2,131 research outputs found
eIF1 modulates the recognition of suboptimal translation initiation sites and steers gene expression via uORFs
Alternative translation initiation mechanisms such as leaky scanning and reinitiation potentiate the polycistronic nature of human transcripts. By allowing for reprogrammed translation, these mechanisms can mediate biological responses to stimuli. We combined proteomics with ribosome profiling and mRNA sequencing to identify the biological targets of translation control triggered by the eukaryotic translation initiation factor 1 (eIF1), a protein implicated in the stringency of start codon selection. We quantified expression changes of over 4000 proteins and 10 000 actively translated transcripts, leading to the identification of 245 transcripts undergoing translational control mediated by upstream open reading frames (uORFs) upon eIF1 deprivation. Here, the stringency of start codon selection and preference for an optimal nucleotide context were largely diminished leading to translational upregulation of uORFs with suboptimal start. Interestingly, genes affected by eIF1 deprivation were implicated in energy production and sensing of metabolic stress
Mean-Field-Type Games in Engineering
A mean-field-type game is a game in which the instantaneous payoffs and/or
the state dynamics functions involve not only the state and the action profile
but also the joint distributions of state-action pairs. This article presents
some engineering applications of mean-field-type games including road traffic
networks, multi-level building evacuation, millimeter wave wireless
communications, distributed power networks, virus spread over networks, virtual
machine resource management in cloud networks, synchronization of oscillators,
energy-efficient buildings, online meeting and mobile crowdsensing.Comment: 84 pages, 24 figures, 183 references. to appear in AIMS 201
Formation control of nonholonomic mobile robots: the virtual structure approach
PhDIn recent years, there has been a considerable growth in applications of
multi-robot systems as opposed to single-robot systems. This thesis
presents our proposed solutions to a formation control problem in
which mobile robots are required to create a desired formation shape
and track a desired trajectory as a whole.
In the first instance, we study the formation control problem for unicycle
mobile robots. We propose two control algorithms based on a
cascaded approach: one based on a kinematic model of a robot and
the other based on a dynamic model. We also propose a saturated
controller in which actuator limitations are explicitly accounted for.
To demonstrate how the control algorithms work, we present an extensive
simulation and experimental study.
Thereafter we move on to formation control algorithms in which the
coordination error is explicitly defined. Thus, we are able to give conditions
for robots keeping their desired formation shape without necessarily
tracking the desired trajectory. We also introduce a controller
in which both trajectory tracking and formation shape maintenance
are achieved as well as a saturated algorithm. We validate the applicability
of the introduced controllers in simulations and experiments.
Lastly, we study the formation control problem for car-like robots. In
this case we develop a controller using the backstepping technique.
We give conditions for robots keeping their desired formation shape
while failing to track their desired trajectories and present simulation
results to demonstrate the applicability of the proposed controlle
Climate Change and Sea Level Rise Projections for Boston
While the broad outlines of how climate change would impact Boston have been known for some time, it is only recently that we have developed a more definitive understanding of what lies ahead. That understanding was advanced considerably with the publication of Climate Change and Sea Level Rise Projections for Boston by the Boston Research Advisory Group (BRAG).The BRAG report is the first major product of "Climate Ready Boston," a project led by the City of Boston in partnership with the Green Ribbon Commission and funded in part by the Barr Foundation. The BRAG team includes 20 leading experts from the region's major universities on subjects ranging from sea level rise to temperature extremes. University of Massachusetts Boston professors Ellen Douglas and Paul Kirshen headed the research.The BRAG report validates earlier studies, concluding Boston will get hotter, wetter, and saltier in the decades ahead (see figures below). But the group has produced a much more definitive set of projections than existed previously, especially for the problem of sea level rise. BRAG also concluded that some of the effects of climate change will come sooner than expected, accelerating the urgency of planning and action
Intelligent Autonomous Decision-Making and Cooperative Control Technology of High-Speed Vehicle Swarms
This book is a reprint of the Special Issue “Intelligent Autonomous Decision-Making and Cooperative Control Technology of High-Speed Vehicle Swarms”,which was published in Applied Sciences
The physics of streamer discharge phenomena
In this review we describe a transient type of gas discharge which is
commonly called a streamer discharge, as well as a few related phenomena in
pulsed discharges. Streamers are propagating ionization fronts with
self-organized field enhancement at their tips that can appear in gases at (or
close to) atmospheric pressure. They are the precursors of other discharges
like sparks and lightning, but they also occur in for example corona reactors
or plasma jets which are used for a variety of plasma chemical purposes. When
enough space is available, streamers can also form at much lower pressures,
like in the case of sprite discharges high up in the atmosphere.
We explain the structure and basic underlying physics of streamer discharges,
and how they scale with gas density. We discuss the chemistry and applications
of streamers, and describe their two main stages in detail: inception and
propagation. We also look at some other topics, like interaction with flow and
heat, related pulsed discharges, and electron runaway and high energy
radiation. Finally, we discuss streamer simulations and diagnostics in quite
some detail.
This review is written with two purposes in mind: First, we describe recent
results on the physics of streamer discharges, with a focus on the work
performed in our groups. We also describe recent developments in diagnostics
and simulations of streamers. Second, we provide background information on the
above-mentioned aspects of streamers. This review can therefore be used as a
tutorial by researchers starting to work in the field of streamer physics.Comment: 89 pages, 29 figure
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