Background: Despite numerous studies of geographic variation in healthcare cost and utilization at the local, regional, and state levels across the U.S., a comprehensive characterization of geographic variation in outcomes has not been published.
View Article and Find Full Text PDFRNA decay plays a crucial role in post-transcriptional regulation of gene expression. Work conducted over the last decades has defined the major mRNA decay pathways, as well as enzymes and their cofactors responsible for these processes. In contrast, our knowledge of the mechanisms of degradation of non-protein coding RNA species is more fragmentary.
View Article and Find Full Text PDFThe exosome-independent exoribonuclease DIS3L2 is mutated in Perlman syndrome. Here, we used extensive global transcriptomic and targeted biochemical analyses to identify novel DIS3L2 substrates in human cells. We show that DIS3L2 regulates pol II transcripts, comprising selected canonical and histone-coding mRNAs, and a novel FTL_short RNA from the ferritin mRNA 5' UTR.
View Article and Find Full Text PDFHuman DIS3, the nuclear catalytic subunit of the exosome complex, contains exonucleolytic and endonucleolytic active domains. To identify DIS3 targets genome-wide, we combined comprehensive transcriptomic analyses of engineered HEK293 cells that expressed mutant DIS3, with Photoactivatable Ribonucleoside-Enhanced Cross-Linking and Immunoprecipitation (PAR-CLIP) experiments. In cells expressing DIS3 with both catalytic sites mutated, RNAs originating from unannotated genomic regions increased ∼2.
View Article and Find Full Text PDFProduction of ribosomes relies on more than 200 accessory factors to ensure the proper sequence of steps and faultless assembly of ribonucleoprotein machinery. Among trans-acting factors are numerous enzymes, including ribonucleases responsible for processing the large rRNA precursor synthesized by RNA polymerase I that encompasses sequences corresponding to mature 18S, 5.8S, and 25/28S rRNA.
View Article and Find Full Text PDFThere is interest in making health care price information more transparent given the increase in enrollment in high-deductible and consumer-directed health plans, and as policy efforts intensify to engage consumers to obtain high value care. We examine the role of private companies that market price transparency tools, primarily to self-insured employers - an important yet understudied topic. What companies exist? How did they emerge? What information do they provide? Where do they get that information? How does the price and quality information provided compare across companies?
View Article and Find Full Text PDFBrownian motion of slender particles near a boundary is ubiquitous in biological systems and in nanomaterial assembly, but the complex hydrodynamic interaction in those systems is still poorly understood. Here, we report experimental and computational studies of the Brownian motion of silicon nanowires tethered on a substrate. An optical interference method enabled direct observation of microscopic rotations of the slender bodies in three dimensions with high angular and temporal resolutions.
View Article and Find Full Text PDFWhile plasticity is typically associated with persistent modifications of synaptic strengths, recent studies indicated that modulations of dendritic excitability may form the other part of the engram and dynamically affect computational processing and output of neuronal circuits. However it remains unknown whether modulation of dendritic excitability is controlled by synaptic changes or whether it can be distinct from them. Here we report the first observation of the induction of a persistent plastic decrease in dendritic excitability decoupled from synaptic stimulation, which is localized and purely activity-based.
View Article and Find Full Text PDFWhen light illuminates a rough metallic surface, hotspots can appear, where the light is concentrated on the nanometre scale, producing an intense electromagnetic field. This phenomenon, called the surface enhancement effect, has a broad range of potential applications, such as the detection of weak chemical signals. Hotspots are believed to be associated with localized electromagnetic modes, caused by the randomness of the surface texture.
View Article and Find Full Text PDFEach step of the kinesin motor involves a force-generating molecular rearrangement. Although significant progress has been made in elucidating the broad features of the kinesin mechanochemical cycle, molecular details of the force generation mechanism remain a mystery. Recent molecular dynamics simulations have suggested a mechanism in which the forward drive is produced when the N-terminal cover strand forms a beta-sheet with the neck linker to yield the cover-neck bundle.
View Article and Find Full Text PDFThe ability to quickly and reliably engineer many-component systems from libraries of standard interchangeable parts is one hallmark of modern technologies. Whether the apparent complexity of living systems will permit biological engineers to develop similar capabilities is a pressing research question. We propose to adapt existing frameworks for describing engineered devices to biological objects in order to (i) direct the refinement and use of biological 'parts' and 'devices', (ii) support research on enabling reliable composition of standard biological parts and (iii) facilitate the development of abstraction hierarchies that simplify biological engineering.
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