled with high habitat heterogeneity along gradients in elevation and topography. We quantified the effects of elevation, topography and forest edge on habitat conditions and woody plant diversity of tropical montane forest fragments.

Location

Tropical montane forest fragments, ‘Yungas’, Bolivia.

Methods

We measured microclimate and sampled soil properties and woody vegetation at forest edges and in the forest interior on ridges and in gorges along an elevational gradient of 600 m. We analysed effects of elevation, topography and forest edge on habitat conditions (i.e. microclimate, soil properties and forest structure), species richness, evenness and composition with linear mixed effects models and detrended correspondence analysis (DCA).

Results

Changes in habitat conditions were weaker along the elevational gradient than between forest interior and forest edge and between different topographies. Species richness was not affected by any gradient, while species evenness was reduced at forest edges. All three gradients affected species composition, while effects of topography and forest edge were stronger than that of elevation.

Conclusions

In general, effects of the 600‐m elevational gradient were weak compared to effects of forest edge and topography. Edge effects shifted species composition towards pioneer species, while topographical heterogeneity is particularly important for generating high diversity in montane forests. These results underscore that edge effects have severe consequences in montane forest remnants and that small‐scale variation between topographical microhabitats should be considered in studies that predict monotonous upslope migrations of plant species in tropical montane forests due to global warming.
Does the Initial Floristic Composition model of succession really work?
Authors: Wilson J. Bastow
Published: December 2013

Harvey & Holzman, in this issue of the Journal of Vegetation Science, describe divergent successional pathways after fire in Pinus muricata forest. Fourteen years after fire, the shrub Ceanothus thyrsiflorus had occupied flat parts of the area. They predicted it would continue to prevent succession to P. muricata forest, as in the initial floristic composition concepts of Clements and Egler.
Climatic niche shifts in the serpentine soil flora of California
Authors: Burge Dylan O. , Salk Carl F.
Published: December 2013

Question

Soil properties are known to have a profound effect on the geographic distribution of plants. Unusual soils seem to allow species to occur outside their ‘typical’ (realized) climatic niche. However, the generality of this pattern, and the mechanisms that drive it, are poorly known. Here, we focus on the tendency for some plant species to occur at unusually low elevations on infertile substrates, especially serpentine soils. We ask whether there is a flora‐wide trend in the state of California toward lower elevations and warmer thermal limits on infertile serpentine soils than on other soils.

Location

State of California, USA.

Methods

We used herbarium data from 19 institutions. We only used species collected from both serpentine and non‐serpentine soils. To focus on plant response to recent climate, we discarded records from before 1979. Finally, we discarded records that did not report latitude and longitude. The final data set consisted of 36 045 specimens representing 814 species. Latitude and longitude were used to infer elevation, temperature and soil type. We then developed a simulation modelling approach to test for significant differences in elevational and thermal distribution between serpentine and non‐serpentine soils.

Results

Serpentine populations are found at lower elevations than non‐serpentine populations, at both the low and high ends of elevation distributions (two tailed t‐test, P < 0.01). This pattern is partially matched by temperature: both high and low temperature data indicate that serpentine populations are limited to less extreme temperatures than non‐serpentine populations (two tailed t‐test, P < 0.01).

Conclusions

We show that there is a flora‐wide trend toward lower elevation limits on serpentine soils in the state of California. Temperature data suggest a slightly different pattern, with serpentine plants occupying more moderate temperatures. We suggest that this difference may be due to a decoupling of elevation and temperature in some parts of California. Overall, our results are consistent with two mechanisms of plant range limitation: (1) a biotic mechanism at lower elevations (high temperatures), where serpentine provides a refuge from competition; and (2) an abiotic limit at upper elevations (low temperatures), where the effect of cold is exacerbated by the infertility of serpentine.
Neutron absorption constraints on the composition of 4 Vesta
Authors: Prettyman Thomas H. , Mittlefehldt David W. , Yamashita Naoyuki , Beck Andrew W. , Feldman William C. , Hendricks John S. , Lawrence David J. , McCoy Timothy J. , McSween Harry Y. , Peplowski Patrick N. , Reedy Robert C. , Toplis Michael J. , Le Corre Lucille , Mizzon Hugau , Reddy Vishnu , Titus Timothy N. , Raymond Carol A. , Russell Christopher T.
Published: December 2013

