270 research outputs found

    Measurement of the electric dipole moments for transitions to rubidium Rydberg states via Autler-Townes splitting

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    We present the direct measurements of electric-dipole moments for 5P3/2→nD5/25P_{3/2}\to nD_{5/2} transitions with 20<n<4820<n<48 for Rubidium atoms. The measurements were performed in an ultracold sample via observation of the Autler-Townes splitting in a three-level ladder scheme, commonly used for 2-photon excitation of Rydberg states. To the best of our knowledge, this is the first systematic measurement of the electric dipole moments for transitions from low excited states of rubidium to Rydberg states. Due to its simplicity and versatility, this method can be easily extended to other transitions and other atomic species with little constraints. Good agreement of the experimental results with theory proves the reliability of the measurement method.Comment: 12 pages, 6 figures; figure 6 replaced with correct versio

    Quantum-enhanced protocols with mixed states using cold atoms in dipole traps

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    We discuss the use of cold atoms in dipole traps to demonstrate experimentally a particular class of protocols for computation and metrology based on mixed states. Modelling of the system shows that, for a specific class of problems (tracing, phase estimation), a quantum advantage can be achieved over classical algorithms for very realistic conditions and strong decoherence. We discuss the results of the models and the experimental implementation

    EuGMS 2019 Congress report: evidence-based medicine in geriatrics

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    This is the final version. Available from Springer Nature via the DOI in this record. The 2019 EuGMS Congress “Evidence-Based Medicine in Geriatrics” was held in Krakow, Poland, and attended by over 1600 participants from 64 different countries. A summary and reflection on the congress was presented in the Closing Ceremony by European Academy for Medicine of Aging graduates, and summarised in this article. Keynote lectures, ‘state of the art’ sessions and symposia presented the evidence relating to different age-related conditions, their prevention, management and treatments. Hot topic areas included frailty and multimorbidity, and evidence-based attempts to address these conditions at different life stages. The field of geriatrics represents unique challenges for evidence-based medicine practice. There is much research going on. Clear leadership is needed to facilitate consensus agreements on standard definitions, methods and relevant outcomes, in collaboration with older people themselves, to maximise the opportunities and benefits of doing this research, and benefiting our patients and society at large

    Acceptability, Feasibility and Preliminary Evaluation of a Novel, Personalised, Home based Physical Activity Intervention for Chronic Heart Failure (Active-at-Home-HF)::A Pilot Study

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    Purpose: Less than 10% of heart failure patients in the UK participate in cardiac rehabilitation programmes. The present pilot study evaluated feasibility, acceptability and physiological effects of a novel, personalised, home-based physical activity intervention in chronic heart failure. Methods: Twenty patients (68±7 years old, 20% females) with stable chronic heart failure due to reduced left ventricular ejection fraction (31±8 %) participated in a single group, pilot study assessing the feasibility and acceptability of a 12-week personalised home-based physical activity intervention aiming to increase daily number of steps by 2000 from baseline (Active-at-Home-HF). Patients completed cardiopulmonary exercise testing with non-invasive gas exchange and haemodynamic measurements and quality of life questionnaire pre- and post-intervention. Patients were supported weekly via telephone and average weekly step count data collected using pedometers. Results: 43 patients were screened and 20 recruited into the study. Seventeen patients (85%) completed the intervention, and 15 (75%) achieved the target step count. Average step count per day increased significantly from baseline to 3 weeks by 2546 (5108±3064 to 7654±3849 P=0.03, n=17), and was maintained until week 12 (9022±3942). Following completion of the intervention, no adverse events were recorded, quality of life improved by 4 points (26±18 vs. 22±19). Peak exercise stroke volume increased by 19% (127±34 vs 151±34 m/beat, P=0.05), while cardiac index increased by 12% (6.8±1.5 vs. 7.6±2.0 L/min/m2, P=0.19). Workload and oxygen consumption at anaerobic threshold also increased by 16% (49±16 vs. 59±14 watts, P=0.01) and 10% (11.5±2.9 vs. 12.8±2.2 ml/kg/min, P=0.39). Conclusion: The Active-at-Home-HF intervention is feasible, acceptable and effective for increasing physical activity in CHF. It may lead to improvements in quality of life, exercise tolerance and haemodynamic function

