11,753 research outputs found
Exploring Research through Design in Animal-Computer Interaction
This paper explores Research through Design (RtD) as a potential methodology for developing new interactive experiences for animals. We present an example study from an on-going project and examine whether RtD offers an appropriate framework for developing knowledge in the context of Animal-Computer Interaction, as well as considering how best to document such work. We discuss the design journey we undertook to develop interactive systems for captive elephants and the extent to which RtD has enabled us to explore concept development and documentation of research. As a result of our explorations, we propose that particular aspects of RtD can help ACI researchers gain fresh perspectives on the design of technology-enabled devices for non-human animals. We argue that these methods of working can support the investigation of particular and complex situations where no idiomatic interactions yet exist, where collaborative practice is desirable and where the designed objects themselves offer a conceptual window for future research and development
Intruder States and their Local Effect on Spectral Statistics
The effect on spectral statistics and on the revival probability of intruder
states in a random background is analysed numerically and with perturbative
methods. For random coupling the intruder does not affect the GOE spectral
statistics of the background significantly, while a constant coupling causes
very strong correlations at short range with a fourth power dependence of the
spectral two-point function at the origin.The revival probability is
significantly depressed for constant coupling as compared to random coupling.Comment: 18 pages, 10 Postscript figure
Diminishing Use of Liver Biopsy among Liver Transplant Recipients for Hepatitis C.
Background and Aims: Hepatitis C virus (HCV) cirrhosis is the leading indication for liver transplantation in the United States and recurrent HCV following liver transplantation is a major cause of allograft loss and mortality. Liver biopsies are commonly used to identify recurrent HCV and determine the need for antiviral therapy. The introduction of direct-acting antiviral agents (DAAs) has changed the management of recurrent HCV infection. This study aimed to describe the role of liver biopsies in liver transplant recipients with HCV after the introduction of DAAs. Methods: A retrospective analysis was performed looking at the rate of liver biopsies post-liver transplantation for HCV. The analysis included 475 adult liver transplants for hepatitis C performed at the University of California, Los Angeles from January 1, 2006 to October 1, 2015. Patients were divided into two eras, pre- and post-introduction of DAAs on December 1, 2013. Results: In the era before the introduction of DAAs, the percentage of patients biopsied was significantly higher compared to the era after the introduction of DAAs (56.1% vs. 26.9%, p < 0.001). Conclusions: The introduction of DAAs has changed the management of liver biopsy following liver transplantation and the management of recurrent HCV. Given that DAAs are well tolerated and have high efficacy, liver biopsies are no longer routinely used to justify the use antiviral therapy following liver transplantation
Social capital, deprivation and self-rated health: Does reporting heterogeneity play a role? Results from the English Longitudinal Study of Ageing
Self-rated health (SRH) is commonly assessed in large surveys, though responses can be influenced by different individuals' perceptions of and beliefs about health. Therefore, instead of providing evidence of ‘true’ health disparities across groups, findings may actually reflect reporting heterogeneity.
Using data from participants aged 50 years and older from the English Longitudinal Study of Ageing (ELSA) Wave 3 (2006/07; participation rate = 73%), associations between three dimensions of social capital (local area & trust, social support and social networks), deprivation and SRH were examined using the vignette methodology in 2341 individuals who completed both the self-report and at least one of the 18 vignettes. Analysis employed a hierarchical probit model (HOPIT).
Individuals expressing low local area & trust social capital (beta = −0.276, p < 0.001) and those with poor social networks (beta = −0.280, p < 0.001) were more likely to report poor SRH in HOPIT models accounting for reporting heterogeneity, but unadjusted ordered probit analyses still correctly show a negative relationship between low local area & trust social capital (beta = −0.243, p < 0.001) and those with poor social networks (beta = −0.210, p < 0.01), though they somewhat tend to underestimate its strength. Neither social support nor deprivation appeared to have any effect on SRH regardless of reporting heterogeneity.
Anchoring vignettes offer a relatively uncomplicated and cost-effective way of identifying and correcting for reporting heterogeneity to improve comparative validity of self-report measures of health. This analysis underlines the need for caution when using unadjusted self-reported measures to study the effects of social capital on health
The motion of two masses coupled to a massive spring
We discuss the classical motion of a spring of arbitrary mass coupled to two
arbitrary massive blocks attached at its ends. A general approach to the
problem is presented and some general results are obtained. Examples for which
a simple elastic function can be inferred are discussed and the normal modes
and normal frequencies obtained. An approximation procedure to the evaluation
of the normel frequencies in the case of uniform elastic function and mass
density is also discussed.Comment: Standard Latex file plus three eps figure
Interactions and Disorder in Quantum Dots: Instabilities and Phase Transitions
Using a fermionic renormalization group approach we analyse a model where the
electrons diffusing on a quantum dot interact via Fermi-liquid interactions.
Describing the single-particle states by Random Matrix Theory, we find that
interactions can induce phase transitions (or crossovers for finite systems) to
regimes where fluctuations and collective effects dominate at low energies.
Implications for experiments and numerical work on quantum dots are discussed.Comment: 4 pages, 1 figure; version to appear in Phys Rev Letter
Estimating the nuclear level density with the Monte Carlo shell model
A method for making realistic estimates of the density of levels in even-even
nuclei is presented making use of the Monte Carlo shell model (MCSM). The
procedure follows three basic steps: (1) computation of the thermal energy with
the MCSM, (2) evaluation of the partition function by integrating the thermal
energy, and (3) evaluating the level density by performing the inverse Laplace
transform of the partition function using Maximum Entropy reconstruction
techniques. It is found that results obtained with schematic interactions,
which do not have a sign problem in the MCSM, compare well with realistic
shell-model interactions provided an important isospin dependence is accounted
for.Comment: 14 pages, 3 postscript figures. Latex with RevTex. Submitted as a
rapid communication to Phys. Rev.
Drying and cracking mechanisms in a starch slurry
Starch-water slurries are commonly used to study fracture dynamics. Drying
starch-cakes benefit from being simple, economical, and reproducible systems,
and have been used to model desiccation fracture in soils, thin film fracture
in paint, and columnar joints in lava. In this paper, the physical properties
of starch-water mixtures are studied, and used to interpret and develop a
multiphase transport model of drying. Starch-cakes are observed to have a
nonlinear elastic modulus, and a desiccation strain that is comparable to that
generated by their maximum achievable capillary pressure. It is shown that a
large material porosity is divided between pore spaces between starch grains,
and pores within starch grains. This division of pore space leads to two
distinct drying regimes, controlled by liquid and vapor transport of water,
respectively. The relatively unique ability for drying starch to generate
columnar fracture patterns is shown to be linked to the unusually strong
separation of these two transport mechanisms.Comment: 9 pages, 8 figures [revised in response to reviewer comments
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