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Humic substances (HS) are heterogeneous, redox-active organic macromolecules. While electron transfer to and from HS under reducing conditions is well investigated, comparatively little is known on the electron donating (i.e., antioxidant) properties of HS under oxic conditions. In this work, the electron donating capacities (EDCs) of terrestrial and aquatic HS were quantified by mediated electrochemical oxidation over a wide range of pH values and applied redox potentials (E(h)) using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) as an electron transfer mediator. Electrochemical oxidation of three model humic acids (HAs) was largely irreversible, and the EDCs of these HAs increased with increasing E(h) and pH. These results suggest that HS contain a wide variety of moieties that are oxidized at different potentials and that, upon oxidation, release protons and undergo irreversible follow-up reactions. At a given pH and E(h), the EDCs of the HS correlated well with their titrated phenol contents suggesting phenolic moieties as major electron donating groups in HS. Comparing the EDCs of 15 HS with their electron accepting capacities (EACs), aquatic HS had higher EDCs and lower EACs than terrestrial HS of comparable aromaticities. These results indicate that oxidative transformation of HS in the environment results in a depletion of electron donating phenolic moieties with antioxidant properties relative to the electron accepting quinone moieties.

This book chapter describes an approach of evaluating user experience in video games by using heuristics. We provide a short overview of video games and explain the concept of user-centred design for games. Furthermore we describe the history of heuristics for video games and the role of user experience of games in general. Based on our previous work and experience we propose a revised framework consisting of two sets of heuristics (game play/game story, virtual interface) to detect the most critical issues in games. To assess its applicability to measure user experience factors we compare the results of expert evaluations of six current games with the user experience-based ratings of various game reviews. Our findings indicate a correlation between the extent to which our framework is satisfied and the game’s average rating.

Personas are a design tool to ensure a strong user-focus within projects. In this case study we compare and discuss seven different persona marketing materials used to increase the acceptance of the personas by the project team. The marketing materials are a mixture of consumables (e.g., wine or cake) and long-living marketing materials (e.g., posters or savings box). The insights gained are encouraging and confirm that marketing materials can be useful for increasing the acceptance and usage of personas.

As a key regulator of the neuroendocrine stress axis and as a neuromodulator in the brain, the neuropeptide corticotropin-releasing hormone (CRH) plays an important role in various diseases of the central nervous system. Its cognate receptor CRH receptor type 1 (CRHR1) is a potential novel target for the therapeutic intervention in major depressive disorder. Therefore, a more precise understanding of involved intracellular signaling mechanisms is essential. The objective of this project was to identify specific target genes of CRHR1-mediated signaling pathways in the corticotrope cell line AtT-20 and in the neuronal cell line HN9 using microarray technology and qRT-PCR, respectively. In addition, we assessed the capacity of validated target genes to directly impact on CRHR1-dependent signaling using reporter assays. Thereby, we identified a set of CRHR1 downstream targets with diverging and cell type-specific roles which strengthen the role of CRH and CRHR1 as dynamic modulators of a variety of signal transduction mechanisms and cellular processes.

In this paper we present uTRUSTit, a project with the goal to increase the users’ understanding of trust in Internet of Things. The Internet of Things consists of complex technology that is often hard to understand for users. Most security properties are hidden in small devices and are not visible for users.Thus, uTRUSTit will display the underlying security implications to the users in order to create a justified level of trust in the Internet of Things.

User-centered design (UCD) processes need to be further extended to the field of privacy enhancing technologies (PETs). The goal of the UCD process for PETs is to provide a means for users to empower them to manage their privacy on the Web. Taking care of privacy and being careful while surfing theWeb are still considered to be cumbersome and time-consuming activities. Hence, PrimeLife aspires to provide easy to use tools for users to manage their privacy. This chapter describes the challenges in UCD that arose during the development of the PrimeLife prototypes. As part of the HCI activities in the PrimeLife project, we have researched the users’ attitudes towards privacy and discovered the main challenges when developing userfriendly PETs. We use two example prototypes to explain how the challenges can be tackled in practice. In general, PETs should neither require much of the user’s attention and time, nor should they require particular technical knowledge. They should, in fact, present the complex methods of privacy enhancing technologies in an easy, understandable and usable way. We will conclude this chapter with a discussion of our findings and implications for further development of user-centered privacy enhancing technologies.

While interacting with others on the internet, users share a lot of personal data with a potentially large but "invisible" audience. An important issue is maintaining control over personal data and therefore, in the first place, users need to be aware to whom they are disclosing which data. Based on the cues-filtered-out theory we introduce a new feature to support the privacy-awareness of forum users and tested it with 313 users. The results of our empirical study show that the presentation of privacy-related context cues indeed increases forum users' privacy-awareness. This is an important precondition for users' willingness to modify privacy settings or to use privacy-enhancing technologies.

RNA interference (RNAi) can be induced in vitro either by application of synthetic short interfering RNAs (siRNAs), or by intracellular expression of siRNAs or short hairpin RNAs (shRNAs) from transfected vectors. The most widely used promoters for siRNA/shRNA expression are based on polymerase III (Pol III)-dependent transcription. We developed an alternative vector for siRNA/shRNA expression, using a mouse RNA polymerase I (Pol I) promoter. Pol I-dependent transcription serves in cells for production of ribosomal RNA (rRNA), and as such, is ubiquitously and stably active in different cell types. As Pol I-dependent transcription is highly species-specific, Pol I-based system provides an important biosafety advantage with respect to silencing of genes with unknown functions.

Die Umsetzung von S4N5Cl (1) mit silylierten Sulfodiimiden oder einem substituierten Harnstoff im Molverhaltnis 1:1 fuhrt zu den Substitutionsprodukten 2a–e. Die Reaktion zu 2a wurde unter verschiedenen Reaktionsbedingungen studiert. Im Molverhaltnis 2:1 erhalt man die auserst explosiven Verbindungen 3a und b mit zwei S4N5-Kafigen, die uber eine Sulfodiimidgruppe verbruckt sind. Covalent Compounds of Tetrasulfur Pentanitride The reaction of S4N5Cl (1) with silylated sulfodiimides or a substituted urea in a molar ratio of 1:1 leads to covalent derivatives 2a–e. The reaction of 2a has been studied under different conditions. In a molar ratio of 2:1, 3a and b were obtained, extremely explosive compounds with two S4N5 cages bridged by a sulfodiimide group.