5,092 research outputs found
Critical Literary Cartography: Text, Maps and a Coleridge Notebook
Mapping Cultures is a collection of essays exploring the diverse practices and cultures of mapping on the one hand, and the mapping of different forms of cultural practice on the other. The book draws on a wide range of disciplinary perspectives, including critical cartography, social anthropology, film and cultural studies, literary studies, art and visual culture, marketing, architecture, and popular music studies. Underpinning the theoretical and methodological approaches of all the contributions is a close engagement with mapping both as a mode of cultural and spatial analysis, and as a point of critical intersection in which ideas and practices of cartography are challenged, re-envisioned and brought into play with a broad range of theoretical perspectives. The collection is loosely organized around three main thematic sections: the cartographic textualities of space, landscape and place; mappings of performance and urban memoryscapes; and the practical, aesthetic and performative cartographies of critical spatial enquiry
Telegraph Hill
The essays and stories in 'Mount London' unpeel London's history, geography and psychogeography, reimagining the city as mountainous terrain and exploring what it's like to move through the urban landscape
External validation of a claims-based algorithm for classifying kidney-cancer surgeries
<p>Abstract</p> <p>Background</p> <p>Unlike other malignancies, there is no literature supporting the accuracy of medical claims data for identifying surgical treatments among patients with kidney cancer. We sought to validate externally a previously published Medicare-claims-based algorithm for classifying surgical treatments among patients with early-stage kidney cancer. To achieve this aim, we compared procedure assignments based on Medicare claims with the type of surgery specified in SEER registry data and clinical operative reports.</p> <p>Methods</p> <p>Using linked SEER-Medicare data, we calculated the agreement between Medicare claims and SEER data for identification of cancer-directed surgery among 6,515 patients diagnosed with early-stage kidney cancer. Next, for a subset of 120 cases, we determined the agreement between the claims algorithm and the medical record. Finally, using the medical record as the reference-standard, we calculated the sensitivity, specificity, and positive and negative predictive values of the claims algorithm.</p> <p>Results</p> <p>Among 6,515 cases, Medicare claims and SEER data identified 5,483 (84.1%) and 5,774 (88.6%) patients, respectively, who underwent cancer-directed surgery (observed agreement = 93%, Îș = 0.69, 95% CI 0.66 â 0.71). The two data sources demonstrated 97% agreement for classification of partial versus radical nephrectomy (Îș = 0.83, 95% CI 0.81 â 0.86). We observed 97% agreement between the claims algorithm and clinical operative reports; the positive predictive value of the claims algorithm exceeded 90% for identification of both partial nephrectomy and laparoscopic surgery.</p> <p>Conclusion</p> <p>Medicare claims represent an accurate data source for ascertainment of population-based patterns of surgical care among patients with early-stage kidney cancer.</p
From Rotating Atomic Rings to Quantum Hall States
Considerable efforts are currently devoted to the preparation of ultracold
neutral atoms in the emblematic strongly correlated quantum Hall regime. The
routes followed so far essentially rely on thermodynamics, i.e. imposing the
proper Hamiltonian and cooling the system towards its ground state. In rapidly
rotating 2D harmonic traps the role of the transverse magnetic field is played
by the angular velocity. For particle numbers significantly larger than unity,
the required angular momentum is very large and it can be obtained only for
spinning frequencies extremely near to the deconfinement limit; consequently,
the required control on experimental parameters turns out to be far too
stringent. Here we propose to follow instead a dynamic path starting from the
gas confined in a rotating ring. The large moment of inertia of the fluid
facilitates the access to states with a large angular momentum, corresponding
to a giant vortex. The initial ring-shaped trapping potential is then
adiabatically transformed into a harmonic confinement, which brings the
interacting atomic gas in the desired quantum Hall regime. We provide clear
numerical evidence that for a relatively broad range of initial angular
frequencies, the giant vortex state is adiabatically connected to the bosonic
Laughlin state, and we discuss the scaling to many particles.Comment: 9 pages, 5 figure
Spatializing and Analyzing Digital Texts: Corpora, GIS, and Places
