786 research outputs found
Vortices and monopole distributions in lattice gauge theory
We examine the occurance of Z(2) and SO(3) vorticies and monopole
distributions in the neighborhood of Wilson loops. We use the Tomboulis
formulation, equivalent to the Wilson action, in which the links are invariant
under Z(2) transformations and new plaquette variables carry the Z(2) degrees
of freedom. This gives new gauge invariant observables to help gain insight
into the area law and structure of the flux tube.Comment: LaTe
A Generic Framework for Hidden Markov Models on Biomedical Data
Background: Biomedical data are usually collections of longitudinal data
assessed at certain points in time. Clinical observations assess the presences
and severity of symptoms, which are the basis for description and modeling of
disease progression. Deciphering potential underlying unknowns solely from the
distinct observation would substantially improve the understanding of
pathological cascades. Hidden Markov Models (HMMs) have been successfully
applied to the processing of possibly noisy continuous signals. The aim was to
improve the application HMMs to multivariate time-series of categorically
distributed data. Here, we used HHMs to study prediction of the loss of free
walking ability as one major clinical deterioration in the most common
autosomal dominantly inherited ataxia disorder worldwide. We used HHMs to
investigate the prediction of loss of the ability to walk freely, representing
a major clinical deterioration in the most common autosomal-dominant inherited
ataxia disorder worldwide.
Results: We present a prediction pipeline which processes data paired with a
configuration file, enabling to construct, validate and query a fully
parameterized HMM-based model. In particular, we provide a theoretical and
practical framework for multivariate time-series inference based on HMMs that
includes constructing multiple HMMs, each to predict a particular observable
variable. Our analysis is done on random data, but also on biomedical data
based on Spinocerebellar ataxia type 3 disease.
Conclusions: HHMs are a promising approach to study biomedical data that
naturally are represented as multivariate time-series. Our implementation of a
HHMs framework is publicly available and can easily be adapted for further
applications
Disaster Resilience Education and Research Roadmap for Europe 2030 : ANDROID Report
A disaster resilience education and research roadmap for Europe 2030 has been launched. This roadmap represents an important output of the ANDROID disaster resilience network, bringing together existing literature in the field, as well as the results of various analysis and study projects undertaken by project partners.The roadmap sets out five key challenges and opportunities in moving from 2015 to 2030 and aimed at addressing the challenges of the recently announced Sendai Framework for Disaster Risk Reduction 2015-2030. This roadmap was developed as part of the ANDROID Disaster Resilience Network, led by Professor Richard Haigh of the Global Disaster Resilience Centre (www.hud.ac.uk/gdrc ) at the School of Art, Design and Architecture at the University of Huddersfield, UK. The ANDROID consortium of applied, human, social and natural scientists, supported by international organisations and a stakeholder board, worked together to map the field in disaster resilience education, pool their results and findings, develop interdisciplinary explanations, develop capacity, move forward innovative education agendas, discuss methods, and inform policy development. Further information on ANDROID Disaster Resilience network is available at: http://www.disaster-resilience.netAn ANDROID Disaster Resilience Network ReportANDROI
The Black Hole Mass and Extreme Orbital Structure in NGC1399
The largest galaxies, and in particular central galaxies in clusters, offer
unique insight into understanding the mechanism for the growth of nuclear black
holes. We present Hubble Space Telescope kinematics for NGC1399, the central
galaxy in Fornax. We find the best-fit model contains a black hole of 5.1 +-0.7
x 10^8 Msun (at a distance of 21.1 Mpc), a factor of over 2 below the
correlation of black hole mass and velocity dispersion. We also find a dramatic
signature for central tangential anisotropy. The velocity profiles on adjacent
sides 0.5" away from the nucleus show strong bimodality, and the central
spectrum shows a large drop in the dispersion. Both of these observations point
to an orbital distribution that is tangentially biased. The best-fit orbital
model suggests a ratio of the tangential to radial internal velocity
dispersions of three. This ratio is the largest seen in any galaxy to date and
will provide an important measure for the mode by which the central black hole
has grown.Comment: 9 pages, accepted for publication in the Astrophysical Journa
The Bullet cluster at its best: weighing stars, gas and dark matter
We present a new strong lensing mass reconstruction of the Bullet cluster (1E
0657-56) at z=0.296, based on WFC3 and ACS HST imaging and VLT/FORS2
spectroscopy. The strong lensing constraints underwent substantial revision
compared to previously published analysis, there are now 14 (six new and eight
previously known) multiply-imaged systems, of which three have
spectroscopically confirmed redshifts (including one newly measured from this
work). The reconstructed mass distribution explicitly included the combination
of three mass components: i) the intra-cluster gas mass derived from X-ray
