14,157 research outputs found
Exact and heuristic allocation of multi-kernel applications to multi-FPGA platforms
FPGA-based accelerators demonstrated high energy efficiency compared to GPUs and CPUs. However, single FPGA designs may not achieve sufficient task parallelism. In this work, we optimize the mapping of high-performance multi-kernel applications, like Convolutional Neural Networks, to multi-FPGA platforms. First, we formulate the system level optimization problem, choosing within a huge design space the parallelism and number of compute units for each kernel in the pipeline. Then we solve it using a combination of Geometric Programming, producing the optimum performance solution given resource and DRAM bandwidth constraints, and a heuristic allocator of the compute units on the FPGA cluster.Peer ReviewedPostprint (author's final draft
DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes
There is some interest in how mammalian oocytes respond to different types of DNA damage because of the increasing expectation of fertility preservation in women undergoing chemotherapy. Double strand breaks (DSBs) induced by ionizing radiation and agents such as neocarzinostatin (NCS), and interstrand crosslinks (ICLs) induced by alkylating agents such as mitomycin C (MMC), are toxic DNA lesions that need to be repaired for cell survival. Here we examined the effects of NCS and MMC treatment on oocytes collected from antral follicles in mice, because potentially such oocytes are readily collected from ovaries and do not need to be in vitro grown to achieve meiotic competency. We found that oocytes were sensitive to NCS, such that this ionizing radiation mimetic blocked meiosis I and caused fragmented DNA. In contrast, MMC had no impact on the completion of either meiosis I or II, even at extremely high doses. However, oocytes treated with MMC did show ?-H2AX foci and following their in vitro maturation and parthenogenetic activation the development of the subsequent embryos was severely compromised. Addition of MMC to 1-cell embryos caused a similarly poor level of development, demonstrating oocytes have eventual sensitivity to this ICL-inducing agent but this does not occur during their meiotic division. In oocytes, the association of Fanconi Anemia protein, FANCD2, with sites of ICL lesions was not apparent until entry into the embryonic cell cycle. In conclusion, meiotic maturation of oocytes is sensitive to DSBs but not ICLs. The ability of oocytes to tolerate severe ICL damage and yet complete meiosis, means that this type of DNA lesion goes unrepaired in oocytes but impacts on subsequent embryo quality
Inducing ferromagnetism and Kondo effect in platinum by paramagnetic ionic gating
Electrically controllable magnetism, which requires the field-effect
manipulation of both charge and spin degrees of freedom, has attracted growing
interests since the emergence of spintronics. In this work, we report the
reversible electrical switching of ferromagnetic (FM) states in platinum (Pt)
thin films by introducing paramagnetic ionic liquid (PIL) as the gating media.
The paramagnetic ionic gating controls the movement of ions with magnetic
moments, which induces itinerant ferromagnetism on the surface of Pt films with
large coercivity and perpendicular anisotropy mimicking the ideal
two-dimensional Ising-type FM state. The electrical transport of the induced FM
state shows Kondo effect at low temperature suggesting spatially separated
coexistence of Kondo scattering beneath the FM interface. The tunable FM state
indicates that paramagnetic ionic gating could serve as a versatile method to
induce rich transport phenomena combining field effect and magnetism at
PIL-gated interfaces.Comment: 17 pages, 4 figure
Protein-DNA computation by stochastic assembly cascade
The assembly of RecA on single-stranded DNA is measured and interpreted as a
stochastic finite-state machine that is able to discriminate fine differences
between sequences, a basic computational operation. RecA filaments efficiently
scan DNA sequence through a cascade of random nucleation and disassembly events
that is mechanistically similar to the dynamic instability of microtubules.
