Through the combining glass

Reflective optical combiners like beam splitters and two way mirrors are used in AR to overlap digital contents on the users' hands or bodies. Augmentations are usually unidirectional, either reflecting virtual contents on the user's body (Situated Augmented Reality) or augmenting user's reflections with digital contents (AR mirrors). But many other novel possibilities remain unexplored. For example, users' hands, reflected inside a museum AR cabinet, can allow visitors to interact with the artifacts exhibited. Projecting on the user's hands as their reflection cuts through the objects can be used to reveal objects' internals. Augmentations from both sides are blended by the combiner, so they are consistently seen by any number of users, independently of their location or, even, the side of the combiner through which they are looking. This paper explores the potential of optical combiners to merge the space in front and behind them. We present this design space, identify novel augmentations/interaction opportunities and explore the design space using three prototypes

Living with multiple myeloma: A focus group study of unmet needs and preferences for survivorship care

Purpose: To describe the unmet informational, psychological, emotional, social, practical, and physical needs and preferences for posttreatment survivorship care of individuals living with multiple myeloma to inform the development of relevant, personcentered, survivorship services. Methods: An exploratory, descriptive study using 2 focus groups with 14 participants, 6 to 49 months postdiagnosis. Results: Thematic analysis revealed 7 key themes: information needs, experience with health-care professionals, coping with side effects, communicating with family and friends, dealing with emotions, support needs, and living with the chronicity of myeloma. Participants described key characteristics of survivorship care relevant to their needs and indicated they would like a more whole of person approach to follow-up when the main treatment phases had completed. Conclusion: Participants in this study described unmet needs across a breadth of domains that varied over time. The development of flexible, person-centered approaches to comprehensive survivorship care is needed to address the considerable quality-of-life issues experienced by people living with multiple myeloma. Nurse-led care may offer 1 viable model to deliver enhanced patient experience—providing the vital “link” that people described as missing from their survivorship care

Non-existence of normal tokamak equilibria with negative central current

Recent tokamak experiments employing off-axis, non-inductive current drive have found that a large central current hole can be produced. The current density is measured to be approximately zero in this region, though in principle there was sufficient current drive power for the central current density to have gone significantly negative. Recent papers have used a large aspect-ratio expansion to show that normal MHD equilibria (with axisymmetric nested flux surfaces, non-singular fields, and monotonic peaked pressure profiles) can not exist with negative central current. We extend that proof here to arbitrary aspect ratio, using a variant of the virial theorem to derive a relatively simple integral constraint on the equilibrium. However, this constraint does not, by itself, exclude equilibria with non-nested flux surfaces, or equilibria with singular fields and/or hollow pressure profiles that may be spontaneously generated.Comment: 5 pages, 3 figures. Submitted to Physics of Plasmas, Feb. 14, 2003. Revised Feb. 24, 2003. Vers. 2: revised May 29 to clarify points raised by referee, add references to recent work. July 18, accepted for publicatio

Collecting single molecules with conventional optical tweezers

The size of particles which can be trapped in optical tweezers ranges from tens of nanometres to tens of micrometres. This size regime also includes large single molecules. Here we present experiments demonstrating that optical tweezers can be used to collect polyethylene oxide (PEO) molecules suspended in water. The molecules that accumulate in the focal volume do not aggregate and therefore represent a region of increased molecule concentration, which can be controlled by the trapping potential. We also present a model which relates the change in concentration to the trapping potential. Since many protein molecules have molecular weights for which this method is applicable the effect may be useful in assisting nucleation of protein crystals.Comment: 5 pages, 4 figure

Mode Bifurcation and Fold Points of Complex Dispersion Curves for the Metamaterial Goubau Line

In this paper the complex dispersion curves of the four lowest-order transverse magnetic modes of a dielectric Goubau line ($\epsilon>0, \mu>0$) are compared with those of a dispersive metamaterial Goubau line. The vastly different dispersion curve structure for the metamaterial Goubau line is characterized by unusual features such as mode bifurcation, complex fold points, both proper and improper complex modes, and merging of complex and real modes

