Internal-quantum-state engineering using magnetic fields

We present a general, semi-classical theory describing the interaction of an atom with an internal state consisting of a number of degenerate energy levels with static and oscillating magnetic fields. This general theory is applied to the 3P2 metastable energy level of neon to determine the dynamics of the populations and coherences that are formed due to the interaction. Through these calculations we demonstrate how the interaction may be used for the internal state preparation of an atom

3D ultrasound reconstruction of sonographic callus:a novel imaging modality for early evaluation of fracture healing

AIMS: The aim of this study was to establish a reliable method for producing 3D reconstruction of sonographic callus. METHODS: A cohort of ten closed tibial shaft fractures managed with intramedullary nailing underwent ultrasound scanning at two, six, and 12 weeks post-surgery. Ultrasound capture was performed using infrared tracking technology to map each image to a 3D lattice. Using echo intensity, semi-automated mapping was performed to produce an anatomical 3D representation of the fracture site. Two reviewers independently performed 3D reconstructions and kappa coefficient was used to determine agreement. A further validation study was undertaken with ten reviewers to estimate the clinical application of this imaging technique using the intraclass correlation coefficient (ICC). RESULTS: Nine of the ten patients achieved union at six months. At six weeks, seven patients had bridging callus of ≥ one cortex on the 3D reconstruction and when present all achieved union. Compared to six-week radiographs, no bridging callus was present in any patient. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8% sensitive and 100% specific to predict union). At 12 weeks, nine patients had bridging callus at ≥ one cortex on 3D reconstruction (100%-sensitive and 100%-specific to predict union). Presence of sonographic bridging callus on 3D reconstruction demonstrated excellent reviewer agreement on ICC at 0.87 (95% confidence interval 0.74 to 0.96). CONCLUSION: 3D fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to enhance the usability and accuracy of identification of early fracture healing. Cite this article: Bone Joint Res 2021;10(12):759–766

The Opacity of Nearby Galaxies from Counts of Background Galaxies: II. Limits of the Synthetic Field Method

Recently, we have developed and calibrated the Synthetic Field Method (SFM) to derive the total extinction through disk galaxies. The method is based on the number counts and colors of distant background field galaxies that can be seen through the foreground object, and has been successfully applied to NGC 4536 and NGC 3664, two late-type galaxies located, respectively, at 16 and 11 Mpc. Here, we study the applicability of the SFM to HST images of galaxies in the Local Group, and show that background galaxies cannot be easily identified through these nearby objects, even with the best resolution available today. In the case of M 31, each pixel in the HST images contains 50 to 100 stars, and the background galaxies cannot be seen because of the intrinsic granularity due to strong surface brightness fluctuations. In the LMC, on the other hand, there is only about one star every six linear pixels, and the lack of detectable background galaxies results from a ``secondary'' granularity, introduced by structure in the wings of the point spread function. The success of the SFM in NGC 4536 and NGC 3664 is a natural consequence of the reduction of the intensity of surface brightness fluctuations with distance. When the dominant confusion factor is structure in the PSF wings, as is the case of HST images of the LMC, and would happen in M 31 images obtained with a 10-m diffraction- limited optical telescope, it becomes in principle possible to improve the detectability of background galaxies by subtracting the stars in the foreground object. However, a much better characterization of optical PSFs than is currently available would be required for an adequate subtraction of the wings. Given the importance of determining the dust content of Local Group galaxies, efforts should be made in that direction.Comment: 45 pages, 10 Postscript figure

The Opacity of Spiral Galaxy Disks VIII: Structure of the Cold ISM

The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper, we compare two techniques, one based on emission and one on absorption, applied on sections of fourteen disk galaxies. The two measurements reflect, respectively the average and apparent optical depth of a disk section. Hence, they depend differently on the average number and optical depth of ISM structures in the disk. The small scale geometry of the cold ISM is critical for accurate models of the overall energy budget of spiral disks. ISM geometry, relative contributions of different stellar populations and dust emissivity are all free parameters in galaxy Spectral Energy Distribution (SED) models; they are also sometimes degenerate, depending on wavelength coverage. Our aim is to constrain typical ISM geometry. The apparent optical depth measurement comes from the number of distant galaxies seen in HST images through the foreground disk. We measure the IR flux in images from the {\it Spitzer} Infrared Nearby Galaxy Survey in the same section of the disk that was covered by HST. A physical model of the dust is fit to the SED to estimate the dust surface density, mean temperature, and brightness in these disk sections. The surface density is subsequently converted into the average optical depth estimate. The two measurements generally agree. The ratios between the measured average and apparent optical depths of the disk sections imply optically thin clouds in these disks. Optically thick disks, are likely to have more than a single cloud along the line-of-sight.Comment: 31 pages, 5 figures, 4 tables, accepted for publication in A

Problematizing Choice: Responsible consumers and sceptical citizens

About the book: Governance, Consumers and Citizens is the first book to bring together a study of governance with consumption, examining the changing place of the consumer as citizen in recent trends in governance, the tensions between competing ideas and practices of consumerism and the active role consumers play in the construction and practice of governance. Radically pushing forward the debate on consumers and governance, this collection outlines new conceptions and posits new policy agendas. Bringing together international experts from political science, history, geography, social policy and media studies, this study shows how governance and consumption are intertwined in crucial aspects of public policy and contemporary politics

Pillared two-dimensional metal-organic frameworks based on a lower-rim acid appended calix[4]arene

Solvothermal reactions of the lower-rim functionalized diacid calix[4]arene 25,27-bis(methoxycarboxylic acid)-26,28-dihydroxy-4-tert-butylcalix[4]arene (LH₂) with Zn(NO₃)₂•6H₂O and the dipyridyl ligands 4,4/-bipyridyl (4,4/-bipy), 1,2-di(4-pyridyl)ethylene (DPE) or 4,4/-azopyridyl (4,4/-azopy) afforded a series of 2-D structures of the formulae {[Zn(4,4/-bipy)(L)]•2¼DEF}n (1), {[Zn₂(L)(DPE)]•DEF}n (2) and {[Zn(OH₂)₂(L)(4,4/-azopy)]•DEF}n (3) (DEF = diethylformamide)

The Rachel Carson Letters and the Making of Silent Spring

Environment, conservation, green, and kindred movements look back to Rachel Carson’s 1962 book Silent Spring as a milestone. The impact of the book, including on government, industry, and civil society, was immediate and substantial, and has been extensively described; however, the provenance of the book has been less thoroughly examined. Using Carson’s personal correspondence, this paper reveals that the primary source for Carson’s book was the extensive evidence and contacts compiled by two biodynamic farmers, Marjorie Spock and Mary T. Richards, of Long Island, New York. Their evidence was compiled for a suite of legal actions (1957-1960) against the U.S. Government and that contested the aerial spraying of dichlorodiphenyltrichloroethane (DDT). During Rudolf Steiner’s lifetime, Spock and Richards both studied at Steiner’s Goetheanum, the headquarters of Anthroposophy, located in Dornach, Switzerland. Spock and Richards were prominent U.S. anthroposophists, and established a biodynamic farm under the tutelage of the leading biodynamics exponent of the time, Dr. Ehrenfried Pfeiffer. When their property was under threat from a government program of DDT spraying, they brought their case, eventually lost it, in the process spent US$100,000, and compiled the evidence that they then shared with Carson, who used it, and their extensive contacts and the trial transcripts, as the primary input for Silent Spring. Carson attributed to Spock, Richards, and Pfeiffer, no credit whatsoever in her book. As a consequence, the organics movement has not received the recognition, that is its due, as the primary impulse for Silent Spring, and it is, itself, unaware of this provenance