617 research outputs found
Have You Updated Your Toaster? Transatlantic Approaches to Governing the Internet of Everything
As Internet-connected devices become ubiquitous, it remains an open question whether security— or privacy—can or will scale, or whether a combination of perverse incentives, new problems, and new impacts of old problems like “technical debt” amassing from products being rushed to market before being fully vetted, will derail progress and exacerbate cyber insecurity. This Article investigates contemporary approaches to Internet of Things (IoT) governance through an in- depth comparative case study focusing on the European Union (EU) and the United States. Particular attention is paid to the impact on IoT security of the General Data Protection Regulation (GDPR) and the Network Information Security (NIS) Directive in the EU, and the influence of the U.S. National Institute for Standards and Technology Cybersecurity Framework (NIST CSF), with a focus on mitigating the risk of politically motivated attacks on civilians. We analyze reform proposals and apply lessons from major prior Internet governance debates to argue for a polycentric approach to improving IoT security and privacy in the transatlantic context
Chromatin proteomic profiling reveals novel proteins associated with histone-marked genomic regions
More than a thousand proteins are thought to contribute to mammalian chromatin and its regulation, but our understanding of the genomic occupancy and function of most of these proteins is limited. Here we describe an approach, which we call “chromatin proteomic profiling,” to identify proteins associated with genomic regions marked by specifically modified histones. We used ChIP-MS to identify proteins associated with genomic regions marked by histones modified at specific lysine residues, including H3K27ac, H3K4me3, H3K79me2, H3K36me3, H3K9me3, and H4K20me3, in ES cells. We identified 332 known and 114 novel proteins associated with these histone-marked genomic segments. Many of the novel candidates have been implicated in various diseases, and their chromatin association may provide clues to disease mechanisms. More than 100 histone modifications have been described, so similar chromatin proteomic profiling studies should prove to be valuable for identifying many additional chromatin-associated proteins in a broad spectrum of cell types.National Institutes of Health (U.S.) (Grant HG002668)National Institutes of Health (U.S.) (Grant HG006046)National Institutes of Health (U.S.) (Grant HD045022
Models of human core transcriptional regulatory circuitries
A small set of core transcription factors (TFs) dominates control of the gene expression program in embryonic stem cells and other well-studied cellular models. These core TFs collectively regulate their own gene expression, thus forming an interconnected auto-regulatory loop that can be considered the core transcriptional regulatory circuitry (CRC) for that cell type. There is limited knowledge of core TFs, and thus models of core regulatory circuitry, for most cell types. We recently discovered that genes encoding known core TFs forming CRCs are driven by super-enhancers, which provides an opportunity to systematically predict CRCs in poorly studied cell types through super-enhancer mapping. Here, we use super-enhancer maps to generate CRC models for 75 human cell and tissue types. These core circuitry models should prove valuable for further investigating cell-type–specific transcriptional regulation in healthy and diseased cells.United States. National Institutes of Health (HG002668
Evolutionary conserved NSL complex/BRD4 axis controls transcription activation via histone acetylation
Cells rely on a diverse repertoire of genes for maintaining homeostasis, but the transcriptional networks underlying their expression remain poorly understood. The MOF acetyltransferase-containing Non-Specific Lethal (NSL) complex is a broad transcription regulator. It is essential in Drosophila, and haploinsufficiency of the human KANSL1 subunit results in the Koolen-de Vries syndrome. Here, we perform a genome-wide RNAi screen and identify the BET protein BRD4 as an evolutionary conserved co-factor of the NSL complex. Using Drosophila and mouse embryonic stem cells, we characterise a recruitment hierarchy, where NSL-deposited histone acetylation enables BRD4 recruitment for transcription of constitutively active genes. Transcriptome analyses in Koolen-de Vries patient-derived fibroblasts reveals perturbations with a cellular homeostasis signature that are evoked by the NSL complex/BRD4 axis. We propose that BRD4 represents a conserved bridge between the NSL complex and transcription activation, and provide a new perspective in the understanding of their functions in healthy and diseased states
Light tracking through ice and water -- Scattering and absorption in heterogeneous media with Photonics
In the field of neutrino astronomy, large volumes of optically transparent
matter like glacial ice, lake water, or deep ocean water are used as detector
media. Elementary particle interactions are studied using in situ detectors
recording time distributions and fluxes of the faint photon fields of Cherenkov
radiation generated by ultra-relativistic charged particles, typically muons or
electrons.
