6,600 research outputs found

    An Emergence Trap for Aquatic Insects

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    Excerpt: The identification of organisms is a prerequisite to developing water quality criteria for aquatic life. Identification is necessary because differences in water quality requirements are specific and may be different for closely allied species. The taxonomy of various species, particularly those associated with the aquatic environment, is much more detailed and better known for adults than for immature instars. To facilitate correlation of adult and larval forms, a trap was needed to collect the emerging adults from the various streams

    ATS-6 flight accelerometers

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    Five accelerometers mounted near the adapter base of the Titan 3-C launch vehicle and three on the hub of the ATS-F spacecraft provided (1) data for verifying basic spacecraft mode shapes and frequencies during powered flight while attached to the launch vehicle; (2) failure mode detection and diagnostic information on in-flight anomalies; and (3) data to be used in the design of future spacecraft to be flown on the Titan 3-C. Because data from the instruments mounted on the spacecraft hub passed through an in-flight disconnect at the separation plane between the transtage and ATS-F, the moment this connector was broken, the signal to the telemetry system showed a step function change. By monitoring these telemetry traces on the ground at appropriate times during flight sequences, a positive indication of spacecraft separation was obtained. Flight data showing dynamic response at spacecraft launch vehicle interface and at the top of ATS spacecraft during significant launch events are presented in tables

    The Carpenter Shift: The Evolution of Fourth Amendment Jurisprudence in the Digital Age

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    The language of the Fourth Amendment protects citizens from warrantless searches of their tangible places and things. For centuries strict interpretation of this Amendment sufficed to protect against invasions of privacy, but developments in modern technology have rendered the Amendment’s initial scope inadequate. Our private information has moved from desks to remote servers, and police surveillance has become both ubiquitous and infallible. In response to these developments, the Supreme Court has expanded the scope of the Fourth Amendment. This thesis explores this doctrinal evolution. Through an analysis of some of the Court’s most consequential Fourth Amendment rulings, this thesis finds support for Orin Kerr’s theory of Equilibrium Adjustment. This theory explains that as new technologies upset the balance between privacy rights and police power, the Supreme Court will adjust the scope of the Fourth Amendment’s protections to restore a proper equilibrium. This thesis then examines the jurisprudential shift that is the result of the Court’s decision in Carpenter v. United States, in which it held that a collection of long-term cell-site location information constitutes a Fourth Amendment search. First, this thesis discusses two interpretations of Carpenter, by Fourth Amendment scholars Orin Kerr and Paul Ohm, and then it explores the actual impact of Carpenter on the evolution of Fourth Amendment law. Matthew Tokson’s empirical study of Carpenter in lower court rulings finds that these courts have largely complied with the Carpenter shift and have begun to flesh out a new Fourth Amendment multi-factor test. This thesis also analyzes the mosaic theory in Fourth Amendment law, which emphasizes that a collection of information implicates privacy concerns to a far greater degree than does a single piece of information, and urges the courts to adopt this approach to the Fourth Amendment in the digital age

    \u3ci\u3eLeucanthiza Dircella\u3c/i\u3e (Lepidoptera: Gracillariidae): A Leafminer of Leatherwood, \u3ci\u3eDirca Palustris\u3c/i\u3e

