1,180 research outputs found
Word Representation Models for Morphologically Rich Languages in Neural Machine Translation
Dealing with the complex word forms in morphologically rich languages is an
open problem in language processing, and is particularly important in
translation. In contrast to most modern neural systems of translation, which
discard the identity for rare words, in this paper we propose several
architectures for learning word representations from character and morpheme
level word decompositions. We incorporate these representations in a novel
machine translation model which jointly learns word alignments and translations
via a hard attention mechanism. Evaluating on translating from several
morphologically rich languages into English, we show consistent improvements
over strong baseline methods, of between 1 and 1.5 BLEU points
3-(4-NitroÂphenÂyl)-N-phenylÂoxirane-2-carboxamide
The molÂecule of the title compound, C15H12N2O4, adopts a syn conformation with the terminal benzene rings located on the same sides of the central epoxide ring. The epoxide ring makes dihedral angles of 71.08 (18) and 60.83 (17)° with the two benzene rings. Weak interÂmolecular C—H⋯O hydrogen bonding is present in the crystal structure
Backdoor Attack on Multilingual Machine Translation
While multilingual machine translation (MNMT) systems hold substantial
promise, they also have security vulnerabilities. Our research highlights that
MNMT systems can be susceptible to a particularly devious style of backdoor
attack, whereby an attacker injects poisoned data into a low-resource language
pair to cause malicious translations in other languages, including
high-resource languages. Our experimental results reveal that injecting less
than 0.01% poisoned data into a low-resource language pair can achieve an
average 20% attack success rate in attacking high-resource language pairs. This
type of attack is of particular concern, given the larger attack surface of
languages inherent to low-resource settings. Our aim is to bring attention to
these vulnerabilities within MNMT systems with the hope of encouraging the
community to address security concerns in machine translation, especially in
the context of low-resource languages.Comment: NAACL main long pape
Fast Ensemble Smoothing
Smoothing is essential to many oceanographic, meteorological and hydrological
applications. The interval smoothing problem updates all desired states within
a time interval using all available observations. The fixed-lag smoothing
problem updates only a fixed number of states prior to the observation at
current time. The fixed-lag smoothing problem is, in general, thought to be
computationally faster than a fixed-interval smoother, and can be an
appropriate approximation for long interval-smoothing problems. In this paper,
we use an ensemble-based approach to fixed-interval and fixed-lag smoothing,
and synthesize two algorithms. The first algorithm produces a linear time
solution to the interval smoothing problem with a fixed factor, and the second
one produces a fixed-lag solution that is independent of the lag length.
Identical-twin experiments conducted with the Lorenz-95 model show that for lag
lengths approximately equal to the error doubling time, or for long intervals
the proposed methods can provide significant computational savings. These
results suggest that ensemble methods yield both fixed-interval and fixed-lag
smoothing solutions that cost little additional effort over filtering and model
propagation, in the sense that in practical ensemble application the additional
increment is a small fraction of either filtering or model propagation costs.
We also show that fixed-interval smoothing can perform as fast as fixed-lag
smoothing and may be advantageous when memory is not an issue
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Adrenergic and mesenchymal signatures are identifiable in cell-free DNA and correlate with metastatic disease burden in children with neuroblastoma
Background: Cell-free DNA (cfDNA) profiles of 5-hydroxymethylcytosine (5-hmC), an epigenetic marker of open chromatin and active gene expression, are correlated with metastatic disease burden in patients with neuroblastoma. Neuroblastoma tumors are comprised of adrenergic (ADRN) and mesenchymal (MES) cells, and the relative abundance of each in tumor biopsies has prognostic implications. We hypothesized that ADRN and MES-specific signatures could be quantified in cfDNA 5-hmC profiles and would augment the detection of metastatic burden in patients with neuroblastoma. Methods: We previously performed an integrative analysis to identify ADRN and MES-specific genes (n = 373 and n = 159, respectively). Purified DNA from cell lines was serial diluted with healthy donor cfDNA. Using Gene Set Variation Analysis (GSVA), ADRN and MES signatures were optimized. We then quantified signature scores, and our prior neuroblastoma signature, in cfDNA from 84 samples from 46 high-risk patients including 21 patients with serial samples. Results: Samples from patients with higher metastatic burden had increased GSVA scores for both ADRN and MES gene signatures (p Conclusions: While it is feasible to identify ADRN and MES signatures using 5-hmC profiles of cfDNA from neuroblastoma patients and correlate these signatures to metastatic burden, additional data are needed to determine the optimal strategies for clinical implementation. Prospective evaluation in larger cohorts is ongoing.</p
