Evorus: A Crowd-powered Conversational Assistant Built to Automate Itself Over Time

Crowd-powered conversational assistants have been shown to be more robust than automated systems, but do so at the cost of higher response latency and monetary costs. A promising direction is to combine the two approaches for high quality, low latency, and low cost solutions. In this paper, we introduce Evorus, a crowd-powered conversational assistant built to automate itself over time by (i) allowing new chatbots to be easily integrated to automate more scenarios, (ii) reusing prior crowd answers, and (iii) learning to automatically approve response candidates. Our 5-month-long deployment with 80 participants and 281 conversations shows that Evorus can automate itself without compromising conversation quality. Crowd-AI architectures have long been proposed as a way to reduce cost and latency for crowd-powered systems; Evorus demonstrates how automation can be introduced successfully in a deployed system. Its architecture allows future researchers to make further innovation on the underlying automated components in the context of a deployed open domain dialog system.Comment: 10 pages. To appear in the Proceedings of the Conference on Human Factors in Computing Systems 2018 (CHI'18

Integrated Molecular Meta-Analysis of 1,000 Pediatric High-Grade and Diffuse Intrinsic Pontine Glioma.

We collated data from 157 unpublished cases of pediatric high-grade glioma and diffuse intrinsic pontine glioma and 20 publicly available datasets in an integrated analysis of >1,000 cases. We identified co-segregating mutations in histone-mutant subgroups including loss of FBXW7 in H3.3G34R/V, TOP3A rearrangements in H3.3K27M, and BCOR mutations in H3.1K27M. Histone wild-type subgroups are refined by the presence of key oncogenic events or methylation profiles more closely resembling lower-grade tumors. Genomic aberrations increase with age, highlighting the infant population as biologically and clinically distinct. Uncommon pathway dysregulation is seen in small subsets of tumors, further defining the molecular diversity of the disease, opening up avenues for biological study and providing a basis for functionally defined future treatment stratification

Functional diversity and co-operativity between subclonal populations of paediatric glioblastoma and diffuse intrinsic pontine glioma cells

The failure to develop effective therapies for pediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG) is in part due to their intrinsic heterogeneity. We aimed to quantitatively assess the extent to which this was present in these tumors through subclonal genomic analyses and to determine whether distinct tumor subpopulations may interact to promote tumorigenesis by generating subclonal patient-derived models in vitro and in vivo. Analysis of 142 sequenced tumors revealed multiple tumor subclones, spatially and temporally coexisting in a stable manner as observed by multiple sampling strategies. We isolated genotypically and phenotypically distinct subpopulations that we propose cooperate to enhance tumorigenicity and resistance to therapy. Inactivating mutations in the H4K20 histone methyltransferase KMT5B (SUV420H1), present in <1% of cells, abrogate DNA repair and confer increased invasion and migration on neighboring cells, in vitro and in vivo, through chemokine signaling and modulation of integrins. These data indicate that even rare tumor subpopulations may exert profound effects on tumorigenesis as a whole and may represent a new avenue for therapeutic development. Unraveling the mechanisms of subclonal diversity and communication in pGBM and DIPG will be an important step toward overcoming barriers to effective treatments

Caring for Ngarrindjeri Country: collaborative research, community development and social justice

On 23 March 2007 at Goolwa near the mouth of the Murray River in South Australia, the Ngarrindjeri Nation launched the Ngarrindjeri Nation Yarluwar-Ruwe Plan: Caring for Ngarrindjeri Sea Country and Culture (the ‘NNYR Plan’). The NNYR Plan is the first Indigenous nation plan developed in South Australia and marks a major change in the way that the Ngarrindjeri leadership proposes to do business with non-Indigenous interests on Ngarrindjeri country. The NNYR Plan provides a strong statement of Ngarrindjeri rights, identity, authority and responsibility, but it is also a conciliatory document charting a vision for future, just collaborations between Ngarrindjeri and non-Indigenous institutions, governments, business and individuals

Wolfe Creek Crater: A continuous sediment fill in the Australian Arid Zone records changes in monsoon strength through the Late Quaternary

A bolide that impacted NW Australia during the Late Quaternary left a circular depression more than 100 m deep and nearly a kilometer in diameter, with a crater rim similar to 30 m above the regional terrain. The resultant crater is a window into the regional water table. The surface of the contemporary central pan is 25 m below the adjacent terrain, coincident with the late Holocene regional water table modified by local evaporative processes. Shielded from aeolian deflation by the crater rim, the central depression has slowly filled with dust, sand, and chemical precipitates, estimated to be 20-100 m thick based on geophysical surveys, one of the few continuous depocenters in the Australian Arid Zone. The nature of the crater's sediment fill is controlled by interactions between the water table, primarily in response to changes in summer monsoon rain, changes in the delivery of sand and dust to the crater by the prevailing easterly winds, and the level of the sedimentary fill surface. Optically Stimulated Luminescence (OSL) and C-14 dates constrain an age model indicating the upper 10 m of sediment fill recovered from the central pan span the past similar to 60 ka. The lowest 3 m consist of clayey sand deposited in perennial water during Marine Isotope Stage (MIS) 3. The water table subsequently dropped rapidly similar to 35 ka and remained more than 7 m below the late Holocene level through most of MIS 2, during which 2 m of sandy clay was deposited on a dry crater floor, confirming a dry and dusty Last Glacial Maximum (LGM) climate. By 14 ka a rising water table intersected the crater surface, modifying the upper 50 cm of LGM sediment, and syndepositionally modifying another 60 cm of subsequent sandy clay deposition. Aeolian sediment delivery effectively ceased similar to 13 ka, and the upper 4.8 m is a gypsum-dominated precipitate, which initially accumulated rapidly, before equilibrating with the late Holocene water table shortly after 6 ka. Lacustrine carbonate encrustations on rocks at the base of the crater wall and similar to 4 m above the central pan with C-14 ages >40 ka document a time when regional groundwater maintained a water body in the crater 3.5 -4.5 m above the modern groundwater level. The crater wall deflected the prevailing easterly winds, creating a horseshoe-dune extending westerly on both sides of the crater, with an extension rate of 35 m ka(-1). An augered hole through the northern dune revealed 10 m of sediment overlying ferricrete. The lowest meter is a mixture of broken ferricrete and sand that we interpret to be debris from the bolide impact. Three OSL dates through the dune project an age for the debris-dune contact of 120 +/- 10 ka. Changes in physical properties and bulk sediment delta C-13 through the 9 m of aeolian sediment indicate the lowest 1.8 m was deposited during MIS 5 (120-85 ka), under a uniformly wetter climate than present. The overlying 4.3 m of sediment was deposited between 85 and 14 ka (MIS 4, 3, 2) and exhibits transitional characteristics between the lower unit and the upper 3.8 of sand, which was deposited primarily during the Holocene. Large changes in the regional water table occurred over the past 60 ka, including an LGM water table persistently >= 7 m lower than late Holocene levels, and 3.5-4.5 m higher prior to 40 ka, plausibly in MIS 5, indicative of a stronger Australian Summer Monsoon than at any time subsequently.JWM acknowledges support for this research under the Australian Research Council1 s Large Research Grant funding (A00104515) and QE II Fellowship award (F00103660).The 1999 field season was funded by the US National Science Foundation grant AGS-502632 to GHM and MLF, and the 2001 field season was funded jointly by the US National Science Foundation grant AGS-082254 to GHM and MLF, and the Australian National University funded the coring rig and personnel to operate. JWM acknowledges support for this research under the Australian Research Council's Large Research Grant funding (A00104515) and QE II Fellowship award (F00103660)