554 research outputs found
Protecting privacy of users in brain-computer interface applications
Machine learning (ML) is revolutionizing research and industry. Many ML applications rely on the use of large amounts of personal data for training and inference. Among the most intimate exploited data sources is electroencephalogram (EEG) data, a kind of data that is so rich with information that application developers can easily gain knowledge beyond the professed scope from unprotected EEG signals, including passwords, ATM PINs, and other intimate data. The challenge we address is how to engage in meaningful ML with EEG data while protecting the privacy of users. Hence, we propose cryptographic protocols based on secure multiparty computation (SMC) to perform linear regression over EEG signals from many users in a fully privacy-preserving(PP) fashion, i.e., such that each individual's EEG signals are not revealed to anyone else. To illustrate the potential of our secure framework, we show how it allows estimating the drowsiness of drivers from their EEG signals as would be possible in the unencrypted case, and at a very reasonable computational cost. Our solution is the first application of commodity-based SMC to EEG data, as well as the largest documented experiment of secret sharing-based SMC in general, namely, with 15 players involved in all the computations
Effect of entropy on the dynamics of supercooled liquids: New results from high pressure data
We show that for arbitrary thermodynamic conditions, master curves of the
entropy are obtained by expressing S(T,V) as a function of TV^g_G, where T is
temperature, V specific volume, and g_G the thermodynamic Gruneisen parameter.
A similar scaling is known for structural relaxation times,tau = f(TV^g);
however, we find g_G < g. We show herein that this inequality reflects
contributions to S(T,V) from processes, such as vibrations and secondary
relaxations, that do not directly influence the supercooled dynamics. An
approximate method is proposed to remove these contributions, S_0, yielding the
relationship tau = f(S-S_0).Comment: 10 pages 7 figure
Pre- and perinatal risk factors for childhood leukaemia and other malignancies: a Scottish case control study
Incidence and survival of childhood bone cancer in northern England and the West Midlands, 1981–2002
There is a paucity of population-based studies examining incidence and survival trends in childhood bone tumours. We used high quality data from four population-based registries in England. Incidence patterns and trends were described using Poisson regression. Survival trends were analysed using Cox regression. There were 374 cases of childhood (ages 0–14 years) bone tumours (206 osteosarcomas, 144 Ewing sarcomas, 16 chondrosarcomas, 8 other bone tumours) registered in the period 1981–2002. Overall incidence (per million person years) rates were 2.63 (95% confidence interval (CI) 2.27–2.99) for osteosarcoma, 1.90 (1.58–2.21) for Ewing sarcoma and 0.21 (0.11–0.31) for chondrosarcoma. Incidence of Ewing sarcoma declined at an average rate of 3.1% (95% CI 0.6–5.6) per annum (P=0.04), which may be due to tumour reclassification, but there was no change in osteosarcoma incidence. Survival showed marked improvement over the 20 years (1981–2000) for Ewing sarcoma (hazard ratio (HR) per annum=0.95 95% CI 0.91–0.99; P=0.02). However, no improvement was seen for osteosarcoma patients (HR per annum=1.02 95% CI 0.98–1.05; P=0.35) over this time period. Reasons for failure to improve survival including potential delays in diagnosis, accrual to trials, adherence to therapy and lack of improvement in treatment strategies all need to be considered
Childhood solid tumours in relation to population mixing around the time of birth
In a retrospective cohort study of 673 787 live births in the Northern Region of England, 1975 - 1994, we investigated whether a higher level of population mixing around birth was a risk factor for solid tumours, by diagnostic group (Hodgkin's disease, brain and spinal tumours, neuroblastoma, other solid tumours), diagnosed during 1975-2001 under age 15 years. Logistic regression was used to relate risk to population mixing, based on (i) all movers and (ii) incomers from outside the region. Both ward and county district level analyses were performed. There was a decreased risk of brain and spinal tumours with increasing population mixing based on incomers from outside the region (OR for trend across three categories = 0.79, 95% CI: 0.66-0.95, P = 0.01 in the ward level analysis). Although this may be because of chance, it is consistent with a role of exposure to infection and immunological response in the aetiology of these tumours. For other tumour groups, there was no consistent evidence of an association between risk and population mixing
Night-sky brightness monitoring in Hong Kong - a city-wide light pollution assessment
Results of the first comprehensive light pollution survey in Hong Kong are
presented. The night-sky brightness was measured and monitored around the city
using a portable light sensing device called the Sky Quality Meter over a
15-month period beginning in March 2008. A total of 1,957 data sets were taken
at 199 distinct locations, including urban and rural sites covering all 18
