11,923 research outputs found
Acute vascular insufficiency in the lower extremities associated with methysergide therapy for migraine
No Abstract
Stakeholder perspectives on the development of a virtual clinic for diabetes care : qualitative study
Background: The development of the Internet has created new opportunities for health care provision, including its use as a
tool to aid the self-management of chronic conditions. We studied stakeholder reactions to an Internet-based âvirtual clinic,â
which would allow people with diabetes to communicate with their health care providers, find information about their condition,
and share information and support with other users.
Objective: The aim of the study was to present the results of a detailed consultation with a variety of stakeholder groups in
order to identify what they regard as the desirable, important, and feasible characteristics of an Internet-based intervention to aid
diabetes self-management.
Methods: Three focus groups were conducted with 12 people with type 1 diabetes who used insulin pumps. Participants were
recruited through a local diabetes clinic. One-on-one interviews were conducted with 5 health care professionals from the same
clinic (2 doctors, 2 nurses, 1 dietitian) and with 1 representative of an insulin pump company. We gathered patient consensus via
email on the important and useful features of Internet-based systems used for other chronic conditions (asthma, epilepsy, myalgic
encephalopathy, mental health problems). A workshop to gather expert consensus on the use of information technology to improve
the care of young people with diabetes was organized.
Results: Stakeholder groups identified the following important characteristics of an Internet-based virtual clinic: being grounded
on personal needs rather than only providing general information; having the facility to communicate with, and learn from, peers;
providing information on the latest developments and news in diabetes; being quick and easy to use. This paper discusses these
characteristics in light of a review of the relevant literature. The development of a virtual clinic for diabetes that embodies these
principles, and that is based on self-efficacy theory, is described.
Conclusions: Involvement of stakeholders is vital early in the development of a complex intervention. Stakeholders have clear
and relevant views on what a virtual clinic system should provide, and these views can be captured and synthesized with relative
ease. This work has led to the design of a system that is able to meet user needs and is currently being evaluated in a pilot study
Endonuclease-resistant apyrimidinic sites formed by neocarzinostatin at cytosine residues in DNA: evidence for a possible role in mutagenesis.
Suppression of geometrical barrier in crystals by Josephson vortex stacks
Differential magneto-optics are used to study the effect of dc in-plane
magnetic field on hysteretic behavior due to geometrical barriers in
crystals. In absence of in-plane field a vortex
dome is visualized in the sample center surrounded by barrier-dominated
flux-free regions. With in-plane field, stacks of Josephson vortices form
vortex chains which are surprisingly found to protrude out of the dome into the
vortex-free regions. The chains are imaged to extend up to the sample edges,
thus providing easy channels for vortex entry and for drain of the dome through
geometrical barrier, suppressing the magnetic hysteresis. Reduction of the
vortex energy due to crossing with Josephson vortices is evaluated to be about
two orders of magnitude too small to account for the formation of the
protruding chains. We present a model and numerical calculations that
qualitatively describe the observed phenomena by taking into account the
demagnetization effects in which flux expulsion from the pristine regions
results in vortex focusing and in the chain protrusion. Comparative
measurements on a sample with narrow etched grooves provide further support to
the proposed model.Comment: 12 figures (low res.) Higher resolution figures are available at the
Phys Rev B version. Typos correcte
Evidence of Skyrmion excitations about in n-Modulation Doped Single Quantum Wells by Inter-band Optical Transmission
We observe a dramatic reduction in the degree of spin-polarization of a
two-dimensional electron gas in a magnetic field when the Fermi energy moves
off the mid-point of the spin-gap of the lowest Landau level, . This
rapid decay of spin alignment to an unpolarized state occurs over small changes
to both higher and lower magnetic field. The degree of electron spin
polarization as a function of is measured through the magneto-absorption
spectra which distinguish the occupancy of the two electron spin states. The
data provide experimental evidence for the presence of Skyrmion excitations
where exchange energy dominates Zeeman energy in the integer quantum Hall
regime at
The Origin of the Electromagnetic Interaction in Einstein's Unified Field Theory with Sources
Einstein's unified field theory is extended by the addition of matter terms
in the form of a symmetric energy tensor and of two conserved currents. From
the field equations and from the conservation identities emerges the picture of
a gravoelectrodynamics in a dynamically polarizable Riemannian continuum.
Through an approximate calculation exploiting this dynamical polarizability it
is argued that ordinary electromagnetism may be contained in the theory.Comment: 8 pages. Misprint in eq. 15 correcte
A Framework for the Game-theoretic Analysis of Censorship Resistance
We present a game-theoretic analysis of optimal solutions for interactions between censors and censorship resistance systems (CRSs) by focusing on the data channel used by the CRS to smuggle clientsâ data past the censors. This analysis leverages the inherent errors (false positives and negatives) made by the censor when trying to classify traffic as either non-circumvention traffic or as CRS traffic, as well as the underlying rate of CRS traffic. We identify Nash equilibrium solutions for several simple censorship scenarios and then extend those findings to more complex scenarios where we find that the deployment of a censorship apparatus does not qualitatively change the equilibrium solutions, but rather only affects the amount of traffic a CRS can support before being blocked. By leveraging these findings, we describe a general framework for exploring and identifying optimal strategies for the censorship circumventor, in order to maximize the amount of CRS traffic not blocked by the censor. We use this framework to analyze several scenarios with multiple data-channel protocols used as cover for the CRS. We show that it is possible to gain insights through this framework even without perfect knowledge of the censorâs (secret) values for the parameters in their utility function
NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist
Tables of ^1H and ^(13)C NMR chemical shifts have been compiled for common organic compounds often used as reagents or found as products or contaminants in deuterated organic solvents. Building upon the work of Gottlieb, Kotlyar, and Nudelman in the Journal of Organic Chemistry, signals for common impurities are now reported in additional NMR solvents (tetrahydrofuran-d_8, toluene-d_8, dichloromethane-d_2, chlorobenzene-d_5, and 2,2,2-trifluoroethanol-d_3) which are frequently used in organometallic laboratories. Chemical shifts for other organics which are often used as reagents or internal standards or are found as products in organometallic chemistry are also reported for all the listed solvents
Extended Gaussian wave packet dynamics
We examine an extension to the theory of Gaussian wave packet dynamics in a
one-dimensional potential by means of a sequence of time dependent displacement
and squeezing transformations. Exact expressions for the quantum dynamics are
found, and relationships are explored between the squeezed system, Gaussian
wave packet dynamics, the time dependent harmonic oscillator, and wave packet
dynamics in a Gauss-Hermite basis. Expressions are given for the matrix
elements of the potential in some simple cases. Several examples are given,
including the propagation of a non-Gaussian initial state in a Morse potential
Speckle Interferometry of Metal-Poor Stars in the Solar Neighborhood. I
We report the results of speckle-interferometric observations of 109 high
proper-motion metal-poor stars made with the 6-m telescope of the Special
Astrophysical Observatory of the Russian Academy of Sciences. We resolve eight
objects -- G102-20, G191-55, BD+19~1185A, G89-14, G87-45, G87-47,
G111-38, and G114-25 -- into individual components and we are the first to
astrometrically resolve seven of these stars. New resolved systems included two
triple (G111-38, G87-47) and one quadruple (G89-14) star. The ratio of
single-to-binary-to-triple-to-quadruple systems among the stars of our sample
is equal to 71:28:6:1.Comment: 8 pages, 4 figures, accepted to Astrophysical Bulleti
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