This paper argues for Geographical Text Analysis (GTA), a new approach based on combining techniques from corpus linguistics and Geographical Information Systems (GIS). First these allow a text to be converted into a GIS. Corpus linguistics allows place-names to be extracted from texts. These place-names can then be matched to a gazetteer to provide grid references which subsequently allow the place-names to be converted into a GIS layer. Once this has been done, GTA also allows the text to summarize and analyze the geographies within the texts. These approaches can be applied to very large bodies of text, potentially millions or billions of words. We argue that this approach does not replace close reading which is more commonly used in the study of texts. Instead it allows very large volumes of text to be summarized and the close readerâs attention to be drawn to the parts of the text that are most relevant to their interest in particular places or the themes associated with these places. The implications of this approach in relation to deep mapping and literary studies are discussed
Paired and clustered quantum Hall states
We briefly summarize properties of quantum Hall states with a pairing or
clustering property. Their study employs a fundamental connection with
parafermionic Conformal Field Theories. We report on closed form expressions
for the many-body wave functions and on multiplicities of the fundamental
quasi-hole excitations.Comment: 13 pages, Contribution to the proceedings of the NATO Advanced
Research Workshop "Statistical Field Theories" Como (Italy), June 18-23 200
An evaluation of the metabolic syndrome in a large multi-ethnic study: the Family Blood Pressure Program
BACKGROUND: The Family Blood Pressure Program is an ongoing, NHLBI-sponsored, multi-center program to study the genetic determinants of high blood pressure. The goal of this particular study was to study patterns of metabolic syndrome (MetS) in four ethnic groups: African Americans, Caucasians, Hispanics, and Asians. METHODS: A major part of participants in three networks GENOA, HyperGEN and SAPPHIRe were recruited mainly through hypertensive probands. MetS was defined as a categorical trait following the National Cholesterol Education Program definition (c-MetS). MetS was also characterized quantitatively through multivariate factor analyses (FA) of 10 risk variables (q-MetS). Logistic regression and frequency tables were used for studying associations among traits. RESULTS: Using the NCEP definition, the Hispanic sample, which by design was enriched for type 2 diabetes (T2D), had a very high prevalence of MetS (73%). In contrast, its prevalence in Chinese was the lowest (17%). In African Americans and Hispanics, c-MetS was more prevalent in women than in men. Association of c-MetS with type 2 diabetes (T2D) was prominent in the Hispanics and African Americans, less pronounced in the Whites and Japanese, (although still significant), and weakest in the Chinese sample. Using FA without rotation, we found that the main factor loaded obesity (OBS) and blood pressure (BP) in African Americans; OBS and insulin (INS) in Hispanics, in Japanese, and in Whites; and OBS alone in Chinese. In Hispanics, Whites, and Japanese, BP loaded as a separate factor. Lipids in combination with INS also loaded in a separate factor. Using FA with Varimax rotation, 4 independent factors were identified: "Obesity-INS," "Blood pressure," "Lipids-INS," and "Central obesity." They explained about 60% of the variance present in the original risk variables. CONCLUSION: MetS ethnic differences were identified. Ascertaining for hypertension or T2D increased the MetS prevalence in networks compared with the one in the US general population. Obesity was the most prominent risk factor contributing to both c-MetS and q-MetS. INS contributed in two important factors (obesity and lipids). The information imbedded into c-MetS trait /q-MetS factors scores can contribute in future research of the MetS, especially its utilization in the genetic analysis
Robust optical delay lines via topological protection
Phenomena associated with topological properties of physical systems are
naturally robust against perturbations. This robustness is exemplified by
quantized conductance and edge state transport in the quantum Hall and quantum
spin Hall effects. Here we show how exploiting topological properties of
optical systems can be used to implement robust photonic devices. We
demonstrate how quantum spin Hall Hamiltonians can be created with linear
optical elements using a network of coupled resonator optical waveguides (CROW)
in two dimensions. We find that key features of quantum Hall systems, including
the characteristic Hofstadter butterfly and robust edge state transport, can be
obtained in such systems. As a specific application, we show that the
topological protection can be used to dramatically improve the performance of
optical delay lines and to overcome limitations related to disorder in photonic
technologies.Comment: 9 pages, 5 figures + 12 pages of supplementary informatio
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