Neuroimaging of Aggressive and Violent Behaviour in Children and Adolescents

In recent years, a number of functional and structural neuroimaging studies have investigated the neural bases of aggressive and violent behaviour in children and adolescents. Most functional neuroimaging studies have persued the hypothesis that pathological aggression is a consequence of deficits in the neural circuits involved in emotion processing. There is converging evidence for abnormal neural responses to emotional stimuli in youths with a propensity towards aggressive behaviour. In addition, recent neuroimaging work has suggested that aggressive behaviour is also associated with abnormalities in neural processes that subserve both the inhibitory control of behaviour and the flexible adaptation of behaviour in accord with reinforcement information. Structural neuroimaging studies in children and adolescents with conduct problems are still scarce, but point to deficits in brain structures in volved in the processing of social information and in the regulation of social and goal-directed behaviour. The indisputable progress that this research field has made in recent years notwithstanding, the overall picture is still rather patchy and there are inconsistencies between studies that await clarification. Despite this, we attempt to provide an integrated view on the neural abnormalities that may contribute to various forms of juvenile aggression and violence, and discuss research strategies that may help to provide a more profound understanding of these important issues in the future

On the Complexity of Reconstructing Chemical Reaction Networks

The analysis of the structure of chemical reaction networks is crucial for a better understanding of chemical processes. Such networks are well described as hypergraphs. However, due to the available methods, analyses regarding network properties are typically made on standard graphs derived from the full hypergraph description, e.g.\ on the so-called species and reaction graphs. However, a reconstruction of the underlying hypergraph from these graphs is not necessarily unique. In this paper, we address the problem of reconstructing a hypergraph from its species and reaction graph and show NP-completeness of the problem in its Boolean formulation. Furthermore we study the problem empirically on random and real world instances in order to investigate its computational limits in practice

The Heterogeneity of Disruptive Behavior Disorders – Implications for Neurobiological Research and Treatment

Disruptive behavior disorders (DBDs) are reflected by a great variety of symptoms ranging from impulsive-hot-tempered quarrels to purposeful and goal-directed acts of cruelty. A growing body of data indicates that there are neurobiological factors that increase the risk for developing DBDs. In this review, we give a broad overview of recent studies investigating physiological, neural, genetic factors, and specific neurotransmitter systems. We also discuss the impact of psychosocial risk and consider the effects of gene-environment interactions. Due to the heterogeneity of DBDs, it is concluded that specific subtypes of disruptive behavior should be considered both in terms their biological basis and in regard to specific treatment needs

Isotopenhydrogeologische Untersuchung des überschobenen Karsts von Zeleni Vir (Äußere Dinariden, Kroatien)

Der Gorski Kotar, ein Nordwest streichender Gebirgszug mit grünem Karst und Gipfeln von einer Höhe bis 1526 m.ü.A. im Nordwesten Kroatiens, wird durch große Karstquellen wie der Kupa, Rijecina oder Zeleni Vir entwässert (BIONDIC et al., 2006). Die Quelle Zeleni Vir entspringt in einem Tal unterhalb der Ortschaft Skrad, östlich von Delnice. Ihre Schüttung schwankt zwischen 0,3 und 65 m3sek-1 (BIONDIĆ et al., 2006). Geologisch wird diese Region, die das Einzugsgebiet für den Oberlauf des Kupa Flusses darstellt, den Äußeren Dinariden zugeordnet und setzt sich aus paläozoischen und mesozoischen Formationen zusammen. Diese Arbeit orientiert sich am tektonischen Konzept von HERAK (1980), in dem jurassische Formationen als verkarstete Aquifergesteine unter überschobenen wasserstauenden Schichten des Perms liegen. Diese Gegebenheit kann als „verdeckter Karst“ bezeichnet werden. Aus tektonischer Sicht ist die Umgebung der Zeleni Vir-Quelle ein tektonisches Fenster in dem die verkarsteten jurassischen Kalkgesteine von wasserundurchlässigen permischen Formationen umgeben und überlagert werden. Diese hydrogeologische Besonderheit bewirkt einen tiefen Karstwasser-Fluss unterhalb des Perms. Ziel dieser Arbeit ist es, detaillierte hydrogeologische Informationen über das komplexe Karstsystem von Zeleni Vir zu gewinnen. Es wurde eine großmaßstäbige geologische Kartierung durchgeführt und Gesteine des Juras und der Trias, sowie des hangenden Perms strukturgeologisch aufgenommen. Die hydrogeologische Wertigkeit der Aquiferlithologien wurde bestimmt. Die spezifische Abfluss- und Speicherdynamik des lokalen Karstaquifers wurde durch eine Ereignisbeprobung anhand stabiler Umweltisotope im Juni 2010 untersucht (STADLER et al., 2010). Um die Abflussdynamik des Karstaquifers mit einem oberflächenabflussdominiertem Gerinne zu vergleichen wurde eine parallele Beprobung einer Quelle und eines Baches (Teufelsschlucht) bewerkstelligt. Durch die Zusammenführung von hydrogeologischen Feldmethoden, Ergebnissen aus der Analyse der Umweltisotope und den gewonnenen Kenntnissen über die lokale Geologie wird in dieser Arbeit ein qualitatives hydrogeologisches Modell erstellt. Ebenfalls bestätigt sich, dass die Karsthydrologie Nordwest-Kroatiens wesentlich mit lokaler Strukturgeologie zusammenhängt. Große Karstquellen des Gebiets (z.B. Kupa, Rijecina, Zeleni Vir) sind an Falten- und Störungsstrukturen der Äußeren Dinariden gebunden.The Gorski Kotar, a southeast tending green karst mountain range in north-western Croatia with altitudes up to 1526 metres is well known for big karst springs such as Kupa, Kupica and Zeleni Vir. East of Delnice the karstic spring “Zeleni Vir” is located in a steep valley below the village Skrad. The discharge of Zeleni Vir Spring ranges between 0.3 and 65 m3sec-1 (BIONDIĆ et al., 2006). Geologically this region of the upper Kupa river catchments belongs to the Outer Dinarides comprising mainly Paleozoic to Mesozoic formations. The thesis follows the tectonic concept of HERAK (1980), who identified Jurassic formations as karst aquifers below overthrusted and confining Permotriassic formations. This condition can be described as “hidden karst”. From the tectonic point of view the surrounding of Zeleni Vir spring appears as a tectonic window, where karstified Jurassic limestones are surrounded and overlain by confining Permian formations. This hydrogeological characteristic causes a deep karst water flow underneath the Permian rocks. The aim of the thesis is to gain detailed hydrogeological information of the complex karst system of Zeleni Vir. A large scale geological mapping was applied and microtectonics of the Jurassic karst aquifer and of the overthrusted capping rocks were studied. The hydrogeological quality of the aquifer´s rocks was quantified. The specific discharge-storage dynamics of a local karst spring was studied during a monitoring of an intense rain event in June 2010 (STADLER et al., 2010). To compare the discharge dynamic of the karst aquifer with a surface runoff dominated creek, a parallel event monitoring of the karst spring and a creek, known by the locals as “Devil´s creek”, was accomplished. Combining hydrogeological field methods, results from environmental isotope analyses with the knowledge of local geology enables to set up a qualitative hydrogeological model within this thesis. The investigations also show again that structural geology is considerably affecting the karst hydrology of northwestern Croatia. Notable karst springs such as Kupa-, Rijecina- and Zeleni Vir Spring are related to fold- and fault structures of the Outer Dinarides