Global maps of the macroscopic thermal neutron absorption cross section of Vesta's regolith by the Gamma Ray and Neutron Detector (GRaND) on board the NASA Dawn spacecraft provide constraints on the abundance and distribution of Fe, Ca, Al, Mg, and other rock‐forming elements. From a circular, polar low‐altitude mapping orbit, GRaND sampled the regolith to decimeter depths with a spatial resolution of about 300 km. At this spatial scale, the variation in neutron absorption is about seven times lower than that of the Moon. The observed variation is consistent with the range of absorption for howardite whole‐rock compositions, which further supports the connection between Vesta and the howardite, eucrite, and diogenite meteorites. We find a strong correlation between neutron absorption and the percentage of eucritic materials in howardites and polymict breccias, which enables petrologic mapping of Vesta's surface. The distribution of basaltic eucrite and diogenite determined from neutron absorption measurements is qualitatively similar to that indicated by visible and near infrared spectroscopy. The Rheasilvia basin and ejecta blanket has relatively low absorption, consistent with Mg‐rich orthopyroxene. Based on a combination of Fe and neutron absorption measurements, olivine‐rich lithologies are not detected on the spatial scales sampled by GRaND. The sensitivity of GRaND to the presence of mantle material is described and implications for the absence of an olivine signature are discussed. High absorption values found in Vesta's “dark” hemisphere, where exogenic hydrogen has accumulated, indicate that this region is richer in basaltic eucrite, representative of Vesta's ancient upper crust.
NEMATIC: a simple and versatile tool for the in silico analysis of plant–nematode interactions
Authors: Cabrera Javier , Bustos Regla , Favery Bruno , Fenoll Carmen , Escobar Carolina
Published: December 2013

Novel approaches for the control of agriculturally damaging nematodes are sorely needed. Endoparasitic nematodes complete their life cycle within the root vascular cylinder, inducing specialized feeding cells: giant cells for root‐knot nematodes and syncytia for cyst nematodes. Both nematodes hijack parts of the transduction cascades involved in developmental processes, or partially mimic the plant responses to other interactions with microorganisms, but molecular evidence of their differences and commonalities is still under investigation. Transcriptomics has been used to describe global expression profiles of their interaction with Arabidopsis, generating vast lists of differentially expressed genes. Although these results are available in public databases and publications, the information is scattered and difficult to handle. Here, we present a rapid, visual, user‐friendly and easy to handle spreadsheet tool, called NEMATIC (NEMatode–Arabidopsis Transcriptomic Interaction Compendium; http://www.uclm.es/grupo/gbbmp/english/nematic.asp). It combines existing transcriptomic data for the interaction between Arabidopsis and plant‐endoparasitic nematodes with data from different transcriptomic analyses regarding hormone and cell cycle regulation, development, different plant tissues, cell types and various biotic stresses. NEMATIC facilitates efficient in silico studies on plant–nematode biology, allowing rapid cross‐comparisons with complex datasets and obtaining customized gene selections through sequential comparative and filtering steps. It includes gene functional classification and links to utilities from several databases. This data‐mining spreadsheet will be valuable for the understanding of the molecular bases subjacent to feeding site formation by comparison with other plant systems, and for the selection of genes as potential tools for biotechnological control of nematodes, as demonstrated in the experimentally confirmed examples provided.
Enhanced nicotinic receptor mediated relaxations in gastroesophageal muscle fibers from Barrett's esophagus patients
Authors: Miller L. S. , Vegesna A. K. , Braverman A. S. , Barbe M. F. , Ruggieri M. R.
Published: December 2013

Background

Increased nicotinic receptor mediated relaxation in the gastroesophageal antireflux barrier may be involved in the pathophysiology of reflux. This study is designed to determine whether the defects we previously identified in gastroesophageal reflux disease patients in‐ vivo are due to abnormalities of the gastric sling, gastric clasp, or lower esophageal circular (LEC) muscle fibers.

Methods

Muscle strips from whole stomachs and esophagi were obtained from 16 normal donors and 15 donors with histologically proven Barrett's esophagus. Contractile and relaxant responses of gastric sling, gastric clasp, or LEC fibers were determined to increasing concentrations of carbachol and to nicotine after inducing maximal contraction to bethanechol. Muscarinic receptor density was measured using subtype selective immunoprecipitation.

