139 research outputs found
Asking More Informative Questions for Grounded Retrieval
When a model is trying to gather information in an interactive setting, it
benefits from asking informative questions. However, in the case of a grounded
multi-turn image identification task, previous studies have been constrained to
polar yes/no questions, limiting how much information the model can gain in a
single turn. We present an approach that formulates more informative,
open-ended questions. In doing so, we discover that off-the-shelf visual
question answering (VQA) models often make presupposition errors, which
standard information gain question selection methods fail to account for. To
address this issue, we propose a method that can incorporate presupposition
handling into both question selection and belief updates. Specifically, we use
a two-stage process, where the model first filters out images which are
irrelevant to a given question, then updates its beliefs about which image the
user intends. Through self-play and human evaluations, we show that our method
is successful in asking informative open-ended questions, increasing accuracy
over the past state-of-the-art by 14%, while resulting in 48% more efficient
games in human evaluations
Symbolic Planning and Code Generation for Grounded Dialogue
Large language models (LLMs) excel at processing and generating both text and
code. However, LLMs have had limited applicability in grounded task-oriented
dialogue as they are difficult to steer toward task objectives and fail to
handle novel grounding. We present a modular and interpretable grounded
dialogue system that addresses these shortcomings by composing LLMs with a
symbolic planner and grounded code execution. Our system consists of a reader
and planner: the reader leverages an LLM to convert partner utterances into
executable code, calling functions that perform grounding. The translated
code's output is stored to track dialogue state, while a symbolic planner
determines the next appropriate response. We evaluate our system's performance
on the demanding OneCommon dialogue task, involving collaborative reference
resolution on abstract images of scattered dots. Our system substantially
outperforms the previous state-of-the-art, including improving task success in
human evaluations from 56% to 69% in the most challenging setting.Comment: Accepted to EMNLP 202
Who Treats Patients with Diabetes and Compensated Cirrhosis
Increasingly, patients with multiple chronic conditions are being managed in patient-centered medical homes (PCMH) that coordinate primary and specialty care. However, little is known about the types of providers treating complex patients with diabetes and compensated cirrhosis
Asymptotic Infrared Fractal Structure of the Propagator for a Charged Fermion
It is well known that the long-range nature of the Coulomb interaction makes
the definition of asymptotic ``in'' and ``out'' states of charged particles
problematic in quantum field theory. In particular, the notion of a simple
particle pole in the vacuum charged particle propagator is untenable and should
be replaced by a more complicated branch cut structure describing an electron
interacting with a possibly infinite number of soft photons. Previous work
suggests a Dirac propagator raised to a fractional power dependent upon the
fine structure constant, however the exponent has not been calculated in a
unique gauge invariant manner. It has even been suggested that the fractal
``anomalous dimension'' can be removed by a gauge transformation. Here, a gauge
invariant non-perturbative calculation will be discussed yielding an
unambiguous fractional exponent. The closely analogous case of soft graviton
exponents is also briefly explored.Comment: Updated with a corrected sign error, longer discussion of fractal
dimension, and more reference
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Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling
Abstract. The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA), with enhancement ratio of OA with respect to carbon monoxide (CO) reaching 0.085±0.003 µg m−3 ppbv−1. At background mixing ratios of CO, up to ∼ 1.8 µg m−3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G) emissions was ∼ 40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF) confirmed a dominant contribution of secondary, oxygenated OA (OOA) in the boundary layer instead of fresh, hydrocarbon-like OA (HOA). Combinations of primary OA (POA) volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to < 5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA) in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA) production. Despite a lower production of bSOA in this scenario, contribution of bSOA to total SOA remained high at 40–54 %. Future studies aiming at a better emissions characterization of POA and intermediate-volatility organic compounds (IVOCs) from the O&G sector are valuable
A MicroRNA Linking Human Positive Selection and Metabolic Disorders
Postponed access: the file will be accessible after 2021-10-14Positive selection in Europeans at the 2q21.3 locus harboring the lactase gene has been attributed to selection for the ability of adults to digest milk to survive famine in ancient times. However, the 2q21.3 locus is also associated with obesity and type 2 diabetes in humans, raising the possibility that additional genetic elements in the locus may have contributed to evolutionary adaptation to famine by promoting energy storage, but which now confer susceptibility to metabolic diseases. We show here that the miR-128-1 microRNA, located at the center of the positively selected locus, represents a crucial metabolic regulator in mammals. Antisense targeting and genetic ablation of miR-128-1 in mouse metabolic disease models result in increased energy expenditure and amelioration of high-fat-diet-induced obesity and markedly improved glucose tolerance. A thrifty phenotype connected to miR-128-1-dependent energy storage may link ancient adaptation to famine and modern metabolic maladaptation associated with nutritional overabundance.acceptedVersio
Survey Sequencing and Comparative Analysis of the Elephant Shark (Callorhinchus milii) Genome
Owing to their phylogenetic position, cartilaginous fishes (sharks, rays, skates, and chimaeras) provide a critical reference for our understanding of vertebrate genome evolution. The relatively small genome of the elephant shark, Callorhinchus milii, a chimaera, makes it an attractive model cartilaginous fish genome for whole-genome sequencing and comparative analysis. Here, the authors describe survey sequencing (1.4× coverage) and comparative analysis of the elephant shark genome, one of the first cartilaginous fish genomes to be sequenced to this depth. Repetitive sequences, represented mainly by a novel family of short interspersed element–like and long interspersed element–like sequences, account for about 28% of the elephant shark genome. Fragments of approximately 15,000 elephant shark genes reveal specific examples of genes that have been lost differentially during the evolution of tetrapod and teleost fish lineages. Interestingly, the degree of conserved synteny and conserved sequences between the human and elephant shark genomes are higher than that between human and teleost fish genomes. Elephant shark contains putative four Hox clusters indicating that, unlike teleost fish genomes, the elephant shark genome has not experienced an additional whole-genome duplication. These findings underscore the importance of the elephant shark as a critical reference vertebrate genome for comparative analysis of the human and other vertebrate genomes. This study also demonstrates that a survey-sequencing approach can be applied productively for comparative analysis of distantly related vertebrate genomes
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When TOD moves into the neighborhood : towards locally-sustainable transit-oriented development
textThis paper investigates how transit-oriented development can protect and enhance
community sustainability. This study explores literature on community capacity, social
capital, and neighborhood change to generate a definition of community sustainability
appropriate for urban neighborhoods in transition. It then looks at current models
proposed in the literature for assessing transit-oriented development (TOD), and finds
little of relevance for the concerns of social sustainability. The study then draws
sustainability indicators from other social science literature and assesses their usefulness
for transit-oriented development. Finally, it develops a set of indicators appropriate for
measuring the performance of TOD in protecting or enhancing community sustainability
in these neighborhoods. These indicators can be used as a starting point for agencies and
local groups to develop outcome-oriented measures of success for the local sustainability
of future transit-oriented developments.Community and Regional Plannin
The use of a real-time computer diary for data acquisition and processing
Behavioural researchers have long relied on the use of diaries for the collection of self-report data. We discuss the characteristics of a programmable hand-held computer used to collect hourly and event generated data for 7 days on 20 subjects with panic disorder. In the application described, subjects answered a series of 19 or more questions on the hour from 0700 to 2300 or when they were having a panic attack. Subjects completed 88% of all the hourly ratings (range 64-98%). The system was well accepted by the subjects and provided relatively inexpensive data collection and management
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