1,056 research outputs found

    The Quantum Socket: Three-Dimensional Wiring for Extensible Quantum Computing

    Get PDF
    Quantum computing architectures are on the verge of scalability, a key requirement for the implementation of a universal quantum computer. The next stage in this quest is the realization of quantum error correction codes, which will mitigate the impact of faulty quantum information on a quantum computer. Architectures with ten or more quantum bits (qubits) have been realized using trapped ions and superconducting circuits. While these implementations are potentially scalable, true scalability will require systems engineering to combine quantum and classical hardware. One technology demanding imminent efforts is the realization of a suitable wiring method for the control and measurement of a large number of qubits. In this work, we introduce an interconnect solution for solid-state qubits: The quantum socket. The quantum socket fully exploits the third dimension to connect classical electronics to qubits with higher density and better performance than two-dimensional methods based on wire bonding. The quantum socket is based on spring-mounted micro wires the three-dimensional wires that push directly on a micro-fabricated chip, making electrical contact. A small wire cross section (~1 mmm), nearly non-magnetic components, and functionality at low temperatures make the quantum socket ideal to operate solid-state qubits. The wires have a coaxial geometry and operate over a frequency range from DC to 8 GHz, with a contact resistance of ~150 mohm, an impedance mismatch of ~10 ohm, and minimal crosstalk. As a proof of principle, we fabricated and used a quantum socket to measure superconducting resonators at a temperature of ~10 mK.Comment: Main: 31 pages, 19 figs., 8 tables, 8 apps.; suppl.: 4 pages, 5 figs. (HiRes figs. and movies on request). Submitte

    Response of cereals to fertilizer N on pulse and other stubbles

    Get PDF
    Non-Peer ReviewedTo optimize cropping systems requires knowledge of effects of the preceding crop on the grain yield and protein and the response to N of a following cereal crop. To gain this knowledge, we grew hard red spring (HRS) wheat, durum wheat, Canadian Prairie Spring (CPS)-class wheat, Canadian Western Extra Strong (CWES)-class wheat, and barley on barley, bean, coriander, fenugreek, kabuli chickpea, lentil, mustard, and pea stubble at different N fertilizer rates over 9 site-yr: Swift Current (1998-2002), Redvers (2001-02), and Canora (1999 and 2002). N rates were medium (recommended rate based on fall soil nitrate in cereal stubble), low (15-30 kg ha-1 less than medium) and high (15-30 kg ha-1). There was a significant effect of stubble on subsequent cereal grain yield. Cereal on cereal stubble was consistently lowest or second lowest yielding (typically 100 – 800 kg ha-1 lower than other stubbles) with the exception of 2001 at Swift Current when it was the highest yielding. This latter effect was attributed to the superior moisture conserving benefits of cereal stubble during this year with extreme early drought. No single cereal crop was consistently highest or lowest yielding. The trend was for greatest grain protein on pulse stubbles although stubble effects on protein were not as great as on yield owing to confounding yield dilution effects. Within this narrow range of fertilizer N rates, yield or protein response to N was weak. Generally, there were no significant interactions between stubble and cereal crop or stubble and fertilizer indicating the effect of stubble was consistent across cereal type and N rates. The cereal yield and protein response to N on the non-cereal stubbles was not significantly different than that on cereal stubble with the exception that barley protein responded more positively to N on lentil stubble than on cereal stubble. Cereals grown on pulse stubbles tended to have higher yields and protein than on other stubbles. For HRS wheat and durum, the chance of achieving high protein grain was greatest with high fertilizer N on pea stubble (>75% of years). Applying a high fertilizer N rate on cereal stubbles did not markedly increase the chance of attaining high protein wheat or durum. For barley, where low protein is desired for malting, the best chance for low protein barley was on cereal and mustard stubble although barley protein appeared less affected by stubble and fertilizer N than wheat or durum

    What next for Shared Lives? Family-based support as a potential option for older people

    Get PDF
    With an ageing population and limited resources the challenge for policy makers and practitioners is how best to provide for the care and support needs of older people. This article draws on findings from two studies, a scoping study of the personalisation of care services and another which aimed to generate evidence about the potential use of family-based support schemes (Shared Lives, SL) for certain groups of older people. Forty-three schemes participated in a survey to gather information about services provided and the extent to which this included older people and their carers, and six staffs were interviewed across two schemes about issues for expanding provision for older people in their local areas. It was evident that SL schemes were already supporting a number of older people and there was support for expansion from both schemes and local authorities. Adequate resources, awareness raising, management commitment, and a pool of suitable carers would be needed to support any expansion effort. There is also still a need for SL to be more widely known and understood by care managers if it is to be considered part of mainstream provision for older people

    Employing an orthotopic model to study the role of epithelial-mesenchymal transition in bladder cancer metastasis.

