1,412 research outputs found
Effects of Media Ratings on Children and Adolescents: A Litmus Test of the Forbidden Fruit Effect
Special section on product development: Introduction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23878/1/0000117.pd
Establishment and characterization of immortalized Gli-null mouse embryonic fibroblast cell lines
<p>Abstract</p> <p>Background</p> <p>Hedgehog (Hh) signaling is a conserved morphogenetic pathway which plays critical roles in embryonic development, with emerging evidence also supporting a role in healing and repair processes and tumorigenesis. The Gli family of transcription factors (Gli1, 2 and 3) mediate the Hedgehog morphogenetic signal by regulating the expression of downstream target genes. We previously characterized the individual and cooperative roles of the Gli proteins in Hh target gene regulation using a battery of primary embryonic fibroblasts from Gli null mice.</p> <p>Results</p> <p>Here, we describe the establishment of spontaneously immortalized mouse embryonic fibroblast (iMEF) cell lines lacking single and multiple Gli genes. These non-clonal cell lines recapitulate the unique ligand mediated transcriptional response of primary MEFs. While loss of Gli1 had no effect on target gene induction, Gli2 null cells demonstrated reduced target gene induction while Gli3 null cells exhibited elevated basal and ligand-induced expression. Target gene response in <it>Gli1</it><sup>-/-</sup><it>2</it><sup>-/- </sup>iMEFs was severely reduced while <it>Gli2</it><sup>-/-</sup><it>3</it><sup>-/- </sup>iMEFs were incapable of ligand-induced transcriptional response. However, we found that both <it>Gli1</it><sup>-/-</sup><it>2</it><sup>-/- </sup>and <it>Gli2</it><sup>-/-</sup><it>3</it><sup>-/- </sup>iMEFs exhibited robust leukotriene synthesis-dependent migration responses to Hh ligand, demonstrating that this response is not transcriptionally-dependent.</p> <p>Conclusion</p> <p>This study provides fundamental characterizations of the transcriptional and non-transcriptional Hh responsiveness of a battery of Gli-null iMEFs. Moving forward, these cell lines should prove a valuable tool set to study the unique functional regulation of the Gli proteins in a Hh-responsive cell-type.</p
Threatened egotism, narcissism, self-esteem, and direct and displaced aggression: Does self-love or self-hate lead to violence?
Automatic mental processes, automatic actions and behaviours in game transfer phenomena: an empirical self-report study using online forum data
Previous studies have demonstrated that the playing of videogames can have both intended and unintended effects. The purpose of this study was to investigate the influence of videogames on players’ mental processes and behaviours in day-to-day settings. A total of 1,023 self-reports from 762 gamers collected from online videogame forums were classified, quantified, described and explained. The data include automatic thoughts, sensations and impulses, automatic mental replays of the game in real life, and voluntary/involuntary behaviours with videogame content. Many gamers reported that they had responded – at least sometimes – to real life stimuli as if they were still playing videogames. This included overreactions, avoidances, and involuntary movements of limbs. These experiences lasted relatively short periods of time but in a minority of players were recurrent. The gamers' experiences appeared to be enhanced by virtual embodiment, repetitive manipulation of game controls, and their gaming habits. However, similar phenomena may also occur when doing other non-gaming activities. The implications of these game transfer experiences are discussed
Violent video games and morality: a meta-ethical approach
This paper considers what it is about violent video games that leads one reasonably minded person to declare "That is immoral" while another denies it. Three interpretations of video game content a re discussed: reductionist, narrow, and broad. It is argued that a broad interpretation is required for a moral objection to be justified. It is further argued that understanding the meaning of moral utterances – like "x is immoral" – is important to an understanding of why there is a lack of moral consensus when it comes to the content of violent video games. Constructive ecumenical expressivism is presented as a means of explaining what it is that we are doing when we make moral pronouncements and why, when it comes to video game content, differing moral attitudes abound. Constructive ecumenical expressivism is also presented as a means of illuminating what would be required for moral consensus to be achieved
The permanently chaperone-active small heat shock protein Hsp17 from Caenorhabditis elegans exhibits topological separation of its N-terminal regions
Small Heat shock proteins (sHsps) are a family of molecular chaperones that bind nonnative proteins in an ATP-independent manner. Caenorhabditis elegans encodes 16 different sHsps, among them Hsp17, which is evolutionarily distinct from other sHsps in the nematode. The structure and mechanism of Hsp17 and how these may differ from other sHsps remain unclear. Here, we find that Hsp17 has a distinct expression pattern, structural organization, and chaperone function. Consistent with its presence under nonstress conditions, and in contrast to many other sHsps, we determined that Hsp17 is a mono-disperse, permanently active chaperone in vitro, which interacts with hundreds of different C. elegans proteins under physiological conditions. Additionally, our cryo-EM structure of Hsp17 reveals that in the 24-mer complex, 12 N-terminal regions are involved in its chaperone function. These flexible regions are located on the outside of the spherical oligomer, whereas the other 12 N-terminal regions are engaged in stabilizing interactions in its interior. This allows the same region in Hsp17 to perform different functions depending on the topological context. Taken together, our results reveal structural and functional features that further define the structural basis of permanently active sHsps
The equation of state of solid nickel aluminide
The pressure-volume-temperature equation of state of the intermetallic
compound NiAl was calculated theoretically, and compared with experimental
measurements. Electron ground states were calculated for NiAl in the CsCl
structure, using density functional theory, and were used to predict the cold
compression curve and the density of phonon states. The Rose form of
compression curve was found to reproduce the ab initio calculations well in
compression but exhibited significant deviations in expansion. A
thermodynamically-complete equation of state was constructed for NiAl. Shock
waves were induced in crystals of NiAl by the impact of laser-launched Cu
flyers and by launching NiAl flyers into transparent windows of known
properties. The TRIDENT laser was used to accelerate the flyers to speeds
between 100 and 600m/s. Point and line-imaging laser Doppler velocimetry was
used to measure the acceleration of the flyer and the surface velocity history
of the target. The velocity histories were used to deduce the stress state, and
hence states on the principal Hugoniot and the flow stress. Flyers and targets
were recovered from most experiments. The effect of elasticity and plastic flow
in the sample and window was assessed. The ambient isotherm reproduced static
compression data very well, and the predicted Hugoniot was consistent with
shock compression data
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