Electromagnetic modes of Maxwell fisheye lens

We provide an analysis of the radial structure of TE and TM modes of the Maxwell fisheye lens, by means of Maxwell equations as applied to the fisheye case. Choosing a lens of size R = 1 cm, we plot some of the modes in the infrared range.Comment: 2+6 pages in Latex, 3 figures to be found in the published referenc

The Real Scalar Field Equation for Nariai Black Hole in the 5D Schwarzschild-de Sitter Black String Space

The Nariai black hole, whose two horizons are lying close to each other, is an extreme and important case in the research of black hole. In this paper we study the evolution of a massless scalar field scattered around in 5D Schwarzschild-de Sitter black string space. Using the method shown by Brevik and Simonsen (2001) we solve the scalar field equation as a boundary value problem, where real boundary condition is employed. Then with convenient replacement of the 5D continuous potential by square barrier, the reflection and transmission coefficients ($R, T$) are obtained. At last, we also compare the coefficients with usual 4D counterpart.Comment: 10 pages,6 figures.To appear in Int. J. Mod. Phys.

Antigenic and genetic evolution of contemporary swine H1 influenza viruses in the United States

Several lineages of influenza A viruses (IAV) currently circulate in North American pigs. Genetic diversity is further increased by transmission of IAV between swine and humans and subsequent evolution. Here, we characterized the genetic and antigenic evolution of contemporary swine H1N1 and H1N2 viruses representing clusters H1-α (1A.1), H1-β (1A.2), H1pdm (1A.3.3.2), H1-γ (1A.3.3.3), H1-δ1 (1B.2.2), and H1-δ2 (1B.2.1) currently circulating in pigs in the United States. The δ1-viruses diversified into two new genetic clades, H1-δ1a (1B.2.2.1) and H1-δ1b (1B.2.2.2), which were also antigenically distinct from the earlier H1-δ1-viruses. Further characterization revealed that a few key amino acid changes were associated with antigenic divergence in these groups. The continued genetic and antigenic evolution of contemporary H1 viruses might lead to loss of vaccine cross-protection that could lead to significant economic impact to the swine industry, and represents a challenge to public health initiatives that attempt to minimize swine-to-human IAV transmission

Efficient nonlinear room-temperature spin injection from ferromagnets into semiconductors through a modified Schottky barrier

We suggest a consistent microscopic theory of spin injection from a ferromagnet (FM) into a semiconductor (S). It describes tunneling and emission of electrons through modified FM-S Schottky barrier with an ultrathin heavily doped interfacial S layer . We calculate nonlinear spin-selective properties of such a reverse-biased FM-S junction, its nonlinear I-V characteristic, current saturation, and spin accumulation in S. We show that the spin polarization of current, spin density, and penetration length increase with the total current until saturation. We find conditions for most efficient spin injection, which are opposite to the results of previous works, since the present theory suggests using a lightly doped resistive semiconductor. It is shown that the maximal spin polarizations of current and electrons (spin accumulation) can approach 100% at room temperatures and low current density in a nondegenerate high-resistance semiconductor.Comment: 7 pages, 2 figures; provides detailed comparison with earlier works on spin injectio

Subtleties on energy calculations in the image method

In this pedagogical work we point out a subtle mistake that can be done by undergraduate or graduate students in the computation of the electrostatic energy of a system containing charges and perfect conductors if they naively use the image method. Specifically, we show that the naive expressions for the electrostatic energy for these systems obtained directly from the image method are wrong by a factor 1/2. We start our discussion with well known examples, namely, point charge-perfectly conducting wall and point charge-perfectly conducting sphere and then proceed to the demonstration of general results, valid for conductors of arbitrary shapes.Comment: 9 pages, 2 figures; Major change in this version: subsection added to Sect.4 (theorem generalization). Minor changes: title replaced; corrections to the English; some explanatory comments adde