1,104 research outputs found

    Planet Four: Terrains - Discovery of Araneiforms Outside of the South Polar Layered Deposits

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    We present the results of a systematic mapping of seasonally sculpted terrains on the South Polar region of Mars with the Planet Four: Terrains (P4T) online citizen science project. P4T enlists members of the general public to visually identify features in the publicly released Mars Reconnaissance Orbiter CTX images. In particular, P4T volunteers are asked to identify: 1) araneiforms (including features with a central pit and radiating channels known as 'spiders'); 2) erosional depressions, troughs, mesas, ridges, and quasi-circular pits characteristic of the South Polar Residual Cap (SPRC) which we collectively refer to as 'Swiss cheese terrain', and 3) craters. In this work we present the distributions of our high confidence classic spider araneiforms and Swiss cheese terrain identifications. We find no locations within our high confidence spider sample that also have confident Swiss cheese terrain identifications. Previously spiders were reported as being confined to the South Polar Layered Deposits (SPLD). Our work has provided the first identification of spiders at locations outside of the SPLD, confirmed with high resolution HiRISE imaging. We find araneiforms on the Amazonian and Hesperian polar units and the Early Noachian highland units, with 75% of the identified araneiform locations in our high confidence sample residing on the SPLD. With our current coverage, we cannot confirm whether these are the only geologic units conducive to araneiform formation on the Martian South Polar region. Our results are consistent with the current CO2 jet formation scenario with the process exploiting weaknesses in the surface below the seasonal CO2 ice sheet to carve araneiform channels into the regolith over many seasons. These new regions serve as additional probes of the conditions required for channel creation in the CO2 jet process. (Abridged)Comment: accepted to Icarus - Supplemental data files are available at https://www.zooniverse.org/projects/mschwamb/planet-four-terrains/about/results - Icarus print version available at http://www.sciencedirect.com/science/article/pii/S001910351730055

    Panel Two: Information Policy Making

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    The second panel of From Conduit to Content: The Emergence of Information Policy and Law addresses the government\u27s response to the policy making challenges presented by information. Panelists from the government and academia explore the question: How has, and how should, the policy-making process respond to the diversity of issues, interests, and policymakers? Participants include Fred H. Cate, Allen S. Hammond, Bruce W. McConnell, Michael Nelson, Janice Obuchowski, and Marc Rotenbergaddresses the government\u27s response to the policy making challenges presented by information. Panelists from the government and academia explore the question: How has, and how should, the policy-making process respond to the diversity of issues, interests, and policymakers? Participants include Fred H. Cate, Allen S. Hammond, Bruce W. McConnell, Michael Nelson, Janice Obuchowski, and Marc Rotenberg. From Conduit to Content: The Emergence of Information Policy and Law. The Annenberg Washington Program. Friday, March 3 1995, Washington, D.C

    Panel Two: Information Policy Making

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    The second panel of From Conduit to Content: The Emergence of Information Policy and Law addresses the government\u27s response to the policy making challenges presented by information. Panelists from the government and academia explore the question: How has, and how should, the policy-making process respond to the diversity of issues, interests, and policymakers? Participants include Fred H. Cate, Allen S. Hammond, Bruce W. McConnell, Michael Nelson, Janice Obuchowski, and Marc Rotenbergaddresses the government\u27s response to the policy making challenges presented by information. Panelists from the government and academia explore the question: How has, and how should, the policy-making process respond to the diversity of issues, interests, and policymakers? Participants include Fred H. Cate, Allen S. Hammond, Bruce W. McConnell, Michael Nelson, Janice Obuchowski, and Marc Rotenberg. From Conduit to Content: The Emergence of Information Policy and Law. The Annenberg Washington Program. Friday, March 3 1995, Washington, D.C

    A Lectin HPLC Method to Enrich Selectively-glycosylated Peptides from Complex Biological Samples

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    Glycans are an important class of post-translational modifications. Typically found on secreted and extracellular molecules, glycan structures signal the internal status of the cell. Glycans on tumor cells tend to have abundant sialic acid and fucose moieties. We propose that these cancer-associated glycan variants be exploited for biomarker development aimed at diagnosing early-stage disease. Accordingly, we developed a mass spectrometry-based workflow that incorporates chromatography on affinity matrices formed from lectins, proteins that bind specific glycan structures. The lectins Sambucus nigra (SNA) and Aleuria aurantia (AAL), which bind sialic acid and fucose, respectively, were covalently coupled to POROS beads (Applied Biosystems) and packed into PEEK columns for high pressure liquid chromatography (HPLC). Briefly, plasma was depleted of the fourteen most abundant proteins using a multiple affinity removal system (MARS-14; Agilent). Depleted plasma was trypsin-digested and separated into flow-through and bound fractions by SNA or AAL HPLC. The fractions were treated with PNGaseF to remove N-linked glycans, and analyzed by LC-MS/MS on a QStar Elite. Data were analyzed using Mascot software. The experimental design included positive controls—fucosylated and sialylated human lactoferrin glycopeptides—and negative controls—high mannose glycopeptides from Saccharomyces cerevisiae—that were used to monitor the specificity of lectin capture. Key features of this workflow include the reproducibility derived from the HPLC format, the positive identification of the captured and PNGaseF-treated glycopeptides from their deamidated Asn-Xxx-Ser/Thr motifs, and quality assessment using glycoprotein standards. Protocol optimization also included determining the appropriate ratio of starting material to column capacity, identifying the most efficient capture and elution buffers, and monitoring the PNGaseF-treatment to ensure full deglycosylation. Future directions include using this workflow to perform mass spectrometry-based discovery experiments on plasma from breast cancer patients and control individuals

    Pion-nucleus elastic scattering on 12C, 40Ca, 90Zr, and 208Pb at 400 and 500 MeV

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    Pion-nucleus elastic scattering at energies above the Delta(1232) resonance is studied using both pi+ and pi- beams on 12C, 40Ca, 90Zr, and 208Pb. The present data provide an opportunity to study the interaction of pions with nuclei at energies where second-order corrections to impulse approximation calculations should be small. The results are compared with other data sets at similar energies, and with four different first-order impulse approximation calculations. Significant disagreement exists between the calculations and the data from this experiment

    Still no convincing evidence for cognitive map use by honeybees

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    Cheeseman et al. (1) claim that an ability of honey bees to travel home through a landscape with conflicting information from a celestial compass proves the bees' use of a cognitive map. Their claim involves a curious assumption about the visual information that can be extracted from the terrain: that there is sufficient information for a bee to identify where it is, but insufficient to guide its path without resorting to a cognitive map. We contend that the authors’ claims are unfounded

    Norms of Presentational Force

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    This is the author's accepted manuscript, made available with permission of the American Forensic Association.Can style or presentational devices reasonably compel us to believe, agree, act? I submit that they can, and that the normative pragmatic project explains how. After describing a normative pragmatic approach to presentational force, I analyze and evaluate presentational force in Susan B. Anthony's "Is it a Crime for a U. S. Citizen to Vote" as it apparently proceeds from logic, emotion, and style. I conclude with reflections on the compatibility of the normative pragmatic approach with the recently-developed pragma-dialectical treatment of presentational devices
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