Spectral properties of finite laser-driven lattices of ultracold Rydberg atoms

We investigate the spectral properties of a finite laser-driven lattice of ultracold Rydberg atoms exploiting the dipole blockade effect in the frozen Rydberg gas regime. Uniform one-dimensional lattices as well as lattices with variable spacings are considered. In the case of a weak laser coupling, we find a multitude of many-body Rydberg states with well-defined excitation properties which are adiabatically accessible starting from the ground state. A comprehensive analysis of the degeneracies of the spectrum as well as of the single and pair excitations numbers of the eigenstates is performed. In the strong laser regime, analytical solutions for the pseudo-fermionic eigenmodes are derived. Perturbative energy corrections for this approximative approach are provided.Comment: 17 pages, 12 figure

USA Swimming: The Data Integration Project

USA Swimming (USAS) is the National Governing Body for the sport of swimming, one of more than 40 National Governing Bodies for amateur sports in the United States. Their mission is, in part, to administer competitive swimming in accordance with the Amateur Sports Act , and to provide programs and services for our members, supporters, affiliates and the interested public The USAS membership community consists of athletes, non-athletes, and clubs. One of the most important functions USAS performs is to gather and maintain information on members in all categories. Maintaining individual swimmers\u27 times in sanctioned meets, for example, forms the basis for swimmers to be ranked nationally. The responsibility for the gathering of data is relegated to 2,800 clubs and 59 local swimming committees scattered across the US. In their previous system, data needed for the USAS master databases was gathered by the clubs and sent to the local swimming committees, which consolidated the data and forwarded it to the national headquarters in Colorado Springs. Unfortunately, by 2002, it became clear that the hodgepodge of different hardware platforms and software used by the clubs and local swimming committees made the data gathering process ripe for errors, which resulted in unreliable data in multiple database systems at USAS headquarters. This case describes the process USAS management followed to establish and manage the development of a new system whose principal features include a new centralized database with a pre-posting holding tank for data cleansing as well as a Web portal providing valuable new functionality to the user community. The project involved significant risks, not the least of which was the widely dispersed user community. Risks were mitigated by the development of a prototype and by engaging an independent verification and validation firm. The new system achieved the benefits that USAS projected when the project was first conceived. The complicated technical infrastructure was replaced by a Web-based architecture that provides faster and more reliable service to the USAS community at a lower cost. The problem of inaccuracies in the data caused by data being stored in multiple databases was eliminated with the establishment of the new centralized database and the holding tank\u27s data cleansing capabilities. Users at USAS headquarters and in the field embraced the new system because it simplified the data gathering process and greatly improved the reliability of the information they obtain from the centralized database. Further, the Web-based portal provides a stable operating environment for day-to-day operations and a platform that allows adding enhancements easily to the system

Disrupted Maturation of the Microbiota and Metabolome among Extremely Preterm Infants with Postnatal Growth Failure

Growth failure during infancy is a major global problem that has adverse effects on long-term health and neurodevelopment. Preterm infants are disproportionately affected by growth failure and its effects. Herein we found that extremely preterm infants with postnatal growth failure have disrupted maturation of the intestinal microbiota, characterized by persistently low diversity, dominance of pathogenic bacteria within the Enterobacteriaceae family, and a paucity of strictly anaerobic taxa including Veillonella relative to infants with appropriate postnatal growth. Metabolomic profiling of infants with growth failure demonstrated elevated serum acylcarnitines, fatty acids, and other byproducts of lipolysis and fatty acid oxidation. Machine learning algorithms for normal maturation of the microbiota and metabolome among infants with appropriate growth revealed a pattern of delayed maturation of the microbiota and metabolome among infants with growth failure. Collectively, we identified novel microbial and metabolic features of growth failure in preterm infants and potentially modifiable targets for intervention

Manipulation and Detection of a Trapped Yb+ Ion Hyperfine Qubit

We demonstrate the use of trapped ytterbium ions as quantum bits for quantum information processing. We implement fast, efficient state preparation and state detection of the first-order magnetic field-insensitive hyperfine levels of 171Yb+, with a measured coherence time of 2.5 seconds. The high efficiency and high fidelity of these operations is accomplished through the stabilization and frequency modulation of relevant laser sources.Comment: 10 pages, 9 figures, 1 tabl

Efficient Photoionization-Loading of Trapped Cadmium Ions with Ultrafast Pulses

Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:Sapphire laser that produces pulses of either 100 fsec or 1 psec duration at a central wavelength of 229 nm. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in high loading efficiencies compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.Comment: 11 pages, 12 figure

Clean Energy Innovation: Sources of Technical and Commercial Breakthroughs

Low-carbon energy innovation is essential to combat climate change, promote economic competitiveness, and achieve energy security. Using U.S. patent data and additional patent-relevant data collected from the Internet, we map the landscape of low-carbon energy innovation in the United States since 1975. We isolate 10,603 renewable and 10,442 traditional energy patents and develop a database that characterizes proxy measures for technical and commercial impact, as measured by patent citations and Web presence, respectively. Regression models and multivariate simulations are used to compare the social, institutional, and geographic drivers of breakthrough clean energy innovation. Results indicate statistically significant effects of social, institutional, and geographic variables on technical and commercial impacts of patents and unique innovation trends between different energy technologies. We observe important differences between patent citations and Web presence of licensed and unlicensed patents, indicating the potential utility of using screened Web hits as a measure of commercial importance. We offer hypotheses for these revealed differences and suggest a research agenda with which to test these hypotheses. These preliminary findings indicate that leveraging empirical insights to better target research expenditures would augment the speed and scale of innovation and deployment of clean energy technologies