Key Results

Barrett's esophagus gastric sling and LEC fibers have decreased carbachol‐induced contractions. Barrett's esophagus sling fibers have decreased M2‐muscarinic receptors and LEC fibers have decreased M3 receptors. Relaxations of all three fiber types are greater in Barrett's esophagus specimens to both high carbachol concentrations and to nicotine following bethanechol precontraction. The maximal response to bethanechol is greater in Barrett esophagus sling and LEC fibers.

Conclusions & Inferences

The increased contractile response to bethanechol in Barrett's specimens indicates that the defect is likely not due to the smooth muscle itself. The enhanced nicotinic receptor mediated response may be involved in greater relaxation of the muscles within the high‐pressure zone of the gastroesophageal junction during transient lower esophageal sphincter relaxations and during deglutitive inhibition and may be involved in the pathophysiology of gastroesophageal reflux disease.
Wood specific gravity and anatomy of branches and roots in 113 Amazonian rainforest tree species across environmental gradients
Authors: Fortunel Claire , Ruelle Julien , Beauchêne Jacques , Fine Paul V. A. , Baraloto Christopher
Published: December 2013

Wood specific gravity (WSG) is a strong predictor of tree performance across environmental gradients. Yet it remains unclear how anatomical elements linked to different wood functions contribute to variation in WSG in branches and roots across tropical forests.

We examined WSG and wood anatomy in white sand, clay terra firme and seasonally flooded forests in French Guiana, spanning broad environmental gradients found throughout Amazonia. We measured 15 traits relating to branches and small woody roots in 113 species representing the 15 most abundant species in each habitat and representative species from seven monophyletic lineages occurring in all habitats.

Fiber traits appear to be major determinants of WSG, independent of vessel traits, in branches and roots. Fiber traits and branch and root WSG increased from seasonally flooded species to clay terra firme species and lastly to white sand species. Branch and root wood traits were strongly phylogenetically constrained. Lineages differed in wood design, but exhibited similar variation in wood structure across habitats.

We conclude that tropical trees can invest differently in support and transport to respond to environmental conditions. Wind disturbance and drought stress represent significant filters driving tree distribution of Amazonian forests; hence we suggest that biophysical explanations should receive more attention.
Rejection is less common in children undergoing liver transplantation for hepatoblastoma
Authors: Ruth N. D. , Kelly D. , Sharif K. , Morland B. , Lloyd C. , McKiernan P. J.
Published: December 2013

To compare the incidence of acute histologically proven rejection in children who have had a liver transplant for hepatoblastoma with a control group of children transplanted for biliary atresia (EHBA). A retrospective case notes based study was performed. Twenty patients were identified with hepatoblastoma who were transplanted at a single unit between 1991 and 2008. These were matched as closely as possible for age, gender, year of transplant and type of immunosuppression used to the control group transplanted for biliary atresia (n = 60). There was a significant decrease in rate of acute rejection as assessed by the rejection activity index (RAI) in the hepatoblastoma group (75% vs. 50%, respectively, p < 0.04). Chronic rejection was rare in both groups, but twice as common in the biliary atresia group. Equal levels of immunosuppression were achieved in both groups. Renal function was noted to be reduced one yr post‐transplant in both groups, as previously reported. A modified immunosuppression regimen could be considered in children with hepatoblastoma undergoing liver transplantation.
Early protocol biopsies in pediatric renal transplantation: Interest for the adaptation of immunosuppression
Authors: Bruel Alexandra , Allain‐Launay Emma , Humbert Julie , Ryckewaert Amélie , Champion Gérard , Moreau Anne , Renaudin Karine , Karam Georges , Roussey‐Kesler Gwenaelle
Published: December 2013