A note on quasi-robust cycle bases

We investigate here some aspects of cycle bases of undirected graphs that allow the iterative construction of all elementary cycles. We introduce the concept of quasi-robust bases as a generalization of the notion of robust bases and demonstrate that a certain class of bases of the complete bipartite graphs K m,n with m,n _> 5 is quasi-robust but not robust. We furthermore disprove a conjecture for cycle bases of Cartesian product graphs

First spatio-spectral Bayesian imaging of SN1006 in X-ray

Supernovae are an important source of energy in the interstellar medium. Young remnants of supernovae have a peak emission in the X-ray region, making them interesting objects for X-ray observations. In particular, the supernova remnant SN1006 is of great interest due to its historical record, proximity and brightness. It has therefore been studied by several X-ray telescopes. Improving the X-ray imaging of this and other remnants is important but challenging as it requires to address a spatially varying instrument response in order to achieve a high signal-to-noise ratio. Here, we use Chandra observations to demonstrate the capabilities of Bayesian image reconstruction using information field theory. Our objective is to reconstruct denoised, deconvolved and spatio-spectral resolved images from X-ray observations and to decompose the emission into different morphologies, namely diffuse and point-like. Further, we aim to fuse data from different detectors and pointings into a mosaic and quantify the uncertainty of our result. Utilizing prior knowledge on the spatial and spectral correlation structure of the two components, diffuse emission and point sources, the presented method allows the effective decomposition of the signal into these. In order to accelerate the imaging process, we introduce a multi-step approach, in which the spatial reconstruction obtained for a single energy range is used to derive an informed starting point for the full spatio-spectral reconstruction. The method is applied to 11 Chandra observations of SN1006 from 2008 and 2012, providing a detailed, denoised and decomposed view of the remnant. In particular, the separated view of the diffuse emission should provide new insights into its complex small-scale structures in the center of the remnant and at the shock front profiles

Sorption-Enhanced Water-Gas Shift Reaction for Synthesis Gas Production from Pure CO: Investigation of Sorption Parameters and Reactor Configurations

A sorption-enhanced water-gas shift (SEWGS) system providing CO2-free synthesis gas (CO + H2) for jet fuel production from pure CO was studied. The water-gas shift (WGS) reaction was catalyzed by a commercial Cu/ZnO/Al2O3 catalyst and carried out with in-situ CO2 removal on a 20 wt% potassium-promoted hydrotalcite-derived sorbent. Catalyst activity was investigated in a fixed bed tubular reactor. Different sorbent materials and treatments were characterized by CO2 chemisorption among other analysis methods to choose a suitable sorbent. Cyclic breakthrough tests in an isothermal packed bed microchannel reactor (PBMR) were performed at significantly lower modified residence times than those reported in literature. A parameter study gave an insight into the effect of pressure, adsorption feed composition, desorption conditions, as well as reactor configuration on breakthrough delay and adsorbed amount of CO2. Special attention was paid to the steam content. The significance of water during adsorption as well as desorption confirmed the existence of different adsorption sites. Various reactor packing concepts showed that the interaction of relatively fast reaction and relatively slow adsorption kinetics plays a key role in the SEWGS process design at low residence time conditions