40 research outputs found
Programming Quantum Computers Using Design Automation
Recent developments in quantum hardware indicate that systems featuring more
than 50 physical qubits are within reach. At this scale, classical simulation
will no longer be feasible and there is a possibility that such quantum devices
may outperform even classical supercomputers at certain tasks. With the rapid
growth of qubit numbers and coherence times comes the increasingly difficult
challenge of quantum program compilation. This entails the translation of a
high-level description of a quantum algorithm to hardware-specific low-level
operations which can be carried out by the quantum device. Some parts of the
calculation may still be performed manually due to the lack of efficient
methods. This, in turn, may lead to a design gap, which will prevent the
programming of a quantum computer. In this paper, we discuss the challenges in
fully-automatic quantum compilation. We motivate directions for future research
to tackle these challenges. Yet, with the algorithms and approaches that exist
today, we demonstrate how to automatically perform the quantum programming flow
from algorithm to a physical quantum computer for a simple algorithmic
benchmark, namely the hidden shift problem. We present and use two tool flows
which invoke RevKit. One which is based on ProjectQ and which targets the IBM
Quantum Experience or a local simulator, and one which is based on Microsoft's
quantum programming language Q.Comment: 10 pages, 10 figures. To appear in: Proceedings of Design, Automation
and Test in Europe (DATE 2018
Space-time optimized table lookup
We describe a space-time optimized circuit for the table lookup subroutine
from lattice-surgery surface code primitives respecting 2D grid connectivity.
Table lookup circuits are ubiquitous in quantum computing, allowing the
presented circuit to be used for applications ranging from cryptography to
quantum chemistry. Surface code is the leading approach to scalable
fault-tolerant quantum computing pursued by industry and academia. We abstract
away surface code implementation details by using a minimal set of operations
supported by the surface code via lattice-surgery. Our exposition is accessible
to a reader not familiar with surface codes and fault-tolerant quantum
computing.Comment: 27 page
QParallel: Explicit Parallelism for Programming Quantum Computers
We present a language extension for parallel quantum programming to (1)
remove ambiguities concerning parallelism in current quantum programming
languages and (2) facilitate space-time tradeoff investigations in quantum
computing. While the focus of similar libraries in the domain of classical
computing (OpenMP, OpenACC, etc.) is to divide a computation into multiple
threads, the main goal of QParallel is to keep the compiler and the runtime
system from introducing parallelism-inhibiting dependencies, e.g., through
reuse of qubits in automatic qubit management. We describe the syntax and
semantics of the proposed language extension, implement a prototype based on
Q#, and present several examples and use cases to illustrate its performance
benefits. Moreover, we introduce a tool that guides programmers in the
placement of parallel regions by identifying the subroutines that profit most
from parallelization, which is especially useful if the programmer's knowledge
of the source code is limited. Support for QParallel can be added to any
multithreading library and language extension, including OpenMP and OpenACC.Comment: 9 pages, 8 figure
Enhanced-depth optical coherence tomography for imaging horizontal rectus muscles in Graves' orbitopathy.
PURPOSE
Graves' orbitopathy (GO) is an extraocular eye disease with symptoms ranging from minor discomfort from dry eyes to strabismus and visual loss. One of the hallmarks of active GO is visible hyperemia at the insertion of the extraocular muscles. The aim of the present study was to evaluate the use of enhanced-depth imaging spectral domain anterior segment optical coherence tomography (EDI SD AS-OCT) for detecting pathological changes in horizontal recti muscles of patients with GO.
METHODS
Prospective cross sectional study of 27 eyes. Only women were included. EDI AS-OCT was used to measure the thickness of the tendons of the horizontal recti muscles in a predefined area in patients with GO and healthy controls.
RESULTS
EDI AS-OCT was able to image the tendons of the horizontal recti muscles in both healthy controls and patients suffering from GO. The mean thickness of the medial rectus muscle (MR) tendon was 256.4 μm [±17.13 μm standard deviation (SD)] in the GO group and, therefore, significantly thicker (p = 0.046) than in the healthy group which had a mean thickness of 214.7 μm (±5.516 μm SD). There was no significant difference in the mean thickness of the tendon of the lateral recti muscles (LRs) between these groups.
