2,245 research outputs found
Geometric multipartite entanglement measures
Within the framework of constructions for quantifying entanglement, we build
a natural scenario for the assembly of multipartite entanglement measures based
on Hopf bundle-like mappings obtained through Clifford algebra representations.
Then, given the non-factorizability of an arbitrary two-qubit density matrix,
we give an alternate quantity that allows the construction of two types of
entanglement measures based on their arithmetical and geometrical averages over
all pairs of qubits in a register of size N, and thus fully characterize its
degree and type of entanglement. We find that such an arithmetical average is
both additive and strongly super additive.Comment: This is the updated, finally published, versio
Qubits and chirotopes
We show that qubit and chirotope concepts are closely related. In fact, we
prove that the qubit concept leads to a generalization of the chirotope
concept, which we call qubitope. Moreover, we argue that a possible qubitope
theory may suggest interesting applications of oriented matroid theory in at
least three physical contexts, in which qubits make their appearance, namely
string theory, black holes and quantum information.Comment: 11 pages, Late
Diffuse Infiltrative Lymphocytosis Syndrome (DILS)
Diffuse infiltrative lymphocytosis syndrome (DILS) is characterised by a persistent CD8+ lymphocytosis and lymphocytic infiltration of various organs. The reported prevalence varies between 0.85 – 3%, and appears to be more common in Africans. Patients with DILS tend to have higher CD4+ cell counts and survive longer than those patients without DILS. Most patients present with bilateral parotid gland enlargement and features of the Sicca syndrome. Extraglandular involvement is common with the lungs being the most common site, followed by peripheral neuropathy and liver involvement. DILS is a benign presentation in most patients with few complications. Therapeutic trials are lacking although there are isolated reports of good response to antiretroviral and steroid therapy. With the high incidence of HIV in our population it is likely that DILS is under diagnosed probably due to our ignorance of this disease. Awareness of its various presentations may bring to light undiscovered patients with DILS. South African Family Practice Vol. 50 (2) 2008: pp. 42-4
Processing Color in Astronomical Imagery
Every year, hundreds of images from telescopes on the ground and in space are
released to the public, making their way into popular culture through
everything from computer screens to postage stamps. These images span the
entire electromagnetic spectrum from radio waves to infrared light to X-rays
and gamma rays, a majority of which is undetectable to the human eye without
technology. Once these data are collected, one or more specialists must process
the data to create an image. Therefore, the creation of astronomical imagery
involves a series of choices. How do these choices affect the comprehension of
the science behind the images? What is the best way to represent data to a
non-expert? Should these choices be based on aesthetics, scientific veracity,
or is it possible to satisfy both? This paper reviews just one choice out of
the many made by astronomical image processors: color. The choice of color is
one of the most fundamental when creating an image taken with modern
telescopes. We briefly explore the concept of the image as translation,
particularly in the case of astronomical images from invisible portions of the
electromagnetic spectrum. After placing modern astronomical imagery and
photography in general in the context of its historical beginnings, we review
the standards (or lack thereof) in making the basic choice of color. We discuss
the possible implications for selecting one color palette over another in the
context of the appropriateness of using these images as science communication
products with a specific focus on how the non-expert perceives these images and
how that affects their trust in science. Finally, we share new data sets that
begin to look at these issues in scholarly research and discuss the need for a
more robust examination of this and other related topics in the future to
better understand the implications for science communications.Comment: 10 pages, 6 figures, published in Studies in Media and Communicatio
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