775 research outputs found
Understanding Risk Extrapolation (REx) and when it finds Invariant Relationships
No full textGeneralizing models for new unknown datasets is a common problem in machine learning. Algorithms that perform well for test instances with the same distribution as their training dataset often perform severely on new datasets with a different distribution. This problem is caused by distributional shifts between the training of the model and applying that model to a test domain. This paper addresses whether and in what situations Risk Extrapolation (REx) can tackle this problem of Out-Of-Distribution generalization by exploiting invariant relationships. These relationships are based on features that are invariant across all domains. By learning these relationships, REx aims to learn the concept of the problem we are trying to solve. We show in what situations REx can learn these invariant relationships and when it does not. We translate the definition of an invariant relationship into a homoscedastic synthetic dataset with either covariate, confounded, anti-causal, or hybrid shift. We expose REx to experiments in sample complexity, the number of training domains, and the training domain distance. We show that REx performs better for invariant prediction in situations with larger sample sizes and training domain distance and that if these criteria are met, REx performs equivalently in all four distributional shifts. We also compare REx to Invariant- and Empirical Risk Minimization and show that; REx is less sensitive and thus robust to the shifting of the average distributional variance in the training domains; REx asymptotically out-performs the methods in the more complex distributional shifts.https://gitlab.com/hofland.jeroen/rex-distributional-shift CodeCSE3000 Research ProjectComputer Science and Engineerin
Rex J. Rowley
No full textAudio recording of the 10/06/13 UNLV Libraries Author Series event featuring Rex. J. Rowley, author of Everyday Las Vegas: Local Life in a Tourist Town. Includes remarks by Libraries Dean Patricia Iannuzzi, CGR Director Dave Schwartz, and Rowley
Juvenile skeletogenesis in anciently diverged sea urchin clades
No full textAbstractMechanistic understanding of evolutionary divergence in animal body plans devolves from analysis of those developmental processes that, in forms descendant from a common ancestor, are responsible for their morphological differences. The last common ancestor of the two extant subclasses of sea urchins, i.e., euechinoids and cidaroids, existed well before the Permian/Triassic extinction (252 mya). Subsequent evolutionary divergence of these clades offers in principle a rare opportunity to solve the developmental regulatory events underlying a defined evolutionary divergence process. Thus (i) there is an excellent and fairly dense (if yet incompletely analyzed) fossil record; (ii) cladistically confined features of the skeletal structures of modern euechinoid and cidaroid sea urchins are preserved in fossils of ancestral forms; (iii) euechinoids and cidaroids are among current laboratory model systems in molecular developmental biology (here Strongylocentrotus purpuratus [Sp] and Eucidaris tribuloides [Et]); (iv) skeletogenic specification in sea urchins is uncommonly well understood at the causal level of interactions of regulatory genes with one another, and with known skeletogenic effector genes, providing a ready arsenal of available molecular tools. Here we focus on differences in test and perignathic girdle skeletal morphology that distinguish all modern euechinoid from all modern cidaroid sea urchins. We demonstrate distinct canonical test and girdle morphologies in juveniles of both species by use of SEM and X-ray microtomography. Among the sharply distinct morphological features of these clades are the internal skeletal structures of the perignathic girdle to which attach homologous muscles utilized for retraction and protraction of Aristotles׳ lantern and its teeth. We demonstrate that these structures develop de novo between one and four weeks after metamorphosis. In order to study the underlying developmental processes, a method of section whole mount in situ hybridization was adapted. This method displays current gene expression in the developing test and perignathic girdle skeletal elements of both Sp and Et juveniles. Active, specific expression of the sm37 biomineralization gene in these muscle attachment structures accompanies morphogenetic development of these clade-specific features in juveniles of both species. Skeletogenesis at these clade-specific muscle attachment structures displays molecular earmarks of the well understood embryonic skeletogenic GRN: thus the upstream regulatory gene alx1 and the gene encoding the vegfR signaling receptor are both expressed at the sites where they are formed. This work opens the way to analysis of the alternative spatial specification processes that were installed at the evolutionary divergence of the two extant subclasses of sea urchins
