Faszination LAN-Partys

Computerspiele sind heutzutage ein wesentlicher Bestandteil der Freizeitbeschäftigung vieler Jugendlicher und junger Erwachsener, fast jeder junge Mensch kommt damit früher oder später in Berührung. Diese große gesellschaftliche Bedeutung macht Computerspiele zu einem erforschenswerten Thema für die Wissenschaft. In der Jugendkultur entwickelte sich mit dem Aufschwung der Computerspiele auch eine neue Form des gemeinschaftlichen Spielens: die LAN-Party, das gemeinsame Spielen in einem lokalen, selbst erstellten Netzwerk. Die vorliegende Arbeit beschäftigt sich mit dieser Form des Zusammenkommens unter Freunden im kleinen Kreis. Anhand der forschungsleitenden Fragen dieser Arbeit soll geklärt werden, warum junge Menschen auf private LAN-Partys gehen, welchen Nutzen sie daraus ziehen und wie ihre Kommunikation dort abläuft. Für die Untersuchung wurden die empirischen Daten mit der Methode des qualitativen Leitfadeninterviews erhoben, die Auswertung erfolgte dann anhand der qualitativen Inhaltsanalyse. Die Forschung wurde dabei von der Spieltheorie, der Theorie der Medienkompetenz und der Theorie des sozialen Kapitals gestützt.Today computer games are an essential part of leisure activity of many teenagers and young adults, nearly every young person encounters computer games. Because of this importance computer games are an issue to society that is worth to be researched. A new way of collaborative playing developed in youth culture: the LAN-Party, which is playing together in a local, self-made network. The following paper deals with this form of meeting friends in a small community. On the basis of the questions, which lead the research, this paper will resolve why young people visit private LAN-Partys and which benefits they get from it and how their communication proceed. Guideline-Interviews were carried out to collect empirical data for the research. The Evaluation of the data occurred with the method of content analysis. The research was supported of the game theory, the theory of media literacy and the theory of social capital

DOC dynamics in soil water, root exudates and plant leaf litter decompsition

Für die vorliegende Studie wurde organische (Boden-)substanz (Bodenwasser, Wurzelexudate, Laub) von Weidenarten verwendet, deren Fähigkeit zur Hyperakkumulation von Cadmium und Zink bekannt ist. Weidenlaub wurde in einem Experiment in verschiedenen Böden und mit unterschiedlichen Magnetit (Fe3O4)-Gaben abgebaut. Die Proben wurden mit hochauflösender Fourier-transformierter Massenspektronomie (FT-MS) analysiert. Die Massensignale wurden anhand geschätzter Elementzusammensetzungen synchronisiert. Die Atomverhältnisse von Sauerstoff (O) zu Kohlenstoff (C) und von Wasserstoff (H) zu Kohlenstoff (C) wurden gemeinsam mit der Molekularmasse in van Krevelen Diagrammen dargestellt und auf Basis empirisch definierter Bereiche für Verbindungsklassen interpretiert. Multivariate Statistik wurde durchgeführt. Die hochauflösende FT-MS- Analyse brachte charakteristische Masssenspektren hervor, die es ermöglichten, die Probentypen (Bodenwasser, Wurzelexudate, Laub) voneinader zu unterscheiden und unterschiedliche Verbindungsklassen in den einzelnen Probentypen zu interpretieren.Dissolvable soil organic matter (soil water, root exudates, plant leaf litter) from Salix species known to hyper-accumulate cadmium, was analyzed in this present study. With the plant leaf litter a decomposition experiment was conducted in different soil types with magnetite (Fe3O4)-amendments. Mass spectra were obtained by high-resolution Fourier-transformed mass spectrometry with an LQT-Orbitrap. Analytes were aligned on the basis of estimated elemental compositions. Atomic ratios between O and C, H and C and molecular mass were visualized in two- and three-dimensional van Krevelen diagrams and interpreted on the basis of empirically defined areas for compound classes. Also multivariate statistical analysis was performed. The high-resolution-FT-MS-analysis yielded characteristic spectra, allowing differentiation of soil water, root exudate and plant leaf litter samples

Receptor for advanced glycation end products (RAGE) regulates sepsis but not the adaptive immune response

This is the publisher's version, also available electronically from http://www.jci.org/articles/view/18704While the initiation of the adaptive and innate immune response is well understood, less is known about cellular mechanisms propagating inflammation. The receptor for advanced glycation end products (RAGE), a transmembrane receptor of the immunoglobulin superfamily, leads to perpetuated cell activation. Using novel animal models with defective or tissue-specific RAGE expression, we show that in these animal models RAGE does not play a role in the adaptive immune response. However, deletion of RAGE provides protection from the lethal effects of septic shock caused by cecal ligation and puncture. Such protection is reversed by reconstitution of RAGE in endothelial and hematopoietic cells. These results indicate that the innate immune response is controlled by pattern-recognition receptors not only at the initiating steps but also at the phase of perpetuation

Effects of soil organic matter properties and microbial community composition on enzyme activities in cryoturbated arctic soils

