4,067 research outputs found
A first step towards on-device monitoring of body sounds in the wild
Body sounds provide rich information about the state of the human body and
can be useful in many medical applications. Auscultation, the practice of
listening to body sounds, has been used for centuries in respiratory and
cardiac medicine to diagnose or track disease progression. To date, however,
its use has been confined to clinical and highly controlled settings. Our work
addresses this limitation: we devise a chest-mounted wearable for continuous
monitoring of body sounds, that leverages data processing algorithms that run
on-device. We concentrate on the detection of heart sounds to perform heart
rate monitoring. To improve robustness to ambient noise and motion artefacts,
our device uses an algorithm that explicitly segments the collected audio into
the phases of the cardiac cycle. Our pilot study with 9 users demonstrates that
it is possible to obtain heart rate estimates that are competitive with
commercial heart rate monitors, with low enough power consumption for
continuous use.ER
Black holes admitting a Freudenthal dual
The quantised charges x of four dimensional stringy black holes may be
assigned to elements of an integral Freudenthal triple system whose
automorphism group is the corresponding U-duality and whose U-invariant quartic
norm Delta(x) determines the lowest order entropy. Here we introduce a
Freudenthal duality x -> \tilde{x}, for which \tilde{\tilde{x}}=-x. Although
distinct from U-duality it nevertheless leaves Delta(x) invariant. However, the
requirement that \tilde{x} be integer restricts us to the subset of black holes
for which Delta(x) is necessarily a perfect square. The issue of higher-order
corrections remains open as some, but not all, of the discrete U-duality
invariants are Freudenthal invariant. Similarly, the quantised charges A of
five dimensional black holes and strings may be assigned to elements of an
integral Jordan algebra, whose cubic norm N(A) determines the lowest order
entropy. We introduce an analogous Jordan dual A*, with N(A) necessarily a
perfect cube, for which A**=A and which leaves N(A) invariant. The two
dualities are related by a 4D/5D lift.Comment: 32 pages revtex, 10 tables; minor corrections, references adde
Detection of respiratory bacterial pathogens causing atypical pneumonia by multiplex Lightmix<sup>Âź</sup> RT-PCR.
Pneumonia is a severe infectious disease. In addition to common viruses and bacterial pathogens (e.g. Streptococcus pneumoniae), fastidious respiratory pathogens like Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp. can cause severe atypical pneumonia. They do not respond to penicillin derivatives, which may cause failure of antibiotic empirical therapy. The same applies for infections with B. pertussis and B. parapertussis, the cause of pertussis disease, that may present atypically and need to be treated with macrolides. Moreover, these fastidious bacteria are difficult to identify by culture or serology, and therefore often remain undetected. Thus, rapid and accurate identification of bacterial pathogens causing atypical pneumonia is crucial. We performed a retrospective method evaluation study to evaluate the diagnostic performance of the new, commercially available Lightmix <sup>Âź</sup> multiplex RT-PCR assay that detects these fastidious bacterial pathogens causing atypical pneumonia. In this retrospective study, 368 clinical respiratory specimens, obtained from patients suffering from atypical pneumonia that have been tested negative for the presence of common agents of pneumonia by culture and viral PCR, were investigated. These clinical specimens have been previously characterized by singleplex RT-PCR assays in our diagnostic laboratory and were used to evaluate the diagnostic performance of the respiratory multiplex Lightmix <sup>Âź</sup> RT-PCR. The multiplex RT-PCR displayed a limit of detection between 5 and 10 DNA copies for different in-panel organisms and showed identical performance characteristics with respect to specificity and sensitivity as in-house singleplex RT-PCRs for pathogen detection. The Lightmix <sup>Âź</sup> multiplex RT-PCR assay represents a low-cost, time-saving and accurate diagnostic tool with high throughput potential. The time-to-result using an automated DNA extraction device for respiratory specimens followed by multiplex RT-PCR detection was below 4âŻh, which is expected to significantly improve diagnostics for atypical pneumonia-associated bacterial pathogens
Generalized spacetimes defined by cubic forms and the minimal unitary realizations of their quasiconformal groups
We study the symmetries of generalized spacetimes and corresponding phase
spaces defined by Jordan algebras of degree three. The generic Jordan family of
formally real Jordan algebras of degree three describe extensions of the
Minkowskian spacetimes by an extra "dilatonic" coordinate, whose rotation,
Lorentz and conformal groups are SO(d-1), SO(d-1,1) XSO(1,1) and
SO(d,2)XSO(2,1), respectively. The generalized spacetimes described by simple
Jordan algebras of degree three correspond to extensions of Minkowskian
spacetimes in the critical dimensions (d=3,4,6,10) by a dilatonic and extra
(2,4,8,16) commuting spinorial coordinates, respectively. The Freudenthal
triple systems defined over these Jordan algebras describe conformally