CONCLUSION
This is the first report showing that EDI AS-OCT is suitable to detect swelling at the insertion site of the MR muscle in GO. MR tendon thickness may be a useful parameter to monitor activity in these patients
mRNA fusion constructs serve in a general cell‐based assay to profile oligonucleotide activity
A cellular assay has been developed to allow measurement of the inhibitory activity of large numbers of oligonucleotides at the protein level. The assay is centred on an mRNA fusion transcript construct comprising of a full‐length reporter gene with a target region of interest inserted into the 3′‐untranslated region. Luciferase and fluorescent reporter genes were used in the constructs. The insert can be from multiple sources (uncharacterised ESTs, partial or full‐length genes, genes from alternate species, etc.). Large numbers of oligonucleotides were screened for antisense activity against a number of such constructs bearing different reporters, in different cell lines and the inhibitory profiles obtained were compared with those observed through screening the oligonucleotides against the corresponding endogenous genes assayed at the mRNA level. A high degree of similarity in the profiles was obtained indicating that the fusion constructs are suitable surrogates for the endogenous messages for characterisation of antisense oligonucleotides (ASOs). Furthermore, the results support the hypothesis that the secondary structure of mRNAs are divided into domains, the nature of which is determined by primary nucleotide sequence. Oligonucleotides whose activity is dependent on the local structure of their target mRNAs (e.g. ASOs, short interfering RNAs) can be characterised via such fusion RNA construct
Stage Specific Glaucomatous Changes of the Macula recorded using Spectral Domain Optical Coherence Tomography.
BACKGROUND
This study aimed to compare the thickness of different macular retinal layers in glaucomatous eyes and healthy controls, and evaluate the diagnostic performance of spectral domain optical coherence tomography (SD-OCT) parameters.
METHODS
In this cross-sectional comparative study, 48 glaucomatous eyes and 44 healthy controls were included. The thickness of the total retina and all retinal layers were obtained using the Early Treatment Diagnostic Retinopathy Study (ETDRS) grid. The minimal and average values of outer and inner ETDRS-rings were calculated. The diagnostic performance for detection of glaucoma was evaluated using the area under the receiver operating characteristic curve (AUC).
RESULTS
The thickness of the total retina, ganglion cell layer (GCL), and inner-plexiform layer (IPL) was significantly thinner in glaucomatous eyes in all sectors except the center (all p<0.05). The thickness of retinal nerve fiber layer (RNFL) was significantly thinner in the glaucoma group except in the center, nasal inner, and temporal outer sectors (all p<0.05). Layer thinning advanced with glaucoma severity. The minimal outer GCL thickness showed the highest AUC value for discrimination between glaucomatous eyes and healthy controls(0.955). The minimal outer IPL showed the highest AUC value for discriminating early-stage glaucomatous eyes from healthy controls (0.938).
CONCLUSIONS
Glaucomatous eyes were found to have significant thinning in the macular region. GCL and IPL showed high ability to discriminate glaucomatous and early-stage glaucomatous eyes from controls. Applying the minimal value to the ETDRS grid has the potential to provide good diagnostic abilities in glaucoma screening
Second Generation of Antisense Oligonucleotides: From Nuclease Resistance to Biological Efficacy in Animals
From efforts to improve the biophysical properties of antisense oligonucleotides by incorporating backbone- or sugar-modified nucleoside analogs, 2'-O-methoxyethyl ribonucleosides 8b were identified as building blocks for a second generation of antisense oligonucleotides. Compounds containing these modifications were demonstrated to combine the benefit of a high binding affinity to the RNA complement with a large increase in nuclease resistance, allowing the use of regular phosphodiester linkages. Chimeric oligonucleotides with 2'-O-methoxyethyl ribonucleosides, 8b, in the wings and a central DNA-phosphorothioate window were shown to efficiently downregulate C-'raf' kinase and PKC-α messenger-RNA in tumor cell lines resulting in a profound inhibition of cell proliferation. The same compounds were able to effectively reduce the growth of tumors in animal models at low concentrations indicating the potential utility of these second generation antisense oligonucleotides for therapeutic applications