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    Leatherwood, Dirca palustris (Thymelaeaceae), is an understory shrub ranging throughout most of the eastern and central United States and adjacent Canada. During 1997-1999, we conducted studies to identify and assess the impact of a leafminer that was causing significant damage to leather- wood plants in eastern Gogebic County, Michigan. Leucanthiza dircella was identified as the only insect responsible for the leaf mining activity on leatherwood. In northern Michigan, L. dircella completed one generation per year. Adult moths were captured on yellow sticky panels suspended from leatherwood branches. In 1997 and 1998, most adults were captured during the first sampling period of each year: 6-12 June 1997 and 3-19 May 199B. In 1999, no moths were collected during 5-29 April but adults were collected between 30 April and 22 June 1999. In 1999, initiation of adult flight coincided with D. palustris leaf flush. In 1997, leaf mines were very noticeable by 30 June. The mean number of live L. dircella larvae per mine was 3.5 on 17 July 1997 and then decreased as the season progressed, with most larvae having exited the mines by late August to pupate in the soil. In late August 1997, the mean surface area of a single leaf was 17.8 cm2 and the mean surface area of a single mine was 5.9 cm2. At the end of the 1997 growing sea­son, 31% of the leatherwood leaves contained L. dircella mines, and 11% of the total leaf surface area had been mined. In 1999, only 8% of the leaves in the study area contained L. dircella mines. No leatherwood mortality was evident as a result of L. dircella leaf mining. Seven species of hymenopteran parasitoids were reared from L. dircella larvae, including one braconid in the genus Pholetesor and six eulophids in the genera Chrysocharis, Closterocerus, Pnigalio, and Sympiesis. Three coleopterans that were commonly observed on leatherwood plants during all years included: Glyptina brunnea (Chrysomelidae), Phyllobius oblongus (Curculionidae) and Polydrusus sericeus (Curculionidae)

    Cosmic Background Explorer (COBE): Emergency support

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    The Cosmic Background Explorer (COBE) Mission will measure the diffuse radiation from the universe in the wavelength band 1 micron to 9.6 mm. The band includes the 3 K cosmic background radiation, the known relic of the primeval cosmic explosion. The COBE satellite will be launched from the Western Space and Missile Center (EWSMC) via a Delta launch vehicle into a circular parking orbit of about 300 km. COBE will be placed into a 900-km altitude circular orbit. Coverage will be provided by the Deep Space Network (DSN) for COBE emergencies that would prevent communications via the normal channels of the Tracking and Data Relay Satellite System (TDRSS). Emergency support will be provided by the DSN 26-m subnetwork. Information is given in tabular form for DSN network support, frequency assignments, telemetry, and command

    Flight-wind restrictions procedure, Atlas/ Centaur AC-6 through AC-15

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    Prelaunch calculation of wind profile effect using axial load and bending moments for Atlas and Centaur launch vehicle

    Molecular Control of the Amount, Subcellular Location and Activity State of Translation Elongation Factor 2 (eEF-2) in Neurons Experiencing Stress

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    Eukaryotic elongation factor 2 (eEF-2) is an important regulator of the protein translation machinery wherein it controls the movement of the ribosome along the mRNA. The activity of eEF-2 is regulated by changes in cellular energy status and nutrient availability, and posttranslational modifications such as phosphorylation and mono-ADP-ribosylation. However, the mechanisms regulating protein translation under conditions of cellular stress in neurons are unknown. Here we show that when rat hippocampal neurons experience oxidative stress (lipid peroxidation induced by exposure to cumene hydroperoxide; CH), eEF-2 is hyperphosphorylated and ribosylated resulting in reduced translational activity. The degradation of eEF-2 requires calpain proteolytic activity and is accompanied by accumulation of eEF-2 in the nuclear compartment. The subcellular localization of both native and phosphorylated forms of eEF-2 is influenced by CRM1 and 14.3.3, respectively. In hippocampal neurons p53 interacts with non-phosphorylated (active) eEF-2, but not with its phosphorylated form. The p53 – eEF-2 complexes are present in cytoplasm and nucleus, and their abundance increases when neurons experience oxidative stress. The nuclear localization of active eEF-2 depends upon its interaction with p53, as cells lacking p53 contain less active eEF-2 in the nuclear compartment. Overexpression of eEF-2 in hippocampal neurons results in increased nuclear levels of eEF-2, and decreased cell death following exposure to CH. Our results reveal novel molecular mechanisms controlling the differential subcellular localization and activity state of eEF-2 that may influence the survival status of neurons during periods of elevated oxidative stress.España, Ministerio de Ciencia e Innovación BFU2010-20882.España, Ministerio de Educación, Cultura y Deporte postdoctoral fellowship (EX2009-0918

