What is the minimum amount of simulated breast movement required for visual detection of blurring? An exploratory investigation

OBJECTIVE

Image blurring in mammography can cause significant image degradation and interpretational problems. A potential source is due to paddle movement during image formation. Paddle movement has been shown to be as much as 1.5 mm. No study has yet been performed to determine how much motion would be noticeable visually. The aim of this study is to determine the minimum amount of simulated breast movement at which blurring can be detected visually.

METHODS

25 artefact-free mammogram images were selected. Mathematical simulation software was created to mimic the effect of blurring produced by breast movement during exposure. Motion simulation was imposed to 15 levels, from 0.1 to 1.5 mm stepping through 0.1 mm increments. 15 degraded images and 1 without blurring were de-identified, randomized and assessed on a blinded basis by two clinical experts to determine the presence or absence of blurring. Statistical testing was carried out to determine the consistency between the two observers.

RESULTS

The probability of simulated blurred image detection is the highest for the gaussian method and the lowest for soft-edged mask estimation.

CONCLUSION

The amount of simulated breast movement at which blurring can be detected visually for gaussian blur, hard-edge mask estimation and soft-edge mask estimation is 0.4, 0.8 and 0.7 mm, respectively. Cohen's kappa for all the levels of simulated blurring is 0.689 (p < 0.05).

ADVANCES IN KNOWLEDGE

This research establishes the concept of using probability to represent visual detection of blurring rather than defining a hard cut-off level.

Digital quantum simulation of fermionic models with a superconducting circuit

One of the key applications of quantum information is simulating nature. Fermions are ubiquitous in nature, appearing in condensed matter systems, chemistry and high energy physics. However, universally simulating their interactions is arguably one of the largest challenges, because of the difficulties arising from anticommutativity. Here we use digital methods to construct the required arbitrary interactions, and perform quantum simulation of up to four fermionic modes with a superconducting quantum circuit. We employ in excess of 300 quantum logic gates, and reach fidelities that are consistent with a simple model of uncorrelated errors. The presented approach is in principle scalable to a larger number of modes, and arbitrary spatial dimensions.

Protocol for a multicentre randomiSed controlled TRial of IntraVEnous immunoglobulin versus standard therapy for the treatment of transverse myelitis in adults and children (STRIVE)

INTRODUCTION

Transverse myelitis (TM) is an immune-mediated disorder of the spinal cord which causes motor and sensory disturbance and limited recovery in 50% of patients. Standard treatment is steroids, and patients with more severe disease appear to respond to plasma exchange (PLEX). Intravenous immunoglobulin (IVIG) has also been used as an adjunct to steroids, but evidence is lacking. We propose the first randomised control trial in adults and children, to determine the benefit of additional treatment with IVIG.

METHODS AND ANALYSIS

170 adults and children aged over 1 year with acute first episode TM or neuromyelitis optica (with myelitis) will be recruited over a 2.5-year period and followed up for 12 months. Participants randomised to the control arm will receive standard therapy of intravenous methylprednisolone (IVMP). The intervention arm will receive the above standard therapy, plus additional IVIG. Primary outcome will be a 2-point improvement on the American Spinal Injury Association (ASIA) Impairment scale at 6 months postrandomisation by blinded assessors. Additional secondary and tertiary outcome measures will be collected: ASIA motor and sensory scales, Kurtzke expanded disability status scale, International Spinal Cord Injury (SCI) Bladder/Bowel Data Set, Client Services Receipt Index, Pediatric Quality of Life Inventory, EQ-5D, SCI Pain and SCI Quality of Life Data Sets. Biological samples will be biobanked for future studies. After 6-months' follow-up of the first 52 recruited patients futility analysis will be carried out. Health economics analysis will be performed to calculate cost-effectiveness. After 6 months' recruitment futility analysis will be performed.

ETHICS AND DISSEMINATION

Research Ethics Committee Approval was obtained: 14/SC/1329. Current protocol: v3.0 (15/01/2015). Study findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

This study is registered with EudraCT (REF: 2014-002335-34), Clinicaltrials.gov (REF: NCT02398994) and ISRCTN (REF: 12127581).

Genetic risk alleles associated with serologic autoimmunity in normal individuals (BA3P.113)

We screened 2628 normal individuals for antibodies binding to the mix of antigens in a human nuclear extract and identified 579 (26.05%) individuals with significant levels of IgG antibodies to self-antigens. Next, we analyzed 639 representative sera from ANA-, ANA+, ILE and SLEs on an autoantigen proteomic array, which identified 33 antigens strongly recognized by IgG autoantibodies in ANA+ group as compared to ANA- normals. Of these 33, 19 antigens were non-nuclear or cytoplasmic proteins and 14 were nuclear proteins, including known SLE associated antigens such as dsDNA and Histones. Antigen cluster analysis showed that DNA and RNA clusters are more frequent in SLE and ILE group, while matrix proteins and antiphospholipid antibodies clusters are more frequent in ANA+ normals. Next, all the individuals were genotyped with immunochip and subset by target sequencing. Quantitative genetic association test identified SNPs associated with ANA and auto-antigens. The strongest association signal was observed at HLA, where SNP rs3117103 near BTNL2, rs9268832 near HLA-DRA and rs2395252 in HLA-DQA2 gene showed strongest (10-7) association. Other signals were in/near BANK1, PTTG1 and CR1L genes. RNA sequencing analysis identified ANA risk alleles associated with up regulation of HLA-DRB1 in monocytes and BANK1 in B cells. Our data suggest that functional variations in or near HLA DRB1 and BANK1 gene may be associated with development of humoral autoimmunity in general population.

