257 research outputs found

    River Otter Reintroduction in Great Smoky Mountains National Park

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    Between 26 February and 31 March, 1986, 11 river otter (Lutra canadensis) were obtained from North Carolina, implanted with radio transmitters, and released on Abrams Creek in Great Smoky Mountains National Park. A total of 635 radio locations were obtained on eight otters. Male home ranges averaged 14.1 km during the study (March - December) while female home ranges averaged 15.9 km. There were no significant differences in home range length (p \u3e 0.05) between sexes. A total of 75 scats (42 samples) were collected during the study. Food items were calculated on frequency of occurrence. Crayfish occurred in 95% of all samples, followed by fish at 90%. Major fish species eaten were white suckers (57%), stonerollers (50%) and northern hogsuckers (40%). No specific size selection of fish was found. Other food items identified included frogs, turtles, salamanders and insects. Den sites were identified during the study. Otters used rock crevices/caves 32% of the time, followed by thick vegetation (24%), animal burrows (24%) and vegetative debris (20%). All but one otter was found to associate with at least one other otter during the study. Ninety-seven percent of the interactions were male/female interactions. Activity centers (areas where the otter spends 10% or more of its time) were identified for seven of the eight otters. All activity centers were in remote or inaccessible areas. Activity centers were shared by two otters in three instances. Only one mortality occurred during the study. A male died two weeks after release. Cause of death was not known, but it is likely the animal starved, due to poor condition of his teeth. No reproduction was recorded during the study. However, males and females interacted throughout the study. Objectives were met for this study and results indicate that the reintroduction was successful. The only remaining question is whether reproduction occurred; further surveys will have to be conducted to verify this important factor

    Variety of idempotents in nonassociative algebras

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    In this paper, we study the variety of all nonassociative (NA) algebras from the idempotent point of view. We are interested, in particular, in the spectral properties of idempotents when algebra is generic, i.e. idempotents are in general position. Our main result states that in this case, there exist at least n−1n-1 nontrivial obstructions (syzygies) on the Peirce spectrum of a generic NA algebra of dimension nn. We also discuss the exceptionality of the eigenvalue λ=12\lambda=\frac12 which appears in the spectrum of idempotents in many classical examples of NA algebras and characterize its extremal properties in metrised algebras.Comment: 27 pages, 1 figure, submitte

    The logbook of Pointed Hopf algebras over the sporadic groups

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    In this notes we give details of the proofs performed with GAP of the theorems of our paper "Pointed Hopf Algebras over the Sporadic Simple Groups".Comment: 22 pages, final versio

    Global cost and weight evaluation of fuselage keel design concepts

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    The Boeing program entitled Advanced Technology Composite Aircraft Structure (ATCAS) is focused on the application of affordable composite technology to pressurized fuselage structure of future aircraft. As part of this effort, a design study was conducted on the keel section of the aft fuselage. A design build team (DBT) approach was used to identify and evaluate several design concepts which incorporated different material systems, fabrication processes, structural configurations, and subassembly details. The design concepts were developed in sufficient detail to accurately assess their potential for cost and weight savings as compared with a metal baseline representing current wide body technology. The cost and weight results, along with an appraisal of performance and producibility risks, are used to identify a globally optimized keel design; one which offers the most promising cost and weight advantages over metal construction. Lastly, an assessment is given of the potential for further cost and weight reductions of the selected keel design during local optimization

    On the Relationship between the Uniqueness of the Moonshine Module and Monstrous Moonshine

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    We consider the relationship between the conjectured uniqueness of the Moonshine Module, Vâ™®{\cal V}^\natural, and Monstrous Moonshine, the genus zero property of the modular invariance group for each Monster group Thompson series. We first discuss a family of possible ZnZ_n meromorphic orbifold constructions of Vâ™®{\cal V}^\natural based on automorphisms of the Leech lattice compactified bosonic string. We reproduce the Thompson series for all 51 non-Fricke classes of the Monster group MM together with a new relationship between the centralisers of these classes and 51 corresponding Conway group centralisers (generalising a well-known relationship for 5 such classes). Assuming that Vâ™®{\cal V}^\natural is unique, we then consider meromorphic orbifoldings of Vâ™®{\cal V}^\natural and show that Monstrous Moonshine holds if and only if the only meromorphic orbifoldings of Vâ™®{\cal V}^\natural give Vâ™®{\cal V}^\natural itself or the Leech theory. This constraint on the meromorphic orbifoldings of Vâ™®{\cal V}^\natural therefore relates Monstrous Moonshine to the uniqueness of Vâ™®{\cal V}^\natural in a new way.Comment: 53 pages, PlainTex, DIAS-STP-93-0

    A 16.7 kb deletion in \u3ci\u3eSipa1l3\u3c/i\u3e is associated with juvenile cataract in mice

