2,149 research outputs found

    On Writ of Certiorari to the United States Court of Appeals for the Ninth Circuit, Brief of Product Liability Advisory Council, Inc., National Association of Manufacturers, Business Roundtable, and Chemical Manufacturers Association as Amici Curiae in Support of Respondent, William Daubert and Joyce Daubert, Individually and as Guardians Ad Litem for Jason Daubert, and Anita De Young, Individually and as Gaurdian Ad Litem for Eric Schuller v. Merrell Dow Pharmaceuticals, Inc.

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    The Federal Rules of Evidence exclude expert scientific testimony when it has been developed without regard for accepted scientific methods. This case focuses on expert scientific evidence. Such evidence plays a vital and often dispositive role in modern litigation. For scientific evidence to be helpful to the factfinder it must meet some minimal threshold of reliability. To hold otherwise would be to allow a system of adjudication based more on chance than on reason

    Spatial controls on dissolved organic carbon in upland waters inferred from a simple statistical model

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    Dissolved organic carbon (DOC) concentrations in upland surface waters in many northern hemisphere industrialised regions are at their highest in living memory, provoking debate over their ‘‘naturalness’’. Because of the implications for drinking water treatment and supply there is increasing interest in the potential for mitigation through local land management, and for forecasting the likely impact of environmental change. However, the dominant controls on DOC production remain unresolved, hindering the establishment of appropriate reference levels for specific locations. Here we demonstrate that spatial variation in long-term average DOC levels draining upland UK catchments is highly predictable using a simplemultiple logistic regression model comprising variables representing wetland soil cover, rainfall, altitude, catchment sensitivity to acidification and current acid deposition. A negative relationship was observed between DOC concentration and altitude that, for catchments dominated by organo-mineral soils, is plausibly explained by the combined effects of changing net primary production and temperature-dependent decomposition. However, the magnitude of the altitude effect was considerably greater for catchments with a high proportion ofwetland cover, suggesting that additional controls influence these sites such as impeded respiratory loss of carbon in wet soils and/or an increased susceptibility to water level drawdown at lower altitudes. The model suggests (1) that continuing reductions in sulphur deposition on acid sensitive organo-mineral soils, will drive further significant increases in DOC and, (2) given the differences in the magnitude of the observed altitude-DOC relationships, that DOC production from catchments with peatdominated soilsmay bemore sensitive to climate change than those dominated by mineral soils. However, given that mechanisms remain unclear, the latter warrants further investigation

    Pre- and Post Impoundment Ichthyoparasite Succession in a New Arkansas Reservoir

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    Helminth and crustacean parasites from 2,387 Micropterus dolomieui, M. punctulatus, and M. salmoides were utilized to monitor annual pre- and postimpoundment succession patterns spanning eight con- tinuous years in Beaver Reservoir, Arkansas. Incidence of infection by ichthyoparasites with direct life cycles (monogenetic trematodes, leeches, and crustaceans) generally increased following impoundment, although leeches remained relatively constant. Exceptions to this general pattern occurred. Incidence of ichthyoparasites with indirect life cycles (digenetic trematodes, cestodes, acanthocephalans, and nematodes) decreased immediately following impoundment with subsequent increases to a point equal or above that of preimpoundment, although exceptions occurred. Time for species adaptation to the reservoir environment varied, with some species disappearing and others occurring for the first time. Diversity indices indicated that a moderate parasite community was maintained in the White River two years prior to its impoundment to form Beaver Reservoir. During the first impoundment year the parasite community declined to the lowest postimpoundment level with the abrupt change in habitat. Throughout the following four post- impoundment years the parasite community gradually increased to become much larger and more complex than it was during preimpoundment. Parasite community succession stabilization occurred in the fifth postimpoundment year and continued the following year indicating the establishment of a climax ichthyoparasite community

    Transcriptome profiling of a toxic dinoflagellate reveals a gene-rich protist and a potential impact on gene expression due to bacterial presence