    Magnetic Properties of Epitaxial and Polycrystalline Fe/Si Multilayers

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    Fe/Si multilayers with antiferromagnetic interlayer coupling have been grown via ion-beam sputtering on both glass and single-crystal substrates. High-angle x-ray diffraction measurements show that both sets of films have narrow Fe peaks, implying a large crystallite size and crystalline iron silicide spacer layers. Low-angle x-ray diffraction measurements show that films grown on glass have rougher interfaces than those grown on single-crystal substrates. The multilayers grown on glass have a larger remanent magnetization than the multilayers grown on single-crystal substrates. The observation of magnetocrystalline anisotropy in hysteresis loops and (hkl)(hkl) peaks in x-ray diffraction demonstrates that the films grown on MgO and Ge are epitaxial. The smaller remanent magnetization in Fe/Si multilayers with better layering suggests that the remanence is not an intrinsic property.Comment: 9 pages, RevTex, 4 figures available by fax. Send email to [email protected] for more info. Submitted to '95 MMM proceeding

    Possible X-ray diagnostic for jet/disk dominance in Type 1 AGN

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    Using Rossi X-ray Timing Explorer Seyfert 1 and 1.2 data spanning 9 years, we study correlations between X-ray spectral features. The sample consists of 350 time-resolved spectra from 12 Seyfert 1 and 1.2 galaxies. Each spectrum is fitted to a model with an intrinsic powerlaw X-ray spectrum produced close to the central black hole that is reprocessed and absorbed by material around the black hole. To test the robustness of our results, we performed Monte Carlo simulations of the spectral sample. We find a complex relationship between the iron line equivalent width (EW) and the underlying power law index (Gamma). The data reveal a correlation between Gamma and EW which turns over at Gamma <~ 2, but finds a weak anti-correlation for steeper photon indices. We propose that this relationship is driven by dilution of a disk spectrum (which includes the narrow iron line) by a beamed jet component and, hence, could be used as a diagnostic of jet-dominance. In addition, our sample shows a strong correlation between the reflection fraction (R) and Gamma, but we find that it is likely the result of modeling degeneracies. We also see the X-ray Baldwin effect (an anti-correlation between the 2-10 keV X-ray luminosity and EW) for the sample as a whole, but not for the individual galaxies and galaxy types.Comment: Accepted for publication in ApJ, 14 page

    Phylogenetic Analyses of Two Mitochondrial Metabolic Genes Sampled in Parallel from Angiosperms Find Fundamental Interlocus Incongruence

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    Plant molecular phylogeneticists have supported an analytical approach of combining loci from different genomes, but the combination of mitochondrial sequences with chloroplast and nuclear sequences is potentially problematic. Low substitution rates in mitochondrial genes should decrease saturation, which is especially useful for the study of deep divergences. However, individual mitochondrial loci are insuffi ciently informative, so that combining congruent loci is necessary. For this study atp1 and cox1 were selected, which are of similar lengths, encode components of the respiratory pathway, and generally lack introns. Thus, these genes might be expected to have similar functional constraints, selection pressures, and evolutionary histories. Strictly parallel sampling of 52 species was achieved as well as six additional composite terminals with representatives from the major angiosperm clades. However, analyses of the separate loci produced strongly incongruent topologies. The source of the incongruence was investigated by validating sequences with questionable affi nities, excluding RNA-edited nucleotides, deleting taxa with unexpected phylogenetic associations, and comparing different phylogenetic methods. However, even after potential artifacts were addressed and sites and taxa putatively associated with confl ict were excluded, the resulting gene trees for the two mitochondrial loci were still substantially incongruent by all measures examined. Therefore, combining these loci in phylogenetic analysis may be counterproductive to the goal of fully resolving the angiosperm phylogeny
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