41,133 research outputs found

    Charm-System Tests of CPT with FOCUS

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    We discuss a search for CPT violation in neutral charm meson oscillations. The data come from the Fermilab fixed-target experiment FOCUS. While flavor mixing in the charm sector is predicted to be small by the standard model, it is still possible to investigate CPT violation through study of the proper time dependence of the asymmetry in right-sign decay rates for D0 and D0-bar. Using present limits for D0-D0-bar mixing we infer bounds on charm CPT violation using data from FOCUS.Comment: 8 pages, invited talk at the Second Meeting on CPT and Lorentz Symmetry, Indiana University, Bloomington, August 15-18, 200

    Confidence assessment in the teaching of basic science

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    A scheme is described for including information about confidence in the computer‐based assessment of students. After each answer, students declare a confidence level of 1, 2, or 3. If the answer is correct, then this is the mark awarded. If not, marks of 0, ‐2, or ‐6 are awarded Students do well on this scheme if they can discriminate between when they are sure of correct answers and when they are partly guessing. In self‐assessment, students are trained to reflect on their reasoning, and to develop the skills of correct confidence judgement. The task of writing tests is simplified, since it becomes less important to ask complex questions. Simple direct questions discriminate better between students than they do with ordinary marking. Good students answer correctly with high confidence, while weak students moderate their confidence level if they know they are uncertain, or else lose heavily when they make mistakes. Preliminary data are presented from self‐assessment trials amongst medical students

    Site Description for the University of Nebraska's Sandhills Agricultural Laboratory

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    The Sandhills Agricultural Laboratory is operated by the University of Nebraska. The laboratory is located in the south-central part of the Nebraska Sandhills near Tryon, Nebraska (41 deg. 37' N; 100 deg. 50' W). The laboratory is surrounded on the west and south by native rangeland vegetation, on the south by a large field of corn irrigated by a center pivot, and on the east by wheat stubble. This site is appropriate for moisture stress studies since rainfall is almost always inadequate to meet evaporative demands of agricultural crops during most of the growing season and the sandy soils (Valentine fine sand) at the site do not store large quantities of water. Various levels of water stress are achieved through irrigation from solid set sprinklers

    U.S. Law of the Sea Cruise to Complete the Mapping of Necker Ridge, Central Pacific Ocean

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    U.S. Law of the Sea Cruise to Complete the Mapping of Necker Ridge, Central Pacific Ocean CRUISE KM1121 July 31, to August 10, 2011 Honolulu, HI to Honolulu, H

    U.S. Law of the Sea Cruise to Map the Foot of the Slope of the Northeast U.S. Atlantic Continental Margin: Leg 6

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    U.S. Law of the Sea Cruise to Map the Foot of the Slope of the Northeast U.S. Atlantic Continental Margin: Leg 6 Cruise KNOX17RR May 1 – 31, 2008 Ft. Lauderdale, FL to Woods Hole, M

    A New Family of Cavernicolous Millipedes with the Description of a New Genus and Species from Idaho (Diplopoda: Chordeumida: Chordeumidea)

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    The Chordeumidea is accumulating species names faster than any other group of North American Diplopoda. About one-half its species, 47, have been described since 1950. This recent growth has occurred because the small size, localized populations, and, frequently, cave habitus of these millipeds have obstructed thorough collection in the past. These factors have only recently been overcome by comprehensive collecting. As a result of this rapidgrowth and the many artificial groupings which result from it, much organization of the higher classification remains to be done. Hoffman (1961) emphasizes that co- operation between workers, more thorough descriptions, more accurate illustrations, and revisions are necessary if a proper classification is to be attained. Described herein is a new cave form unique among the known North American Chordeumidea. Related to Cleidogonidae, Conotylidae, and Bactropidae, it is distinguished from these families by having the ninth legs reduced and unsegmented. This species represents the type of a new family, which we name after the state in which it was collected