Flame-Made Pt/K/Al2O3 for NO x Storage-Reduction (NSR) Catalysts

High surface area Pt/K/Al2O3 catalysts were prepared with a 2-nozzle flame spray method resulting in Pt clusters on γ-Al2O3 and amorphous K storage material as evidenced by Raman spectroscopy. The powders had a high NO x storage capacity and were regenerated fast in a model exhaust gas environment. From 300 to 400°C no excess NO x was detected in the off gas during transition from fuel lean to fuel rich conditions, resulting in a highly effective NO x removal performance. Above 500°C, the NSR activity was lost and not recovered at lower temperatures as K-compounds were partially crystallized on the catalys

Effect of the Proximity of Pt to Ce or Ba in Pt/Ba/CeO2 Catalysts on NO x Storage-Reduction Performance

The effect of Pt location in Pt/Ba/CeO2 catalysts for NO x storage-reduction (NSR) was analyzed. The Pt location on BaCO3 or CeO2 support was controlled by changing the angle (φ) between the two flame sprays producing these two components. As-prepared flame-made catalysts contain PtO x which must be reduced during the fuel rich phase to become active for NO x storage and reduction of NO x . For Pt on BaCO3 this process was significantly faster than for Pt on CeO2. The increased reduction ability of Pt on Ba is reflected in the light off temperatures: for Pt on CeO2 temperatures around 330°C were needed to combust 20% of C3H6 in air while for Pt on BaCO3 only 250°C were required for the same conversion. The ability to control the location of Pt or other noble metals is, therefore, essential to optimize the catalysts for a given Pt/Ba/CeO2 weight ratio. The best performance was observed when most of the Pt constituent was located near Ba-containing site

"Urban Plant" light-weight solar system for parking and other urban double use applications

Innovations on all aspects of BOS and solar cell integration into the module are essential to further reducing the costs of PV electricity and substantial progress has been made in the past years. One other important aspect is the availability of space for PV power production, especially in densely occupied urban areas. Roof space is limited or only partially useable. A promising other application for PV power production in urban areas today are PV carports on parking lots, which require massive structures and foundations. The approach presented here is a newly developed PV plant which automatically stores the PV modules in a protection box in case of bad weather conditions. Avoiding bad weather conditions implies that only a fraction of the mechanical load is present on the PV modules and the structure, enabling light weight structural design. The newly developed PV plant is folding the PV generator into a protection box and will pull out the PV generator, carried on two supporting cables for operation during good weather conditions. An innovative autonomous control system was developed based on local meteo sensors and regional weather information. The PV modules of the Urban Plant are mounted six meters above a parking lot with the benefit of full double use of the land below. Thus a PV system has been built with currently 52 kW nominal power, 16 meter wide, with a folding roof of PV modules expanding 24 meters in one direction. The system can be extended to 104 kWp with a second folding roof expanding into the other direction. As special PV system design was developed with a light weight PV generator using module laminates with special mounting elements. Moreover the system comprises innovative string wiring and inverters that can be also integrated into the safety box. A first 250kW commercial system is scheduled to be set into operation in Jan 2014 in Southern Germany

The structure of psychopathology in adolescence and its common personality and cognitive correlates

The traditional view that mental disorders are distinct, categorical disorders has been challenged by evidence that disorders are highly comorbid and exist on a continuum (e.g., Caspi et al., 2014; Tackett et al., 2013). The first objective of this study was to use structural equation modeling to model the structure of psychopathology in an adolescent community-based sample (N = 2,144) including conduct disorder, attention-deficit/hyperactivity disorder (ADHD), oppositional-defiant disorder (ODD), obsessive-compulsive disorder, eating disorders, substance use, anxiety, depression, phobias, and other emotional symptoms, assessed at 16 years. The second objective was to identify common personality and cognitive correlates of psychopathology, assessed at 14 years. Results showed that psychopathology at 16 years fit 2 bifactor models equally well: (a) a bifactor model, reflecting a general psychopathology factor, as well as specific externalizing (representing mainly substance misuse and low ADHD) and internalizing factors; and (b) a bifactor model with a general psychopathology factor and 3 specific externalizing (representing mainly ADHD and ODD), substance use and internalizing factors. The general psychopathology factor was related to high disinhibition/impulsivity, low agreeableness, high neuroticism and hopelessness, high delay-discounting, poor response inhibition and low performance IQ. Substance use was specifically related to high novelty-seeking, sensation-seeking, extraversion, high verbal IQ, and risk-taking. Internalizing psychopathology was specifically related to high neuroticism, hopelessness and anxiety-sensitivity, low novelty-seeking and extraversion, and an attentional bias toward negatively valenced verbal stimuli. Findings reveal several nonspecific or transdiagnostic personality and cognitive factors that may be targeted in new interventions to potentially prevent the development of multiple psychopathologies

Personality, attentional biases towards emotional faces and symptoms of mental disorders in an adolescent sample