Measuring the Behavioural Component of the S&P 500 and its Relationship to Financial Stress and Aggregated Earnings Surprises
Scholars in management and economics have shown increasing interest in isolating the
behavioural dimension of market evolution. Indeed, by improving forecast accuracy and
precision, this exercise would certainly help firms to anticipate economic fluctuations,
thus leading to more profitable business and investment strategies. Yet, how to extract
the behavioural component from real market data remains an open question. By using
monthly data on the returns of the constituents of the S&P 500 index, we propose a
Bayesian methodology to measure the extent to which market data conform to what is
predicted by prospect theory (the behavioural perspective), relative to the (standard) subjective
expected utility theory baseline.We document a significant behavioural component
that reaches its peaks during recession periods and is correlated to measures of financial
volatility, market sentiment and financial stress with expected sign. Moreover, the behavioural
component decreases around macroeconomic corporate earnings news, while it
reacts positively to the number of surprising announcements
Efficient Coding Theory Predicts a Tilt Aftereffect from Viewing Untilted Patterns
The brain is bombarded with a continuous stream of sensory information, but biological limitations on the data-transmission rate require this information to be encoded very efficiently [1]. Li and Atick [2] proposed that the two eyes? signals are coded efficiently in the brain using mutually decorrelated binocular summation and differencing channels; when a channel is strongly stimulated by the visual input, such that sensory noise is negligible, the channel should undergo temporary desensitization (known as adaptation). To date, the evidence for this theory has been limited [3 and 4], and the binocular differencing channel is missing from many models of binocular integration [5, 6, 7, 8, 9 and 10]. Li and Atick?s theory makes the remarkable prediction that perceived direction of tilt (clockwise or counterclockwise) of a test pattern can be controlled by pre-exposing observers to visual adaptation patterns that are untilted or even have no orientation signal. Here, we confirm this prediction. Each test pattern consisted of different images presented to the two eyes such that the binocular summation and difference signals were tilted in opposite directions, to give ambiguous information about tilt; by selectively desensitizing one or other of the binocular channels using untilted or non-oriented binocular adaptation patterns, we controlled the perceived tilt of the test pattern. Our results provide compelling evidence that the brain contains binocular summation and differencing channels that adapt to the prevailing binocular statistics
Ultrahigh Thermoelectric Performance in Mosaic Crystals
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111928/1/adma201501030-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111928/2/adma201501030.pd
DGST : a dual-generator network for text style transfer
We propose DGST, a novel and simple Dual-Generator network architecture for text Style Transfer. Our model employs two generators only, and does not rely on any discriminators or parallel corpus for training. Both quantitative and qualitative experiments on the Yelp and IMDb datasets show that our model gives competitive performance compared to several strong baselines with more complicated architecture designs
LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma
LGR5 is a marker of normal and cancer stem cells in various tissues where it functions as a receptor for R-spondins and increases canonical Wnt signalling amplitude. Here we report that LGR5 is also highly expressed in a subset of high grade neuroblastomas. Neuroblastoma is a clinically heterogenous paediatric cancer comprising a high proportion of poor prognosis cases (~40%) which are frequently lethal. Unlike many cancers, Wnt pathway mutations are not apparent in neuroblastoma, although previous microarray analyses have implicated deregulated Wnt signalling in high-risk neuroblastoma. We demonstrate that LGR5 facilitates high Wnt signalling in neuroblastoma cell lines treated with Wnt3a and R-spondins, with SK-N-BE(2)-C, SK-N-NAS and SH-SY5Y cell-lines all displaying strong Wnt induction. These lines represent MYCN-amplified, NRAS and ALK mutant neuroblastoma subtypes respectively. Wnt3a/R-Spondin treatment also promoted nuclear translocation of β-catenin, increased proliferation and activation of Wnt target genes. Strikingly, short-interfering RNA mediated knockdown of LGR5 induces dramatic Wnt-independent apoptosis in all three cell-lines, accompanied by greatly diminished phosphorylation of mitogen/extracellular signal-regulated kinases (MEK1/2) and extracellular signal-regulated kinases (ERK1/2), and an increase of BimEL, an apoptosis facilitator downstream of ERK. Akt signalling is also decreased by a Rictor dependent, PDK1-independent mechanism. LGR5 expression is cell cycle regulated and LGR5 depletion triggers G1 cell-cycle arrest, increased p27 and decreased phosphorylated retinoblastoma protein. Our study therefore characterises new cancer-associated pathways regulated by LGR5, and suggest that targeting of LGR5 may be of therapeutic benefit for neuroblastomas with diverse etiologies, as well as other cancers expressing high LGR5
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