3,739 research outputs found
Incidence of symptomatic toxoplasma eye disease: aetiology and public health implications.
Ocular disease is the commonest disabling consequence of toxoplasma infection. Incidence and lifetime risk of ocular symptoms were determined by ascertaining affected patients in a population-based, active reporting study involving ophthalmologists serving a population of 7.4 million. Eighty-seven symptomatic episodes were attributed to toxoplasma infection. Bilateral visual acuity of 6/12 or less was found in seven episodes (8%) and was likely to have been transient in most cases. Black people born in West Africa had a 100-fold higher incidence of symptoms than white people born in Britain. Only two patients reported symptoms before 10 years of age. The estimated lifetime risk of symptoms in British born individuals (52% of all episodes) was 18/100000 (95% confidence interval: 10.8-25.2). The low risk and mild symptoms in an unscreened British population indicate limited potential benefits of prenatal or postnatal screening. The late age at presentation suggests a mixed aetiology of postnatally acquired and congenital infection for which primary prevention may be appropriate, particularly among West Africans
Mapping Ice Sheet Grounding Lines With CryoSat-2
The boundary between grounded and floating ice is an important glaciological parameter, because it delineates the lateral extent of an ice sheet and it marks the optimal location for computing ice discharge. We present a method for detecting the grounding line as the break in ice sheet surface slope, computed from CryoSat-2 elevation measurements using a plane-fitting solution. We apply this technique to map the break in surface slope in four topographically diverse sectors of Antarctica - Filchner-Ronne Ice Shelf, Ekström Ice Shelf, Amundsen Sea sector, and the Larsen-C Ice Shelf - using CryoSat-2 observations acquired between July 2010 and May 2014. An inter-comparison of the CryoSat-2 break in surface slope with independent measurements of the hinge line determined from quadruple-difference SAR interferometry (QDInSAR) shows good overall agreement between techniques, with a mean separation of 4.5 km. In the Amundsen Sea sector, where in places over 35 km of hinge line retreat has occurred since 1992, the CryoSat-2 break in surface slope coincides with the most recent hinge line position, recorded in 2011. The technique we have developed is automatic, is computationally-efficient, can be repeated given further data, and offers a complementary tool for monitoring changes in the lateral extent of grounded ice
An empirical investigation of domestic energy data visualizations
Which device in your home uses the most electricity? Many people have a poor understanding of their domestic energy consumption. In this paper, we evaluated three data visualizations used to deliver feedback. These were: (1) an aggregated line graph – showing changes in total electricity consumption over time, (2) a disaggregated line graph – showing changes in electricity consumed over time but separated out at the appliance-level, and (3) an area-based visualization – showing the cumulative energy consumed by different appliances over a given time period. In an experiment, 65 participants used one of these three visualizations to make sense of the same pattern of domestic electricity data. Participants who used the area-based visualization gained a more accurate understanding of how much electricity different domestic appliances were using compared to participants who were shown time series data. These results suggest that the choice of data visualization will impact people's understanding from smart metering systems, and that appliance-wise disaggregation offers the most promising approach for visualizing domestic electricity consumption data
Ocular sequelae of congenital toxoplasmosis in Brazil compared with Europe
Toxoplasmic retinochoroiditis appears to be more severe in Brazil, where it is a leading cause of blindness, than in Europe, but direct comparisons are lacking. Evidence is accumulating that more virulent genotypes of Toxoplasma gondii predominate in South America
Resolution requirements for numerical simulations of transition
The resolution requirements for direct numerical simulations of transition to turbulence are investigated. A reliable resolution criterion is determined from the results of several detailed simulations of channel and boundary-layer transition
Does data visualization affect users' understanding of electricity consumption?
