Efficient preparation and detection of microwave dressed-state qubits and qutrits with trapped ions

We demonstrate a method for preparing and detecting all eigenstates of a three-level microwave dressed system with a single trapped ion. The method significantly reduces the experimental complexity of gate operations with dressed-state qubits, as well as allowing all three of the dressed states to be prepared and detected, thereby providing access to a qutrit that is well protected from magnetic field noise. In addition, we demonstrate individual addressing of the clock transitions in two ions using a strong static magnetic field gradient, showing that our method can be used to prepare and detect microwave dressed states in a string of ions when performing multi-ion quantum operations with microwave and radio frequency fields. The individual addressability of clock transitions could also allow for the control of pairwise interaction strengths between arbitrary ions in a string using lasers

Robust and Deterministic Preparation of Bosonic Logical States in a Trapped Ion

Encoding logical qubits in bosonic modes provides a potentially hardware-efficient implementation of fault-tolerant quantum information processing. Recent advancements in trapped ions and superconducting microwave cavities have led to experimental realizations of high-quality bosonic states and demonstrations of error-corrected logical qubits encoded in bosonic modes. However, current protocols for preparing bosonic code words lack robustness to common noise sources and can be experimentally challenging to implement, limiting the quality and breadth of codes that have been realized to date. Here, we combine concepts of error suppression via robust control with quantum error correction encoding and experimentally demonstrate high-fidelity, deterministic preparation of highly non-classical target bosonic states in the mechanical motion of a trapped ion. Our approach implements numerically optimized dynamical modulation of laser-driven spin-motion interactions to generate the target state in a single step. The optimized control pulses are tailored towards experimental constraints and are designed to be robust against the dominant source of error. Using these protocols, we demonstrate logical fidelities for the Gottesman-Kitaev-Preskill (GKP) state as high as $\bar{\mathcal{F}}=0.940(8)$, achieve the first realization of a distance-3 binomial logical state with an average fidelity of $\mathcal{F}=0.807(7)$, and demonstrate a 12.91(5) dB squeezed vacuum state.Comment: 12 pages, 8 figure

Electron paramagnetic resonance study of ferroelectric phase transition and dynamic effects in a Mn²⁺ doped [NH₄][Zn(HCOO)₃] hybrid formate framework

We present an X- and Q-band continuous wave (CW) and pulse electron paramagnetic resonance (EPR) study of a manganese doped [NH4][Zn(HCOO)3] hybrid framework, which exhibits a ferroelectric structural phase transition at 190 K. The CW EPR spectra obtained at different temperatures exhibit clear changes at the phase transition temperature. This suggests a successful substitution of the Zn2+ ions by the paramagnetic Mn2+ centers, which is further confirmed by the pulse EPR and 1H ENDOR experiments. Spectral simulations of the CW EPR spectra are used to obtain the temperature dependence of the Mn2+ zero-field splitting, which indicates a gradual deformation of the MnO6 octahedra indicating a continuous character of the transition. The determined data allow us to extract the critical exponent of the order parameter (β = 0.12), which suggests a quasi two-dimensional ordering in [NH4][Zn(HCOO)3]. The experimental EPR results are supported by the density functional theory calculations of the zero-field splitting parameters. Relaxation time measurements of the Mn2+ centers indicate that the longitudinal relaxation is mainly driven by the optical phonons, which correspond to the vibrations of the metal–oxygen octahedra. The temperature behavior of the transverse relaxation indicates a dynamic process in the ordered ferroelectric phase

In silico evaluation of ultrafiltration and nanofiltration membrane cascades for continuous fractionation of protein hydrolysate from tuna processing byproduct

The present work proposes the design of cascades that integrate ultrafiltration (UF) and nanofiltration (NF) membranes to separate the different protein fractions from the protein hydrolysate obtained after hydrolysis of tuna byproducts. Experimental data (permeate flux and rejection of protein fractions under different applied pressures) previously obtained and published by this research group were fitted to empirical models, which were the basis for a process simulation model. High recovery rates (0.9) in the UF stages implied high process yields by reduced desired fraction losses, while similar recovery rates in the NF stages were required for high product purity. However, the applied pressures were not so influential over the performance of the system. Optimization problems were solved to identify the optimal design and operation conditions to maximize the product purity or the process yield. Maximal purity of the preferred 1-4 kDa fraction (49.3% from 19.0% in feed stream) obtained by the configuration with 3 UF stages and another 3 NF stages implied 2 and 5 bar pressures applied in the UF and NF stages, respectively, while 0.9 was the optimal recovery rate value for all the stages. These maximal purity conditions resulted in 62.6% process yield, defined as the percentage of the 1-4 kDa fraction in the feed stream recovered in the product stream. In addition, multiobjective optimization of the process was also carried out to obtain the Pareto graphs that represent the counterbalance between maximal yields and purities

Trapped-ion quantum logic with global radiation fields

Trapped ions are a promising tool for building a large-scale quantum computer. However, the number of required radiation fields for the realization of quantum gates in any proposed ion-based architecture scales with the number of ions within the quantum computer, posing a major obstacle when imagining a device with millions of ions. Here, we present a fundamentally different approach for trapped-ion quantum computing where this detrimental scaling vanishes. The method is based on individually controlled voltages applied to each logic gate location to facilitate the actual gate operation analogous to a traditional transistor architecture within a classical computer processor. To demonstrate the key principle of this approach we implement a versatile quantum gate method based on long-wavelength radiation and use this method to generate a maximally entangled state of two quantum engineered clock qubits with fidelity 0.985(12). This quantum gate also constitutes a simple-to-implement tool for quantum metrology, sensing, and simulation

