MR-Compatible Blood Sampler for PET

Over the last few years, the idea of simultaneous MR-PET imaging has attracted more and more research interest. This new bimodal technique promises accurate structural and functional information of the investigated object at the same time. While PET-CT has already established as a powerful bimodal imaging technique, MR offers better distinction of soft matter, which can be advantageous especially for brain research. Future studies in this field could also include simultaneous scans with fMRI and PET. For certain measurements (e.g. cerebral blood flow, metabolic rates), the quantitative analysis of PET data requires knowledge of the arterial input function (time-activity-curve of patient blood). In other words, the amount of radioactivity in the arterial blood has to be monitored constantly. Ordinary, commercially available blood sampling systems are based on Photo Multiplier Tubes (PMTs) that cannot be operated in an MR environment. An MR-compatible blood sampler was therefore designed and built to be able to exploit the full potential of hybrid MR-PET. Basically, the new device works as follows. Arterial blood is drawn out of the patient and conducted via a catheter through the detector unit of the blood sampler. The two annihilation photons that emerge after positron decay are detected separately by two scintillation crystals (50mm x 40mm x 30mm Lutetium Oxyorthosilicate (LSO)) that surround the catheter in a sandwich-like geometry. Each scintillation crystal is coupled to a single Avalanche Photodiode (APD). Both signals are fed through a 12m cable to the MR filter plate, where they are low-pass filtered. The pulse processing electronics, which are set behind the filter plate, are essentially performing a coincidence detection of annihilation photons. A major technical challenge was to deal with the pronounced temperature sensitivity and the relatively noisy signals of APDs. Besides appropriate considerations for the mechanical and electronical design, the solution involved the development of a new online algorithm that monitors the effective gain of the APDs and corrects for gain drifts. The prototype system was successfully tested for MR-compatibility in a Siemens Magnetom Trio MR tomograph. Furthermore, the blood sampler was used during PET scans of rats to prove the applicability of the new device

Frustration-Aggression Theory

Frustration-aggression theory, also known as the frustration-aggression hypothesis, is one of the most seminal theories in aggression research. Since it was first formulated in the late 1930s, it has been applied and studied in many fields, including psychology, ethnology, sociology, and criminology. While there have been several reformulations, additions, and changes, the basic assumption of the frustration-aggression hypothesis is still that frustration, typically understood as an event instead of an emotion, increases the tendency to act or react aggressively. A substantial proportion of the research has dealt with the identification of boundary conditions or moderators and mediators of the causal path from frustration to aggression. Irrespective of these refinements and modifications, there is ample empirical evidence for the existence of this effect and, despite a decline in the overall number of publications that refer to it, frustration-aggression theory has recently found novel applications in particular areas, such as media psychology

Why so serious? On the relation of serious games and learning

Serious games have become a key segment in the games market as well as in academic research. Although the number of games that identify themselves as belonging to this category as well as the research done on their effects has been rapidly growing, there has thus far been no attempt to define all of the various opportunities that digital games provide for learning. To address this issue we look at existing definitions of serious games and their potential for learning. We identify the shortcomings of existing definitions and typologies. We discuss opportunities for an educational use of serious games which have been marginalized so far and develop a more flexible classification system for serious games in order to include commercial-off-the-shelf (COTS) games for learning purposes and description options for future developments of gaming technology. This classification system for digital and serious games uses labels and tags as a preferable solution instead of fixed genre categories. The aim of this paper is to move the focus from what serious games and their uses for learning currently are to what they can be

Quantitative PCR assay for detection of bois noir phytoplasmas in grape and insect tissue

In Europe's vineyards "Bois noir" (BN) is an expanding yellows disease on Vitis vinifera. It is associated with phytoplasmas of the stolbur group (16SrXII-A). Two subtypes are important, one is associated with Urtica dioica and one with Convolvulus arvensis. Both phytoplasma types are transmitted by the insect Hyalesthes obsoletus. A nucleic acid extraction method for V. vinifera and H. obsoletus was developed together with a real time PCR (qPCR) assay based on a polymorphic sequence with homology to a putative dimethyladenosine transferase. The comparison of the conventional detection method with the qPCR assay of 40 insect and 40 V. vinifera samples showed a 10% higher sensitivity of qPCR in plant samples. The titer of phytoplasmas in H. obsoletus was 2643-fold increased in the strongest infected samples compared to the lowest ones. The results suggest this real-time PCR as a valid and fast alternative procedure for the detection and quantification of BN phytoplasmas. The assay allows to discriminate the two phytoplasma types and to quantify phytoplasmas in H. obsoletus

Aggression and Preference for First-Person Shooter and Action Games: Data From a Large-Scale Survey of German Gamers Aged 14 and Above

Cross-sectional studies on video game violence and aggression have yielded contradictory results. Parts of this inconclusiveness can be attributed to the limitation to particular age groups. The present study investigated the relationship between preference for action and first-person shooter (FPS) games and aggression for the groups of adolescents (14-18), younger (19-39), and older adults (40+) in a sample of German gamers (N = 4,500). The strength of the association differed between age groups. Even after controlling for gender, education, social support, self-efficacy, and overall video game use, we found a significant relationship between preference for action and FPS games and physical aggression that was strongest for the adolescents. We found no such association for anger and verbal aggression. The results indicate that potential selection or socialization effects are likely to differ with age and that research on video games and aggression can benefit from the inclusion of more heterogeneous samples

Violent acts (Video Games)

