2,384 research outputs found
Retrieve and Refine: Improved Sequence Generation Models For Dialogue
Sequence generation models for dialogue are known to have several problems:
they tend to produce short, generic sentences that are uninformative and
unengaging. Retrieval models on the other hand can surface interesting
responses, but are restricted to the given retrieval set leading to erroneous
replies that cannot be tuned to the specific context. In this work we develop a
model that combines the two approaches to avoid both their deficiencies: first
retrieve a response and then refine it -- the final sequence generator treating
the retrieval as additional context. We show on the recent CONVAI2 challenge
task our approach produces responses superior to both standard retrieval and
generation models in human evaluations
Rational Catalan Numbers for Complex Reflection Groups
Assuming standard conjectures, we show that the canonical symmetrizing trace
evaluated at powers of a Coxeter element produces rational Catalan numbers for
irreducible spetsial complex reflection groups. This extends a technique used
by Galashin, Lam, Trinh, and Williams to uniformly prove the enumeration of
their noncrossing Catalan objects for finite Coxeter groups.Comment: 28 pages, 2 figure
Strongly non embeddable metric spaces
Enflo constructed a countable metric space that may not be uniformly embedded
into any metric space of positive generalized roundness. Dranishnikov, Gong,
Lafforgue and Yu modified Enflo's example to construct a locally finite metric
space that may not be coarsely embedded into any Hilbert space. In this paper
we meld these two examples into one simpler construction. The outcome is a
locally finite metric space which is strongly non
embeddable in the sense that it may not be embedded uniformly or coarsely into
any metric space of non zero generalized roundness. Moreover, we show that both
types of embedding may be obstructed by a common recursive principle. It
follows from our construction that any metric space which is Lipschitz
universal for all locally finite metric spaces may not be embedded uniformly or
coarsely into any metric space of non zero generalized roundness. Our
construction is then adapted to show that the group
admits a Cayley graph which
may not be coarsely embedded into any metric space of non zero generalized
roundness. Finally, for each and each locally finite metric space
, we prove the existence of a Lipschitz injection .Comment: 10 page
Elevated cerebral spinal fluid biomarkers in children with mucopolysaccharidosis I-H.
Mucopolysaccharidosis (MPS) type-IH is a lysosomal storage disease that results from mutations in the IDUA gene causing the accumulation of glycosaminoglycans (GAGs). Historically, children with the severe phenotype, MPS-IH (Hurler syndrome) develop progressive neurodegeneration with death in the first decade due to cardio-pulmonary complications. New data suggest that inflammation may play a role in MPS pathophysiology. To date there is almost no information on the pathophysiologic changes within the cerebral spinal fluid (CSF) of these patients. We evaluated the CSF of 25 consecutive patients with MPS-IH. While CSF glucose and total protein were within the normal range, we found a significantly mean elevated CSF opening pressure at 24 cm H2O (range 14-37 cm H2O). We observed a 3-fold elevation in CSF heparan sulfate and a 3-8 fold increase in MPS-IH specific non-reducing ends, I0S0 and I0S6. Cytokine analyses in CSF of children with MPS-IH showed significantly elevated inflammatory markers including: MCP-1 SDF-1a, IL-Ra, MIP-1b, IL-8, and VEGF in comparison to unaffected children. This is the largest report of CSF characteristics in children with MPS-IH. Identification of key biomarkers may provide further insight into the inflammatory-mediated mechanisms related to MPS diseases and perhaps lead to improved targeted therapies
State-of-the-art glycosaminoglycan characterization
Glycosaminoglycans (GAGs) are heterogeneous acidic polysaccharides involved in a range of biological functions. They have a significant influence on the regulation of cellular processes and the development of various diseases and infections. To fully understand the functional roles that GAGs play in mammalian systems, including disease processes, it is essential to understand their structural features. Despite having a linear structure and a repetitive disaccharide backbone, their structural analysis is challenging and requires elaborate preparative and analytical techniques. In particular, the extent to which GAGs are sulfated, as well as variation in sulfate position across the entire oligosaccharide or on individual monosaccharides, represents a major obstacle. Here, we summarize the current state-of-the-art methodologies used for GAG sample preparation and analysis, discussing in detail liquid chromatograpy and mass spectrometry-based approaches, including advanced ion activation methods, ion mobility separations and infrared action spectroscopy of mass-selected species
Hope for resurrecting a functionally extinct parrot or squandered social capital? Landholder attitudes towards the Orange-bellied Parrot (Neophema chrysogaster) in Victoria, Australia
In early 2010, after 27 years of recovery effort, the orange-bellied parrot (OBP; Neophema chrysogaster) was expected to be extinct in the wild within a few years. Shortly before the imminent wild extinction became evident, we surveyed landholders (114 responses of 783 surveys delivered) in part of the main non-breeding area, according to three classes of modelled habitat suitability (\u27high\u27, \u27medium\u27, and \u27low\u27). Predictions of the habitat models appear to correlate with landholder perceptions of the presence of OBP habitat on private land, thus the models appear a tractable way to identify key stakeholders worthy of priority consultation in relation to habitat works. Landholders were sympathetic to wetlands and birds, including OBPs (89.4% were aware of OBPs). Most indicated that they would be upset if the OBP went extinct and agreed that critical habitat should be protected; 80.7% were prepared to consider changes to the way they managed their land to benefit the species, and sought more information on how they could do so (64.0%). This study suggests that the habitat model usefully identified key stakeholders and the OBP enjoyed high awareness, concern, and engagement among many stakeholders, shortly before the species was considered functionally extinct. The maintenance of landholder support is likely to be critical if future attempts are made to reintroduce the species to the wild
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