137 research outputs found

    High-fidelity trapped-ion quantum logic using near-field microwaves

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    We demonstrate a two-qubit logic gate driven by near-field microwaves in a room-temperature microfabricated ion trap. We measure a gate fidelity of 99.7(1)\%, which is above the minimum threshold required for fault-tolerant quantum computing. The gate is applied directly to 43^{43}Ca+^+ "atomic clock" qubits (coherence time T2∗≈50 sT_2^*\approx 50\,\mathrm{s}) using the microwave magnetic field gradient produced by a trap electrode. We introduce a dynamically-decoupled gate method, which stabilizes the qubits against fluctuating a.c.\ Zeeman shifts and avoids the need to null the microwave field

    Probing Qubit Memory Errors at the Part-per-Million Level

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    Robust qubit memory is essential for quantum computing, both for near-term devices operating without error correction, and for the long-term goal of a fault-tolerant processor. We directly measure the memory error ϵm\epsilon_m for a 43^{43}Ca+^+ trapped-ion qubit in the small-error regime and find ϵm<10−4\epsilon_m<10^{-4} for storage times t\lesssim50\,\mbox{ms}. This exceeds gate or measurement times by three orders of magnitude. Using randomized benchmarking, at t=1\,\mbox{ms} we measure ϵm=1.2(7)×10−6\epsilon_m=1.2(7)\times10^{-6}, around ten times smaller than that extrapolated from the T2∗T_{2}^{\ast} time, and limited by instability of the atomic clock reference used to benchmark the qubit.Comment: 8 pages, 5 figure

    Fungi in a Warmer World: Fungal Diversity in the Tropical Miocene Climate Optimum of the Clarkia Region of Idaho, USA

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    A knowledge gap associated with how fungal communities change in response to climate was identified in the 2018 State of the World Fungi report (Willis, 2018). While it is virtually impossible to test in the present, fungal assemblage changes can be studied in sediments from a warmer-than-present period such as the Miocene Climate Optimum (MCO) (Romero et al. 2021; O’Keefe 2017). The Fungi in a Warmer World project aims to generate and analyze a global-scale data set of fungal biodiversity, ecology, and associated flora from MCO sediments. This dataset will be used to model past fungal assemblage changes across the MCO and forecast future changes in line with IPCC RCP 4.5-8.5 warming.https://scholarworks.moreheadstate.edu/celebration_posters_2022/1003/thumbnail.jp

    Illness Beliefs Predict Mortality in Patients with Diabetic Foot Ulcers

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    Background - Patients’ illness beliefs have been associated with glycaemic control in diabetes and survival in other conditions. Objective - We examined whether illness beliefs independently predicted survival in patients with diabetes and foot ulceration. Methods - Patients (n = 169) were recruited between 2002 and 2007. Data on illness beliefs were collected at baseline. Data on survival were extracted on 1st November 2011. Number of days survived reflected the number of days from date of recruitment to 1st November 2011. Results - Cox regressions examined the predictors of time to death and identified ischemia and identity beliefs (beliefs regarding symptoms associated with foot ulceration) as significant predictors of time to death. Conclusions - Our data indicate that illness beliefs have a significant independent effect on survival in patients with diabetes and foot ulceration. These findings suggest that illness beliefs could improve our understanding of mortality risk in this patient group and could also be the basis for future therapeutic interventions to improve survival

    Stiffness-matched biomaterial implants for cell delivery: clinical, intraoperative ultrasound elastography provides a ‘target’ stiffness for hydrogel synthesis in spinal cord injury

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    Safe hydrogel delivery requires stiffness-matching with host tissues to avoid iatrogenic damage and reduce inflammatory reactions. Hydrogel-encapsulated cell delivery is a promising combinatorial approach to spinal cord injury therapy, but a lack of in vivo clinical spinal cord injury stiffness measurements is a barrier to their use in clinics. We demonstrate that ultrasound elastography – a non-invasive, clinically established tool – can be used to measure spinal cord stiffness intraoperatively in canines with spontaneous spinal cord injury. In line with recent experimental reports, our data show that injured spinal cord has lower stiffness than uninjured cord. We show that the stiffness of hydrogels encapsulating a clinically relevant transplant population (olfactory ensheathing cells) can also be measured by ultrasound elastography, enabling synthesis of hydrogels with comparable stiffness to canine spinal cord injury. We therefore demonstrate proof-of-principle of a novel approach to stiffness-matching hydrogel-olfactory ensheathing cell implants to ‘real-life’ spinal cord injury values; an approach applicable to multiple biomaterial implants for regenerative therapies