    Get PDF
    Epithelial-to-mesenchymal transition (EMT) has been implicated in the progression of bladder cancer. To study its contribution to bladder cancer metastasis, we established new xenograft models derived from human bladder cancer cell lines utilizing an orthotopic "recycling" technique that allowed us to isolate and examine the primary tumor and its corresponding circulating tumor cells (CTC's) and metastatic lesions. Using whole genome mRNA expression profiling, we found that a reversible epithelial-to-mesenchymal transition (EMT) characterized by TGFβ pathway activation and SNAIL expression was associated with the accumulation of CTCs. Finally, we observed that conditional silencing of SNAIL completely blocked CTC production and regional/distant metastasis. Using this unique bladder cancer xenograft model, we conclude that metastasis is dependent on a reversible EMT mediated by SNAIL

    A comparison of methods to quantify greenhouse gas emissions of cropping systems in LCA

    Get PDF
    Carbon dioxide and nitrous oxide are two important greenhouse gases (GHG) released from cropping systems. Their emissions can vary substantially with climate, soil, and crop management. While different methods are available to account for GHG emissions in life cycle assessments (LCA) of crop production, there are no standard procedures. In this study, the objectives were: (i) to compare several methods of estimating CO2 and N2O emissions for a LCA of cropping systems and (ii) to estimate the relative contribution of soil GHG emissions to the overall global warming potential (GWP) using results from a field experiment located in Manitoba, Canada. The methods were: (A) measurements; (B) Tier I and (C) Tier II IPCC (Intergovernmental panel on Climate Change) methodology, (D) a simple carbon model combined with Intergovernmental Panel for Climate Change (IPCC) Tier II methodology for soil N2O emissions, and (E) the DNDC (DeNitrification DeComposition) agroecosystem model. The estimated GWPs (−7.2–17 Mg CO2eq ha−1 y−1; −80 to 600 kg CO2eq GJ−1 y−1) were similar to previous results in North America and no statistical difference was found between GWP based on methods D and E and GWP based on observations. The five methods gave estimates of soil CO2 emissions that were not statistically different from each other, whereas for N2O emissions only DNDC estimates were similar to observations. Across crop types, all methods gave comparable CO2 and N2O emission estimates for perennial and legume crops, but only DNDC gave similar results with respect to observations for both annual and cereal crops. Whilst the results should be confirmed for other locations, the agroecosystem model and method D can be used, at certainly one selected site, in place of observations for estimating GHGs in agricultural LCA

    p63 Expression Defines a Lethal Subset of Muscle-Invasive Bladder Cancers

    Get PDF
    <div><h3>Background</h3><p>p63 is a member of the p53 family that has been implicated in maintenance of epithelial stem cell compartments. Previous studies demonstrated that p63 is downregulated in muscle-invasive bladder cancers, but the relationship between p63 expression and survival is not clear.</p> <h3>Methodology/Principal Findings</h3><p>We used real-time PCR to characterize p63 expression and several genes implicated in epithelial-to-mesenchymal transition (EMT) in human bladder cancer cell lines (n = 15) and primary tumors (n = 101). We correlated tumor marker expression with stage, disease-specific (DSS), and overall survival (OS). Expression of E-cadherin and p63 correlated directly with one another and inversely with expression of the mesenchymal markers Zeb-1, Zeb-2, and vimentin. Non-muscle-invasive (Ta and T1) bladder cancers uniformly expressed high levels of E-cadherin and p63 and low levels of the mesenchymal markers. Interestingly, a subset of muscle-invasive (T2–T4) tumors maintained high levels of E-cadherin and p63 expression. As expected, there was a strongly significant correlation between EMT marker expression and muscle invasion (p<0.0001). However, OS was shorter in patients with muscle-invasive tumors that retained p63 (p = 0.007).</p> <h3>Conclusions/Significance</h3><p>Our data confirm that molecular markers of EMT are elevated in muscle-invasive bladder cancers, but interestingly, retention of the “epithelial” marker p63 in muscle-invasive tumors is associated with a worse outcome.</p> </div

    DNA methylation epi-signature is associated with two molecularly and phenotypically distinct clinical subtypes of Phelan-McDermid syndrome

    Get PDF
    Background: Phelan-McDermid syndrome is characterized by a range of neurodevelopmental phenotypes with incomplete penetrance and variable expressivity. It is caused by a variable size and breakpoint microdeletions in the distal long arm of chromosome 22, referred to as 22q13.3 deletion syndrome, including the SHANK3 gene. Genetic defects in a growing number of neurodevelopmental genes have been shown to cause genome-wide disruptions in epigenomic profiles referred to as epi-signatures in affected individuals. Results: In this study we assessed genome-wide DNA methylation profiles in a cohort of 22 individuals with Phelan-McDermid syndrome, including 11 individuals with large (2 to 5.8 Mb) 22q13.3 deletions, 10 with small deletions (\u3c 1 Mb) or intragenic variants in SHANK3 and one mosaic case. We describe a novel genome-wide DNA methylation epi-signature in a subset of individuals with Phelan-McDermid syndrome. Conclusion: We identified the critical region including the BRD1 gene as responsible for the Phelan-McDermid syndrome epi-signature. Metabolomic profiles of individuals with the DNA methylation epi-signature showed significantly different metabolomic profiles indicating evidence of two molecularly and phenotypically distinct clinical subtypes of Phelan-McDermid syndrome
    corecore