Aalto University

About: Aalto University is a education organization based out in Espoo, Finland. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 9969 authors who have published 32648 publications receiving 829626 citations. The organization is also known as: TKK & Aalto-korkeakoulu.

Modulation of TET2 expression and 5-methylcytosine oxidation by the CXXC domain protein IDAX

Abstract: The CXXC domains of TET2 (encoded by the distinct gene IDAX) and TET3 are found to have previously unknown roles in the regulation of TET proteins through the activation of caspases and subsequent reduction in TET catalytic activity; this regulation is dependent on DNA binding through the CXXC domain. TET family proteins modify the methylation status of DNA by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine (5hmC, sometimes called the 'fifth base' of DNA) and other intermediates. TET1 and TET3 contain a CXXC domain but the ancestral CXXC domain of TET2 is encoded by a distinct gene, IDAX (or CXXC4). This paper demonstrates that IDAX binds unmethylated CpG-rich DNA via its CXXC domain and recruits TET2. The separate and linked CXXC domains of TET2 and TET3 are shown to act as regulators of caspase activation and TET enzymatic activity. The authors suggest that future studies should focus on the genomic targets of TET2, IDAX and the IDAX-related protein CXXC5 in normal development and in cancer. TET (ten-eleven-translocation) proteins are Fe(ii)- and α-ketoglutarate-dependent dioxygenases1,2,3 that modify the methylation status of DNA by successively oxidizing 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxycytosine1,3,4,5, potential intermediates in the active erasure of DNA-methylation marks5,6. Here we show that IDAX (also known as CXXC4), a reported inhibitor of Wnt signalling7 that has been implicated in malignant renal cell carcinoma8 and colonic villous adenoma9, regulates TET2 protein expression. IDAX was originally encoded within an ancestral TET2 gene that underwent a chromosomal gene inversion during evolution, thus separating the TET2 CXXC domain from the catalytic domain. The IDAX CXXC domain binds DNA sequences containing unmethylated CpG dinucleotides, localizes to promoters and CpG islands in genomic DNA and interacts directly with the catalytic domain of TET2. Unexpectedly, IDAX expression results in caspase activation and TET2 protein downregulation, in a manner that depends on DNA binding through the IDAX CXXC domain, suggesting that IDAX recruits TET2 to DNA before degradation. IDAX depletion prevents TET2 downregulation in differentiating mouse embryonic stem cells, and short hairpin RNA against IDAX increases TET2 protein expression in the human monocytic cell line U937. Notably, we find that the expression and activity of TET3 is also regulated through its CXXC domain. Taken together, these results establish the separate and linked CXXC domains of TET2 and TET3, respectively, as previously unknown regulators of caspase activation and TET enzymatic activity.

Naturalistic FMRI mapping reveals superior temporal sulcus as the hub for the distributed brain network for social perception.

Abstract: Despite the abundant data on brain networks processing static social signals, such as pictures of faces, the neural systems supporting social perception in naturalistic conditions are still poorly understood. Here we delineated brain networks subserving social perception under naturalistic conditions in 19 healthy humans who watched, during 3-tesla functional magnetic imaging (fMRI), a set of 137 short (~16 s each, total 27 min) audiovisual movie clips depicting pre-selected social signals. Two independent raters estimated how well each clip represented eight social features (faces, human bodies, biological motion, goal-oriented actions, emotion, social interaction, pain, and speech) and six filler features (places, objects, rigid motion, people not in social interaction, non-goal-oriented action and non-human sounds) lacking social content. These ratings were used as predictors in the fMRI analysis. The posterior superior temporal sulcus (STS) responded to all social features but not to any non-social features, and the anterior STS responded to all social features except bodies and biological motion. We also found four partially segregated, extended networks for processing of specific social signals: 1) a fronto-temporal network responding to multiple social categories, 2) a fronto-parietal network preferentially activated to bodies, motion and pain, 3) a temporo-amygdalar network responding to faces, social interaction and speech, and 4) a fronto-insular network responding to pain, emotions, social interactions, and speech. Our results highlight the role of the posterior STS in processing multiple aspects of social information, as well as the feasibility and efficiency of fMRI mapping under conditions that resemble the complexity of real life.

Qualitative Marketing Research: A Cultural Approach

Abstract: Aimed at both graduate and undergraduate students majoring in business administration and in other fields of social sciences, Qualitative Marketing Research unpacks the emerging cultural approach in the field of marketing and consumer research and provides an interesting and informed study for anyone interested in cultural approaches to economic and social theory. The book also provides insights for MBA students and other business professionals who work in the field of marketing, advertising, media planning and qualitative market research, offering methodological resources for keeping professional skills up to date and help with designing and conducting relevant and skillful market research which is sensitive to the cultural dynamics of the marketplace behaviour.

Dynamical Casimir effect in a Josephson metamaterial

Abstract: The zero-point energy stored in the modes of an electromagnetic cavity has experimentally detectable effects, giving rise to an attractive interaction between the opposite walls, the static Casimir effect. A dynamical version of this effect was predicted to occur when the vacuum energy is changed either by moving the walls of the cavity or by changing the index of refraction, resulting in the conversion of vacuum fluctuations into real photons. Here, we demonstrate the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity at 5.4 GHz. We modulate the effective length of the cavity by flux-biasing the metamaterial based on superconducting quantum interference devices (SQUIDs), which results in variation of a few percentage points in the speed of light. We extract the full 4 × 4 covariance matrix of the emitted microwave radiation, demonstrating that photons at frequencies symmetrical with respect to half of the modulation frequency are generated in pairs. At large detunings of the cavity from half of the modulation frequency, we find power spectra that clearly show the theoretically predicted hallmark of the Casimir effect: a bimodal, “sparrow-tail” structure. The observed substantial photon flux cannot be assigned to parametric amplification of thermal fluctuations; its creation is a direct consequence of the noncommutativity structure of quantum field theory.

Why Do People Watch Others Play Video Games? An Empirical Study on the Motivations of Twitch Users

Abstract: This study investigates why people consume live peer-produced online videogame content, an emerging form of new media phenomenon. To study this video streaming phenomenon we employ a questionnaire study (N=1097). Utilising the uses and gratifications theory we examine five distinct types of motivations: cognitive, affective, personal integrative, social integrative and tension release. We find that tension release, social integrative and affective motivations are positively associated with how many hours people watch streams. We also find that social integrative motivations are the primary predictor of subscription behaviour. This study lays groundwork for understanding the motivations to consume this emerging form of new media related to online games and video streams.