162 research outputs found
Brain regions and cell type specific Wnt signalling changes in Parkinson’s disease mouse models
Parkinson’s disease (PD) is a late onset neurodegenerative disease characterised by the loss of dopaminergic neurons with motor and cognitive symptoms. Different mutations have been identified as a risk factor or direct cause of the disease. LRRK2 gene mutation is a major cause of sporadic and inherited Parkinson’s disease (PD), but the exact mechanism of how LRRK2 mutation causes PD remains to be revealed. LRRK2 is a huge complex protein with both GTPase and Kinase domains. G2019S is the most common LRRK2 mutation on the kinase domain. There is accumulate evidence showing LRRK2 as a scaffolding protein interacts with canonical and noncanonical Wnt signalling pathways. These pathways play an important role on immune responses, nerves system development as well as neuronal maintenance./
This project aims to study how LRRK2 influence Wnt signalling pathways activities, we used LRRK2 wild type (WT), LRRK2 knock-out (KO) and G2019S knock-in (KI)
mouse models in the project. We identified the brain regions with Wnt and NFAT signalling activities by applying biosensor system via lentiviral construct transduction
into the brain at P0 and investigated the signalling activation by immunohistochemistry at 6 months old. We discovered LRRK2 KO and G2019S KI alter Wnt signalling activity in several brain regions including the PD important striatum. mRNA and protein expression level analysis in selected brain regions showed a region specific
dysregulation of Wnt signalling cascade components, the dysregulation was differed between male and female mice./
We discovered Wnt and NFAT signalling activity might be higher in glial cells than neurons in primary culture experiment, which lead us to put our focus on astrocytes.
LRRK2 KO and G2019S mutation caused changes in Wnt and NFAT signalling activities in astrocytes under basal and stimulated conditions. These differences were reflected in mRNA expression levels of signalling mediators./
Taken together, these data suggest astrocytes might hold a key insight towards a better understanding of the correlation between Wnt signalling dysregulation and PD
progression
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Benchmarking the Intel®Xeon®Platinum 8160 Processor
This report presents a set of results for different microbenchmarks and applications on the Intel
Xeon Platinum8160 Processor, formerly known as Skylake. For simplicity, we will use both Skylake
and SKX to refer to this processor. We use the Skylake nodes that will be available in Stampede2.
This systemwill provide Intel Knights Landing and Skylake chips interconnected by a 100 Gb/sec
Intel Omni-Path (OPA) network with a fat tree topology. The peak performance of the system will
be 18 PF.Texas Advanced Computing Center (TACC
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On Tetrahedralisations Containing Knotted and Linked Line Segments
This paper considers a set of twisted line segments in 3d such that they form a knot (a closed curve) or a link of two closed curves. Such line segments appear on the boundary of a family of 3d indecomposable polyhedra (like the Schönhardt polyhedron) whose interior cannot be tetrahedralised without additional vertices added. On the other hand, a 3d (non-convex) polyhedron whose boundary contains such line segments may still be decomposable as long as the twist is not too large. It is therefore interesting to consider the question: when there exists a tetrahedralisation contains a given set of knotted or linked line segments?
In this paper, we studied a simplified question with the assumption that all vertices of the line segments are in convex position. It is straightforward to show that no tetrahedralisation of 6 vertices (the three-line-segments case) can contain a trefoil knot. Things become interesting when the number of line segments increases. Since it is necessary to create new interior edges to form a tetrahedralisation. We provided a detailed analysis for the case of a set of 4 line segments. This leads to a crucial condition on the orientation of pairs of new interior edges which determines whether this set is decomposable or not. We then prove a new theorem about the decomposability for a set of n (n ≥ 3) knotted or linked line segments. This theorem implies that the family of polyhedra generalised from the Schonhardt polyhedron by Rambau [1] are all indecomposable
On Tetrahedralisations Containing Knotted and Linked Line Segments
This paper considers a set of twisted line segments in 3d such that they form a knot (a closed curve) or a link of two closed curves. Such line segments appear on the boundary of a family of 3d indecomposable polyhedra (like the Schönhardt polyhedron) whose interior cannot be tetrahedralised without additional vertices added. On the other hand, a 3d (non-convex) polyhedron whose boundary contains such line segments may still be decomposable as long as the twist is not too large. It is therefore interesting to consider the question: when there exists a tetrahedralisation contains a given set of knotted or linked line segments?