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    © The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 5 (2010): e9688, doi:10.1371/journal.pone.0009688.Dinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear DNA is thwarted by their massive genome sizes that are often several times that in humans. However, modern transcriptomic methods offer promising approaches to tackle this challenging system. Here, we used massively parallel signature sequencing (MPSS) to understand global transcriptional regulation patterns in Alexandrium tamarense cultures that were grown under four different conditions. We generated more than 40,000 unique short expression signatures gathered from the four conditions. Of these, about 11,000 signatures did not display detectable differential expression patterns. At a p-value < 1E-10, 1,124 signatures were differentially expressed in the three treatments, xenic, nitrogen-limited, and phosphorus-limited, compared to the nutrient-replete control, with the presence of bacteria explaining the largest set of these differentially expressed signatures. Among microbial eukaryotes, dinoflagellates contain the largest number of genes in their nuclear genomes. These genes occur in complex families, many of which have evolved via recent gene duplication events. Our expression data suggest that about 73% of the Alexandrium transcriptome shows no significant change in gene expression under the experimental conditions used here and may comprise a “core” component for this species. We report a fundamental shift in expression patterns in response to the presence of bacteria, highlighting the impact of biotic interaction on gene expression in dinoflagellates.This work was primarily funded by a collaborative grant from the National Institutes of Health (R01 ES 013679-01A2) awarded to DB, DMA, and M. Bento Soares. Funding support for DMA and DLE was also provided from the Woods Hole Center for Oceans and Human Health from the NSF/NIEHS Centers for Oceans and Human Health program, NIEHS (P50 ES 012742) and (NSF OCE-043072). Additional support came from the National Science Foundation (EF-0732440) in a grant awarded to F. Gerald Plumley, DB, JDH, and DMA. AM was supported by an Institutional NRSA (T 32 GM98629)

    An Initial Survey of White Dwarfs in the Sloan Digital Sky Survey

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    An initial assessment is made of white dwarf and hot subdwarf stars observed in the Sloan Digital Sky Survey. In a small area of sky (190 square degrees), observed much like the full survey will be, 269 white dwarfs and 56 hot subdwarfs are identified spectroscopically where only 44 white dwarfs and 5 hot subdwarfs were known previously. Most are ordinary DA (hydrogen atmosphere) and DB (helium) types. In addition, in the full survey to date, a number of WDs have been found with uncommon spectral types. Among these are blue DQ stars displaying lines of atomic carbon; red DQ stars showing molecular bands of C_2 with a wide variety of strengths; DZ stars where Ca and occasionally Mg, Na, and/or Fe lines are detected; and magnetic WDs with a wide range of magnetic field strengths in DA, DB, DQ, and (probably) DZ spectral types. Photometry alone allows identification of stars hotter than 12000 K, and the density of these stars for 15<g<20 is found to be ~2.2 deg^{-2} at Galactic latitudes 29-62 deg. Spectra are obtained for roughly half of these hot stars. The spectra show that, for 15<g<17, 40% of hot stars are WDs and the fraction of WDs rises to ~90% at g=20. The remainder are hot sdB and sdO stars.Comment: Accepted for AJ; 43 pages, including 12 figures and 5 table

    Very Red and Extremely Red Galaxies in the Fields of z ~ 1.5 Radio-Loud Quasars

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    We previously identified an excess of mostly red galaxies around 31 RLQs at z=1-2. These fields have an ERO (extremely red object, R-K>6) density 2.7 times higher than the field. Assuming the EROs are passively evolved galaxies at the quasar redshifts, they have characteristic luminosities of only ~L^*. We also present new observations of four z~1.54 RLQ fields: (1) Wide-field J & Ks data confirm an Abell richness ~2 excess within 140" of Q0835+580 but an excess only within 50" of Q1126+101. (2) In 3 fields we present deep narrow-band redshifted H-alpha observations. We detect five candidate galaxies at the quasar redshifts, a surface density 2.5x higher than the field. (3) SCUBA sub-mm observations of 3 fields detect 2 quasars and 2 galaxies with SEDs best fit as highly reddened galaxies at the quasar z. (4) H-band adaptive optics (AO) imaging is used to estimate redshifts for 2 red, bulge-dominated galaxies using the Kormendy relation. Both have structural redshifts foreground to the quasar, but these are not confirmed by photometric redshifts, possibly because their optical photometry is corrupted by scattered light from the AO guidestar. (5) We use quantitative SED fits to constrain the photometric redshifts z_ph for some galaxies. Most galaxies near Q0835+580 are consistent with being at its redshift, including a candidate very old passively evolving galaxy. Many very & extremely red objects have z_ph z_q, and dust reddening is required to fit most of them, including many objects whose fits also require relatively old stellar populations. Large reddenings of E(B-V)~0.6 are required to fit four J-K selected EROs, though all but one of them have best-fit z_ph>z_q. These objects may represent a population of dusty high-z galaxies underrepresented in optically selected samples. (Abridged)Comment: Missing object 1126.424 added to Table 4; title changed to save people the apparent trouble of reading the abstract. 38 pages, 16 figures, 2 in color; all-PostScript figure version available from http://astro.princeton.edu/~pathall/tp3.ps.g
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