2,989 research outputs found

    Radiation budget measurement/model interface

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    This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments

    Neutrino CP violating parameters from nontrivial quark-lepton correlation: a S3xGUT model

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    We investigate the prediction on the lepton phases in theories with a non trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices. We show that the actual evidence, under the only assumption that the correlation matrix VMV^M product of CKMCKM and PMNSPMNS has a zero in the entry (1,3)(1,3), gives us a prediction for the three CP-violating invariants JJ, S1S_1, and S2S_2. A better determination of the lepton mixing angles will give a strong prediction of the CP-violating invariants in the lepton sector. These will be tested in the next generation experiments. To clarify how our prediction works, we show how a model based on a Grand Unified Theory and the permutation flavor symmetry S3S_3 predicts V13M=0V^M_{13}=0.Comment: 7 pages, 3 figures. V2: new figure adde

    Polacy i ukraińcy w Odessie na przełomie XIX і XX w.: liczebność, struktura i kontakty obu diaspor

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    Здійснено аналіз розвитку міста Одеси на межі ХІХ – ХХ ст. Визначено місце польської громади в суспільно-політичному і економічному житті міста, її взаємовідносини з українською громадою Одеси.Осуществлен анализ развития города Одессы на рубеже ХІХ – ХХ в. Определено место польской общины в общественно-политической и экономической жизни города, ее взаимоотношения с украинской общиной Одессы.The analysis of the Odessa city development at the turn of the XIX – XX cent. is made. The place of Polish community in the city socio-political and economic life, its relationship with the Ukrainian community of Odessa is specified

    Incremental document map formation: multi-stage approach

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    The paper presents methodology for the incremental map formation in a multi-stage process of a search engine with the map based user interface1. The architecture of the experimental system allows for comparative evaluation of different constituent technologies for various stages of the process. The quality of the map generation process has been investigated based on a number of clustering and classification measures. Some conclusions concerning the impact of various technological solutions on map quality are presented

    Maximal LpL^p-regularity for stochastic evolution equations

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    We prove maximal LpL^p-regularity for the stochastic evolution equation \{{aligned} dU(t) + A U(t)\, dt& = F(t,U(t))\,dt + B(t,U(t))\,dW_H(t), \qquad t\in [0,T], U(0) & = u_0, {aligned}. under the assumption that AA is a sectorial operator with a bounded HH^\infty-calculus of angle less than 12π\frac12\pi on a space Lq(O,μ)L^q(\mathcal{O},\mu). The driving process WHW_H is a cylindrical Brownian motion in an abstract Hilbert space HH. For p(2,)p\in (2,\infty) and q[2,)q\in [2,\infty) and initial conditions u0u_0 in the real interpolation space \XAp we prove existence of unique strong solution with trajectories in L^p(0,T;\Dom(A))\cap C([0,T];\XAp), provided the non-linearities F:[0,T]\times \Dom(A)\to L^q(\mathcal{O},\mu) and B:[0,T]\times \Dom(A) \to \g(H,\Dom(A^{\frac12})) are of linear growth and Lipschitz continuous in their second variables with small enough Lipschitz constants. Extensions to the case where AA is an adapted operator-valued process are considered as well. Various applications to stochastic partial differential equations are worked out in detail. These include higher-order and time-dependent parabolic equations and the Navier-Stokes equation on a smooth bounded domain \OO\subseteq \R^d with d2d\ge 2. For the latter, the existence of a unique strong local solution with values in (H^{1,q}(\OO))^d is shown.Comment: Accepted for publication in SIAM Journal on Mathematical Analysi

    Multi-objective improvement of software using co-evolution and smart seeding

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    Optimising non-functional properties of software is an important part of the implementation process. One such property is execution time, and compilers target a reduction in execution time using a variety of optimisation techniques. Compiler optimisation is not always able to produce semantically equivalent alternatives that improve execution times, even if such alternatives are known to exist. Often, this is due to the local nature of such optimisations. In this paper we present a novel framework for optimising existing software using a hybrid of evolutionary optimisation techniques. Given as input the implementation of a program or function, we use Genetic Programming to evolve a new semantically equivalent version, optimised to reduce execution time subject to a given probability distribution of inputs. We employ a co-evolved population of test cases to encourage the preservation of the program’s semantics, and exploit the original program through seeding of the population in order to focus the search. We carry out experiments to identify the important factors in maximising efficiency gains. Although in this work we have optimised execution time, other non-functional criteria could be optimised in a similar manner

    Structural rearrangements in the mitochondrial genome of Drosophila melanogaster induced by elevated levels of the replicative DNA helicase

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    Pathological conditions impairing functions of mitochondria often lead to compensatory upregulation of the mitochondrial DNA (mtDNA) replisome machinery, and the replicative DNA helicase appears to be a key factor in regulating mtDNA copy number. Moreover, mtDNA helicase mutations have been associated with structural rearrangements of themitochondrial genome. To evaluate the effects of elevated levels of the mtDNA helicase on the integrity and replication of the mitochondrial genome, we overexpressed the helicase in Drosophila melanogaster Schneider cells and analyzed the mtDNA by two-dimensional neutral agarose gel electrophoresis and electron microscopy. We found that elevation of mtDNA helicase levels increases the quantity of replication intermediates and alleviates pausing at the replication slow zones. Though we did not observe a concomitant alteration in mtDNA copy number, we observed deletions specific to the segment of repeated elements in the immediate vicinity of the origin of replication, and an accumulation of species characteristic of replication fork stalling. We also found elevated levels of RNA that are retained in the replication intermediates. Together, our results suggest that upregulation of mtDNA helicase promotes the process of mtDNA replication but also results in genome destabilization.Peer reviewe

    T-cell contact-dependent regulation of CC and CXC chemokine production in monocytes through differential involvement of NFκB: implications for rheumatoid arthritis

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    We and others have reported that rheumatoid arthritis (RA) synovial T cells can activate human monocytes/macrophages in a contact-dependent manner to induce the expression of inflammatory cytokines, including tumour necrosis factor alpha (TNFα). In the present study we demonstrate that RA synovial T cells without further activation can also induce monocyte CC and CXC chemokine production in a contact-dependent manner. The transcription factor NFκB is differentially involved in this process as CXC chemokines but not CC chemokines are inhibited after overexpression of IκBα, the natural inhibitor of NFκB. This effector function of RA synovial T cells is also shared by T cells activated with a cytokine cocktail containing IL-2, IL-6 and TNFα, but not T cells activated by anti-CD3 cross-linking that mimics TCR engagement. This study demonstrates for the first time that RA synovial T cells as well as cytokine-activated T cells are able to induce monocyte chemokine production in a contact-dependent manner and through NFκB-dependent and NFκB-independent mechanisms, in a process influenced by the phosphatidyl-inositol-3-kinase pathway. Moreover, this study provides further evidence that cytokine-activated T cells share aspects of their effector function with RA synovial T cells and that their targeting in the clinic has therapeutic potential

    Random walk on the range of random walk

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    We study the random walk X on the range of a simple random walk on ℤ d in dimensions d≥4. When d≥5 we establish quenched and annealed scaling limits for the process X, which show that the intersections of the original simple random walk path are essentially unimportant. For d=4 our results are less precise, but we are able to show that any scaling limit for X will require logarithmic corrections to the polynomial scaling factors seen in higher dimensions. Furthermore, we demonstrate that when d=4 similar logarithmic corrections are necessary in describing the asymptotic behavior of the return probability of X to the origin
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