In this paper, we studied a simplified question with the assumption that all vertices of the line segments are in convex position. It is straightforward to show that no tetrahedralisation of 6 vertices (the three-line-segments case) can contain a trefoil knot. Things become interesting when the number of line segments increases. Since it is necessary to create new interior edges to form a tetrahedralisation. We provided a detailed analysis for the case of a set of 4 line segments. This leads to a crucial condition on the orientation of pairs of new interior edges which determines whether this set is decomposable or not. We then prove a new theorem about the decomposability for a set of n (n ≥ 3) knotted or linked line segments. This theorem implies that the family of polyhedra generalised from the Schonhardt polyhedron by Rambau [1] are all indecomposable
Relativistic Brueckner-Hartree-Fock in nuclear matter without the average momentum approximation
Brueckner-Hartree-Fock theory allows to derive the -matrix as an effective
interaction between nucleons in the nuclear medium. It depends on the center of
mass momentum of the two particles and on the two relative momenta
and before and after the scattering process. In the
evaluation of the total energy per particle in nuclear matter usually the angle
averaged center of mass momentum approximation has been used. We derive in
detail the exact expressions of the angular integrations of the momentum
within relativistic Brueckner-Hartree-Fock (RBHF) theory, especially
for the case of asymmetric nuclear matter. In order to assess the reliability
of the conventional average momentum approximation for the binding energy, the
saturation properties of symmetric and asymmetric nuclear matter are
systematically investigated based on the realistic Bonn nucleon-nucleon
potential. It is found that the exact treatment of the center of mass momentum
leads to non-negligible contributions to the higher order physical quantities.
The correlation between the symmetry energy , the slope
parameter , and the curvature of the symmetry energy are
investigated. The results of our RBHF calculations for the bulk parameters
characterizing the equation of state are compared with recent constraints
extracted from giant monopole resonance and isospin diffusion experiments.Comment: 28 pages, 5 figure
A Cooperative Deception Strategy for Covert Communication in Presence of a Multi-antenna Adversary
Covert transmission is investigated for a cooperative deception strategy,
where a cooperative jammer (Jammer) tries to attract a multi-antenna adversary
(Willie) and degrade the adversary's reception ability for the signal from a
transmitter (Alice). For this strategy, we formulate an optimization problem to
maximize the covert rate when three different types of channel state
information (CSI) are available. The total power is optimally allocated between
Alice and Jammer subject to Kullback-Leibler (KL) divergence constraint.
Different from the existing literature, in our proposed strategy, we also
determine the optimal transmission power at the jammer when Alice is silent,
while existing works always assume that the jammer's power is fixed.
Specifically, we apply the S-procedure to convert infinite constraints into
linear-matrix-inequalities (LMI) constraints. When statistical CSI at Willie is
available, we convert double integration to single integration using asymptotic
approximation and substitution method. In addition, the transmission strategy
without jammer deception is studied as a benchmark. Finally, our simulation
results show that for the proposed strategy, the covert rate is increased with
the number of antennas at Willie. Moreover, compared to the benchmark, our
proposed strategy is more robust in face of imperfect CSI.Comment: 33 pages, 8 Figure
Guaranteed quality isotropic surface remeshing based on uniformization
Surface remeshing plays a significant role in computer graphics and visualization. Numerous surface remeshing methods have been developed to produce high quality meshes. Generally, the mesh quality is improved in terms of vertex sampling, regularity, triangle size and triangle shape. Many of such surface remeshing methods are based on Delaunay refinement. In particular, some surface remeshing methods generate high quality meshes by performing the planar Delaunay refinement on the conformal uniformization domain. However, most of these methods can only handle topological disks. Even though some methods can cope with high-genus surfaces, they require partitioning a high-genus surface into multiple simply connected segments, and remesh each segment in the parameterized domain.
In this work, we propose a novel surface remeshing method based on uniformization theorem using dynamic discrete Yamabe flow and Delaunay refinement, which is capable of handling surfaces with complicated topologies, without the need of partitioning. The proposed method has the following merits: Dimension deduction, it converts all 3D surface remeshing to 2D planar meshing; Theoretic rigor, the existence of the constant curvature measures and the lower bound of the corner angles of the generated meshes can be proven. Experimental results demonstrate the efficiency and efficacy of our proposed method
Generalized Regular Quadrilateral Mesh Generation based on Surface Foliation
This work introduces a novel algorithm for quad-mesh generation based on surface foliation theory. The algorithm is based on the equivalence among colorable quad-meshes, measure foliations and holomorphic differentials. The holomorphic differentials can be obtained by graph-valued harmonic maps. The algorithm has several merits: it can be applied for surfaces with general topologies; the resulting quad-meshes have global tensor product structure and the least number of singularities; the algorithmic pipeline is fully automatic. The experimental results demonstrate the efficiency and efficacy of the proposed method
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