Andreas Baierl

Range and severity of a plant disease increased by global warming

Climate change affects plants in natural and agricultural ecosystems throughout the world but little work has been done on the effects of climate change on plant disease epidemics. To illustrate such effects, a weather-based disease forecasting model was combined with a climate change model predicting UK temperature and rainfall under high- and low-carbon emissions for the 2020s and 2050s. Multi-site data collected over a 15-year period were used to develop and validate a weather-based model forecasting severity of phoma stem canker epidemics on oilseed rape across the UK. This was combined with climate change scenarios to predict that epidemics will not only increase in severity but also spread northwards by the 2020s. These results provide a stimulus to develop models to predict the effects of climate change on other plant diseases, especially in delicately balanced agricultural or natural ecosystems. Such predictions can be used to guide policy and practice in adapting to effects of climate change on food security and wildlife.

Chin up: are the bright throats of male common frogs a condition-independent visual cue?

Male mating success is generally governed by either female choice or male–male competition and multiple cues may influence both processes. Anuran amphibians are best known for acoustic communication but visual cues have also been found to play a role. Little is known, however, about visual cues in explosively breeding anurans in which sexual selection is based almost exclusively on male–male competition. During their search for mates, males may not distinguish between the sexes or species and mismating attempts are known to occur. Assuming that mismatings are costly for males, one would expect selection to favour a trait that facilitates sex recognition. We determined the colour of the explosively breeding common frog, Rana temporaria, during reproduction by spectrophotometry. While reflectance of all body parts in both sexes decreased from immigration to spawning, reflectance of male throats increased significantly. The mean luminance of male throats was more than twice that of female throats. Male throats contrasted most against male flanks with luminance contrast being significantly higher than chromatic contrast. In an experiment with individually marked frogs, throat luminance was not correlated with male size, body condition or the physical presence of females, whereas temperature showed a significantly positive effect. Our results give no hint that throats indicate male status or indicate male quality. Considering the high densities during breeding, our results suggest that bright male throats can act as a visual signal among males to facilitate gender recognition and avoid attacks by other males.

MNS16A tandem repeats minisatellite of human telomerase gene: a risk factor for colorectal cancer

Telomerase reactivation and expression of human telomerase gene [human telomerase reverse transcriptase (hTERT)] are hallmarks of unlimited proliferation potential of cancer cells. A polymorphic tandem repeats minisatellite of hTERT gene, termed MNS16A was reported to influence hTERT expression. To assess the role of MNS16A as potential biomarker for colorectal cancer (CRC), we investigated for the first time the association of MNS16A genotypes with risk of colorectal polyps and CRC. In the ongoing colorectal cancer study of Austria (CORSA), 3842 Caucasian participants were recruited within a large screening project in the province Burgenland including 90 CRC cases, 308 high-risk polyps, 1022 low-risk polyps and 1822 polyp free controls verified by colonoscopy. MNS16A genotypes were determined by polymerase chain reaction from genomic DNA. Associations of MNS16A genotypes with CRC risk were estimated by logistic regression analysis computing odds ratios (ORs) and 95% confidence intervals (CIs). We identified five different variable number of tandem repeats (VNTRs) of MNS16A including VNTR-364, a newly discovered rare variant. VNTR-274 allele was associated with a 2.7-fold significantly increased risk of CRC compared with the VNTR-302 wild-type (OR = 2.69; 95% CI = 1.11-6.50; P = 0.028). In our CORSA study, the medium length VNTR-274 was identified as risk factor for CRC. Although, this population-based study herewith reports the largest cohort size concerning MNS16A thus far, further large-scale studies in diverse populations are warranted to confirm hTERT MNS16A genotype as potential biomarker for assessment of CRC risk.

Differential effects of polymorphic alleles of FGF receptor 4 on colon cancer growth and metastasis.