observation, ii) the cluster galaxies modeled by their fundamental plane
scaling relations and iii) dark matter. The model that includes the
intra-cluster gas is the one with the best Bayesian evidence. This model has a
total RMS value of 0.158" between the predicted and measured image positions
for the 14 multiple images considered. The proximity of the total RMS to
resolution of HST/WFC3 and ACS (0.07-0.15" FWHM) demonstrates the excellent
precision of our mass model. The derived mass model confirms the spatial offset
between the X-ray gas and dark matter peaks. The fraction of the galaxy halos
mass to total mass is found to be f_s=11+/-5% for a total mass of 2.5+/-0.1 x
10^14 solar mass within a 250 kpc radial aperture.Comment: Accepted by A&A 15 pages, 12 figure
A Quintet Of Black Hole Mass Determinations
We report five new measurements of central black hole masses based on Space Telescope Imaging Spectrograph and Wide Field Planetary Camera 2 observations with the Hubble Space Telescope (HST) and on axisymmetric, three-integral, Schwarzschild orbit-library kinematic models. We selected a sample of galaxies within a narrow range in velocity dispersion that cover a range of galaxy parameters (including Hubble type and core/power-law surface density profile) where we expected to be able to resolve the galaxy's sphere of influence based on the predicted value of the black hole mass from the M-sigma relation. We find masses for the following galaxies: NGC3585, M(BH) = 3.4(-0.6)(+1.5) x 10(8) M(circle dot;) NGC 3607, M(BH) = 1.2(-0.4)(+0.4) x 10(8) M(circle dot); NGC 4026, M(BH) = 2.1(-0.4)(+0.7) x 10(8) M(circle dot); and NGC 5576, M(BH) = 1.8(-0.4)(+0.3) x 10(8) M(circle dot), all significantly excluding M(BH) = 0. For NGC 3945, M(BH) = 9(-21)(+17) x 10(6) M(circle dot), which is significantly below predictions from M-sigma and M-L relations and consistent with MBH = 0, though the presence of a double bar in this galaxy may present problems for our axisymmetric code.NASA/HST GO-5999, GO-6587, GO-6633, GO-7468, GO-9107NASA NAS 5-26555Astronom
Differential diagnostic challenge of chronic neutrophilic leukemia in a patient with prolonged leukocytosis
Our interesting case deals with the clinical and morphological aspects of a chronic neutrophilic leukemia and the critical evaluation of differential diagnosis of leukemoid reaction in bone marrow biopsies
The M-sigma and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter
We derive improved versions of the relations between supermassive black hole
mass (M_BH) and host-galaxy bulge velocity dispersion (sigma) and luminosity
(L) (the M-sigma and M-L relations), based on 49 M_BH measurements and 19 upper
limits. Particular attention is paid to recovery of the intrinsic scatter
(epsilon_0) in both relations. We find log(M_BH / M_sun) = alpha + beta *
log(sigma / 200 km/s) with (alpha, beta, epsilon_0) = (8.12 +/- 0.08, 4.24 +/-
0.41, 0.44 +/- 0.06) for all galaxies and (alpha, beta, epsilon_0) = (8.23 +/-
0.08, 3.96 +/- 0.42, 0.31 +/- 0.06) for ellipticals. The results for
ellipticals are consistent with previous studies, but the intrinsic scatter
recovered for spirals is significantly larger. The scatter inferred reinforces
the need for its consideration when calculating local black hole mass function
based on the M-sigma relation, and further implies that there may be
substantial selection bias in studies of the evolution of the M-sigma relation.
We estimate the M-L relationship as log(M_BH / M_sun) = alpha + beta * log(L_V
/ 10^11 L_sun,V) of (alpha, beta, epsilon_0) = (8.95 +/- 0.11, 1.11 +/- 0.18,
0.38 +/- 0.09); using only early-type galaxies. These results appear to be
insensitive to a wide range of assumptions about the measurement errors and the
distribution of intrinsic scatter. We show that culling the sample according to
the resolution of the black hole's sphere of influence biases the relations to
larger mean masses, larger slopes, and incorrect intrinsic residuals.Comment: 27 pages, 18 figures, 7 tables, ApJ accepte
The Importance of <em>Sceletium tortuosum</em> (L.) N.E. Brown and Its Viability as a Traditional African Medicinal Plant
Sceletium tortuosum is a succulent plant that belongs to the family Mesembryanthemaceae (Aizoaceae). It is indigenous to South Africa, where it is well known by the indigenous people, especially in Namaqualand where the plant is utilized regularly for its medicinal and psycho-active properties. The main alkaloids responsible for these properties are mesembrine, mesembrenine (mesembrenone), and mesembrenol. The potential of the plant to be an alternative supplement in the promotion of health and treating a variety of psychological and psychiatric disorders such as depression and anxiety has stimulated interest in its pharmacological property and possibility of its commercialization. The economic value of indigenous medicinal plants in South Africa is approximately US$60 000 000 or R4 000 000 000 annually. Thus, interest in the knowledge and use of Traditional African Medicinal Plants (TAMP) as well as meeting pharmacological and economic needs of ever-increasing human population has led to the commercialization of traditional African medicines at a fast rate. It was found that S. tortuosum has clear pharmaceutical and economical importance and is one of the only known plants to contain the alkaloids mesembrenone and mesembrine which can be utilized for the promotion of health and/or treating a variety of psychological disorders such as anxiety and depression
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