    Ozone observations and a model of marine boundary layer photochemistry during SAGA 3

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    A major purpose of the third joint Soviet‐American Gases and Aerosols (SAGA 3) oceanographic cruise was to examine remote tropical marine O3 and photochemical cycles in detail. On leg 1, which took place between Hilo, Hawaii, and Pago‐Pago, American Samoa, in February and March 1990, shipboard measurements were made of O3, CO, CH4, nonmethane hydrocarbons (NMHC), NO, dimethyl sulfide (DMS), H2S, H2O2, organic peroxides, and total column O3. Postcruise analysis was performed for alkyl nitrates and a second set of nonmethane hydrocarbons. A latitudinal gradient in O3 was observed on SAGA 3, with O3 north of the intertropical convergence zone (ITCZ) at 15–20 parts per billion by volume (ppbv) and less than 12 ppbv south of the ITCZ but never ≀3 ppbv as observed on some previous equatorial Pacific cruises (Piotrowicz et al., 1986; Johnson et al., 1990). Total column O3 (230–250 Dobson units (DU)) measured from the Akademik Korolev was within 8% of the corresponding total ozone mapping spectrometer (TOMS) satellite observations and confirmed the equatorial Pacific as a low O3 region. In terms of number of constituents measured, SAGA 3 may be the most photochemically complete at‐sea experiment to date. A one‐dimensional photochemical model gives a self‐consistent picture of O3‐NO‐CO‐hydrocarbon interactions taking place during SAGA 3. At typical equatorial conditions, mean O3 is 10 ppbv with a 10–15% diurnal variation and maximum near sunrise. Measurements of O3, CO, CH4, NMHC, and H2O constrain model‐calculated OH to 9 × 105 cm−3 for 10 ppbv O3 at the equator. For DMS (300–400 parts per trillion by volume (pptv)) this OH abundance requires a sea‐to‐air flux of 6–8 × 109 cm−2 s−1, which is within the uncertainty range of the flux deduced from SAGA 3 measurements of DMS in seawater (Bates et al., this issue). The concentrations of alkyl nitrates on SAGA 3 (5–15 pptv total alkyl nitrates) were up to 6 times higher than expected from currently accepted kinetics, suggesting a largely continental source for these species. However, maxima in isopropyl nitrate and bromoform near the equator (Atlas et al., this issue) as well as for nitric oxide (Torres and Thompson, this issue) may signify photochemical and biological sources of these species

    Genealogies of Slavery

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    This chapter addresses the concept of slavery, exploring its character and significance as a dark page in history, but also as a specifically criminological and zemiological problem, in the context of international law and human rights. By tracing the ambiguities of slavery in international law and international development, the harms associated with slavery are considered. Harms include both those statutorily proscribed, and those that are not, but that can still be regarded as socially destructive. Traditionally, antislavery has been considered within the parameters of abolition and criminalization. In this context recently, anti-trafficking has emerged as a key issue in contemporary anti-slavery work. While valuable, anti-trafficking is shown to have significant limitations. It advances criminalization and stigmatization of the most vulnerable and further perpetuates harm. At the same time, it identifies structural conditions like poverty, vulnerability, and “unfreedom” of movement only to put them aside. Linked to exploitation, violence and zemia, the chapter brings to the fore some crucial questions concerning the prospects of systemic theory in the investigation of slavery, that highlight the root causes of slavery, primarily poverty and inequality. Therefore, the chapter counterposes an alternative approach in which the orienting target is not abolition of slavery but advancing structural changes against social harm

    Omnichannel Value Chain: Mapping Digital Technologies for Channel Integration Activities

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    In order to provide a seamless customer experience, researchers and practitioners have proposed creation of an omnichannel retailing environment by integrating online and offline channels. Channel integration necessitates use of digital technologies and there are myriads of technological solutions available. However, retailers are struggling with selection and implementation of suitable technologies to add value through channel integration. Despite the strong practical need, this issue has not been effectively addressed in the academic literature. This paper presents an omnichannel value chain underpinned by Porter’s value chain model. We identify ten channel integration activities for value creation by carrying out a synthesis of current research on omnichannel retailing. Enabling digital technologies are then mapped to these activities using technology implementation examples and provide a guideline for retailers to select appropriate technologies for the identified value creation activities
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