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    Congenital or juvenile cataract is a disease condition in which opacification of the lenses is present at birth or manifests early in life. It has been attributed to different monogenic factors with a high degree of heterogeneity and is often studied using mouse models. A spontaneous mutation was identified in a mouse line selected for heat loss that influenced lens formation and resulted in juvenile cataracts in mice homozygous for the recessive allele. Genetic dissection of this selection line by combining high-density genotypes and homozygosity mapping uncovered a 906 kb fragment on MMU7 encompassing 21 SNPs split into two groups of con-secutive, homozygous segments specific to the cataract phenotype. Haplotype analysis revealed a 197.5 kb segment unique to cataract-affected mice that in-cluded a single known transcript consisting of the first 14 exons of Sipa1l3. In this region, we discovered a deletion of 1114 bp at the mRNA level, spanning four coding exons, predicted to produce a truncated Sipa1l3 protein lacking a portion of a Rap-GAP domain and two other potentially vital domains. At the genome level, the deletion consisted of 16,733 bp. Genotyping across different samples confirmed that only affected mice were homozygous for the deletion and normal mice were either heterozygous or homozygous for the wild-type allele. Further studies will be required to determine the impact of the truncated Sipa1l3 domains on eye development

    On finite groups with many supersoluble subgroups

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    The solubility of a finite group with less than 6 non-supersoluble subgroups is confirmed in the paper. Moreover we prove that a finite insoluble group has exactly 6 non-supersoluble subgroups if and only if it is isomorphic to A5 or SL2(5). Furthermore, it is shown that a finite insoluble group has exactly 22 non-nilpotent subgroups if and only if it is isomorphic to A5 or SL2(5). This confirms a conjecture of Zarrin (Arch Math (Basel) 99:201-206, 2012)

    G(2) quivers

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    We present, in explicit matrix representation and a modernity befitting the community, the classification of the finite discrete subgroups of G2 and compute the McKay quivers arising therefrom. Of physical interest are the classes of Script N = 1 gauge theories descending from M-theory and of mathematical interest are possible steps toward a systematic study of crepant resolutions to smooth G2 manifolds as well as generalised McKay Correspondences. This writing is a companion monograph to hep-th/9811183 and hep-th/9905212, wherein the analogues for Calabi-Yau three- and four-folds were considered

    Advanced Technology Composite Fuselage - Repair and Damage Assessment Supporting Maintenance

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    Under the NASA-sponsored contracts for Advanced Technology Composite Aircraft Structures (ATCAS) and Materials Development Omnibus Contract (MDOC), Boeing is studying the technologies associated with the application of composite materials to commercial transport fuselage structure. Included in the study is the incorporation of maintainability and repairability requirements of composite primary structure into the design. This contractor report describes activities performed to address maintenance issues in composite fuselage applications. A key aspect of the study was the development of a maintenance philosophy which included consideration of maintenance issues early in the design cycle, multiple repair options, and airline participation in design trades. Fuselage design evaluations considered trade-offs between structural weight, damage resistance/tolerance (repair frequency), and inspection burdens. Analysis methods were developed to assess structural residual strength in the presence of damage, and to evaluate repair design concepts. Repair designs were created with a focus on mechanically fastened concepts for skin/stringer structure and bonded concepts for sandwich structure. Both a large crown (skintstringer) and keel (sandwich) panel were repaired. A compression test of the keel panel indicated the demonstrated repairs recovered ultimate load capability. In conjunction with the design and manufacturing developments, inspection methods were investigated for their potential to evaluate damaged structure and verify the integrity of completed repairs

    The Impact of Non-Equipartition on Cosmological Parameter Estimation from Sunyaev-Zel'dovich Surveys

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    The collisionless accretion shock at the outer boundary of a galaxy cluster should primarily heat the ions instead of electrons since they carry most of the kinetic energy of the infalling gas. Near the accretion shock, the density of the intracluster medium is very low and the Coulomb collisional timescale is longer than the accretion timescale. Electrons and ions may not achieve equipartition in these regions. Numerical simulations have shown that the Sunyaev-Zel'dovich observables (e.g., the integrated Comptonization parameter Y) for relaxed clusters can be biased by a few percent. The Y-mass relation can be biased if non-equipartition effects are not properly taken into account. Using a set of hydrodynamical simulations, we have calculated three potential systematic biases in the Y-mass relations introduced by non-equipartition effects during the cross-calibration or self-calibration when using the galaxy cluster abundance technique to constraint cosmological parameters. We then use a semi-analytic technique to estimate the non-equipartition effects on the distribution functions of Y (Y functions) determined from the extended Press-Schechter theory. Depending on the calibration method, we find that non-equipartition effects can induce systematic biases on the Y functions, and the values of the cosmological parameters Omega_8, sigma_8, and the dark energy equation of state parameter w can be biased by a few percent. In particular, non-equipartition effects can introduce an apparent evolution in w of a few percent in all of the systematic cases we considered. Techniques are suggested to take into account the non-equipartition effect empirically when using the cluster abundance technique to study precision cosmology. We conclude that systematic uncertainties in the Y-mass relation of even a few percent can introduce a comparable level of biases in cosmological parameter measurements.Comment: 10 pages, 3 figures, accepted for publication in the Astrophysical Journal, abstract abridged slightly. Typos corrected in version
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