Creating exotic condensates via quantum-phase-revival dynamics in engineered lattice potentials

In the field of ultracold atoms in optical lattices a plethora of phenomena governed by the hopping energy $J$ and the interaction energy $U$ have been studied in recent years. However, the trapping potential typically present in these systems sets another energy scale and the effects of the corresponding time scale on the quantum dynamics have rarely been considered. Here we study the quantum collapse and revival of a lattice Bose-Einstein condensate (BEC) in an arbitrary spatial potential, focusing on the special case of harmonic confinement. Analyzing the time evolution of the single-particle density matrix, we show that the physics arising at the (temporally) recurrent quantum phase revivals is essentially captured by an effective single particle theory. This opens the possibility to prepare exotic non-equilibrium condensate states with a large degree of freedom by engineering the underlying spatial lattice potential.Comment: 9 pages, 6 figure

Operationally Responsive Space (ORS): An Architecture and Enterprise Model for Adaptive Integration, Test and Logistics

The capability to rapidly deploy tactical satellites to meet a Joint Force Commander\u27s immediate battlespace requirements is a well-documented joint capability need. Key U.S. strategic documentation cites the need for the capability to maintain persistent surveillance or an unblinking eye over battlespace and to rapidly reconstitute critical space capabilities to preserve situational awareness. The warfighter requires a tactical space-based deployment capability which employs a request to launch and operational deployment window of 90 to 120 days. This master\u27s thesis executed two (2) major areas of work: apply, and reinforce the Operationally Responsive Space (ORS) mission tasks using the Joint Capabilities Integration Development System (JCIDS) process; then based on capability gap data generated from the process, analyze and define the capability gap of an ORS Adaptive Integration, Test and Logistics (IT&L) process for payload to bus deployment to meet the identified time scales. This document recommends engineering solutions and processes for the ORS IT&L to-be state for this warfighter capability. The ORS adaptive IT&L CONOPS developed as part of this work focuses on the Tactical Satellite Rapid Deployment System (TSRDS), which is an adaptive integration, test and logistics capability that enables rapid and effective payload to bus integration to meet a 90- to 120-day warfighter window

Black Hole Genealogy: Identifying Hierarchical Mergers with Gravitational Waves

In dense stellar environments, the merger products of binary black hole mergers may undergo additional mergers. These hierarchical mergers are naturally expected to have higher masses than the first generation of black holes made from stars. The components of hierarchical mergers are expected to have significant characteristic spins, imprinted by the orbital angular momentum of the previous mergers. However, since the population properties of first-generation black holes are uncertain, it is difficult to know if any given merger is first-generation or hierarchical. We use observations of gravitational waves to reconstruct the binary black hole mass and spin spectrum of a population including the possibility of hierarchical mergers. We employ a phenomenological model that captures the properties of merging binary black holes from simulations of globular clusters. Inspired by recent work on the formation of low-spin black holes, we include a zero-spin subpopulation. We analyze binary black holes from LIGO and Virgo's first two observing runs, and find that this catalog is consistent with having no hierarchical mergers. We find that the most massive system in this catalog, GW170729, is mostly likely a first-generation merger, having a 4% probability of being a hierarchical merger assuming a 5 × 10⁵ M_⊙ globular cluster mass. Using our model, we find that 99% of first-generation black holes in coalescing binaries have masses below 44 M_⊙, and the fraction of binaries with near-zero component spins is less than 0.16 (90% probability). Upcoming observations will determine if hierarchical mergers are a common source of gravitational waves

The use of live attenuated influenza vaccine (LAIV) in healthcare personnel (HCP): Guidance from the society for healthcare epidemiology of America (SHEA)

Because of the live viral backbone of live attenuated influenza vaccine (LAIV), questions have arisen regarding infection control precautions and restrictions surrounding its use in healthcare personnel (HCP). This document provides guidance from the Society for Healthcare Epidemiology of America regarding use of LAIV in HCP and the infection control precautions that are recommended with its use in this population. Infect Control Hosp Epidemiol 2012;33(10):981-98

Accuracy of hiatal hernia diagnosis in bariatric patients : preoperative endoscopy versus intraoperative reference

