10,374 research outputs found
Singular Behavior of Eigenstates in Anderson's Model of Localization
We observe a singularity in the electronic properties of the Anderson Model
of Localization with bounded diagonal disorder, which is clearly distinct from
the well-established mobility edge (localization-delocalization transition)
that occurs in dimensions . We present results of numerical calculations
for Anderson's original (box) distribution of onsite disorder in dimensions
= 1, 2 and 3. To establish this hitherto unreported behavior, and to understand
its evolution with disorder, we contrast the behavior of two different measures
of the localization length of the electronic wavefunctions - the averaged
inverse participation ratio and the Lyapunov exponent. Our data suggest that
Anderson's model exhibits richer behavior than has been established so far.Comment: Correction to v1: Fig.3 caption now displaye
Beurling algebra analogues of the classical theorems of Wiener and Levy on absolutely convergent Fourier series
Let be a continuous function on the unit circle , whose Fourier
series is -absolutely convergent for some weight on the set of
integers . If is nowhere vanishing on , then there
exists a weight on such that had -absolutely
convergent Fourier series. This includes Wiener's classical theorem. As a
corollary, it follows that if is holomorphic on a neighbourhood of the
range of , then there exists a weight on such that
\hbox{} has -absolutely convergent Fourier series. This is a
weighted analogue of L\'{e}vy's generalization of Wiener's theorem. In the
theorems, and are non-constant if and only if is
non-constant. In general, the results fail if or is required to be
the same weight .Comment: 4 page
The Augustan Principate and the Emergence of Biopolitics: A Comparative Historical Perspective
This paper uses Foucault’s concepts “discipline” and “biopower” to expose the complexity of power relations in Augustan Rome and its historiography. Focusing on Augustus’ Res Gestae and Tacitus’ Annales, I argue that the absolute sovereignty of the emperor did not preclude the advancement of techniques to classify, hierarchize and normalize individuals, nor did Imperial sovereignty work against the development of a discourse about the enhancement and protection of the population. By demonstrating the conceptual and historical relevancy of Foucault’s modern power triad of “sovereignty-discipline-government” to first century CE Rome, the paper suggests that biopolitical societies have a far more extensive history than the one said to have started around the turn of the eighteenth century
NGC 7419: A young open cluster with a number of very young intermediate mass pre-MS stars
We present a photometric and spectroscopic study of the young open cluster
NGC 7419, which is know to host a large number of classical Be stars for
reasons not well understood. Based on CCD photometric observations of 327 stars
in UBV passbands, we estimated the cluster parameters as, reddening E(B-V) =
1.65 +/- 0.15 mag and distance = 2900 +/- 400 pc. The turn off age of the
cluster was estimated as 25 +/- 5 Myr using isochrone fits. UBV data of the
stars were combined with JHK data from 2MASS and were used to create the near
infrared (NIR) (J-H) vs (H-K) colour-colour diagram. A large fraction of stars
(42%) was found to have NIR excess and their location in the diagram was used
to identify them as intermediate mass pre-MS stars. The isochrone fits to
pre-MS stars in the optical colour-magnitude diagram showed that the turn-on
age of the cluster is 0.3 - 3 Myr. This indicates that there has been a recent
episode of star formation in the vicinity of the cluster. Slit-less spectra
were used to identify 27 stars which showed H-alpha in emission in the field of
the cluster, of which 6 are new identifications. All these stars were found to
show NIR excess and located closer to the region populated by Herbig Ae/Be
stars in the (J-H) vs (H-K) diagram. Slit spectra of 25 stars were obtained in
the region 3700A - 9000A. The spectral features were found to be very similar
to those of Herbig Be stars. Those stars were found to be more reddened than
the main sequence stars by 0.4 mag on an average. Thus the emission line stars
found in this cluster are more similar to the Herbig Be type stars where the
circumstellar material is the remnant of the accretion disk.Comment: 20 pages, 11 figures, Accepted for publishing in MNRAS on April 19,
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An interactive tool for real time feedback on diagnosis and treatment plan of arthritis based on C++ programing language
Arthritis causes joint inflammation where body’s immunity against disease or injury becomes overactive leading to swelling, pain and stiffness and it also can lead to tissue damage. Anatomically, arthritis usually affects the synovial joints in majority where the articular bones are covered by hyaline cartilages. The clinically significant arthritis are Osteoarthritis, Rheumatoid Arthritis, Septic arthritis and Juvenile Arthritis which features pain in the joints and typically worsen with age. Since the clinical burden due to arthritis is huge and due to the difficulties in proper differentiation and diagnosis of a particular arthritis, the examiner should determine the nature of the underlying pathologic process. Arthritis can be infectious (infection with Neisseria gonorrhea or Mycobacterium tuberculosis), crystal-induced (gout, pseudo-gout), immune-related [rheumatoid arthritis (RA), systemic lupus erythematous (SLE)], reactive (rheumatic fever, Reiter's syndrome), or idiopathic. Current project imposes the use of C++ programming language in order to construct an interactive platform for the diagnosis and treatment of Arthritis. Huge amount of work has been done on various diseases to design a platform where on the basis of symptoms, diseases can be treated promptly; however, in the field of arthritis, study is lacking. Briefly, an algorithm was prepared for classifying the types of arthritis based upon the symptoms and signs as obtained from the patient
Understanding the effectiveness of government interventions against the resurgence of COVID-19 in Europe
As European governments face resurging waves of COVID-19, non-pharmaceutical interventions (NPIs) continue to be the primary tool for infection control. However, updated estimates of their relative effectiveness have been absent for Europe’s second wave, largely due to a lack of collated data that considers the increased subnational variation and diversity of NPIs. We collect the largest dataset of NPI implementation dates in Europe, spanning 114 subnational areas in 7 countries, with a systematic categorisation of interventions tailored to the second wave. Using a hierarchical Bayesian transmission model, we estimate the effectiveness of 17 NPIs from local case and death data. We manually validate the data, address limitations in modelling from previous studies, and extensively test the robustness of our estimates. The combined effect of all NPIs was smaller relative to estimates from the first half of 2020, indicating the strong influence of safety measures and individual protective behaviours--such as distancing--that persisted after the first wave. Closing specific businesses was highly effective. Gathering restrictions were highly effective but only for the strictest limits. We find smaller effects for closing educational institutions compared to the first wave, suggesting that safer operation of schools was possible with a set of stringent safety measures including testing and tracing, preventing mixing, and smaller classes. These results underscore that effectiveness estimates from the early stage of an epidemic are measured relative to pre-pandemic behaviour. Updated estimates are required to inform policy in an ongoing pandemic
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