1,394 research outputs found
The Chawton House Experience - Augmenting the Grounds of a Historic Manor House
Museum research is a burgeoning area of research where ubiquitous computing has already made an impact in enhancing user experiences. The goal of the Chawton House project is to extend this work by introducing ubicomp not to a museum as such, but a historic English manor house and its grounds. This presents a number of novel challenges relating to the kinds of visitors, the nature of visits, the specific character of the estate, the creation of a persistent and evolving system, and the process of developing it together with Chawton House staff
Estimating within-household contact networks from egocentric data
Acute respiratory diseases are transmitted over networks of social contacts.
Large-scale simulation models are used to predict epidemic dynamics and
evaluate the impact of various interventions, but the contact behavior in these
models is based on simplistic and strong assumptions which are not informed by
survey data. These assumptions are also used for estimating transmission
measures such as the basic reproductive number and secondary attack rates.
Development of methodology to infer contact networks from survey data could
improve these models and estimation methods. We contribute to this area by
developing a model of within-household social contacts and using it to analyze
the Belgian POLYMOD data set, which contains detailed diaries of social
contacts in a 24-hour period. We model dependency in contact behavior through a
latent variable indicating which household members are at home. We estimate
age-specific probabilities of being at home and age-specific probabilities of
contact conditional on two members being at home. Our results differ from the
standard random mixing assumption. In addition, we find that the probability
that all members contact each other on a given day is fairly low: 0.49 for
households with two 0--5 year olds and two 19--35 year olds, and 0.36 for
households with two 12--18 year olds and two 36+ year olds. We find higher
contact rates in households with 2--3 members, helping explain the higher
influenza secondary attack rates found in households of this size.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS474 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Estimating within-school contact networks to understand influenza transmission
Many epidemic models approximate social contact behavior by assuming random
mixing within mixing groups (e.g., homes, schools and workplaces). The effect
of more realistic social network structure on estimates of epidemic parameters
is an open area of exploration. We develop a detailed statistical model to
estimate the social contact network within a high school using friendship
network data and a survey of contact behavior. Our contact network model
includes classroom structure, longer durations of contacts to friends than
nonfriends and more frequent contacts with friends, based on reports in the
contact survey. We performed simulation studies to explore which network
structures are relevant to influenza transmission. These studies yield two key
findings. First, we found that the friendship network structure important to
the transmission process can be adequately represented by a dyad-independent
exponential random graph model (ERGM). This means that individual-level sampled
data is sufficient to characterize the entire friendship network. Second, we
found that contact behavior was adequately represented by a static rather than
dynamic contact network.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS505 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Using a hypothetical scenario to assess public preferences for colorectal surveillance following screening-detected, intermediate-risk adenomas: annual home-based stool test vs. triennial colonoscopy
Background To assess public preferences for colorectal cancer (CRC) surveillance tests for intermediate-risk adenomas, using a hypothetical scenario. Methods Adults aged 45–54 years without CRC were identified from three General Practices in England (two in Cumbria, one in London). A postal survey was carried out during a separate study on preferences for different first-line CRC screening modalities (non- or full-laxative computed tomographic colonography, flexible sigmoidoscopy, or colonoscopy). Individuals were allocated at random to receive a pack containing information on one first-line test, and a paragraph describing CRC surveillance recommendations for people who are diagnosed with intermediate-risk adenomas during screening. All participants received a description of two surveillance options: annual single-sample, home-based stool testing (consistent with Faecal Immunochemical Tests; FIT) or triennial colonoscopy. Invitees were asked to imagine they had been diagnosed with intermediate-risk adenomas, and then complete a questionnaire on their surveillance preferences. Results 22.1 % (686/3,100) questionnaires were returned. 491 (15.8 %) were eligible for analysis. The majority of participants stated a surveillance preference for the stool test over colonoscopy (60.8 % vs 31.0 %; no preference: 8.1 %; no surveillance: 0.2 %). Women were more likely to prefer the stool test than men (66.7 % vs. 53.6 %; p = .011). The primary reason for preferring the stool test was that it would be done more frequently. The main reason to prefer colonoscopy was its superiority at finding polyps. Conclusions A majority of participants stated a preference for a surveillance test resembling FIT over colonoscopy. Future research should test whether this translates to greater adherence in a real surveillance setting
Estimating Influenza Vaccine Efficacy From Challenge and Community-based Study Data
In this paper, the authors provide estimates of 4 measures of vaccine efficacy for live, attenuated and inactivated influenza vaccine based on secondary analysis of 5 experimental influenza challenge studies in seronegative adults and community-based vaccine trials. The 4 vaccine efficacy measures are for susceptibility (VES), symptomatic illness given infection (VEP), infection and illness (VESP), and infectiousness (VEI). The authors also propose a combined (VEC) measure of the reduction in transmission in the entire population based on all of the above efficacy measures. Live influenza vaccine and inactivated vaccine provided similar protection against laboratory-confirmed infection (for live vaccine: VES = 41%, 95% confidence interval (CI): 15, 66; for inactivated vaccine: VES = 43%, 95% CI: 8, 79). Live vaccine had a higher efficacy for illness given infection (VEP = 67%, 95% CI: 24, 100) than inactivated vaccine (VEP = 29%, 95% CI: −19, 76), although the difference was not statistically significant. VESP for the live vaccine was higher than for the inactivated vaccine. VEI estimates were particularly low for these influenza vaccines. VESP and VEC can remain high for both vaccines, even when VEI is relatively low, as long as the other 2 measures of vaccine efficacy are relatively high
Impact of spatiotemporal heterogeneity in heat pump loads on generation and storage requirements
This paper investigates how spatiotemporal heterogeneity in inflexible
residential heat pump loads affects the need for storage and generation in the
electricity system under business-as-usual and low-carbon emissions budgets.
