1,307 research outputs found
Identifying and Alleviating Concept Drift in Streaming Tensor Decomposition
Tensor decompositions are used in various data mining applications from
social network to medical applications and are extremely useful in discovering
latent structures or concepts in the data. Many real-world applications are
dynamic in nature and so are their data. To deal with this dynamic nature of
data, there exist a variety of online tensor decomposition algorithms. A
central assumption in all those algorithms is that the number of latent
concepts remains fixed throughout the entire stream. However, this need not be
the case. Every incoming batch in the stream may have a different number of
latent concepts, and the difference in latent concepts from one tensor batch to
another can provide insights into how our findings in a particular application
behave and deviate over time. In this paper, we define "concept" and "concept
drift" in the context of streaming tensor decomposition, as the manifestation
of the variability of latent concepts throughout the stream. Furthermore, we
introduce SeekAndDestroy, an algorithm that detects concept drift in streaming
tensor decomposition and is able to produce results robust to that drift. To
the best of our knowledge, this is the first work that investigates concept
drift in streaming tensor decomposition. We extensively evaluate SeekAndDestroy
on synthetic datasets, which exhibit a wide variety of realistic drift. Our
experiments demonstrate the effectiveness of SeekAndDestroy, both in the
detection of concept drift and in the alleviation of its effects, producing
results with similar quality to decomposing the entire tensor in one shot.
Additionally, in real datasets, SeekAndDestroy outperforms other streaming
baselines, while discovering novel useful components.Comment: 16 Pages, Accepted at ECML-PKDD 201
Gabapentin and pregabalin: do the benefits outweigh the harms?
Gabapentin and pregabalin prescribing in Scotland has increased substantially over recent years. Evidence suggests that prescribers may be advocating the use of these medicines off-label to avoid prescribing opioid analgesics. The evidence to support gabapentin and pregabalin use in non-neuropathic pain disorders indicates they are less effective than several other licensed non-opioid analgesics. Notably, patients may not benefit from gabapentin and pregabalin but remain at risk of adverse drug reactions. Furthermore, greater availability has resulted in increased diversion of gabapentin and pregabalin; creating problems within the opioid misuse population and prison service. As a consequence, both gabapentin and pregabalin may soon be controlled under the Misuse of Drugs Act 1971. Prescribers should be aware of the very limited clinical evidence for use of gabapentin and pregabalin outside their licensed indications, as well as their capacity to do harm
Bioorthogonal, Bifunctional Linker for Engineering Synthetic Glycoproteins
Post-translational glycosylation of proteins results in complex mixtures of heterogeneous protein glycoforms. Glycoproteins have many potential applications from fundamental studies of glycobiology to potential therapeutics, but generating homogeneous recombinant glycoproteins using chemical or chemoenzymatic reactions to mimic natural glycoproteins or creating homogeneous synthetic neoglycoproteins is a challenging synthetic task. In this work, we use a site-specific bioorthogonal approach to produce synthetic homogeneous glycoproteins. We develop a bifunctional, bioorthogonal linker that combines oxime ligation and strain-promoted azide–alkyne cycloaddition chemistry to functionalize reducing sugars and glycan derivatives for attachment to proteins. We demonstrate the utility of this minimal length linker by producing neoglycoprotein inhibitors of cholera toxin in which derivatives of the disaccharide lactose and GM1os pentasaccharide are attached to a nonbinding variant of the cholera toxin B-subunit that acts as a size- and valency-matched multivalent scaffold. The resulting neoglycoproteins decorated with GM1 ligands inhibit cholera toxin B-subunit adhesion with a picomolar IC50
Consultation meeting on the development of therapeutic vaccines for post kala azar dermal leishmaniasis
The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
Quasars are thought to be powered by supermassive black holes accreting
surrounding gas. Central to this picture is a putative accretion disk which is
believed to be the source of the majority of the radiative output. It is well
known, however, that the most extensively studied disk model -- an optically
thick disk which is heated locally by the dissipation of gravitational binding
energy -- is apparently contradicted by observations in a few major respects.
In particular, the model predicts a specific blue spectral shape asymptotically
from the visible to the near-infrared, but this is not generally seen in the
visible wavelength region where the disk spectrum is observable. A crucial
difficulty was that, toward the infrared, the disk spectrum starts to be hidden
under strong hot dust emission from much larger but hitherto unresolved scales,
and thus has essentially been impossible to observe. Here we report
observations of polarized light interior to the dust-emiting region that enable
us to uncover this near-infrared disk spectrum in several quasars. The revealed
spectra show that the near-infrared disk spectrum is indeed as blue as
predicted. This indicates that, at least for the outer near-infrared-emitting
radii, the standard picture of the locally heated disk is approximately
correct. The model problems at shorter wavelengths should then be directed
toward a better understanding of the inner parts of the revealed disk. The
newly uncovered disk emission at large radii, with more future measurements,
will also shed totally new light on the unanswered critical question of how and
where the disk ends.Comment: published in Nature, 24 July 2008 issue. Supplementary Information
can be found at
http://www.mpifr-bonn.mpg.de/div/ir-interferometry/suppl_info.pdf Published
version can be accessed from
http://www.nature.com/nature/journal/v454/n7203/pdf/nature07114.pd
Does type 2 diabetes influence the risk of oesophageal adenocarcinoma?