Impacts of innovation, productivity and specialization on tourism competitiveness - a spatial econometric analysis on European regions

Tourism is clearly a place-based activity, while in many advanced economies it is increasingly becoming a knowledge-based activity, with a high potential for the development of practice- and place-based innovation strategies. This study analyses whether and how regional systems of innovation influence the competiveness of tourism destinations in Europe. Impacts of both traditional production factors (physical and human capital), productivity, specialization and other contextual variables - related to the territorial capital of each region - on regional tourism performance of 237 European regions (NUTS 2) are analysed over a period of 8 years, using advanced techniques for spatial econometric analysis. The results reveal lower levels of productivity in those regions where tourism services are more labour intensive, while regions where education, innovation and productivity demonstrate higher levels are those where gross value added in tourism is less important for the regional economy. Policy implications are discussed, taking into consideration the principles for smart specialisation strategies in European regions and the possibility for cross-border regional cooperation. This work also confirms the research potential of spatial econometric analysis - and in particular spatial autocorrelation techniques - for tourism studies.Fundacao para a Ciencia e a TecnologiaPortuguese Foundation for Science and TechnologyFEDER/COMPETEEuropean Union (EU) [UID/ECO/04007/2013, SFRH/BPD/98938/2013]info:eu-repo/semantics/publishedVersio

An mRNA processing pathway suppresses metastasis by governing translational control from the nucleus

Cancer cells often co-opt post-transcriptional regulatory mechanisms to achieve pathologic expression of gene networks that drive metastasis. Translational control is a major regulatory hub in oncogenesis; however, its effects on cancer progression remain poorly understood. Here, to address this, we used ribosome profiling to compare genome-wide translation efficiencies of poorly and highly metastatic breast cancer cells and patient-derived xenografts. We developed dedicated regression-based methods to analyse ribosome profiling and alternative polyadenylation data, and identified heterogeneous nuclear ribonucleoprotein C (HNRNPC) as a translational controller of a specific mRNA regulon. We found that HNRNPC is downregulated in highly metastatic cells, which causes HNRNPC-bound mRNAs to undergo 3′ untranslated region lengthening and, subsequently, translational repression. We showed that modulating HNRNPC expression impacts the metastatic capacity of breast cancer cells in xenograft mouse models. In addition, the reduced expression of HNRNPC and its regulon is associated with the worse prognosis in breast cancer patient cohorts

Integrating Entrepreneurship into the Design Classroom: Case Studies from the Developing World

© 2017, Springer Science+Business Media, LLC. Developing countries are more and more committed to building a knowledge-based economy as a means to diversify from their current resource-based economy. The current focus of many governments is on technology with real insights on creative economy and arts. In this context, universities are seen as a key partner of the government. This article presents the results of two innovative case studies of professors working in the College of Art and Design collaborating with a professor in the College of Business to integrate the concepts of entrepreneurship into their interior design courses. This was done through designing space for entrepreneurial projects and by the students acting as entrepreneurs themselves with an external client. This dual model of training combines (1) learning processes about the habits and the needs of entrepreneurs and (2) learning by acting as an entrepreneur. Such methods demonstrate the role of universities to provide a proper theoretical background for students and to foster entrepreneurial behaviors through arts entrepreneurship education. Furthermore, the central role of professors to introduce innovative teaching methods to combine entrepreneurship and the creative economy into non-business courses is an important finding in these case studies

Effect of SGLT2 inhibitors on stroke and atrial fibrillation in diabetic kidney disease: Results from the CREDENCE trial and meta-analysis

BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-Analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus. METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-Analysis. RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: Total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]). CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms

The additional value of patient-reported health status in predicting 1-year mortality after invasive coronary procedures: A report from the Euro Heart Survey on Coronary Revascularisation

Objective: Self-perceived health status may be helpful in identifying patients at high risk for adverse outcomes. The Euro Heart Survey on Coronary Revascularization (EHS-CR) provided an opportunity to explore whether impaired health status was a predictor of 1-year mortality in patients with coronary artery disease (CAD) undergoing angiographic procedures. Methods: Data from the EHS-CR that included 5619 patients from 31 member countries of the European Society of Cardiology were used. Inclusion criteria for the current study were completion of a self-report measure of health status, the EuroQol Questionnaire (EQ-5D) at discharge and information on 1-year follow-up, resulting in a study population of 3786 patients. Results: The 1-year mortality was 3.2% (n = 120). Survivors reported fewer problems on the five dimensions of the EQ-5D as compared with non-survivors. A broad range of potential confounders were adjusted for, which reached a p<0.10 in the unadjusted analyses. In the adjusted analyses, problems with self-care (OR 3.45; 95% CI 2.14 to 5.59) and a low rating (≤ 60) on health status (OR 2.41; 95% CI 1.47 to 3.94) were the most powerful independent predictors of mortality, among the 22 clinical variables included in the analysis. Furthermore, patients who reported no problems on all five dimensions had significantly lower 1-year mortality rates (OR 0.47; 95% CI 0.28 to 0.81). Conclusions: This analysis shows that impaired health status is associated with a 2-3-fold increased risk of all-cause mortality in patients with CAD, independent of other conventional risk factors. These results highlight the importance of including patients' subjective experience of their own health status in the evaluation strategy to optimise risk stratification and management in clinical practice