The depiction of violence is the focus of many content analyses of video games. Typically, the occurrence and nature of acts of violence or aggression are coded to quantify the amount of violent content in a particular game.   Field of application/theoretical foundation: Quantifying the amount of violence in video games can inform media effects research that looks at the relationship between the exposure to violent video game content and aggression. This allows for more precise measures and hypotheses than simply coding a game as violent or nonviolent which is often done in experimental research in this area. What is commonly coded in content analyses of violent content in video games is the number and nature of aggressive or violent actions. Specific attributes of these acts, such as their realism, graphicness or (narrative) justification (Tamborini et al., 2013) are only considered in a few studies (e.g., Lachlan et al., 2005). While the focus in most studies is on acts of physical aggression/violence in interactions with/between game characters, there are also studies that have investigated verbal aggression between players (Holz Ivory et al., 2017).   References/combination with other methods of data collection: Content analysis of violence in video games can be complemented by survey data asking players about the games they play and their rating of the degree of violence they contain and/or age rating from institutions like ESRB or PEGI (see Busching et al., 2015).   Example studies Coding material Measure Operationalization Unit(s) of analysis Source(s) (reported reliability of coding) Video recording of playing session Number and duration of violent interactions (attacking and being attacked) (a) combat: “periods of playing time in which a player [i.e., the character controlled by the player] fires his gun” (p. 1021) (b) “under attack–the player is attacked by an opponent before or after using his own weapon” (p. 1022)  Distinct phases/events in up to 12 minutes of solo play of the first-person shooter game Tactical Ops: Assault on Terror Weber et al., 2009 (Cohen’s kappa = 0.81) Video recording of the whole game Depictions of injury (present/not present) “An injured or dead character lying on the ground or remnants of blood from a known violent act” (p. 403) 1-second intervals of the game recordings Thompson et al., 2006 (Cohen’s kappa = 0.93) Video recording of the whole game Depictions of violent acts (present/not present) “Intentional acts in which the aggressor causes or attempts to cause physical injury or death to another character” (p. 403) 1-second intervals of the game recordings Thompson et al., 2006 (Cohen’s kappa = 0.93) Video recording of the first 10 minutes of gameplay Depicted harm/pain (none, mild, moderate, extreme) in aggressive exchanges between in-game characters “physical injury or incapacitation of the victim” (p. 64) “an aggressive exchange that occurs between a perpetrator (P) engaging in a particular type of act (A) against a target (T)” (p. 63) Smith et al., 2003 (coefficient according to “Potter and Levine-Donnerstein's (1999) reliability formula for multiple coders”, p. 65: 0.87)   References Busching, R., Gentile, D. A., Krahé, B., Möller, I., Khoo, A., Walsh, D. A., & Anderson, C. A. (2015). Testing the reliability and validity of different measures of violent video game use in the United States, Singapore, and Germany. Psychology of Popular Media Culture, 4(2), 97–111. https://doi.org/10.1037/ppm0000004 Holz Ivory, A., Ivory, J. D., & Wu, W. (2017). Harsh Words and Deeds: Systematic Content Analyses of Offensive User Behavior in the Virtual Environments of Online First-Person Shooter Games. Journal of Virtual Worlds Research, 10(2), 19. Lachlan, K. A., Smith, S. L., & Tamborini, R. (2005). Models for aggressive behavior: The attributes of violent characters in popular video games. Communication Studies, 56(4), 313–329. https://doi.org/10.1080/10510970500319377 Smith, S. L., Lachlan, K. A., & Tamborini, R. (2003). Popular video games: Quantifying the presentation of violence and its context. Journal of Broadcasting & Electronic Media, 47(1), 58–76. https://doi.org/10.1207/s15506878jobem4701_4 Tamborini, R., Weber, R., Bowman, N. D., Eden, A., & Skalski, P. (2013). “Violence is a many-splintered thing”: The importance of realism, justification, and graphicness in understanding perceptions of and preferences for violent films and video games. Projections, 7(1), 100–118. https://doi.org/10.3167/proj.2013.070108 Thompson, K. M., Tepichin, K., & Haninger, K. (2006). Content and ratings of mature-rated video games. Archives of Pediatrics & Adolescent Medicine, 160(4), 402–410. https://doi.org/10.1001/archpedi.160.4.402 Weber, R., Behr, K.-M., Tamborini, R., Ritterfeld, U., & Mathiak, K. (2009). What Do We Really Know About First-Person-Shooter Games? An Event-Related, High-Resolution Content Analysis. Journal of Computer-Mediated Communication, 14(4), 1016–1037. https://doi.org/10.1111/j.1083-6101.2009.01479.

Data Linking - Linking survey data with geospatial, social media, and sensor data (Version 1.0)

Survey data are still the most commonly used type of data in the quantitative social sciences. However, as not everything that is of interest to social scientists can be measured via surveys, and the self-report data they provide have certain limitations, such as recollection or social desirability bias, researchers have increasingly used other types of data that are not specifically created for research. These data are often called "found data" or "non-designed data" and encompass a variety of different data types. Naturally, these data have their own sets of limitations. One way of combining the unique strengths of survey data and these other data types and dealing with some of their respective limitations is to link them. This guideline first describes why linking survey data with other types of data can be useful for researchers. After that, it focuses on the linking of survey data with three types of data that are becoming increasingly popular in the social sciences: geospatial data, social media data, and sensor data. Following a discussion of the advantages and challenges associated with linking survey data with these types of data, the guideline concludes by comparing their similarities, presenting some general recommendations regarding linking surveys with other types of (found/non-designed) data, and providing an outlook on current developments in survey research with regard to data linking