This iterative cascade is a multistage kinetic proofreading process that
amplifies minute differences, even a single base change. Our measurements
suggest that this stochastic Turing-like machine can compute certain integral
transforms.Comment: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC129313/
http://www.pnas.org/content/99/18/11589.abstrac
Analyzing direct dark matter detection data with unrejected background events by the AMIDAS website
In this talk I have presented the data analysis results of extracting
properties of halo WIMPs: the mass and the (ratios between the)
spin-independent and spin-dependent couplings/cross sections on nucleons by the
AMIDAS website by taking into account possible unrejected background events in
the analyzed data sets. Although non-standard astronomical setup has been used
to generate pseudodata sets for our analyses, it has been found that, without
prior information/assumption about the local density and velocity distribution
of halo Dark Matter, these WIMP properties have been reconstructed with ~ 2% to
<~ 30% deviations from the input values.Comment: 9 pages, 10 eps figures, 1 table, to appear in the proceedings of the
Seventh International Workshop on the Dark Side of the Universe (DSU 2011),
September 26-30, 2011, Beijing, Chin
Families of Graphs With Chromatic Zeros Lying on Circles
We define an infinite set of families of graphs, which we call -wheels and
denote , that generalize the wheel () and biwheel ()
graphs. The chromatic polynomial for is calculated, and
remarkably simple properties of the chromatic zeros are found: (i) the real
zeros occur at for even and for odd;
and (ii) the complex zeros all lie, equally spaced, on the unit circle
in the complex plane. In the limit, the zeros
on this circle merge to form a boundary curve separating two regions where the
limiting function is analytic, viz., the exterior and
interior of the above circle. Connections with statistical mechanics are noted.Comment: 8 pages, Late
Holographic Superconductor for a Lifshitz fixed point
We consider the gravity dual of strongly coupled system at a Lifshitz-fixed
point and finite temperature, which was constructed in a recent work
arXiv:0909.0263. We construct an Abelian Higgs model in that background and
calculate condensation and conductivity using holographic techniques. We find
that condensation happens and DC conductivity blows up when temperature turns
below a critical value.Comment: 14 pages, 4 figures, v4: improved version, references adde
Universal description of S-wave meson spectra in a renormalized light-cone QCD-inspired model
A light-cone QCD-inspired model, with the mass squared operator consisting of
a harmonic oscillator potential as confinement and a Dirac-delta interaction,
is used to study the S-wave meson spectra. The two parameters of the harmonic
potential and quark masses are fixed by masses of rho(770), rho(1450), J/psi,
psi(2S), K*(892) and B*. We apply a renormalization method to define the model,
in which the pseudo-scalar ground state mass fixes the renormalized strength of
the Dirac-delta interaction. The model presents an universal and satisfactory
description of both singlet and triplet states of S-wave mesons and the
corresponding radial excitations.Comment: RevTeX, 17 pages, 7 eps figures, to be published in Phys. Rev.
Phase Diagram of the 1D Anderson Lattice
We map out the phase diagram of the one--dimensional Anderson lattice by
studying the ground state magnetization as a function of band--filling using
the density matrix renormalization group technique. For strong coupling, we
find that the quarter--filled system has an S=0 ground state with strong
antiferromagnetic correlations. As additional electrons are put in, we find
first a ferromagnetic phase, as reported by M\"{o}ller and W\"{o}lfle, and then
a phase in which the ground state has total spin . Within this
phase, we find RKKY oscillations in the spin--spin correlation functions.Comment: REVTEX manuscript with 5 Postcript figures included in uu file.
Submitted to Phys. Rev.
Bis[(E)-N-(pyridin-3-ylÂmethylÂidene)hydroxylÂamine-ÎșN 1]silver(I) perchlorate
Each of the ions in the title salt, [Ag(C6H6N2O)2]ClO4, is completed by the application of crystallographic twofold symmetry. The AgI atom is coordinated by two pyridine N atoms in an almost linear fashion [NâAgâN = 170.0â
(2)°], with the T-shaped coordination geometry being completed by a weakly associated perchlorate-O atom. SupraÂmolecular zigzag chains along [100] mediated by OâHâŻN hydrogen bonds [as parts of R
2
2(6) loops] feature in the crystal packing. The perchlorate O atoms are disordered over two sets of sites in a statistical ratio
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