1,106 research outputs found
Deregulation of methylation of transcribed-ultra conserved regions in colorectal cancer and their value for detection of adenomas and adenocarcinomas
Expression of Transcribed Ultraconserved Regions (T-UCRs) is often deregulated in cancer. The present study assesses the expression and methylation of three T-UCRs (Uc160, Uc283 and Uc346) in colorectal cancer (CRC) and explores the potential of T-UCR methylation in circulating DNA for the detection of adenomas and adenocarcinomas. Expression levels of Uc160, Uc283 and Uc346 were lower in neoplastic tissues from 64 CRC patients (statistically significant for Uc160, p<0.001), compared to non-malignant tissues, while methylation levels displayed the inverse pattern (p<0.001, p=0.001 and p=0.004 respectively). In colon cancer cell lines, overexpression of Uc160 and Uc346 led to increased proliferation and migration rates. Methylation levels of Uc160 in plasma of 50 CRC, 59 adenoma patients, 40 healthy subjects and 12 patients with colon inflammation or diverticulosis predicted the presence of CRC with 35% sensitivity and 89% specificity (p=0.016), while methylation levels of the combination of all three T-UCRs resulted in 45% sensitivity and 74.3% specificity (p=0.013). In conclusion, studied T-UCRs’ expression and methylation status are deregulated in CRC while Uc160 and Uc346 appear to have a complicated role in CRC progression. Moreover their methylation status appears a promising non-invasive screening test for CRC, provided that the sensitivity of the assay is improved
Ambipolar charge injection and transport in a single pentacene monolayer island
Electrons and holes are locally injected in a single pentacene monolayer
island. The two-dimensional distribution and concentration of the injected
carriers are measured by electrical force microscopy. In crystalline monolayer
islands, both carriers are delocalized over the whole island. On disordered
monolayer, carriers stay localized at their injection point. These results
provide insight into the electronic properties, at the nanometer scale, of
organic monolayers governing performances of organic transistors and molecular
devices.Comment: To be published in Nano Letter
Belowground DNA-based techniques: untangling the network of plant root interactions
Contains fulltext :
91591.pdf (publisher's version ) (Closed access)7 p
Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout
The enormous stiffness and low density of graphene make it an ideal material
for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and
electrical readout of monolayer graphene resonators, and test their response to
changes in mass and temperature. The devices show resonances in the MHz range.
The strong dependence of the resonant frequency on applied gate voltage can be
fit to a membrane model, which yields the mass density and built-in strain.
Upon removal and addition of mass, we observe changes in both the density and
the strain, indicating that adsorbates impart tension to the graphene. Upon
cooling, the frequency increases; the shift rate can be used to measure the
unusual negative thermal expansion coefficient of graphene. The quality factor
increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing
many of the basic attributes of monolayer graphene resonators, these studies
lay the groundwork for applications, including high-sensitivity mass detectors
Power, norms and institutional change in the European Union: the protection of the free movement of goods
How do institutions of the European Union change? Using an institutionalist approach, this article highlights the interplay between power, cognitive limits, and the normative order that underpins institutional settings and assesses their impact upon the process of institutional change. Empirical evidence from recent attempts to reinforce the protection of the free movement of goods in the EU suggests that, under conditions of uncertainty, actors with ambiguous preferences assess attempts at institutional change on the basis of the historically defined normative order which holds a given institutional structure together. Hence, path dependent and incremental change occurs even when more ambitious and functionally superior proposals are on offer
The Case for Asymmetric Systolic Array Floorplanning
The widespread proliferation of deep learning applications has triggered the
need to accelerate them directly in hardware. General Matrix Multiplication
(GEMM) kernels are elemental deep-learning constructs and they inherently map
onto Systolic Arrays (SAs). SAs are regular structures that are well-suited for
accelerating matrix multiplications. Typical SAs use a pipelined array of
Processing Elements (PEs), which communicate with local connections and
pre-orchestrated data movements. In this work, we show that the physical layout
of SAs should be asymmetric to minimize wirelength and improve energy
efficiency. The floorplan of the SA adjusts better to the asymmetric widths of
the horizontal and vertical data buses and their switching activity profiles.
It is demonstrated that such physically asymmetric SAs reduce interconnect
power by 9.1% when executing state-of-the-art Convolutional Neural Network
(CNN) layers, as compared to SAs of the same size but with a square (i.e.,
symmetric) layout. The savings in interconnect power translate, in turn, to
2.1% overall power savings.Comment: CNNA 202
Low-Power Data Streaming in Systolic Arrays with Bus-Invert Coding and Zero-Value Clock Gating
Systolic Array (SA) architectures are well suited for accelerating matrix
multiplications through the use of a pipelined array of Processing Elements
(PEs) communicating with local connections and pre-orchestrated data movements.
Even though most of the dynamic power consumption in SAs is due to
multiplications and additions, pipelined data movement within the SA
constitutes an additional important contributor. The goal of this work is to
reduce the dynamic power consumption associated with the feeding of data to the
SA, by synergistically applying bus-invert coding and zero-value clock gating.
By exploiting salient attributes of state-of-the-art CNNs, such as the value
distribution of the weights, the proposed SA applies appropriate encoding only
to the data that exhibits high switching activity. Similarly, when one of the
inputs is zero, unnecessary operations are entirely skipped. This selectively
targeted, application-aware encoding approach is demonstrated to reduce the
dynamic power consumption of data streaming in CNN applications using Bfloat16
arithmetic by 1%-19%. This translates to an overall dynamic power reduction of
6.2%-9.4%.Comment: International Conference on Modern Circuits and Systems Technologies
(MOCAST
On the Munn-Silbey approach to polaron transport with off-diagonal coupling
Improved results using a method similar to the Munn-Silbey approach have been
obtained on the temperature dependence of transport properties of an extended
Holstein model incorporating simultaneous diagonal and off-diagonal
exciton-phonon coupling. The Hamiltonian is partially diagonalized by a
canonical transformation, and optimal transformation coefficients are
determined in a self-consistent manner. Calculated transport properties exhibit
substantial corrections on those obtained previously by Munn and Silbey for a
wide range of temperatures thanks to a numerically exact evaluation and an
added momentum-dependence of the transformation matrix. Results on the
diffusion coefficient in the moderate and weak coupling regime show distinct
band-like and hopping-like transport features as a function of temperature.Comment: 12 pages, 6 figures, accpeted in Journal of Physical Chemistry B:
Shaul Mukamel Festschrift (2011
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
ArrayFlex: A Systolic Array Architecture with Configurable Transparent Pipelining
Convolutional Neural Networks (CNNs) are the state-of-the-art solution for
many deep learning applications. For maximum scalability, their computation
should combine high performance and energy efficiency. In practice, the
convolutions of each CNN layer are mapped to a matrix multiplication that
includes all input features and kernels of each layer and is computed using a
systolic array. In this work, we focus on the design of a systolic array with
configurable pipeline with the goal to select an optimal pipeline configuration
for each CNN layer. The proposed systolic array, called ArrayFlex, can operate
in normal, or in shallow pipeline mode, thus balancing the execution time in
cycles and the operating clock frequency. By selecting the appropriate pipeline
configuration per CNN layer, ArrayFlex reduces the inference latency of
state-of-the-art CNNs by 11%, on average, as compared to a traditional
fixed-pipeline systolic array. Most importantly, this result is achieved while
using 13%-23% less power, for the same applications, thus offering a combined
energy-delay-product efficiency between 1.4x and 1.8x.Comment: DATE 202
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