Background and Aim: Obesity is becoming increasingly prevalent in Asia. Bariatric surgery in the region is growing in popularity to reflect increasing demand. Hiatal hernia (HH) is common among the obese population. There is a lack of evidence comparing preoperative endoscopy against intraoperative findings as a standard of reference for HH diagnosis. Methods: This was a retrospective analysis of a bariatric procedure database from a single tertiary teaching hospital and high-volume endoscopy center. Electronic medical records were reviewed. Endoscopy results were compared to intraoperative findings, and subgroup analysis of >2 cm hernias was performed. Sensitivity, specificity, predictive values, likelihood ratios, and global diagnostic test accuracy were calculated. Results: A total of 434 patients were eligible for this study, of which HH was detected in 37 patients (prevalence rate 8.55%). Mean age was 41.51 ± 11.07 years, and body mass index was 39.37 ± 5.67 kg/m2 . Endoscopy sensitivity was 75.68% (95% confidence interval, 58.80–88.23%) and specificity 91.44% (88.24–94.00%). Positive likelihood ratio was 8.53 (6.11–12.79) and negative likelihood ratio 0.27 (0.15–0.47). Positive predictive value was 45.16% (36.27–54.38%) and negative predictive value 97.58% (95.80–98.62%). Accuracy of endoscopy for preoperative HH diagnosis was 90.09% (86.89–92.74%). Conclusion: Endoscopy can have a high diagnostic accuracy of preoperative HH diagnosis in obese Asian patients using intraoperative diagnosis as the reference standard

Design of a vehicle based system to prevent ozone loss

This project is designed to be completed over a three year period. Overall project goals are: (1) to understand the processes that contribute to stratospheric ozone loss; (2) to determine the best scheme to prevent ozone loss; and (3) to design a vehicle based system to carry out the prevention scheme. The 1993/1994 design objectives included: (1) to review the results of the 1992/1993 design team, including a reevaluation of the key assumptions used; (2) to develop a matrix of baseline vehicle concepts as candidates for the delivery vehicle; and (3) to develop a selection criteria and perform quantitative trade studies to use in the selection of the specific vehicle concept

The role of religion in the longer-range future, April 6, 7, and 8, 2006

This repository item contains a single issue of the Pardee Conference Series, a publication series that began publishing in 2006 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. This conference that took place during April 6, 7, and 8, 2006. Co-organized by David Fromkin, Director, Frederick S. Pardee Center for the Study of the Longer-Range Future, and Ray L. Hart, Dean ad interim Boston University School of TheologyThe conference brought together some 40 experts from various disciplines to ponder upon the “great dilemma” of how science, religion, and the human future interact. In particular, different panels looked at trends in what is happening to religion around the world, questions about how religion is impacting the current political and economic order, and how the social dynamics unleashed by science and by religion can be reconciled.Carnegie Council on Ethics and International Affair

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

Background: Our ability to monitor populations or species that were once threatened or endangered and in the process of recovery is enhanced by using genetic methods to assess overall population stability and size over time. This can be accomplished most directly by obtaining genetic measures from temporally-spaced samples that reflect the overall stability of the population as given by changes in genetic diversity levels (allelic richness and heterozygosity), degree of population differentiation (FST and DEST), and effective population size (Ne). The primary goal of any recovery effort is to produce a longterm self-sustaining population, and these genetic measures provide a metric by which we can gauge our progress and help make important management decisions. Methodology/Principal Findings: The peregrine falcon in North America (Falco peregrinus tundrius and anatum) was delisted in 1994 and 1999, respectively, and its abundance will be monitored by the species Recovery Team every three years until 2015. Although the United States Fish and Wildlife Service makes a distinction between tundrius and anatum subspecies, our genetic results based on eleven microsatellite loci suggest limited differentiation that can be attributed to an isolation by distance relationship and warrant no delineation of these two subspecies in its northern latitudinal distribution from Alaska through Canada into Greenland. Using temporal samples collected at Padre Island, Texas during migration (seven temporal time periods between 1985–2007), no significant differences in genetic diversity or significant population differentiation in allele frequencies between time periods were observed and were indistinguishable from those obtained from tundrius/anatum breeding locations throughout their northern distribution. Estimates of harmonic mean Ne were variable and imprecise, but always greater than 500 when employing multiple temporal genetic methods. Conclusions/Significance: These results, including those from simulations to assess the power of each method to estimate Ne, suggest a stable or growing population, which is consistent with ongoing field-based monitoring surveys. Therefore, historic and continuing efforts to prevent the extinction of the peregrine falcon in North America appear successful with no indication of recent decline, at least from the northern latitude range-wide perspective. The results also further highlight the importance of archiving samples and their use for continual assessment of population recovery and long-term viability