The Photonics software package was developed to determine photon flux and
time distributions throughout a volume containing a light source through Monte
Carlo simulation. Photons are propagated and time distributions are recorded
throughout a cellular grid constituting the simulation volume, and Mie
scattering and absorption are realised using wavelength and position dependent
parameterisations. The photon tracking results are stored in binary tables for
transparent access through ANSI-C and C++ interfaces. For higher-level physics
applications, like simulation or reconstruction of particle events, it is then
possible to quickly acquire the light yield and time distributions for a
pre-specified set of light source and detector properties and geometries
without real-time photon propagation.
In this paper the Photonics light propagation routines and methodology are
presented and applied to the IceCube and Antares neutrino telescopes. The way
in which inhomogeneities of the Antarctic glacial ice distort the signatures of
elementary particle interactions, and how Photonics can be used to account for
these effects, is described.Comment: 22 pages, 8 Postscript figures, uses elsart.cl
Total synthesis and biological mode of action of largazole: A potent class I histone deacetylase inhibitor
The efficient total synthesis of the recently described natural substance largazole (1) and its active metabolite largazole thiol (2) is described. The synthesis required eight linear steps and proceeded in 37% overall yield. It is demonstrated that largazole is a pro-drug that is activated by removal of the octanoyl residue from the 3-hydroxy-7-mercaptohept-4-enoic acid moiety to generate the active metabolite 2, which is an extraordinarily potent Class I histone deacetylase inhibitor. Synthetic largazole and 2 have been evaluated side-by-side with FK228 and SAHA for inhibition of HDACs 1, 2, 3, and 6. Largazole and largazole thiol were further assayed for cytotoxic activity against a panel of chemoresistant melanoma cell lines, and it was found that largazole is substantially more cytotoxic than largazole thiol; this difference is attributed to differences in the cell permeability of the two substances
Inhibiting the oncogenic translation program is an effective therapeutic strategy in multiple myeloma
Published in final edited form as: Sci Transl Med. 2017 May 10; 9(389). https://doi.org/10.1126/scitranslmed.aal2668.Multiple myeloma (MM) is a frequently incurable hematological cancer in which overactivity of MYC plays a central role, notably through up-regulation of ribosome biogenesis and translation. To better understand the oncogenic program driven by MYC and investigate its potential as a therapeutic target, we screened a chemically diverse small-molecule library for anti-MM activity. The most potent hits identified were rocaglate scaffold inhibitors of translation initiation. Expression profiling of MM cells revealed reversion of the oncogenic MYC-driven transcriptional program by CMLD010509, the most promising rocaglate. Proteome-wide reversion correlated with selective depletion of short-lived proteins that are key to MM growth and survival, most notably MYC, MDM2, CCND1, MAF, and MCL-1. The efficacy of CMLD010509 in mouse models of MM confirmed the therapeutic relevance of these findings in vivo and supports the feasibility of targeting the oncogenic MYC-driven translation program in MM with rocaglates
Pojamide: An HDAC3-selective ferrocene analogue with remarkably enhanced redox-triggered ferrocenium activity in cells.
A ferrocene containing ortho-aminoanilide, N1-(2-aminophenyl)-N8-ferrocenyloctanediamide, 2b (Pojamide) displayed nanomolar potency vs. HDAC3. Compared to RGFP966, a potent and selective HDAC3 inhibitor, Pojamide displayed superior activity in HCT116 colorectal cancer cell invasion assays; however, TCH106 and Romidepsin, potent HDAC1 inhibitors, outperformed Pojamide in cellular proliferation and colony formation assays. Together, these data suggest that HDAC 1 & 3 inhibition is desirable to achieve maximum anti-cancer benefits. Additionally, we explored Pojamide-induced redox-pharmacology. Indeed, treating HCT116 cells with Pojamide, SNP (sodium nitroprusside) and glutathione (GSH) led to greatly enhanced cytotoxicity and DNA damage attributed to activation to an Fe(III) species
Balancing the dilution and oddity effects: Decisions depend on body size
Background Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack). Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the ‘oddity’ effect). Thus, animals should choose group mates close in appearance to themselves (eg. similar size), whilst also choosing a large group. Methodology and Principal Findings We used the Trinidadian guppy (Poecilia reticulata), a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity. Conclusions and Significance Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling decisions
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