Since hyperinsulinaemia may promote obesity-linked cancers, we compared type 2 diabetes prevalence among oesophageal adenocarcinoma (OAC) patients and population controls. Diabetes increased the risk of OAC (adjusted odds ratio 1.59, 95% confidence interval (CI) 1.04–2.43), although the risk was attenuated after further adjusting for body mass index (1.32, 95% CI 0.85–2.05)
Fatty Acid and Peptide Profiles in Plasma Membrane and Membrane Rafts of PUFA Supplemented RAW264.7 Macrophages
The eukaryotic cell membrane possesses numerous complex functions, which are essential for life. At this, the composition and the structure of the lipid bilayer are of particular importance. Polyunsaturated fatty acids may modulate the physical properties of biological membranes via alteration of membrane lipid composition affecting numerous physiological processes, e.g. in the immune system. In this systematic study we present fatty acid and peptide profiles of cell membrane and membrane rafts of murine macrophages that have been supplemented with saturated fatty acids as well as PUFAs from the n-3, the n-6 and the n-9 family. Using fatty acid composition analysis and mass spectrometry-based peptidome profiling we found that PUFAs from both the n-3 and the n-6 family have an impact on lipid and protein composition of plasma membrane and membrane rafts in a similar manner. In addition, we found a relation between the number of bis-allyl-methylene positions of the PUFA added and the unsaturation index of plasma membrane as well as membrane rafts of supplemented cells. With regard to the proposed significance of lipid microdomains for disease development and treatment our study will help to achieve a targeted dietary modulation of immune cell lipid bilayers
Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF
If the Technicolor omega_T particle exists, a likely decay mode is omega_T ->
gamma pi_T, followed by pi_T -> bb-bar, yielding the signature gamma bb-bar. We
have searched 85 pb^-1 of data collected by the CDF experiment at the Fermilab
Tevatron for events with a photon and two jets, where one of the jets must
contain a secondary vertex implying the presence of a b quark. We find no
excess of events above standard model expectations. We express the result of an
exclusion region in the M_omega_T - M_pi_T mass plane.Comment: 14 pages, 2 figures. Available from the CDF server (PS with figs):
http://www-cdf.fnal.gov/physics/pub98/cdf4674_omega_t_prl_4.ps
FERMILAB-PUB-98/321-
Measurement of the B0 anti-B0 oscillation frequency using l- D*+ pairs and lepton flavor tags
The oscillation frequency Delta-md of B0 anti-B0 mixing is measured using the
partially reconstructed semileptonic decay anti-B0 -> l- nubar D*+ X. The data
sample was collected with the CDF detector at the Fermilab Tevatron collider
during 1992 - 1995 by triggering on the existence of two lepton candidates in
an event, and corresponds to about 110 pb-1 of pbar p collisions at sqrt(s) =
1.8 TeV. We estimate the proper decay time of the anti-B0 meson from the
measured decay length and reconstructed momentum of the l- D*+ system. The
charge of the lepton in the final state identifies the flavor of the anti-B0
meson at its decay. The second lepton in the event is used to infer the flavor
of the anti-B0 meson at production. We measure the oscillation frequency to be
Delta-md = 0.516 +/- 0.099 +0.029 -0.035 ps-1, where the first uncertainty is
statistical and the second is systematic.Comment: 30 pages, 7 figures. Submitted to Physical Review
Search for New Particles Decaying to top-antitop in proton-antiproton collisions at squareroot(s)=1.8 TeV
We use 106 \ipb of data collected with the Collider Detector at Fermilab to
search for narrow-width, vector particles decaying to a top and an anti-top
quark. Model independent upper limits on the cross section for narrow, vector
resonances decaying to \ttbar are presented. At the 95% confidence level, we
exclude the existence of a leptophobic \zpr boson in a model of
topcolor-assisted technicolor with mass M_{\zpr} 480 \gev for natural
width = 0.012 M_{\zpr}, and M_{\zpr} 780 \gev for =
0.04 M_{\zpr}.Comment: The CDF Collaboration, submitted to PRL 25-Feb-200
- …