Reliability of dose volume constraint inference from clinical data

Dose volume histogram points (DVHPs) frequently serve as dose constraints in radiotherapy treatment planning. An experiment was designed to investigate the reliability of DVHP inference from clinical data for multiple cohort sizes and complication incidence rates. The experimental background was radiation pneumonitis in non-small cell lung cancer and the DVHP inference method was based on logistic regression. From 102 NSCLC real-life dose distributions and a postulated DVHP model, an 'ideal' cohort was generated where the most predictive model was equal to the postulated model. A bootstrap and a Cohort Replication Monte Carlo (CoRepMC) approach were applied to create 1000 equally sized populations each. The cohorts were then analyzed to establish inference frequency distributions. This was applied to nine scenarios for cohort sizes of 102 (1), 500 (2) to 2000 (3) patients (by sampling with replacement) and three postulated DVHP models. The Bootstrap was repeated for a 'non-ideal' cohort, where the most predictive model did not coincide with the postulated model. The Bootstrap produced chaotic results for all models of cohort size 1 for both the ideal and non-ideal cohorts. For cohort size 2 and 3, the distributions for all populations were more concentrated around the postulated DVHP. For the CoRepMC, the inference frequency increased with cohort size and incidence rate. Correct inference rates  >[Formula: see text] were only achieved by cohorts with more than 500 patients. Both Bootstrap and CoRepMC indicate that inference of the correct or approximate DVHP for typical cohort sizes is highly uncertain. CoRepMC results were less spurious than Bootstrap results, demonstrating the large influence that randomness in dose-response has on the statistical analysis.

Suppressed decomposition of organometal halide perovskites by impermeable electron-extraction layers in inverted solar cells

The area of thin-film photovoltaics has been overwhelmed by organometal halide perovskites. Unfortunately, serious stability concerns arise with perovskite solar cells. For example, methyl-ammonium lead iodide is known to decompose in the presence of water and, more severely, even under inert conditions at elevated temperatures. Here, we demonstrate inverted perovskite solar cells, in which the decomposition of the perovskite is significantly mitigated even at elevated temperatures. Specifically, we introduce a bilayered electron-extraction interlayer consisting of aluminium-doped zinc oxide and tin oxide. We evidence tin oxide grown by atomic layer deposition does form an outstandingly dense gas permeation barrier that effectively hinders the ingress of moisture towards the perovskite and—more importantly—it prevents the egress of decomposition products of the perovskite. Thereby, the overall decomposition of the perovskite is significantly suppressed, leading to an outstanding device stability.

The stability issue of perovskite-based solar cells is in part due to electrode corrosion. Here, Brinkmann et al. develop an impermeable bilayered electron-extraction layer between the active layer and the electrode, suppressing decomposition of the perovskite and preventing corrosion from the inside.

A Fusarium graminearum strain-comparative proteomic approach identifies regulatory changes triggered by agmatine

Plant pathogens face different environmental clues depending on the stage of the infection cycle they are in. Fusarium graminearum infects small grain cereals producing trichothecenes type B (TB) that act as virulence factor in the interaction with the plant and have important food safety implications. This study addresses at the proteomic level the effect of an environmental stimulus (such as the presence of a polyamine like agmatine) possibly encountered by the fungus when it is already within the plant. Because biological diversity affects the proteome significantly, a multistrain (n=3) comparative approach was used to identify consistent effects caused on the fungus by the nitrogen source (agmatine or glutamic acid). Proteomics analyses were performed by the use of 2D-DIGE. Results showed that agmatine augmented TB production but not equally in all strains. The polyamine reshaped drastically the proteome of the fungus activating specific pathways linked to the translational control within the cell. Chromatin restructuring, ribosomal regulations, protein and mRNA processing enzymes were modulated by the agmatine stimulus as well as metabolic, structural and virulence-related proteins, suggesting the need to reshape specifically the fungal cell for TB production, a key step for the pathogen spread within the spike.

