929 research outputs found

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    Nebraska is a major agricultural state. Nebraska ranks first in the nation in number of cattle on feed and fed cattle marketed, second in cash receipts from all livestock marketing, first in production of Great Northern beans, popcorn and alfalfa meal, and third in corn production. Agriculture is important to the state\u27s economy. Some economists project that one-half of Nebraska workers depend on agriculture and the many related industries for their employment. The annual value of agricultural production in Nebraska is more than 8 billion dollars. Agriculture and wildlife damage problems often go hand-in-hand. We have problems in agricultural situations with native coyotes, prairie dogs, pocket gophers, and ground squirrels, and with the imported starlings, house sparrows, and commensal rodents (Norway rats and house mice). Other animals including several game species cause agricultural damage at times. A variety of animals ranging from snakes and woodpeckers to bats and skunks are nuisances occasionally for homeowners. University of Nebraska Cooperative Extension plays an important educational role in helping Nebraskans handle these problems in an effective, safe and appropriate manner

    OPENING ADDRESS:

    Get PDF
    Nebraska is a major agricultural state. Nebraska ranks first in the nation in number of cattle on feed and fed cattle marketed, second in cash receipts from all livestock marketing, first in production of Great Northern beans, popcorn and alfalfa meal, and third in corn production. Agriculture is important to the state\u27s economy. Some economists project that one-half of Nebraska workers depend on agriculture and the many related industries for their employment. The annual value of agricultural production in Nebraska is more than 8 billion dollars. Agriculture and wildlife damage problems often go hand-in-hand. We have problems in agricultural situations with native coyotes, prairie dogs, pocket gophers, and ground squirrels, and with the imported starlings, house sparrows, and commensal rodents (Norway rats and house mice). Other animals including several game species cause agricultural damage at times. A variety of animals ranging from snakes and woodpeckers to bats and skunks are nuisances occasionally for homeowners. University of Nebraska Cooperative Extension plays an important educational role in helping Nebraskans handle these problems in an effective, safe and appropriate manner

    Amorphous interface layer in thin graphite films grown on the carbon face of SiC

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    Cross-sectional transmission electron microscopy (TEM) is used to characterize an amorphous layer observed at the interface in graphite and graphene films grown via thermal decomposition of C-face 4H-SiC. The amorphous layer does not to cover the entire interface, but uniform contiguous regions span microns of cross-sectional interface. Annular dark field scanning transmission electron microscopy (ADF-STEM) images and electron energy loss spectroscopy (EELS) demonstrate that the amorphous layer is a carbon-rich composition of Si/C. The amorphous layer is clearly observed in samples grown at 1600{\deg}C for a range of growth pressures in argon, but not at 1500{\deg}C, suggesting a temperature-dependent formation mechanism

    General Relativity as Classical Limit of Evolutionary Quantum Gravity

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    We analyze the dynamics of the gravitational field when the covariance is restricted to a synchronous gauge. In the spirit of the Noether theorem, we determine the conservation law associated to the Lagrangian invariance and we outline that a non-vanishing behavior of the Hamiltonian comes out. We then interpret such resulting non-zero ``energy'' of the gravitational field in terms of a dust fluid. This new matter contribution is co-moving to the slicing and it accounts for the ``materialization'' of a synchronous reference from the corresponding gauge condition. Further, we analyze the quantum dynamics of a generic inhomogeneous Universe as described by this evolutionary scheme, asymptotically to the singularity. We show how the phenomenology of such a model overlaps the corresponding Wheeler-DeWitt picture. Finally, we study the possibility of a Schr\"odinger dynamics of the gravitational field as a consequence of the correspondence inferred between the ensemble dynamics of stochastic systems and the WKB limit of their quantum evolution. We demonstrate that the time dependence of the ensemble distribution is associated with the first order correction in \hbar to the WKB expansion of the energy spectrum.Comment: 23 pages, to appear on Class. Quant. Gra

    Hawking Temperature in Taub-NUT (A)dS spaces via the Generalized Uncertainty Principle

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    Using the extended forms of the Heisenberg uncertainty principle from string theory and the quantum gravity theory, we drived Hawking temperature of a Taub-Nut-(A)dS black hole. In spite of their distinctive natures such as asymptotically locally flat and breakdown of the area theorem of the horizon for the black holes, we show that the corrections to Hawking temperature by the generalized versions of the the Heisenberg uncertainty principle increases like the Schwarzschild-(A)dS black hole and give the reason why the Taub-Nut-(A)dS metric may have AdS/CFT dual picture.Comment: version published in General Relativity and Gravitatio

    Quantum Gravitational Corrections to the Real Klein-Gordon Field in the Presence of a Minimal Length