Memo from Rex J. Stanton, Supt., Heart Mountain Relocation Projec,t to Mr. Shoji Nagumo, January 16, 1943
No full textMemorandum of understanding from Rex Stanton to Shoji Nagumo regarding a job opening for a plumber-fireman position at Heart Mountain incarceration camp.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
On the Border: A Book and a Movie
No full textMark Hainds is the author of Border Walk. Rex Jones is the director of La Frontera
Peter B. Maling, Christchurch, New Zealand [picture] /
No full textTitle devised from compactus card.; Inscriptions: "Peter B. Maling. Photograph for reference"--On compactus card, "Print U/1633 11535"--In pencil on verso; photographers stamp.; Rex Nan Kivell Collection NK11535.; Also available online http://nla.gov.au/nla.pic-vn6093270. Dr Peter B. Maling is a New Zealand author and historian. He was a friend and correspondent of Rex Nan Kivell
A sea-lion and lioness [picture] /
No full textPl. no. [15] of: A voyage round the world in the years MDCCXL, I, II, III, IV, by George Anson. London : Printed for the author by John and Paul Knapton ... , 1748.; Rex Nan Kivell Collection NK7032, NK724.; U4907; U6134.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-an9098967; Rex Nan Kivell Collection NK7032, NK724.; U4907; U6134
β-diversity of deep-sea holothurians and asteroids along a bathymetric gradient (NE Atlantic)
No full textMeasuring and understanding patterns of ?-diversity remain major challenges in community ecology. Recently, ?-diversity has been shown to consist of 2 distinct components: (1) spatial turnover and (2) species loss leading to nestedness. Both components structure deep-sea macrofaunal assemblages but vary in importance among taxa and ocean basins and with energy availability. Here, we present the first evidence for turnover and nestedness along a bathymetric gradient in 2 major megafaunal taxa, holothurians and asteroids. Turnover is the dominant component of ?-diversity throughout bathyal and abyssal zones in both taxa, despite major differences in ?-diversity and trophic composition. High spatial turnover suggests a role for evolutionary adaptation to environmental circumstances within depth bands. This pattern differs fundamentally from those in some macrofaunal groups in low-energy environments where abyssal nestedness is high and diversity low, with diversity maintained partly by source-sink dynamics
Innovation : an expert's insight on the issue in Arizona
No full textabstract: Innovation—introducing something new—in the 21st century mostly derives from technological advances. Innovation drives the modern economy, leading to gains in productivity and prosperity. In this edition of Indicator Insight, author Tom Rex discusses innovation in Arizona in terms of human capital, financial capital, and high-technology employment.Indicator insight ; volume 3, issue 3The Arizona Indicators Panel is a partnership of Arizona State University, The Arizona Republic, Arizona Community Foundation, Valley of the Sun United Way, and the Arizona Dept. of Commerce
Eurasian images of Singapore in the fiction of Rex Shelley
No full textIn a series of four novels, amounting to a substantial personal literary output, the author Rex Shelley has fashioned a portrait of Singapore that differs significantly from the conventional ones, both official and literary. Shelley comes from the numerically small Eurasian community, and it is the distinctive historical experience of this minority, also known colloquially as mesticos, serani, or geragok, that richly frames his fiction. Yet Shelley’s achievement is often curiously overlooked in Singaporean literary criticism.
The Singapore of Rex Shelley’s fiction is not primarily the success story of the overseas Chinese who so quickly became a large and dominant majority of the Singaporean population, though their economic achievements do form a necessary context for Shelley’s works. Nor is it a nostalgic vision of Bangsa Melayu as dreamed by generations of once rural Malays. Nor is it the ravaged evocation of Indian diaspora so eloquently chronicled by K S Maniam. Rather, Shelley’s attention is upon the very human consequences of Western colonialism in Southeast Asia, namely the products of unions, legitimate or otherwise, between European males and local females. As Shelley told Ronald Klein in a recent interview “, I wanted to put down some record of the social history of this Eurasian minority community.” (1) The result is an impressive, if structurally flawed, portrait of vivid integrity amongst Singapore’s Eurasian community over time. As personified by the characters in the four novels, Shelley’s Eurasians are not marginal, post-colonial oddities, but an engaging, multi-dimensional community who laugh, cry, work, play, dream, struggle, gossip, and intrigue, just like any other. They may not be Malay, Chinese, Indian, European, or Arab, but they are involved, patriotic participants in the shaping of Singapore nonetheles
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