BIOLOGICAL SIGNIFICANCE

Induction of toxin synthesis by plant compounds plays a crucial role in toxin contamination of food and feed, in particular trichothecenes type B produced mainly by F. graminearum on wheat. This work describes the level of diversity of 3 strains facing 2 toxin inducing plant derived compounds. This knowledge is of use for the research community on toxigenic Fusarium strains in cereals for understanding the role of fungal diversity in toxin inducibility. This work also suggests that environmental clues that can be found within the plant during infection (like different nitrogen compounds) are crucial stimuli for reshaping the proteome profile and consequently the specialization profiling of the fungus, ultimately leading to very different toxin contamination levels in the plant.

Statistical thermodynamics of non-stoichiometric ceria and ceria zirconia solid solutions

The statistical mechanics of lattice configurations are used to develop an analytical model of non-stoichiometry in ceria and ceria zirconia.

Incontinence in children with treated attention-deficit/hyperactivity disorder

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) and incontinence (nocturnal enuresis, daytime urinary incontinence and fecal incontinence) are common disorders in childhood. Both disorders are strongly associated with each other.

OBJECTIVE

ADHD can affect compliance to incontinence therapy in a negative way; it can also affect outcome. The aim of the present study was to assess the prevalence of incontinence, age of bladder and bowel control, and psychological symptoms in children having treatment for ADHD compared to a control group.

STUDY DESIGN

Forty children having treatment for ADHD (75% boys, mean age 11.4 years) and 43 matched controls (60.5% boys, mean age 10.7 years) were assessed. Their parents filled out questionnaires to assess: child psychopathology (Child Behavior Checklist), incontinence (Parental Questionnaire: Enuresis/Urinary Incontinence; Encopresis Questionnaire - Screening Version) and symptoms of the lower urinary tract (International-Consultation-on-Incontinence-Questionnaire - Pediatric Lower Urinary Tract Symptoms). The ICD-10 diagnoses and children's IQ were measured by standardized instruments (Kinder-DIPS, Coloured Progressive Matrices/Standard Progressive Matrices).

RESULTS

Rates of incontinence in the ADHD group (5% nocturnal enuresis, 5% daytime urinary incontinence, 2.5% fecal incontinence) did not differ significantly from incontinence rates in the control group (4.7% daytime urinary incontinence). More children in the ADHD group had Child Behavior Checklist scores in the clinical range. Further ICD-10 disorders were present in eight children with ADHD and in one control child. More children with ADHD had delayed daytime and nighttime bladder control, as well as delayed bowel control, than the controls.

DISCUSSION

The present study showed that if children are treated for their ADHD, according to standard practice guidelines, incontinence rates are similar to those without ADHD. More children with ADHD reached continence at a later age than the controls, which could be an indicator of maturational deficits in the central nervous system. Additionally, children with ADHD showed higher rates of clinically relevant psychological symptoms.

CONCLUSION

This study provides further information of the association between ADHD and incontinence. Treatment of ADHD may be associated with positive effects on incontinence outcomes. Therefore, children with ADHD should always be screened for incontinence problems and children with incontinence problems should also be screened for ADHD if symptoms of hyperactivity, inattention and/or impulsivity are also present.

Harmonized European human biomonitoring in small countries: Challenges, opportunities and lessons learned in Cyprus and Luxembourg from the DEMOCOPHES study

Background: To advance human biomonitoring (HBM) for policy support in Europe, a harmonized approach was developed (COPHES project, FP7 2009- 2012) and evaluated in 17 countries (DEMOCOPHES project, Life+, 2010-2012). Cyprus (CY) and Luxembourg (LU) tested the hypothesis that the COPHES European Protocol is applicable to small countries.Materials and methods: In 2011-12, the European Protocol was adopted and tested by CY and LU for the harmonized biomonitoring of 60 children and their mothers for cadmium, phthalates and cotinine in urine and for mercury in scalp hair in two sampling areas (urban, rural). Results: Both small countries achieved the preset goals for recruitment, sample collection and analysis, which allowed for the first time the assessment of children’s and mothers’ exposures to the selected chemicals in comparison with other countries. Capacity building was accomplished and communication actions were particularly effective, with both countries taking advantage of their small size to access participants, policy makers, other stakeholders and the press. Time constrains and requirements for capacity building were limiting factors. Conclusion: The COPHES European Protocol for HBM surveys is attainable in small countries. The following elements are fundamental in the design of a harmonized European HBM program, from the perspective of small countries: (a) consultation with and active involvement of the implementing countries, (b) flexibility for national decisions, while not compromising harmonization, (c) elaboration of standardized methods, procedures and documents (d) quality assurance mechanisms, (e) means of training and support.