Different data visualizations are investigated for how they enable occupants to learn about domestic energy consumption. Smart metering can potentially encourage householders to change their behaviour and save energy. However, concerns exist about whether users understand domestic energy feedback. Two challenges are addressed: feedback displays typically show aggregate consumption and they show time-series data visualizations, which are difficult to relate to everyday actions in the household. A laboratory experiment (N = 43) assessed changes in participants’ knowledge of how much electricity everyday actions consume after being exposed to different forms of energy-consumption data visualizations: (1) an aggregated time-series line graph, (2) a disaggregated time-series line graph and (3) a normalized disaggregated visualization that deemphasized time. Participants played an energy game both before and after they saw the simulation. Participants in condition (3) were more accurate and more confident in their post-test judgments about everyday domestic electricity consumption than other participants. These findings suggest that the type of data visualization affects users’ understanding of domestic electricity consumption. The visualization of disaggregated energy feedback at the appliance level should be considered for future generations of technology
Irregular behaviour of class numbers and Euler-Kronecker constants of cyclotomic fields: the log log log devil at play
Kummer (1851) and, many years later, Ihara (2005) both posed conjectures on
invariants related to the cyclotomic field with a
prime. Kummer's conjecture concerns the asymptotic behaviour of the first
factor of the class number of and Ihara's the positivity
of the Euler-Kronecker constant of (the ratio of the
constant and the residue of the Laurent series of the Dedekind zeta function
at ). If certain standard conjectures in
analytic number theory hold true, then one can show that both conjectures are
true for a set of primes of natural density 1, but false in general.
Responsible for this are irregularities in the distribution of the primes. With
this survey we hope to convince the reader that the apparently dissimilar
mathematical objects studied by Kummer and Ihara actually display a very
similar behaviour.Comment: 20 pages, 1 figure, survey, to appear in `Irregularities in the
Distribution of Prime Numbers - Research Inspired by Maier's Matrix Method',
Eds. J. Pintz and M. Th. Rassia
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Deaths in people from Black, Asian and minority ethnic communities from both COVID-19 and non-COVID causes in the first weeks of the pandemic in London: a hospital case note review
Objective To undertake a case review of deaths in a 6-week period during the COVID-19 pandemic commencing with the first death in the hospital from COVID-19 on 12th of March 2020 and contrast this with the same period in 2019.
Setting A large London teaching hospital.
Participants Three groups were compared: group 1—COVID-19-associated deaths in the 6-week period (n=243), group 2—non-COVID deaths in the same period (n=136) and group 3—all deaths in a comparison period of the same 6 weeks in 2019 (n=194).
Primary and secondary outcome measures This was a descriptive analysis of death case series review and as such no primary or secondary outcomes were pre-stipulated.
Results Deaths in patients from the Black, Asian and minority ethnic (BAME) communities in the pandemic period significantly increased both in the COVID-19 group (OR=2.43, 95% CI=1.60–3.68, p<0.001) and the non-COVID group (OR=1.76, 95% CI=1.09–2.83, p=0.02) during this time period and the increase was independent of differences in comorbidities, sex, age or deprivation. While the absolute number of deaths increased in 2020 compared with 2019, across all three groups the distribution of deaths by age was very similar. Our analyses confirm major risk factors for COVID-19 mortality including male sex, diabetes, having multiple comorbidities and background from the BAME communities.
Conclusions There was no evidence of COVID-19 deaths occurring disproportionately in the elderly compared with non-COVID deaths in this period in 2020 and 2019. Deaths in the BAME communities were over-represented in both COVID-19 and non-COVID groups, highlighting the need for detailed research in order to fully understand the influence of ethnicity on susceptibility to illness, mortality and health-seeking behaviour during the pandemic
Improving well-being in Higher Education: Adopting a compassionate approach
© Springer Nature Switzerland AG 2019. This is a post-peer-review, pre-copyedit version of a chapter published in the 'Values of the University in a Time of Uncertainty'. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-15970-2_18Peer reviewe
Stability Constraints on Classical de Sitter Vacua
We present further no-go theorems for classical de Sitter vacua in Type II
string theory, i.e., de Sitter constructions that do not invoke
non-perturbative effects or explicit supersymmetry breaking localized sources.
By analyzing the stability of the 4D potential arising from compactification on
manfiolds with curvature, fluxes, and orientifold planes, we found that
additional ingredients, beyond the minimal ones presented so far, are necessary
to avoid the presence of unstable modes. We enumerate the minimal setups for
(meta)stable de Sitter vacua to arise in this context.Comment: 18 pages; v2: argument improved, references adde
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