A computational method for selecting short peptide sequences for inorganic material binding

Discovering or designing biofunctionalized materials with improved quality highly depends on the ability to manipulate and control the peptide‐inorganic interaction. Various peptides can be used as assemblers, synthesizers, and linkers in the material syntheses. In another context, specific and selective material‐binding peptides can be used as recognition blocks in mining applications. In this study, we propose a new in silico method to select short 4‐mer peptides with high affinity and selectivity for a given target material. This method is illustrated with the calcite (104) surface as an example, which has been experimentally validated. A calcite binding peptide can play an important role in our understanding of biomineralization. A practical aspect of calcite is a need for it to be selectively depressed in mining sites.     

Signalling-Dependent Adverse Health Effects of Carbon Nanoparticles Are Prevented by the Compatible Solute Mannosylglycerate (Firoin) In Vitro and In Vivo

The inhalation of combustion-derived nanoparticles leads to adverse health effects in the airways. In this context the induction of membrane-coupled signalling is considered as causative for changes in tissue homeostasis and pro-inflammatory reactions. The identification of these molecular cell reactions allowed to seek for strategies which interfere with these adverse effects. In the current study, we investigated the structurally different compatible solutes mannosylglycerate (firoin) from thermophilic bacteria and ectoine from halophilic bacteria for their capability to reduce signalling pathways triggered by carbon nanoparticles in target cells in the lung. The pre-treatment of lung epithelial cells with both substances decreased the particle-specific activation of mitogen-activated protein kinases and also the endpoints proliferation and apoptosis. Firoin applied into the lungs of animals, like ectoine, led to a significant reduction of the neutrophilic lung inflammation induced by particle exposure. The pro-inflammatory effect of carbon nanoparticles on human neutrophil granulocytes ex vivo was significantly reduced by both substances via the reduction of the anti-apoptotic membrane-dependent signalling. The data of this study together with earlier studies demonstrate that two structurally non-related compatible solutes are able to prevent pathogenic reactions of the airways to carbon nanoparticles by interfering with signalling events. The findings highlight the preventive or therapeutic potential of compatible solutes for adverse health effects caused by particle exposure of the airways.     

On the use of the substitution method in left-censored environmental data

In risk assessment and environmental monitoring studies, concentration measurements frequently fall below detection limits (DL) of measuring instruments, resulting in left-censored data. The principal approaches for handling censored data include the substitution-based method, maximum likelihood estimation, robust regression on order statistics, and Kaplan-Meier. In practice, censored data are substituted with an arbitrary value prior to use of traditional statistical methods. Although some studies have evaluated the substitution performance in estimating population characteristics, they have focused mainly on normally and lognormally distributed data that contain a single DL. We employ Monte Carlo simulations to assess the impact of substitution when estimating population parameters based on censored data containing multiple DLs. We also consider different distributional assumptions including lognormal, Weibull, and gamma. We show that the reliability of the estimates after substitution is highly sensitive to distributional characteristics such as mean, standard deviation, skewness, and also data characteristics such as censoring percentage. The results highlight that although the performance of the substitution-based method improves as the censoring percentage decreases, its performance still depends on the population's distributional characteristics. Practical implications that follow from our findings indicate that caution must be taken in using the substitution method when analyzing censored environmental data.     

Phylogeography of the Oenanthe hispanica–pleschanka–cypriaca complex (Aves,Muscicapidae: Saxicolinae): Diversification history of open‐habitat specialists based on climate niche models,genetic data,and morphometric data

The succession of glacials and interglacials during the Pleistocene strongly influenced the diversification and distribution patterns in birds. In contrast to species of temperate regions, open‐habitat specialists should have experienced range expansion during the longer glacial periods, while range contractions occurred during the shorter interglacials. However, only few studies have tested this prediction so far. We studied the Oenanthe hispanica–pleschanka–cypriaca (Aves, Muscicapidae: Saxicolinae) complex characteristic of open habitats in the Palearctic. Based on three mitochondrial and one Z‐linked nuclear marker, we inferred its phylogeny, historical diversification, and demography. Ecological niche modeling was used to reconstruct potential distributions during the last glacial maximum and the last interglacial. Using 19 morphological traits, we tested for morphometric differences among the different taxa. Mitochondrial markers revealed strong genetic differences between O. h. hispanica and the other taxa with a divergence event at around 1.7 million years ago. No consistent genetic differences were revealed between O. cypriaca, O. h. melanoleuca, and O. pleschanka. The latter two hybridize in contact zones, which might explain partly the lack of genetic differentiation; yet, further analyses using genomic data are needed to infer the true divergence history of the complex. Signs of population expansions in the clade comprising O. h. melanoleuca, O. pleschanka, and O. cypriaca at 90,000 years ago coincided with the last glacial as predicted. Population expansion then was also supported by ecological climate niche models. O. h. hispanica was not consistently separated from the other taxa in morphometrics. It might nonetheless warrant species status, pending further analyses.     

Effects of the Positive Action Program on Indicators of Positive Youth Development Among Urban Youth

This study evaluated effects of Positive Action, a school-based social-emotional and character development intervention, on indicators of positive youth development (PYD) among a sample of low-income, ethnic minority youth attending 14 urban schools. The study used a matched-pair, cluster-randomized controlled design at the school level. A multiple-measure self-report protocol assessed four key strengths and resources for PYD: self-concept, peer affiliations, ethics, and social skills. Students (n = 1170) were assessed from grades 3 to 8; the duration of the intervention, with drop-outs and late entrants was included in analyses. Growth curve analyses revealed evidence of favorable program effects on each of the four types of resources. The study contributes to PYD research by providing evidence for school-based interventions in low-income, urban contexts for ethnic minority youth.     

BMI and Lifetime Changes in BMI and Cancer Mortality Risk

Body Mass Index (BMI) is known to be associated with cancer mortality, but little is known about the link between lifetime changes in BMI and cancer mortality in both males and females. We studied the association of BMI measurements (at baseline, highest and lowest BMI during the study-period) and lifetime changes in BMI (calculated over different time periods (i.e. short time period: annual change in BMI between successive surveys, long time period: annual change in BMI over the entire study period) with mortality from any cancer, and lung, colorectal, prostate and breast cancer in a large cohort study (n=8,645. Vlagtwedde-Vlaardingen, 1965-1990) with a follow-up on mortality status on December 31^st 2008. We used multivariate Cox regression models with adjustments for age, smoking, sex, and place of residence. Being overweight at baseline was associated with a higher risk of prostate cancer mortality (hazard ratio (HR) =2.22; 95% CI 1.19-4.17). Obesity at baseline was associated with a higher risk of any cancer mortality [all subjects (1.23 (1.01-1.50)), and females (1.40 (1.07-1.84))]. Chronically obese females (females who were obese during the entire study-period) had a higher risk of mortality from any cancer (2.16 (1.47-3.18), lung (3.22 (1.06-9.76)), colorectal (4.32 (1.53-12.20)), and breast cancer (2.52 (1.15-5.54)). We found no significant association between long-term annual change in BMI and cancer mortality risk. Both short-term annual increase and decrease in BMI were associated with a lower mortality risk from any cancer [all subjects: (0.67 (0.47-0.94)) and (0.73 (0.55-0.97)), respectively]. In conclusion, a higher BMI is associated with a higher cancer mortality risk. This study is the first to show that short-term annual changes in BMI were associated with lower mortality from any type of cancer.