The life and significance of Charles Lucas (1713-1771)

Charles Lucas (1713-1771) was one of the most controversial popular politicians to stride the Irish political stage in the eighteenth century. Though the descendant of a beneficiary of the Cromwellian plantation, Lucas's personal inheritance was small, and he was apprenticed in his teens to an apothecary in Dublin. Lucas prospered in that capacity, both as an advocate of higher standards within the profession, and as a representative on the lower house (the common council) of Dublin Corporation. Predisposed to challenge what he perceived as abuses by vested and established interests, Lucas made a name for himself as an outspoken critic of the oligarchical pretensions of the lord mayor and aldermen, which comprised the upper chamber of the Corporation. His successes were few, but he was possessed of a fluent pen, and a precocious awareness that he could best communicate with his natural audience through the use of print. As a result, he became the darling of an emerging popular political interest, which shared his vision of a reformed Protestant constitution. Encouraged by this positive response, Lucas offered himself to the electorate of Dublin in 1749, but though he campaigned vigorously, and polled well, he was not elected. More consequently for Lucas personally, his extension of his critical gaze from the municipality to the larger canvas of national and Anglo-Irish politics elicited the hostile notice of the most powerful figures in the land, which prompted him to flee the country to avoid imprisonment. Lucas was not inactive during his eleven-year 'exile', but these were comparatively quiet years by comparison with his final decade when, following his return to Ireland in 1761, he acquired a national profile as MP for Dublin City, a vigorous advocate, and a tireless proponent of Patriot policies.

Remote chemotherapy supervision model for rural cancer care: perspectives of health professionals

Townsville Cancer Centre (TCC), a tertiary cancer centre in North Queensland, Australia, provides chemotherapy services to surrounding small rural towns using the Queensland Remote Chemotherapy Supervision model (QReCS). Under this model, selected chemotherapy regimens are administered in rural hospitals by rural based generalist doctors and nurses, under the supervision of TCC-based medical oncologists and chemotherapy competent nurses through videoconferencing. We sought to explore the perspectives of health professionals participating in QReCS. This qualitative study used semi-structured interviews with 19 participants, including nine nurses, eight doctors, one rural pharmacist and one administration officer. The interviews were recorded and transcribed. Transcripts were examined using iterative thematic analysis. Four major themes were identified from the data: (1) benefits of the model, (2) enablers of implementation, (3) operational requirements for optimal functioning and (4) disadvantages of the model. The reported benefits of the model were patient convenience, inter-professional communication across health district borders, expanded scope of practice, continuity of care and maintenance of patient safety and compliance with guidelines while delivering chemotherapy. Further improvements in the quality of training for rural nurses, coordination between urban and rural sites and between health professionals and documentation of clinical encounters would optimise the operation of the model. QReCS appears to provide many benefits to patients and health professionals and a framework for safe administration of chemotherapy in rural areas. Coordination of care, the quality of training for rural nurses as well as clinical documentation needs to improve to optimise the operation of the model.

State preservation by repetitive error detection in a superconducting quantum circuit

Quantum computing becomes viable when a quantum state can be protected from environment-induced error. If quantum bits (qubits) are sufficiently reliable, errors are sparse and quantum error correction (QEC) is capable of identifying and correcting them. Adding more qubits improves the preservation of states by guaranteeing that increasingly larger clusters of errors will not cause logical failure-a key requirement for large-scale systems. Using QEC to extend the qubit lifetime remains one of the outstanding experimental challenges in quantum computing. Here we report the protection of classical states from environmental bit-flip errors and demonstrate the suppression of these errors with increasing system size. We use a linear array of nine qubits, which is a natural step towards the two-dimensional surface code QEC scheme, and track errors as they occur by repeatedly performing projective quantum non-demolition parity measurements. Relative to a single physical qubit, we reduce the failure rate in retrieving an input state by a factor of 2.7 when using five of our nine qubits and by a factor of 8.5 when using all nine qubits after eight cycles. Additionally, we tomographically verify preservation of the non-classical Greenberger-Horne-Zeilinger state. The successful suppression of environment-induced errors will motivate further research into the many challenges associated with building a large-scale superconducting quantum computer.