A gly(388)arg polymorphism (rs351855) in the transmembrane domain of the fibroblast growth factor receptor (FGFR4) is associated with increased risk, staging, and metastasis in several different types of cancer. To specifically assess the impact of the polymorphic FGFR4 in colorectal cancer (CRC), we engineered CRC cell lines with distinct endogenous expression patterns to overexpress either the FGFR4(gly) or FGFR4(arg) alleles. The biologic analyses revealed an oncogenic importance for both polymorphic alleles, but FGFR4(gly) was the stronger inducer of tumor growth, whereas FGFR4(arg) was the stronger inducer of migration. An evaluation of clinical specimens revealed that FGFR4 was upregulated in 20/71 patients independent of gly(388)arg status. There was no correlation between the presence of an FGFR4(arg) allele and CRC or polyp risk in 3,471 participants of the CORSA study. However, among 182 patients with CRC, FGFR4(arg)-carriers had a fivefold higher risk of tumors that were stage II or greater. Together, our results established that both allelic forms of FGFR4 exert an oncogenic impact and may serve equally well as therapeutic targets in CRC. One important implication of our findings is that FGFR4(arg)-carriers are at a higher risk for more aggressive tumors and therefore may profit from early detection measures.

Locating multiple interacting quantitative trait loci using rank-based model selection

In previous work, a modified version of the Bayesian information criterion (mBIC) was proposed to locate multiple interacting quantitative trait loci (QTL). Simulation studies and real data analysis demonstrate good properties of the mBIC in situations where the error distribution is approximately normal. However, as with other standard techniques of QTL mapping, the performance of the mBIC strongly deteriorates when the trait distribution is heavy tailed or when the data contain a significant proportion of outliers. In the present article, we propose a suitable robust version of the mBIC that is based on ranks. We investigate the properties of the resulting method on the basis of theoretical calculations, computer simulations, and a real data analysis. Our simulation results show that for the sample sizes typically used in QTL mapping, the methods based on ranks are almost as efficient as standard techniques when the data are normal and are much better when the data come from some heavy-tailed distribution or include a proportion of outliers.

The effect of six months of elastic band resistance training, nutritional supplementation or cognitive training on chromosomal damage in institutionalized elderly

Increased DNA and chromosomal damage are linked to aging and age-related diseases like cardiovascular diseases, diabetes or cancer. Physical activity and an optimal status of micro- and macronutrients are known to reduce the incidence of MN, a marker for chromosomal instability and mutagenicity. Once older people reach a certain age they change from a home-living situation to an institutionalized situation, which is often accompanied by malnutrition, depression and inactivity. We conducted the current study to investigate the effect of a six month progressive resistance training (RT), with or without protein and vitamin supplementation (RTS) or cognitive training (CT) only, on chromosomal damage measured by the cytokinesis block micronucleus cytome assay in 97 Austrian institutionalized women and men (65-98years). All three intervention groups demonstrated a tendency of a reduced frequency of cells with MN (-15%) as well as for the total number of MN (-20%), however no significant time-effect was observed. Besides a significant increase in plasma B12 and red blood cell folate status, the six month change of B12 was negatively correlated with the six month change of the MN frequency in the RTS group (r=-0.584, p=0.009). Our results suggest that in this age group either physical or cognitive training may result in similar biochemical changes and therefore enhance resistance against genomic instability. Supplementation with the vitamins B12 and folic acid could contribute to reduced chromosomal damage in institutionalized elderly.

Association of genetic variants of human telomerase with colorectal polyps and colorectal cancer risk.