Objective To investigate the role of personality factors and attentional biases towards emotional faces, in establishing concurrent and prospective risk for mental disorder diagnosis in adolescence. Method Data were obtained as part of the IMAGEN study, conducted across 8 European sites, with a community sample of 2257 adolescents. At 14 years, participants completed an emotional variant of the dot-probe task, as well two personality measures, namely the Substance Use Risk Profile Scale and the revised NEO Personality Inventory. At 14 and 16 years, participants and their parents were interviewed to determine symptoms of mental disorders. Results Personality traits were general and specific risk indicators for mental disorders at 14 years. Increased specificity was obtained when investigating the likelihood of mental disorders over a 2-year period, with the Substance Use Risk Profile Scale showing incremental validity over the NEO Personality Inventory. Attentional biases to emotional faces did not characterise or predict mental disorders examined in the current sample. Discussion Personality traits can indicate concurrent and prospective risk for mental disorders in a community youth sample, and identify at-risk youth beyond the impact of baseline symptoms. This study does not support the hypothesis that attentional biases mediate the relationship between personality and psychopathology in a community sample. Task and sample characteristics that contribute to differing results among studies are discussed

Evidence of amygdala hypersensitivity to signals of threat

Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n = 70) of 14-year olds with a history of cannabis use to a group (n = 70) of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at- risk for mood disorders in adulthood

The relationship between negative life events and cortical structural connectivity in adolescents

Adolescence is a crucial period for physical and psychological development. The impact of negative life events represents a risk factor for the onset of neuropsychiatric disorders. This study aims to investigate the relationship between negative life events and structural brain connectivity, considering both graph theory and connectivity strength. A group (n = 487) of adolescents from the IMAGEN Consortium was divided into Low and High Stress groups. Brain networks were extracted at an individual level, based on morphological similarity between grey matter regions with regions defined using an atlas-based region of interest (ROI) approach. Between-group comparisons were performed with global and local graph theory measures in a range of sparsity levels. The analysis was also performed in a larger sample of adolescents (n = 976) to examine linear correlations between stress level and network measures. Connectivity strength differences were investigated with network-based statistics. Negative life events were not found to be a factor influencing global network measures at any sparsity level. At local network level, between-group differences were found in centrality measures of the left somato-motor network (a decrease of betweenness centrality was seen at sparsity 5%), of the bilateral central visual and the left dorsal attention network (increase of degree at sparsity 10% at sparsity 30% respectively). Network-based statistics analysis showed an increase in connectivity strength in the High stress group in edges connecting the dorsal attention, limbic and salience networks. This study suggests negative life events alone do not alter structural connectivity globally, but they are associated to connectivity properties in areas involved in emotion and attention.</p

Ventral striatum connectivity during reward anticipation in adolescent smokers

Substance misusers, including adolescent smokers, often have reduced reward system activity during processing of non-drug rewards. Using a psychophysiological interaction approach, we examined functional connectivity with the ventral striatum during reward anticipation in a large (N = 206) sample of adolescent smokers. Increased smoking frequency was associated with (1) increased connectivity with regions involved in saliency and valuation, including the orbitofrontal cortex and (2) reduced connectivity between the ventral striatum and regions associated with inhibition and risk aversion, including the right inferior frontal gyrus. These results demonstrate that functional connectivity during reward processing is relevant to adolescent addiction

Inattention and reaction time variability are linked to ventromedial prefrontal volume in adolescents

Background Neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) have most commonly reported volumetric abnormalities in the basal ganglia, cerebellum, and prefrontal cortices. Few studies have examined the relationship between ADHD symptomatology and brain structure in population-based samples. We investigated the relationship between dimensional measures of ADHD symptomatology, brain structure, and reaction time variability—an index of lapses in attention. We also tested for associations between brain structural correlates of ADHD symptomatology and maps of dopaminergic gene expression. Methods Psychopathology and imaging data were available for 1538 youths. Parent ratings of ADHD symptoms were obtained using the Development and Well-Being Assessment and the Strengths and Difficulties Questionnaire (SDQ). Self-reports of ADHD symptoms were assessed using the youth version of the SDQ. Reaction time variability was available in a subset of participants. For each measure, whole-brain voxelwise regressions with gray matter volume were calculated. Results Parent ratings of ADHD symptoms (Development and Well-Being Assessment and SDQ), adolescent self-reports of ADHD symptoms on the SDQ, and reaction time variability were each negatively associated with gray matter volume in an overlapping region of the ventromedial prefrontal cortex. Maps of DRD1 and DRD2 gene expression were associated with brain structural correlates of ADHD symptomatology. Conclusions This is the first study to reveal relationships between ventromedial prefrontal cortex structure and multi-informant measures of ADHD symptoms in a large population-based sample of adolescents. Our results indicate that ventromedial prefrontal cortex structure is a biomarker for ADHD symptomatology. These findings extend previous research implicating the default mode network and dopaminergic dysfunction in ADHD