Unstressed antepartum cardiotocography in the management of the fetus suspected of growth retardation

A detailed analysis of the antenatal cardiotocographs (CTGs) in 57 patients with suspected fetal growth retardation is presented. Four traces were normal and 53 were 'non-reactive. 'Non-reactive' traces can be sub-divided into three categories, which, in order of severity are, 'suspect', 'flat' and 'ominous'. When compared with the 'suspect' group, perinatal mortality was significantly increased and the Apgar scores at one and five minutes significantly decreased in the 'flat' and 'ominous' groups. The presence of fetal distress in labour was significantly higher in the 'flat' group as compared with the 'suspect' group. Intrauterine deaths occurred only in the 'ominous' group. With experience, ten patients later in the series with 'ominous' patterns were delivered within 24 hours of the detection of such and nine infants survived. At follow-up between 6 and 34 months after birth, psychomotor development was normal in 47 of the 49 surviving infants.

Extra patient movement during mammographic imaging: an experimental study

OBJECTIVE

To determine if movement external to the patient occurring during mammography may be a source of image blur.

METHODS

Four mammography machines with eight flexible and eight fixed paddles were evaluated. In the first stage, movement at the paddle was measured mechanically using two calibrated linear potentiometers. A deformable breast phantom was used to mimic a female breast. For each paddle, the movement in millimetres and change in compression force in Newton was recorded at 0.5- and 1-s intervals, respectively, for 40 s with the phantom in an initially compressed state under a load of 80 N. In the second stage, clinical audit on 28 females was conducted on one mammography machine with the 18 × 24- and 24 × 29-cm flexible paddles.

RESULTS

Movement at the paddle followed an exponential decay with a settling period of approximately 40 s. The compression force readings for both fixed and flexible paddles decreased exponentially with time, while fixed paddles had a larger drop in compression force than did flexible paddles. There is a linear relationship between movement at the paddle and change in compression force.

CONCLUSION

Movement measured at the paddle during an exposure can be represented by a second order system. The amount of extra patient movement during the actual exposure can be estimated using the linear relationship between movement at the paddle and the change in compression force.

ADVANCES IN KNOWLEDGE

This research provides a possible explanation to mammography image blurring caused by extra patient movement and proposes a theoretical model to analyse the movement.

Qubit Architecture with High Coherence and Fast Tunable Coupling

We introduce a superconducting qubit architecture that combines high-coherence qubits and tunable qubit-qubit coupling. With the ability to set the coupling to zero, we demonstrate that this architecture is protected from the frequency crowding problems that arise from fixed coupling. More importantly, the coupling can be tuned dynamically with nanosecond resolution, making this architecture a versatile platform with applications ranging from quantum logic gates to quantum simulation. We illustrate the advantages of dynamical coupling by implementing a novel adiabatic controlled-z gate, with a speed approaching that of single-qubit gates. Integrating coherence and scalable control, the introduced qubit architecture provides a promising path towards large-scale quantum computation and simulation.

The 100 most cited publications in cardiac surgery: a bibliometric analysis

INTRODUCTION

This study is a citation analysis of the top 100 most cited papers in adult cardiac surgery. Bibliometric analyses are viewed as a proxy marker of a paper's influence and, therefore, an analysis of the most influential papers published in recent decades.

METHODS

Impact factor ranking as of 2012 was used to decide which journals to include in our searches. The Thompson Reuters Web of Knowledge was used to search for citations of all papers relevant to cardiac surgery within selected journals. Journals in the areas of surgery, cardiothoracic surgery, general medicine, anaesthesia, perfusion and pathology were included.

RESULTS

The most frequently cited paper was found to be that of Nashef et al. (Eur J Cardiothorac Surg 16(1):9-13, 1999) introducing the EuroSCORE operative risk evaluation system. A number of authors including Alderman, Carpentier and Cox had more than one paper in the top 100.

CONCLUSION

Despite the potential flaws with bibliometric analysis, and its application to cardiac surgery, there is inherent merit in an analysis of this type.

Optimal quantum control using randomized benchmarking

We present a method for optimizing quantum control in experimental systems, using a subset of randomized benchmarking measurements to rapidly infer error. This is demonstrated to improve single- and two-qubit gates, minimize gate bleedthrough, where a gate mechanism can cause errors on subsequent gates, and identify control crosstalk in superconducting qubits. This method is able to correct parameters so that control errors no longer dominate and is suitable for automated and closed-loop optimization of experimental systems.

Fast accurate state measurement with superconducting qubits

Faster and more accurate state measurement is required for progress in superconducting qubit experiments with greater numbers of qubits and advanced techniques such as feedback. We have designed a multiplexed measurement system with a bandpass filter that allows fast measurement without increasing environmental damping of the qubits. We use this to demonstrate simultaneous measurement of four qubits on a single superconducting integrated circuit, the fastest of which can be measured to 99.8% accuracy in 140 ns. This accuracy and speed is suitable for advanced multiqubit experiments including surface-code error correction.