Evidence for hierarchical black hole mergers in the second LIGO--Virgo gravitational-wave catalog

We study the population properties of merging binary black holes in the second LIGO--Virgo Gravitational-Wave Transient Catalog assuming they were all formed dynamically in gravitationally bound clusters. Using a phenomenological population model, we infer the mass and spin distribution of first-generation black holes, while self-consistently accounting for hierarchical mergers. Considering a range of cluster masses, we see compelling evidence for hierarchical mergers in clusters with escape velocities $\gtrsim 100~\mathrm{km\,s^{-1}}$. For our most probable cluster mass, we find that the catalog contains at least one second-generation merger with $99\%$ credibility. We find that the hierarchical model is preferred over an alternative model with no hierarchical mergers (Bayes factor $\mathcal{B} > 1400$) and that GW190521 is favored to contain two second-generation black holes with odds $\mathcal{O}>700$, and GW190519, GW190602, GW190620, and GW190706 are mixed-generation binaries with $\mathcal{O} > 10$. However, our results depend strongly on the cluster escape velocity, with more modest evidence for hierarchical mergers when the escape velocity is $\lesssim 100~\mathrm{km\,s^{-1}}$. Assuming that all binary black holes are formed dynamically in globular clusters with escape velocities on the order of tens of $\mathrm{km\,s^{-1}}$, GW190519 and GW190521 are favored to include a second-generation black hole with odds $\mathcal{O}>1$. In this case, we find that $99\%$ of black holes from the inferred total population have masses that are less than $49\,M_{\odot}$, and that this constraint is robust to our choice of prior on the maximum black hole mass.Comment: 15 pages, 11 figures, 1 appendi

Ozone depletion events observed in the high latitude surface layer during the TOPSE aircraft program

During the Tropospheric Ozone Production about the Spring Equinox (TOPSE) aircraft program, ozone depletion events (ODEs) in the high latitude surface layer were investigated using lidar and in situ instruments. Flight legs of 100 km or longer distance were flown 32 times at 30 m altitude over a variety of regions north of 58° between early February and late May 2000. ODEs were found on each flight over the Arctic Ocean but their occurrence was rare at more southern latitudes. However, large area events with depletion to over 2 km altitude in one case were found as far south as Baffin Bay and Hudson Bay and as late as 22 May. There is good evidence that these more southern events did not form in situ but were the result of export of ozone-depleted air from the surface layer of the Arctic Ocean. Surprisingly, relatively intact transport of ODEs occurred over distances of 900–2000 km and in some cases over rough terrain. Accumulation of constituents in the frozen surface over the dark winter period cannot be a strong prerequisite of ozone depletion since latitudes south of the Arctic Ocean would also experience a long dark period. Some process unique to the Arctic Ocean surface or its coastal regions remains unidentified for the release of ozone-depleting halogens. There was no correspondence between coarse surface features such as solid ice/snow, open leads, or polynyas with the occurrence of or intensity of ozone depletion over the Arctic or subarctic regions. Depletion events also occurred in the absence of long-range transport of relatively fresh “pollution” within the high latitude surface layer, at least in spring 2000. Direct measurements of halogen radicals were not made. However, the flights do provide detailed information on the vertical structure of the surface layer and, during the constant 30 m altitude legs, measurements of a variety of constituents including hydroxyl and peroxy radicals. A summary of the behavior of these constituents is made. The measurements were consistent with a source of formaldehyde from the snow/ice surface. Median NOx in the surface layer was 15 pptv or less, suggesting that surface emissions were substantially converted to reservoir constituents by 30 m altitude and that ozone production rates were small (0.15–1.5 ppbv/d) at this altitude. Peroxyacetylnitrate (PAN) was by far the major constituent of NOy in the surface layer independent of the ozone mixing ratio