Administrative Districts of Hong Kong. The survey shows that the environmental
light pollution problem in Hong Kong is severe - the urban night-skies (sky
brightness at 15.0 mag per arcsec square) are on average ~100 times brighter
than at the darkest rural sites (20.1 mag per arcsec square), indicating that
the high lighting densities in the densely populated residential and commercial
areas lead to light pollution. In the worst polluted urban location studied,
the night-sky at 13.2 mag per arcsec square can be over 500 times brighter than
the darkest sites in Hong Kong. The observed night-sky brightness is found to
be affected by human factors such as land utilization and population density of
the observation sites, together with meteorological and/or environmental
factors. Moreover, earlier night-skies (at 9:30pm local time) are generally
brighter than later time (at 11:30pm), which can be attributed to some public
and commercial lightings being turned off later at night. On the other hand, no
concrete relationship between the observed sky brightness and air pollutant
concentrations could be established with the limited survey sampling. Results
from this survey will serve as an important database for the public to assess
whether new rules and regulations are necessary to control the use of outdoor
lightings in Hong Kong.Comment: 33 pages, 13 figures, Environmental Monitoring and Assessment, in
pres
Data Descriptor: Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
CMS was funded by the ‘Nornex’ project jointly by UK BBSRC (BBS/E/J/000CA5323) and DEFRA and a BBSRC Tools and Resources grant (BB/N021452/1) awarded to M.G. and D.J.S
Experimental testing of reciprocal effects of nutrition and parasitism in wild black capuchin monkeys
Nutritional stress may predispose individuals to infection, which in turn can have further detrimental effects on physical condition, thus creating an opportunity for reciprocal effects between nutrition and parasitism. Little experimental investigation has been conducted on this "vicious circle" hypothesis in wild animals, especially under natural conditions. We evaluated the reciprocal effects of nutritional status and parasitism using an experimental approach in two groups of wild black capuchin monkeys (Sapajus nigritus). Across two consecutive winters, we collected faecal samples from identified capuchins to determine presence and load of gastrointestinal helminthes, and measured individual body mass as a proxy of physical condition. Food availability was manipulated by provisioning monkeys with bananas, and parasite burdens by applying anti-parasitic drugs to selected individuals. We found no effect of anti-parasitic drugs on physical condition, but parasite loads decreased in response to high levels of food availability. Our results represent the first experimental evidence that the nutritional status may drive parasite dynamics in a primate.Fil: Agostini, Ilaria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Nordeste. Instituto de BiologÃa Subtropical. Universidad Nacional de Misiones. Instituto de BiologÃa Subtropical; Argentina. Centro de Investigaciones del Bosque Atlántico; ArgentinaFil: Vanderhoeven, Ezequiel Andres. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Nordeste; Argentina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Centro de Investigaciones del Bosque Atlántico; ArgentinaFil: Di Bitetti, Mario Santiago. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Nordeste. Instituto de BiologÃa Subtropical. Universidad Nacional de Misiones. Instituto de BiologÃa Subtropical; Argentina. Centro de Investigaciones del Bosque Atlántico; ArgentinaFil: Beldomenico, Pablo MartÃn. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de EcologÃa de Enfermedades; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; Argentin
Cancer incidence among the south Asian and non-south Asian population under 30 years of age in Yorkshire, UK.
Few studies have examined epidemiological differences between ethnic groups for children and young adults with cancer
Foundations of Black Hole Accretion Disk Theory
This review covers the main aspects of black hole accretion disk theory. We
begin with the view that one of the main goals of the theory is to better
understand the nature of black holes themselves. In this light we discuss how
accretion disks might reveal some of the unique signatures of strong gravity:
the event horizon, the innermost stable circular orbit, and the ergosphere. We
then review, from a first-principles perspective, the physical processes at
play in accretion disks. This leads us to the four primary accretion disk
models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin)
disks, slim disks, and advection-dominated accretion flows (ADAFs). After
presenting the models we discuss issues of stability, oscillations, and jets.
Following our review of the analytic work, we take a parallel approach in
reviewing numerical studies of black hole accretion disks. We finish with a few
select applications that highlight particular astrophysical applications:
measurements of black hole mass and spin, black hole vs. neutron star accretion
disks, black hole accretion disk spectral states, and quasi-periodic
oscillations (QPOs).Comment: 91 pages, 23 figures, final published version available at
http://www.livingreviews.org/lrr-2013-
- …