Large emergency-response exercises: qualitative characteristics - a survey

Exercises, drills, or simulations are widely used, by governments, agencies and commercial organizations, to simulate serious incidents and train staff how to respond to them. International cooperation has led to increasingly large-scale exercises, often involving hundreds or even thousands of participants in many locations. The difference between ‘large’ and ‘small’ exercises is more than one of size: (a) Large exercises are more ‘experiential’ and more likely to undermine any model of reality that single organizations may create; (b) they create a ‘play space’ in which organizations and individuals act out their own needs and identifications, and a ritual with strong social implications; (c) group-analytic psychotherapy suggests that the emotions aroused in a large group may be stronger and more difficult to control. Feelings are an unacknowledged major factor in the success or failure of exercises; (d) successful large exercises help improve the nature of trust between individuals and the organizations they represent, changing it from a situational trust to a personal trust; (e) it is more difficult to learn from large exercises or to apply the lessons identified; (f) however, large exercises can help develop organizations and individuals. Exercises (and simulation in general) need to be approached from a broader multidisciplinary direction if their full potential is to be realized

Quantum Interference of Photon Pairs from Two Trapped Atomic Ions

We collect the fluorescence from two trapped atomic ions, and measure quantum interference between photons emitted from the ions. The interference of two photons is a crucial component of schemes to entangle atomic qubits based on a photonic coupling. The ability to preserve the generated entanglement and to repeat the experiment with the same ions is necessary to implement entangling quantum gates between atomic qubits, and allows the implementation of protocols to efficiently scale to larger numbers of atomic qubits.Comment: 4 pages, 4 figure

Impact of 90Y PET gradient-based tumor segmentation on voxel-level dosimetry in liver radioembolization

Abstract Background The purpose was to validate 90Y PET gradient-based tumor segmentation in phantoms and to evaluate the impact of the segmentation method on reported tumor absorbed dose (AD) and biological effective dose (BED) in 90Y microsphere radioembolization (RE) patients. A semi-automated gradient-based method was applied to phantoms and patient tumors on the 90Y PET with the initial bounding volume for gradient detection determined from a registered diagnostic CT or MR; this PET-based segmentation (PS) was compared with radiologist-defined morphologic segmentation (MS) on CT or MRI. AD and BED volume histogram metrics (D90, D70, mean) were calculated using both segmentations and concordance/correlations were investigated. Spatial concordance was assessed using Dice similarity coefficient (DSC) and mean distance to agreement (MDA). PS was repeated to assess intra-observer variability. Results In phantoms, PS demonstrated high accuracy in lesion volumes (within 15%), AD metrics (within 11%), high spatial concordance relative to morphologic segmentation (DSC > 0.86 and MDA  0.99, MDA < 0.2 mm, AD/BED metrics within 2%). For patients (58 lesions), spatial concordance between PS and MS was degraded compared to in-phantom (average DSC = 0.54, average MDA = 4.8 mm); the average mean tumor AD was 226 ± 153 and 197 ± 138 Gy, respectively for PS and MS. For patient AD metrics, the best Pearson correlation (r) and concordance correlation coefficient (ccc) between segmentation methods was found for mean AD (r = 0.94, ccc = 0.92), but worsened as the metric approached the minimum dose (for D90, r = 0.77, ccc = 0.69); BED metrics exhibited a similar trend. Patient PS showed low intra-observer variability (average DSC = 0.81, average MDA = 2.2 mm, average AD/BED metrics within 3.0%). Conclusions 90Y PET gradient-based segmentation led to accurate/robust results in phantoms, and showed high concordance with MS for reporting mean tumor AD/BED in patients. However, tumor coverage metrics such as D90 exhibited worse concordance between segmentation methods, highlighting the need to standardize segmentation methods when reporting AD/BED metrics from post-therapy 90Y PET. Estimated differences in reported AD/BED metrics due to segmentation method will be useful for interpreting RE dosimetry results in the literature including tumor response data.https://deepblue.lib.umich.edu/bitstream/2027.42/146544/1/40658_2018_Article_230.pd

Using the collaborative intervention planning framework to adapt a health-care manager intervention to a new population and provider group to improve the health of people with serious mental illness

Background: Health-care manager interventions improve the physical health of people with serious mental illness (SMI) and could be widely implemented in public mental health clinics. Local adaptations and customization may be needed to increase the reach of these interventions in the public mental health system and across different racial and ethnic communities. In this study, we describe how we used the collaborative intervention planning framework to customize an existing health-care manager intervention to a new patient population (Hispanics with SMI) and provider group (social workers) to increase its fit with our local community. Methods: The study was conducted in partnership with a public mental health clinic that serves predominantly Hispanic clients. A community advisory board (CAB) composed of researchers and potential implementers (e.g., social workers, primary care physicians) used the collaborative intervention planning framework, an approach that combines community-based participatory research principles and intervention mapping (IM) procedures, to inform intervention adaptations. Results: The adaptation process included four steps: fostering collaborations between CAB members; understanding the needs of the local population through a mixed-methods needs assessment, literature reviews, and group discussions; reviewing intervention objectives to identify targets for adaptation; and developing the adapted intervention. The application of this approach enabled the CAB to identify a series of cultural and provider level-adaptations without compromising the core elements of the original health-care manager intervention. Conclusions: Reducing health disparities in people with SMI requires community engagement, particularly when preparing existing interventions to be used with new communities, provider groups, and practice settings. Our study illustrates one approach that can be used to involve community stakeholders in the intervention adaptation process from the very beginning to enhance the transportability of a health-care manager intervention in order to improve the health of people with SMI