GPB are often performed in PRT to detect subclinical acute rejection or IF/TA. Reducing immunosuppression side effects without increasing rejection is a major concern in PRT. We report the results of GPB in children transplanted with a steroid‐sparing protocol adapted to immunological risk. Children under 18 yr who received a renal transplantation between April 1, 2009 and May 31, 2012 were included. Immunosuppression consisted of an antibody induction therapy, tacrolimus, and MMF for all recipients. CSs were administered to children under five yr old, or receiving a second allograft. Twenty‐eight children were included, 50% were CSs free. GPB were performed between three and six months. IF/TA was documented in seven biopsies; four of these seven children were CS free. One child, with CSs, presented a borderline rejection, and another child, steroid free, with significant inflammatory interstitial infiltrate, considered as a subclinical rejection, was treated with CSs pulses. The median eGFR was stable (74, 67.5, and 82 mL/min/1.73 m² at, respectively, seven days, three months, and one yr). Patient and graft survival were 100%. These results have to be confirmed in a larger cohort, with long‐term follow‐up.
Management of late‐onset portal vein complications in pediatric living‐donor liver transplantation
Authors: Cho Yong‐Pil , Kim Kyung‐Mo , Ha Tae‐Yong , Ko Gi‐Young , Hwang Jae‐Yeon , Park Hojong , Chung Young Soo , Yoon Taein , Hwang Shin , Jun Heungman , Kwon Tae‐Won , Lee Sung‐Gyu
Published: December 2013

The purpose of this study was to evaluate retrospectively the results of PTA for late‐onset PV complications after pediatric LDLT and to assess whether a meso‐Rex shunt is a viable option for treating restenosis of the PV after PTA in selected cases. Seventy‐five children who underwent adult‐to‐child LDLT were included in this study, and there were six late‐onset PV complications (8.0%). The initial therapeutic approach was PTA, with or without stent: PTA with balloon dilation for three children, PTA with stent placement for one child, and failure to cannulate the occluded PV for two children. A meso‐Rex shunt was performed in the two children after failed PTA: One suffered complete obstruction of the main PV, and the other, restenosis with total thrombosis after PTA with stent. The PTA was a technical and clinical success in four with PV stenosis of the six patients (66.7%), and successful application of a meso‐Rex shunt in the other two children resulted in restoration of PV flow. In conclusion, PTA is a safe and effective procedure for treating late‐onset PV stenosis after pediatric LDLT. However, in growing pediatric recipients with restenosis of the PV after PTA or chronic PV thrombosis, a meso‐Rex shunt may be a better choice for late‐onset PV complications.
BK virus nephropathy complicated with meningoencephalitis after kidney transplantation
Authors: Rocha Ana , Faria Sameiro , Costa Teresa , Marques Laura , Freitas Cristina , Mota Conceição
Published: December 2013

BK disease is an opportunistic infection in organ transplant recipients and patients with other cellular immunodeficiencies. To the best of our knowledge, we report the second case of BK meningoencephalitis associated with nephropathy in a kidney transplant recipient. A 15‐yr‐old boy underwent a cadaveric kidney transplant without complications; however, 11 wk after the transplantation, he was admitted to the hospital for graft dysfunction and cytopenia, which were confirmed by BK nephropathy (plasma viral replication and histological evidence). Four days after his hospital admission, he developed a high‐grade fever and headache. CSF analysis revealed pleocytosis with a positive PCR for BK virus. Reduction in immunosuppression and supportive care conducting cycles of immunoglobulin and cidofovir were successful in treating the patient. BK meningoencephalitis should be considered in kidney transplant recipients who present with signs and symptoms of meningoencephalitis.
Phytic acid in green leaves
Authors: Hadi Alkarawi H. , Zotz G.
Published: December 2013

Phytic acid or phytate, the free‐acid form of myo‐inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid‐P averaged 2.3 mg·g−1, and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid‐P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention.
The hard life of Phytophthora infestans: when trade‐offs shape evolution in a biotrophic plant pathogen
Authors: Andrivon D. , Montarry J. , Corbière R. , Pasco C. , Glais I. , Marquer B. , Clément J. A. J. , Castel M. , Hamelin F. M.
Published: December 2013

The strict dependency of biotrophic pathogens upon living host tissue for multiplication and survival makes them particularly exposed to evolutionary trade‐offs. Such trade‐offs can occur both between life history traits directly involved in pathogenicity (e.g. fitness costs due to unnecessary virulence factors), or between traits involved in either pathogenicity (within‐season fitness) or survival (between‐season fitness). Both types of trade‐offs should result in the limitation of maximum pathogenicity, and shape the invasive potential of pathogen genotypes. While strong theoretical developments have been made on evolutionary consequences, including recent work taking seasonality into account (i.e. periodic host absence and/or periodic sexual/asexual reproduction), experimental evidence to confirm theoretical predictions is still scarce. This paper will therefore attempt to illustrate the different kinds of trade‐offs that can be measured, and their likely consequences, taking Phytophthora infestans (the cause of potato and tomato late blight) as a case study.