Homogeneous and heterogeneous heat pump loads are generated using
population-weighted average and local temperature, respectively, assuming
complete residential heat pump penetration. The results of a storage and
generation optimal expansion model with network effects for spatiotemporally
homogeneous and heterogeneous load profiles are compared. A case study is
performed using a 3-bus network of London, Manchester, and Glasgow in Britain
for load and weather data for representative weeks. Using heterogeneous heating
demand data changes storage sizing: under a business-as-usual budget, 26% more
total storage is built on an energy and power basis, and this storage is
distributed among all of the buses in the heterogeneous case. Under a
low-carbon budget, total energy storage at all buses increases 2 times on an
energy basis and 40% on a power basis. The energy to power ratio of storage at
each bus also increases when accounting for heterogeneity; this change suggests
that storage will be needed to provide energy support in addition to power
support for electric heating in high-renewable power systems. Accounting for
heterogeneity also increases modeled systems costs, particularly capital costs,
because of the need for higher generation capacity in the largest load center
and coincidence of local peak demand at different buses. These results show the
importance of accounting for heat pump load heterogeneity in power system
planning.Comment: 6 pages, 4 figures, to be published in the proceedings of the IEEE
Power and Energy Society General Meeting 202
Data-based, high spatiotemporal resolution heat pump demand for power system planning
Decarbonizing the residential building sector by replacing gas boilers with electric heat pumps will dramatically
increase electricity demand. Existing models of future heat pump demand either use daily heating demand
profiles that do not capture heat pump use or do not represent sub-national heating demand variation. This
work presents a novel method to generate high spatiotemporal resolution residential heat pump demand
profiles based on heat pump field trial data. These spatially varied demand profiles are integrated into
a generation, storage, and transmission expansion planning model to assess the impact of spatiotemporal
variations in heat pump demand. This method is demonstrated and validated using the British power system in
the United Kingdom (UK), and the results are compared with those obtained using spatially uniform demand
profiles. The results show that while spatially uniform heating demand can be used to estimate peak and total
annual heating demand and grid-wide systems cost, high spatiotemporal resolution heating demand data is
crucial for spatial power system planning. Using spatially uniform heating demand profiles leads to 15.1 GW
of misplaced generation and storage capacity for a 90% carbon emission reduction from 2019. For a 99%
reduction in carbon emissions, the misallocated capacity increases to 16.9-23.9 GW. Meeting spatially varied
heating load with the system planned for uniform national heating demand leads to 5% higher operational
costs for a 90% carbon emission reduction. These results suggest that high spatiotemporal resolution heating
demand data is especially important for planning bulk power systems with high shares of renewable generation
The role of 1,25-dihydroxyvitamin D in the inhibition of bone formation induced by skeletal unloading
Skeletal unloading results in osteopenia. To examine the involvement of vitamin D in this process, the rear limbs of growing rats were unloaded and alterations in bone calcium and bone histology were related to changes in serum calcium (Ca), inorganic phosphorus (P sub i), 25-hydroxyvitamin D (25-OH-D), 24,25-dihydroxyvitamin D (24,25(OH)2D and 1,25-dihydroxyvitamin D (1,25(OH)2D. Acute skeletal unloading induced a transitory inhibition of Ca accumulation in unloaded bones. This was accompanied by a transitory rise in serum Ca, a 21% decrease in longitudinal bone growth (P 0.01), a 32% decrease in bone surface lined with osteoblasts (P .05), no change in bone surface lined with osteoclasts and a decrease in circulating (1,25(OH)2D. No significant changes in the serum concentrations of P sub i, 25-OH-D or 24,25(OH)2D were observed. After 2 weeks of unloading, bone Ca stabilized at approximately 70% of control and serum Ca and 1,25(OH)2D returned to control values. Maintenance of a constant serum 1,25(OH)2D concentration by chronic infusion of 1,25(OH)2D (Alza osmotic minipump) throughout the study period did not prevent the bone changes induced by acute unloading. These results suggest that acute skeletal unloading in the growing rat produces a transitory inhibition of bone formation which in turn produces a transitory hypercalcemia
A Reusable, Extensible Infrastructure for Augmented Field Trips
This paper describes a reusable pervasive information infrastructure developed as part of the Equator IRC, designed to allow the construction of literacy based eLearning activities on top of material created as part of a more traditional visitors system. The architecture of the system is described along with details of the creation of the curated material and the subsequent adaption of the system by local primary school teachers to create a literacy experiences. Results of the first trials of the system are presented with conclusions drawn and discussion of future directions
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