598 research outputs found
Long-distance entanglement-based quantum key distribution over optical fiber
We report the first entanglement-based quantum key distribution (QKD) experiment over a 100-km optical fiber. We used superconducting single photon detectors based on NbN nanowires that provide high-speed single photon detection for the 1.5-µm telecom band, an efficient entangled photon pair source that consists of a fiber coupled periodically poled lithium niobate waveguide and ultra low loss filters, and planar lightwave circuit Mach-Zehnder interferometers (MZIs) with ultra stable operation. These characteristics enabled us to perform an entanglement-based QKD experiment over a 100-km optical fiber. In the experiment, which lasted approximately 8 hours, we successfully generated a 16 kbit sifted key with a quantum bit error rate of 6.9 % at a rate of 0.59 bits per second, from which we were able to distill a 3.9 kbit secure key
Megabits secure key rate quantum key distribution
Quantum cryptography (QC) can provide unconditional secure communication
between two authorized parties based on the basic principles of quantum
mechanics. However, imperfect practical conditions limit its transmission
distance and communication speed. Here we implemented the differential phase
shift (DPS) quantum key distribution (QKD) with up-conversion assisted hybrid
photon detector (HPD) and achieved 1.3 M bits per second secure key rate over a
10-km fiber, which is tolerant against the photon number splitting (PNS)
attack, general collective attacks on individual photons, and any other known
sequential unambiguous state discrimination (USD) attacks.Comment: 14 pages, 4 figure
Nonimmunoglobulin target loci of activation-induced cytidine deaminase (AID) share unique features with immunoglobulin genes.
Activation-induced cytidine deaminase (AID) is required for both somatic hypermutation and class-switch recombination in activated B cells. AID is also known to target nonimmunoglobulin genes and introduce mutations or chromosomal translocations, eventually causing tumors. To identify as-yet-unknown AID targets, we screened early AID-induced DNA breaks by using two independent genome-wide approaches. Along with known AID targets, this screen identified a set of unique genes (SNHG3, MALAT1, BCL7A, and CUX1) and confirmed that these loci accumulated mutations as frequently as Ig locus after AID activation. Moreover, these genes share three important characteristics with the Ig gene: translocations in tumors, repetitive sequences, and the epigenetic modification of chromatin by H3K4 trimethylation in the vicinity of cleavage sites
Image informatics approaches to advance cancer drug discovery
High content image-based screening assays utilise cell based models to extract and quantify morphological
phenotypes induced by small molecules. The rich datasets produced can be used to
identify lead compounds in drug discovery efforts, infer compound mechanism of action, or aid
biological understanding with the use of tool compounds. Here I present my work developing and
applying high-content image based screens of small molecules across a panel of eight genetically
and morphologically distinct breast cancer cell lines.
I implemented machine learning models to predict compound mechanism of action from morphological
data and assessed how well these models transfer to unseen cell lines, comparing the
use of numeric morphological features extracted using computer vision techniques against more
modern convolutional neural networks acting on raw image data.
The application of cell line panels have been widely used in pharmacogenomics in order to compare
the sensitivity between genetically distinct cell lines to drug treatments and identify molecular
biomarkers that predict response. I applied dimensional reduction techniques and distance metrics
to develop a measure of differential morphological response between cell lines to small molecule
treatment, which controls for the inherent morphological differences between untreated cell lines.
These methods were then applied to a screen of 13,000 lead-like small molecules across the eight
cell lines to identify compounds which produced distinct phenotypic responses between cell lines.
Putative hits from a subset of approved compounds were then validated in a three-dimensional
tumour spheroid assay to determine the functional effect of these compounds in more complex
models, as well as proteomics to determine the responsible pathways.
Using data generated from the compound screen, I carried out work towards integrating knowledge
of chemical structures with morphological data to infer mechanistic information of the unannotated
compounds, and assess structure activity relationships from cell-based imaging data
Field test of quantum key distribution in the Tokyo QKD Network
A novel secure communication network with quantum key distribution in a
metropolitan area is reported. Different QKD schemes are integrated to
demonstrate secure TV conferencing over a distance of 45km, stable long-term
operation, and application to secure mobile phones.Comment: 21 pages, 19 figure
Relationship Between CarotidIntima-Media Thickness and Silent Cerebral Infarction in Japanese Subjects With Type 2 Diabetes
Reverse Phase Protein Arrays elucidate mechanisms-of-action and phenotypic response in 2D and 3D models
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