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    The (D+1)-dimensional (β,β)(\beta,\beta')-two-parameter Lorentz-covariant deformed algebra introduced by Quesne and Tkachuk [C. Quesne and V. M. Tkachuk, J. Phys. A: Math. Gen. \textbf {39}, 10909 (2006).], leads to a nonzero minimal uncertainty in position (minimal length). The Klein-Gordon equation in a (3+1)-dimensional space-time described by Quesne-Tkachuk Lorentz-covariant deformed algebra is studied in the case where β=2β\beta'=2\beta up to first order over deformation parameter β\beta. It is shown that the modified Klein-Gordon equation which contains fourth-order derivative of the wave function describes two massive particles with different masses. We have shown that physically acceptable mass states can only exist for β<18m2c2\beta<\frac{1}{8m^{2}c^{2}} which leads to an isotropic minimal length in the interval 1017m<(Xi)0<1015m10^{-17}m<(\bigtriangleup X^{i})_{0}<10^{-15}m. Finally, we have shown that the above estimation of minimal length is in good agreement with the results obtained in previous investigations.Comment: 10 pages, no figur

    Integrin-mediated Tyrosine Phosphorylation and Cytokine Message Induction in Monocytic Cells: A POSSIBLE SIGNALING ROLE FOR THE Syk TYROSINE KINASE

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    Activation of cytoplasmic tyrosine kinases is an important aspect of signal transduction mediated by integrins. In the human monocytic cell line THP-1, either integrin-dependent cell adhesion to fibronectin or ligation of beta 1 integrins with antibodies causes a rapid and intense tyrosine phosphorylation of two sets of proteins of about 65-75 and 120-125 kDa. In addition, integrin ligation leads to nuclear translocation of the p50 and p65 subunits of the NF-kappa B transcription factor, to activation of a reporter gene driven by a promoter containing NF-kappa B sites, and to increased levels of mRNAs for immediate-early genes, including the cytokine interleukin (IL)-1 beta. The tyrosine kinase inhibitors genistein and herbimycin A block both integrin-mediated tyrosine phosphorylation and increases in IL-1 beta message levels, indicating a causal relationship between the two events. The components tyrosine phosphorylated subsequent to cell adhesion include paxillin, pp125FAK, and the SH2 domain containing tyrosine kinase Syk. In contrast, integrin ligation with antibodies induces tyrosine phosphorylation of Syk but not of FAK or paxillin. In adhering cells, pre-treatment with cytochalasin D suppresses tyrosine phosphorylation of FAK and paxillin but not of Syk, while IL-1 beta message induction is unaffected. These observations indicate that the Syk tyrosine kinase may be an important component of an integrin signaling pathway in monocytic cells, leading to activation of NF-kappa B and to increased levels of cytokine messages

    String-inspired cosmology: Late time transition from scaling matter era to dark energy universe caused by a Gauss-Bonnet coupling

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    The Gauss-Bonnet (GB) curvature invariant coupled to a scalar field ϕ\phi can lead to an exit from a scaling matter-dominated epoch to a late-time accelerated expansion, which is attractive to alleviate the coincident problem of dark energy. We derive the condition for the existence of cosmological scaling solutions in the presence of the GB coupling for a general scalar-field Lagrangian density p(ϕ,X)p(\phi, X), where X=(1/2)(ϕ)2X=-(1/2)(\nabla \phi)^2 is a kinematic term of the scalar field. The GB coupling and the Lagrangian density are restricted to be in the form f(ϕ)eλϕf(\phi) \propto e^{\lambda \phi} and p=Xg(Xeλϕ)p=Xg (Xe^{\lambda \phi}), respectively, where λ\lambda is a constant and gg is an arbitrary function. We also derive fixed points for such a scaling Lagrangian with a GB coupling f(ϕ)eμϕf(\phi) \propto e^{\mu \phi} and clarify the conditions under which the scaling matter era is followed by a de-Sitter solution which can appear in the presence of the GB coupling. Among scaling models proposed in the current literature, we find that the models which allow such a cosmological evolution are an ordinary scalar field with an exponential potential and a tachyon field with an inverse square potential, although the latter requires a coupling between dark energy and dark matter.Comment: 18 pages, 4 figures, version to appear in JCA

    Meningococcus genome informatics platform: a system for analyzing multilocus sequence typing data

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    The Meningococcus Genome Informatics Platform (MGIP) is a suite of computational tools for the analysis of multilocus sequence typing (MLST) data, at http://mgip.biology.gatech.edu. MLST is used to generate allelic profiles to characterize strains of Neisseria meningitidis, a major cause of bacterial meningitis worldwide. Neisseria meningitidis strains are characterized with MLST as specific sequence types (ST) and clonal complexes (CC) based on the DNA sequences at defined loci. These data are vital to molecular epidemiology studies of N. meningitidis, including outbreak investigations and population biology. MGIP analyzes DNA sequence trace files, returns individual allele calls and characterizes the STs and CCs. MGIP represents a substantial advance over existing software in several respects: (i) ease of use—MGIP is user friendly, intuitive and thoroughly documented; (ii) flexibility—because MGIP is a website, it is compatible with any computer with an internet connection, can be used from any geographic location, and there is no installation; (iii) speed—MGIP takes just over one minute to process a set of 96 trace files; and (iv) expandability—MGIP has the potential to expand to more loci than those used in MLST and even to other bacterial species
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