Detection of multiple mycotoxin occurrences in soy animal feed by traditional mycological identification combined with molecular species identification

Soy products are a main component of animal feed. Because mycotoxins may harm farm animals, undermining productivity and health, a mycological and toxigenic screening was carried out on 36 batches used in animal feed, collected in 2008, 2009 and 2010 in Italy. The investigated mycoflora of a subset of soy seed (n = 6) suggested that Aspergillus spp. and Fusarium spp. frequently colonize soy seeds. Aflatoxins, fumonisins and deoxynivalenol were detected in 88.9%, 72.2% and 30.6% of samples, respectively. Co-occurrence of at least two toxins was observed in 72% of cases. The molecular analysis of the Fusarium spp. population identified Fusarium verticillioides as potential producers of fumonisins, but no known deoxynivalenol producers were detected. It is suggested that the widespread presence of toxins can be due to non-optimal storing conditions of the feed. Moreover, our results suggest that mycotoxin thresholds should be adapted to consider the frequent case of toxin co-occurrence. This approach would better reflect the real toxigenic risk of feedstuffs.

Necroptosis drives motor neuron death in models of both sporadic and familial ALS

Most cases of neurodegenerative diseases are sporadic, hindering the use of genetic mouse models to analyze disease mechanisms. Focusing on the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS), we therefore devised a fully humanized coculture model composed of human adult primary sporadic ALS (sALS) astrocytes and human embryonic stem-cell-derived MNs. The model reproduces the cardinal features of human ALS: sALS astrocytes, but not those from control patients, trigger selective death of MNs. The mechanisms underlying this non-cell-autonomous toxicity were investigated in both astrocytes and MNs. Although causal in familial ALS (fALS), SOD1 does not contribute to the toxicity of sALS astrocytes. Death of MNs triggered by either sALS or fALS astrocytes occurs through necroptosis, a form of programmed necrosis involving receptor-interacting protein 1 and the mixed lineage kinase domain-like protein. The necroptotic pathway therefore constitutes a potential therapeutic target for this incurable disease.

Towards a synthetic view of potato cold and salt stress response by transcriptomic and proteomic analyses

Potato can suffer from several abiotic stresses such as cold temperature, high soil salinity, lack of water or heavy metal exposure, to name a few. They are known to affect plant growth as well as productivity, with differential regulations at several levels. Potato response to cold and salt exposure was investigated at both transcriptomic and proteomic levels in a growth chamber experiment. Cold exposure in potato resulted in a higher number of significantly differentially regulated genes compared to salt exposure, whereas there were nearly three times more differentially regulated proteins after salt exposure when compared to cold exposure. The allocation of up and down-regulated genes at the functional category level also differed between salt and cold exposure although common trends, previously described in various abiotic stresses, were observed. In both stresses, the majority of photosynthesis-related genes were down-regulated whereas cell rescue and transcription factor-related genes were mostly up-regulated. In the other functional categories no common trend was observed; salt exposure results displayed a strong down-regulation of genes implicated in primary metabolism, detoxication apparatus and signal transduction, whereas upon cold exposure, up and down-regulated genes were similar in number. At the proteomic level, the abundance of the majority of identified proteins was increased except for the photosynthesis-related proteins, which were mostly less abundant after both salt and cold exposure. Common responses between salt and cold stress and specific responses inherent to these abiotic stresses are described.