Enzyme-mediated decomposition of soil organic matter (SOM) is controlled, amongst other factors, by organic matter properties and by the microbial decomposer community present. Since microbial community composition and SOM properties are often interrelated and both change with soil depth, the drivers of enzymatic decomposition are hard to dissect. We investigated soils from three regions in the Siberian Arctic, where carbon rich topsoil material has been incorporated into the subsoil (cryoturbation). We took advantage of this subduction to test if SOM properties shape microbial community composition, and to identify controls of both on enzyme activities. We found that microbial community composition (estimated by phospholipid fatty acid analysis), was similar in cryoturbated material and in surrounding subsoil, although carbon and nitrogen contents were similar in cryoturbated material and topsoils. This suggests that the microbial community in cryoturbated material was not well adapted to SOM properties. We also measured three potential enzyme activities (cellobiohydrolase, leucine-amino-peptidase and phenoloxidase) and used structural equation models (SEMs) to identify direct and indirect drivers of the three enzyme activities. The models included microbial community composition, carbon and nitrogen contents, clay content, water content, and pH. Models for regular horizons, excluding cryoturbated material, showed that all enzyme activities were mainly controlled by carbon or nitrogen. Microbial community composition had no effect. In contrast, models for cryoturbated material showed that enzyme activities were also related to microbial community composition. The additional control of microbial community composition could have restrained enzyme activities and furthermore decomposition in general. The functional decoupling of SOM properties and microbial community composition might thus be one of the reasons for low decomposition rates and the persistence of 400 Gt carbon stored in cryoturbated material

Immune profiling in multiple sclerosis: a single-center study of 65 cytokines, chemokines, and related molecules in cerebrospinal fluid and serum

IntroductionThe understanding of the pathophysiology of multiple sclerosis (MS) has evolved alongside the characterization of cytokines and chemokines in cerebrospinal fluid (CSF) and serum. However, the complex interplay of pro- and anti-inflammatory cytokines and chemokines in different body fluids in people with MS (pwMS) and their association with disease progression is still not well understood and needs further investigation. Therefore, the aim of this study was to profile a total of 65 cytokines, chemokines, and related molecules in paired serum and CSF samples of pwMS at disease onset.MethodsMultiplex bead-based assays were performed and baseline routine laboratory diagnostics, magnetic resonance imaging (MRI), and clinical characteristics were assessed. Of 44 participants included, 40 had a relapsing–remitting disease course and four a primary progressive MS.ResultsThere were 29 cytokines and chemokines that were significantly higher in CSF and 15 in serum. Statistically significant associations with moderate effect sizes were found for 34 of 65 analytes with sex, age, CSF, and MRI parameters and disease progression.DiscussionIn conclusion, this study provides data on the distribution of 65 different cytokines, chemokines, and related molecules in CSF and serum in newly diagnosed pwMS

Detailed scanning probe microscopy tip models determined from simultaneous atom-resolved AFM and STM studies of the TiO2(110) surface

Enevoldsen GH, Pinto HP, Foster AS, et al. Detailed scanning probe microscopy tip models determined from simultaneous atom-resolved AFM and STM studies of the TiO2(110) surface. Physical Review B. 2008;78(4):045416.The atomic-scale contrast in noncontact atomic force microscopy (nc-AFM) images is determined by the geometry and exact atomic structure of the tip apex. However, the tip state is an experimentally unknown parameter, and the lack of insight into the tip apex often limits the possibilities of extracting precise quantitative and qualitative atomistic information on the surface under inspection. From an interplay between simultaneously recorded nc-AFM and scanning tunneling microscopy (STM) data, and atomistic STM simulations based on multiple scattering theory, we demonstrate how the state of the scanning probe microscopy (SPM) tip in the experiments may be determined. The analysis of a large number of experimental SPM images recorded with different tips reveals that no general correlation exists between the contrast observed in the nc-AFM and the tunneling current (I-t) images on TiO2(110) surface. The exact state of the SPM tip must, therefore, be determined for each specific case, which is normally a very difficult endeavor. However, our analysis of the AFM contrast on TiO2(110) surface allows us to considerably reduce the number of tips to be considered in a full simulation. By carefully evaluating the contrast of a handpicked library of SPM tips, we manage to determine a very accurate model of the SPM tip used in an experiment for the first time. It is envisioned that the approach presented here may eventually be used in future studies to screen for and select a SPM tip with a special functionalization prior to imaging an unknown sample, and in that way facilitate precise modeling and chemical identification of surface species

GC-MS analyses and chemometric processing to discriminate the local and long-distance sources of PAHs associated to atmospheric PM2.5

Purpose . This study presents a procedure to differentiate the local and remote sources of particulate-bound polycyclic aromatic hydrocarbons (PAHs). Methods. Data were collected during an extended PM2.5 sampling campaign (2009–2010) carried out for 1 year in Venice-Mestre, Italy, at three stations with different emissive scenarios: urban, industrial, and semirural background. Diagnostic ratios and factor analysis were initially applied to point out the most probable sources. In a second step, the areal distribution of the identified sources was studied by applying the discriminant analysis on factor scores. Third, samples collected in days with similar atmospheric circulation patterns were grouped using a cluster analysis on wind data. Local contributions to PM2.5 and PAHs were then assessed by interpreting cluster results with chemical data. Results. Results evidenced that significantly lower levels of PM2.5 and PAHs were found when faster winds changed air masses, whereas in presence of scarce ventilation, locally emitted pollutants were trapped and concentrations increased. This way, an estimation of pollutant loads due to local sources can be derived from data collected in days with similar wind patterns. Long-range contributions were detected by a cluster analysis on the air mass back-trajectories. Results revealed that PM2.5 concentrations were relatively high when air masses had passed over the Po Valley. However, external sources do not significantly contribute to the PAHs load. Conclusions. The proposed procedure can be applied to other environments with minor modifications, and the obtained information can be useful to design local and national air pollution control strategies