Human telomerase reverse transcriptase (TERT) gene encodes the catalytic subunit of telomerase and is located on chromosome 5p15, a genomic region which was found to be associated with multiple cancer types. But no associations with colorectal cancer (CRC) have been reported until recently. Therefore, the purpose of this study was to investigate the influence of seven single‐nucleotide polymorphisms (SNPs) of TERT on susceptibility to colorectal polyps and CRC. The study population of our ongoing colorectal cancer study of Austria (CORSA) comprised 3,842 Caucasian participants. A total of 3,264 participants was genotyped including 142 CRC cases, 492 high‐risk polyps, 837 low‐risk polyps, and 1,793 polyp‐free controls verified by colonoscopy. Genotyping was performed by TaqMan assay using genomic DNA. The impact of each SNP was estimated by multiple logistic regression analyses performed with R Version 2.11.1. None of the investigated TERT SNPs (rs2736122, rs2853676, rs2735940, rs2736098, rs2075786, rs2736100, rs4975605) were found to be associated with risk of CRC nor colonic polyps. However, the haplotype CGTATGG was associated with a significantly increased risk of high‐risk polyps (OR = 1.48, 95% CI 1.01–2.17, P = 0.043). In accordance with other studies our results suggest no major influence of the investigated TERT SNPs on CRC and colorectal polyp risk. However, relevance of telomerase in tumorigenesis of multiple malignancies demands further investigations of the 5p15 locus concerning CRC susceptibility.

Influence of a multiple emulsion, liposomes and a microemulsion gel on sebum, skin hydration and TEWL

In this study, the influence of three cosmetically relevant, priorly characterized vehicles on skin hydration, sebum content and transepidermal water loss was investigated. The chosen vehicles included a liposomal pre‐formulation, a multiple W/O/W emulsion and a microemulsion gel. The in vivo effects of these vehicles were demonstrated and compared among them.

Genetic Ablation of Fgf23 or Klotho Does not Modulate Experimental Heart Hypertrophy Induced by Pressure Overload.

Left ventricular hypertrophy (LVH) ultimately leads to heart failure in conditions of increased cardiac pre- or afterload. The bone-derived phosphaturic and sodium-conserving hormone fibroblast growth factor-23 (FGF23) and its co-receptor Klotho have been implicated in the development of uremic LVH. Using transverse aortic constriction (TAC) in gene-targeted mouse models, we examine the role of Fgf23 and Klotho in cardiac hypertrophy and dysfunction induced by pressure overload. TAC profoundly increases serum intact Fgf23 due to increased cardiac and bony Fgf23 transcription and downregulation of Fgf23 cleavage. Aldosterone receptor blocker spironolactone normalizes serum intact Fgf23 levels after TAC by reducing bony Fgf23 transcription. Notably, genetic Fgf23 or Klotho deficiency does not influence TAC-induced hypertrophic remodelling, LV functional impairment, or LV fibrosis. Despite the profound, aldosterone-mediated increase in circulating intact Fgf23 after TAC, our data do not support an essential role of Fgf23 or Klotho in the pathophysiology of pressure overload-induced cardiac hypertrophy.

Spatial Aspects of Light Leaf Spot (Pyrenopeziza brassicae) Epidemic Development on Winter Oilseed Rape (Brassica napus) in the United Kingdom

ABSTRACT In microplot experiments in 1998-99 and 1999-2000, the start of light leaf spot epidemics could be predicted from weather data, using empirical equations for Pyrenopeziza brassicae apothecial (ascospore) development, ascospore infection criteria, and the latent period of P. brassicae. The dates when P. brassicae sporulation was first observed fitted predictions and initial spread of light leaf spot from an inoculum source was mostly in the prevailing wind direction, with differences between the two growing seasons attributable to differences in wind patterns. Subsequent secondary spread of disease could be predicted using temperature and rainfall data, and observations fitted predicted dates. In both 1998-99 and 1999-2000, initial spatial patterns of observed disease in January were random, because data were not significantly different from a binomial distribution (P = 0.18). Analysis of spatial data from samples in February and March indicated aggregation, because data fit was significantly different from a binomial distribution (P </= 0.026). These data were described by a beta-binomial distribution, suggesting that the spatial distribution of light leaf spot becomes aggregated as secondary spread occurs. The importance of wind-dispersed ascospores in initiating epidemics and rain-splashed conidia in secondary localized spread in relation to strategies for sampling winter oilseed rape crops in the United Kingdom to assess light leaf spot is discussed.