    The case for investment in tobacco control: lessons from four countries in the Americas

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    Objective. To synthesize learnings from four national tobacco control investment cases conducted in the Ameri- cas (Colombia, Costa Rica, El Salvador, Suriname) under the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) 2030 project, to describe results and how national health authorities have used the cases, and to discuss implications for the role of investment cases in advancing tobacco control. Methods. We draw on findings from four national investment cases that included 1) a cost-of-illness analysis calculating the health and economic burden of tobacco use, 2) a return-on-investment analysis of implement- ing key tobacco control demand reduction measures, and 3) a subsidiary analysis of one tobacco control topic of national interest (e.g., equity implications of cigarette taxation). Co-authors reported how cases have been used to advance tobacco control. Results. In Colombia, Costa Rica, El Salvador, and Suriname, tobacco use causes social and economic losses equivalent to between 1.0 to 1.8 percent of GDP. Across these countries, implementing WHO FCTC demand reduction measures would save an average of 11 400 lives per year over the next 15 years. Benefits of the mea- sures would far outweigh the costs of implementation and enforcement. Governments are using the cases to advance tobacco control, including to improve tobacco control laws and their enforcement, strengthen tobacco taxation, prioritize tobacco control planning, coordinate a multisectoral response, and engage political leaders. Conclusions. National investment cases can help to strengthen tobacco control in countries, including by increasing public and political support for implementation of the WHO FCTC and by informing effective plan- ning, legislation, coordination and financing

    Differential Expression of Alpha 4 Integrins on Effector Memory T Helper Cells during Bordetella Infections. Delayed Responses in Bordetella pertussis

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    Bordetella pertussis (B. pertussis) is the causative agent of whooping cough, a respiratory disease that is reemerging worldwide. Mechanisms of selective lymphocyte trafficking to the airways are likely to be critical in the immune response to this pathogen. We compared murine infection by B. pertussis, B. parapertussis, and a pertussis toxin-deleted B. pertussis mutant (BpΔPTX) to test the hypothesis that effector memory T-helper cells (emTh) display an altered pattern of trafficking receptor expression in B. pertussis infection due to a defect in imprinting. Increased cell recruitment to the lungs at 5 days post infection (p.i.) with B. parapertussis, and to a lesser extent with BpΔPTX, coincided with an increased frequency of circulating emTh cells expressing the mucosal-associated trafficking receptors α4β7 and α4β1 while a reduced population of these cells was observed in B. pertussis infection. These cells were highly evident in the blood and lungs in B. pertussis infection only at 25 days p.i. when B. parapertussis and BpΔPTX infections were resolved. Although at 5 days p.i., an equally high percentage of lung dendritic cells (DCs) from all infections expressed maturation markers, this expression persisted only in B. pertussis infection at 25 days p.i. Furthermore, at 5 days p.i with B. pertussis, lung DCs migration to draining lymph nodes may be compromised as evidenced by decreased frequency of CCR7+ DCs, inhibited CCR7-mediated in vitro migration, and fewer DCs in lung draining lymph nodes. Lastly, a reduced frequency of allogeneic CD4+ cells expressing α4β1 was detected following co-culture with lung DCs from B. pertussis-infected mice, suggesting a defect in DC imprinting in comparison to the other infection groups. The findings in this study suggest that B. pertussis may interfere with imprinting of lung-associated trafficking receptors on T lymphocytes leading to extended survival in the host and a prolonged course of disease

    Agriculture: Steps to sustainable livestock

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    With improved breeding and cultivation, ruminant animals can yield food that is better for people and the planet, say Mark C. Eisler, Michael R. F. Lee and colleagues
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