Deciphering the molecular basis of pluripotency is fundamental to our understanding of development and embryonic stem cell function. Here, we report that TAF3, a TBP-associated core promoter factor, ...is highly enriched in ES cells. In this context, TAF3 is required for endoderm lineage differentiation and prevents premature specification of neuroectoderm and mesoderm. In addition to its role in the core promoter recognition complex TFIID, genome-wide binding studies reveal that TAF3 localizes to a subset of chromosomal regions bound by CTCF/cohesin that are selectively associated with genes upregulated by TAF3. Notably, CTCF directly recruits TAF3 to promoter distal sites and TAF3-dependent DNA looping is observed between the promoter distal sites and core promoters occupied by TAF3/CTCF/cohesin. Together, our findings support a new role of TAF3 in mediating long-range chromatin regulatory interactions that safeguard the finely-balanced transcriptional programs underlying pluripotency.
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► High levels of TAF3 in ES cells enable balanced early lineage segregation ► TAF3 is localized to both core promoters and distal enhancer-like sites ► Distal TAF3/CTCF sites distinguish TAF3-activated from TAF3-repressed genes ► Vertebrate-specific domain of TAF3 binds CTCF and mediates DNA looping.
At endodermal genes, TAF3 moves beyond its role at the promoter and engages distal enhancers by interacting with CTCF.
At a cultural moment in which the horrifying is central, what are the pedagogical options available by which to teach and think with our students? Horror movies, like all media, are mythmakers; media ...and culture reflect and reproduce but also create or consolidate. Teaching horror leads to new conversations, makes the familiar strange, and gives students new language and tools through which to assess and rewrite cultural and social narratives. This conversation bridges sociology, gender studies, and media studies to highlight the importance and usefulness of film analysis and theoretical texts that fall outside of sociology in developing robust sociological and interdisciplinary dialogue. We review the films, texts, themes, and approaches that we have used to get students to read difficult theory, think collaboratively and critically, and write in ways that push their voices and ideas beyond that with which they are accustomed and comfortable.
Plasma equilibria reconstructed from the Mega-Amp Spherical Tokamak have sufficient resolution to capture plasma evolution during the short period between edge-localized modes (ELMs). Immediately ...after the ELM, steep gradients in pressure, P, and density, n(e), form pedestals close to the separatrix, and they then expand into the core. Local gyrokinetic analysis over the ELM cycle reveals the dominant microinstabilities at perpendicular wavelengths of the order of the ion Larmor radius. These are kinetic ballooning modes in the pedestal and microtearing modes in the core close to the pedestal top. The evolving growth rate spectra, supported by gyrokinetic analysis using artificial local equilibrium scans, suggest a new physical picture for the formation and arrest of this pedestal.
This article interrogates the depiction of working‐class and subaltern characters in neoliberal US cinema. Deploying a Marxian class schema in a content analysis of 53 top‐grossing films released ...between 1980 and 2010, we find working‐class characters unexpectedly prominent. They appear in most films, lead in a plurality, and are far more often heroes than heavies. Yet the vast majority are white, male and US‐born while exhibiting near ubiquitous subordination to up‐class co‐leads, mainly professional‐managers. Most working‐class characters also die or exit their class by film's end, abdicating agency and leaving up‐class figures in charge. We argue this amounts to a metaframe of nostalgic resignation: a collective image mobilizing masculinity and Eurocentrism to justify a historic loss of working‐class power. In contrast to critical, disconnected or escapist models of mass media's relation to actual social inequality, we argue these findings support a reproductionist (Althusser 2014) or propagandist (Herman and Chomsky 2002) understanding of that dynamic enriched by Hall's “racially structured dominance” approach (1980).
It is widely accepted that newly arisen duplicate gene pairs experience an altered selective regime that is often manifested as an increase in the rate of protein sequence evolution. Many details ...about the nature of the rate acceleration remain unknown, however, including its typical magnitude and duration, and whether it applies to both gene copies or just one. We provide initial answers to these questions by comparing the rate of protein sequence evolution among eight yeast species, between a large set of duplicate gene pairs that were created by a whole-genome duplication (WGD) and a set of genes that were returned to single-copy after this event. Importantly, we use a new method that takes into account the tendency for slowly evolving genes to be retained preferentially in duplicate. We show that, on average, proteins encoded by duplicate gene pairs evolved at least three times faster immediately after the WGD than single-copy genes to which they behave identically in non-WGD lineages. Although the high rate in duplicated genes subsequently declined rapidly, it has not yet returned to the typical rate for single-copy genes. In addition, we show that although duplicate gene pairs often have highly asymmetric rates of evolution, even the slower members of pairs show evidence of a burst of protein sequence evolution immediately after duplication. We discuss the contribution of neofunctionalization to duplicate gene preservation and propose that a form of subfunctionalization mediated by coding region activity-reducing mutations is likely to have played an important role.
Microtearing modes (MTMs) are unstable in the shallow gradient region just inside the top of the pedestal in the spherical tokamak experiment MAST, and may play an important role in the pedestal ...evolution. The linear properties of these instabilities are compared with MTMs deeper inside the core, and further detailed investigations in s-α geometry expose the basic drive mechanism, which is not well described by existing theories. In particular, the growth rate of the dominant edge MTM does not peak at a finite collision frequency, as frequently reported for MTMs further into the core. Our study suggests that the edge MTM is driven by a collisionless trapped particle mechanism that is sensitive to magnetic drifts. This drive is enhanced in the outer region of MAST at high magnetic shear and high trapped particle fraction. Observations of similar modes in conventional aspect ratio devices suggest this drive mechanism may be somewhat ubiquitous towards the edge of current day and future hot tokamaks.
Sustained edge-localized mode (ELM) mitigation has been achieved using resonant magnetic perturbations (RMPs) with a toroidal mode number of n = 4 and n = 6 in lower single null and with n = 3 in ...connected double null plasmas on MAST. The ELM frequency increases by up to a factor of eight with a similar reduction in ELM energy loss. A threshold current for ELM mitigation is observed above which the ELM frequency increases approximately linearly with current in the coils. A comparison of the filament structures observed during the ELMs in the natural and mitigated stages shows that the mitigated ELMs have the characteristics of type I ELMs even though their frequency is higher, their energy loss is reduced and the pedestal pressure gradient is decreased. During the ELM mitigated stage clear lobe structures are observed in visible-light imaging of the X-point region. The size of these lobes is correlated with the increase in ELM frequency observed. The RMPs produce a clear 3D distortion to the plasma and it is likely that these distortions explain why ELMs are destabilized and hence why ELM mitigation occurs.
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