2,322 research outputs found
New & Noteworthy, March 2019
Contents include: Q&A | Mei Ann Teo; The Kennedy Center New Play Dramaturgy Intensive 2019; Upcoming Regional Events; Call for Translators.https://soundideas.pugetsound.edu/lmdanewsletter/1042/thumbnail.jp
Oxidative Stress and MicroRNAs in Endothelial Cells under Metabolic Disorders
Reactive oxygen species (ROS) are radical oxygen intermediates that serve as important second messengers in signal transduction. However, when the accumulation of these molecules exceeds the buffering capacity of antioxidant enzymes, oxidative stress and endothelial cell (EC) dysfunction occur. EC dysfunction shifts the vascular system into a pro-coagulative, proinflammatory state, thereby increasing the risk of developing cardiovascular (CV) diseases and metabolic disorders. Studies have turned to the investigation of microRNA treatment for CV risk factors, as these post-transcription regulators are known to co-regulate ROS. In this review, we will discuss ROS pathways and generation, normal endothelial cell physiology and ROS-induced dysfunction, and the current knowledge of common metabolic disorders and their connection to oxidative stress. Therapeutic strategies based on microRNAs in response to oxidative stress and microRNA’s regulatory roles in controlling ROS will also be explored. It is important to gain an in-depth comprehension of the mechanisms generating ROS and how manipulating these enzymatic byproducts can protect endothelial cell function from oxidative stress and prevent the development of vascular disorders
Towards Generalized Robot Assembly through Compliance-Enabled Contact Formations
Contact can be conceptualized as a set of constraints imposed on two bodies
that are interacting with one another in some way. The nature of a contact,
whether a point, line, or surface, dictates how these bodies are able to move
with respect to one another given a force, and a set of contacts can provide
either partial or full constraint on a body's motion. Decades of work have
explored how to explicitly estimate the location of a contact and its dynamics,
e.g., frictional properties, but investigated methods have been computationally
expensive and there often exists significant uncertainty in the final
calculation. This has affected further advancements in contact-rich tasks that
are seemingly simple to humans, such as generalized peg-in-hole insertions. In
this work, instead of explicitly estimating the individual contact dynamics
between an object and its hole, we approach this problem by investigating
compliance-enabled contact formations. More formally, contact formations are
defined according to the constraints imposed on an object's available
degrees-of-freedom. Rather than estimating individual contact positions, we
abstract out this calculation to an implicit representation, allowing the robot
to either acquire, maintain, or release constraints on the object during the
insertion process, by monitoring forces enacted on the end effector through
time. Using a compliant robot, our method is desirable in that we are able to
complete industry-relevant insertion tasks of tolerances <0.25mm without prior
knowledge of the exact hole location or its orientation. We showcase our method
on more generalized insertion tasks, such as commercially available
non-cylindrical objects and open world plug tasks
REPROVIDE:is a randomised controlled trial testing the effectiveness of domestic violence perpetrator programmes (DVPPS), acceptable to perpetrators and their (ex)partners?
Structural Characterization of Tick Cement Cones Collected From \u3ci\u3ein vivo\u3c/i\u3e and Artifical Membrane Blood-Fed Lone Star Ticks (\u3ci\u3eAmbylomma americanum\u3c/i\u3e)
The Lone Star tick, Amblyomma americanum, is endemic to the southeastern United States and capable of transmitting pathogenic diseases and causing non-pathogenic conditions. To remain firmly attached to the host, the tick secretes a proteinaceous matrix termed the cement cone which hardens around the tick’s mouthparts to assist in the attachment of the tick as well as to protect the mouthparts from the host immune system. Cement cones collected from ticks on a host are commonly contaminated with host skin and hair making analysis of the cone difficult. To reduce the contamination found in the cement cone, we have adapted an artificial membrane feeding system used to feed long mouthpart ticks. Cones collected from in vivo and membrane fed ticks are analyzed to determine changes in the cone morphology. Comparisons of the cement cones using light microscopy shows similar structures and color however using scanning electron microscopy the cones have drastically different structures. The in vivo cones contain fibrils, sheets, and are heavily textured whereas cones from membrane fed ticks are remarkably smooth with no distinct structures. Analysis of the secondary protein structures using FTIR-ATR show both in vivo and membrane fed cement cones contain β sheets but only in vivo cement cones contain helical protein structures. Additionally, proteomic analysis using LC–MS/MS identifies many proteins including glycine rich proteins, metalloproteases, and protease inhibitors. Proteomic analysis of the cones identified both secreted and non-secreted tick proteins. Artificial membrane feeding is a suitable model for increased collection of cement cones for proteomic analysis however, structurally there are significant differences
S-wave Scattering Lengths in the SU(2) NJL Model Beyond Mean-field Approximation
The S-wave scattering lengths and are calculated to
the lowest order of expansion in the general framework of SU(2) NJL
model beyond mean-field approximation. It is shown that using the universal
curve of and the four NJL parameters, i.e., the current quark mass
, the four fermion coupling constant , the quark momentum cut-off
and the meson momentum cut-off , also the S-wave scattering lengths in NJL model can be uniquely determined.Comment: 12 pages, Revtex, 2 eps files, uses axodraw.st
Modelling human embryoid body cell adhesion to a combinatorial library of polymer surfaces
Designing materials to control biology is an intense focus of biomaterials and regenerative medicine research. Discovering and designing materials with appropriate biological compatibility or active control of cells and tissues is being increasingly undertaken using high
throughput synthesis and assessment methods. We report a relatively simple but powerful machine-learning method of generating modelsthat link microscopic or molecular properties of polymers or other materials to their biological effects. We illustrate the potential of these methods by developing the first robust, predictive, quantitative, and purely computational models of adhesion of human embryonic stem cell embryoid bodies (hEB) to the surfaces of 496-member polymers
Polymers with hydro-responsive topography identified using high throughput AFM of an acrylate microarray
Atomic force microscopy has been applied to an acrylate polymer microarray to achieve a full topographic characterisation. This process discovered a small number of hydro-responsive materials created from monomers with disparate hydrophilicities that show reversibility between pitted and protruding nanoscale topographies.Wellcome Trust (London, England) (Grant number 085245/Z/08/Z
Superconductors with Magnetic Impurities: Instantons and Sub-gap States
When subject to a weak magnetic impurity potential, the order parameter and
quasi-particle energy gap of a bulk singlet superconductor are suppressed.
According to the conventional mean-field theory of Abrikosov and Gor'kov, the
integrity of the energy gap is maintained up to a critical concentration of
magnetic impurities. In this paper, a field theoretic approach is developed to
critically analyze the validity of the mean field theory. Using the
supersymmetry technique we find a spatially homogeneous saddle-point that
reproduces the Abrikosov-Gor'kov theory, and identify instanton contributions
to the density of states that render the quasi-particle energy gap soft at any
non-zero magnetic impurity concentration. The sub-gap states are associated
with supersymmetry broken field configurations of the action. An analysis of
fluctuations around these configurations shows how the underlying supersymmetry
of the action is restored by zero modes. An estimate of the density of states
is given for all dimensionalities. To illustrate the universality of the
present scheme we apply the same method to study `gap fluctuations' in a normal
quantum dot coupled to a superconducting terminal. Using the same instanton
approach, we recover the universal result recently proposed by Vavilov et al.
Finally, we emphasize the universality of the present scheme for the
description of gap fluctuations in d-dimensional superconducting/normal
structures.Comment: 18 pages, 9 eps figure
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