covariant phase spaces. Following hep-th/0008063, we give a unified geometric
realization of the quasiconformal groups that act on their conformal phase
spaces extended by an extra "cocycle" coordinate. For the generic Jordan family
the quasiconformal groups are SO(d+2,4), whose minimal unitary realizations are
given. The minimal unitary representations of the quasiconformal groups F_4(4),
E_6(2), E_7(-5) and E_8(-24) of the simple Jordan family were given in our
earlier work hep-th/0409272.Comment: A typo in equation (37) corrected and missing titles of some
references added. Version to be published in JHEP. 38 pages, latex fil
The effective mass of two--dimensional 3He
We use structural information from diffusion Monte Carlo calculations for
two--dimensional 3He to calculate the effective mass. Static effective
interactions are constructed from the density-- and spin structure functions
using sumrules. We find that both spin-- and density-- fluctuations contribute
about equally to the effective mass. Our results show, in agreement with recent
experiments, a flattening of the single--particle self--energy with increasing
density, which eventually leads to a divergent effective mass.Comment: 4 pages, accepted in PR
Recommended from our members
Computational Studies of the Skid Test: Evaluation of the Non-Shock Ignition of LX-10 Using HERMES
Aharonov-Bohm cages in two-dimensional structures
We present an extreme localization mechanism induced by a magnetic field for
tight-binding electrons in two-dimensional structures. This spectacular
phenomenon is investigated for a large class of tilings (periodic,
quasiperiodic, or random). We are led to introduce the Aharonov-Bohm cages
defined as the set of sites eventually visited by a wavepacket that can, for
particular values of the magnetic flux, be bounded. We finally discuss the
quantum dynamics which exhibits an original pulsating behaviour.Comment: 4 pages Latex, 3 eps figures, 1 ps figur
Recommended from our members
Mothers behaving badly: chaotic hedonism and the crisis of neoliberal social reproduction
This article focuses on the significance of the plethora of representations of mothers âbehaving badlyâ in contemporary anglophone media texts, including the films Bad Moms, Fun Mom Dinner and Bad Momâs Christmas, the book and online cartoons Hurrah for Gin and the recent TV comedy dramas Motherland, The Let Down and Catastrophe. All these media texts include representations of, first, mothers in the midst of highly chaotic everyday spaces where any smooth routine of domesticity is conspicuous by its absence; and second, mothers behaving hedonistically, usually through drinking and partying, behaviour that is more conventionally associated with men or women without children. After identifying the social type of the mother behaving badly (MBB), the article locates and analyses it in relation to several different social and cultural contexts. These contexts are: a neoliberal crisis in social reproduction marked by inequality and overwork; the continual if contested role of women as âfoundation parentsâ; and the negotiation of longer-term discourses of female hedonism. The title gestures towards a popular British sitcom of the 1990s, Men Behaving Badly, which popularized the idea of the ânew ladâ; and this article suggests that the new ladâs counterpart, the ladette, is mutating into the mother behaving badly, or the âlad momâ. Asking what work this figure does now, in a later neoliberal context, it argues that the mother behaving badly is simultaneously indicative of a widening and liberating range of maternal subject positions and symptomatic of a profound contemporary crisis in social reproduction. By focusing on the classed and racialised dynamics of the MBB â by examining who exactly is permitted to be hedonistic, and how â and by considering the MBBâs limited and partial imagining of progressive social change, the article concludes by emphasizing the urgency of creating more connections between such discourses and âparents behaving politicallyâ
Electromagnetic Moments of the Baryon Decuplet
We compute the leading contributions to the magnetic dipole and electric
quadrupole moments of the baryon decuplet in chiral perturbation theory. The
measured value for the magnetic moment of the is used to determine
the local counterterm for the magnetic moments. We compare the chiral
perturbation theory predictions for the magnetic moments of the decuplet with
those of the baryon octet and find reasonable agreement with the predictions of
the large-- limit of QCD. The leading contribution to the quadrupole
moment of the and other members of the decuplet comes from one--loop
graphs. The pionic contribution is shown to be proportional to (and so
will not contribute to the quadrupole moment of nuclei), while the
contribution from kaons has both isovector and isoscalar components. The chiral
logarithmic enhancement of both pion and kaon loops has a coefficient that
vanishes in the limit. The third allowed moment, the magnetic octupole,
is shown to be dominated by a local counterterm with corrections arising at two
loops. We briefly mention the strange counterparts of these moments.Comment: Uses harvmac.tex, 15 pages with 3 PostScript figures packed using
uufiles. UCSD/PTH 93-22, QUSTH-93-05, Duke-TH-93-5
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