23,558 research outputs found

    Deductive Verification of Unmodified Linux Kernel Library Functions

    Full text link
    This paper presents results from the development and evaluation of a deductive verification benchmark consisting of 26 unmodified Linux kernel library functions implementing conventional memory and string operations. The formal contract of the functions was extracted from their source code and was represented in the form of preconditions and postconditions. The correctness of 23 functions was completely proved using AstraVer toolset, although success for 11 functions was achieved using 2 new specification language constructs. Another 2 functions were proved after a minor modification of their source code, while the final one cannot be completely proved using the existing memory model. The benchmark can be used for the testing and evaluation of deductive verification tools and as a starting point for verifying other parts of the Linux kernel.Comment: 18 pages, 2 tables, 6 listings. Accepted to ISoLA 2018 conference. Evaluating Tools for Software Verification trac

    Polarimetry of Compact Symmetric Objects

    Get PDF
    We present multi-frequency VLBA observations of two polarized Compact Symmetric Objects (CSOs), J0000+4054 and J1826+1831, and a polarized CSO candidate, J1915+6548. Using the wavelength-squared dependence of Faraday rotation, we obtained rotation measures (RMs) of -180 \pm 10 rad m^-2 and 1540 \pm 7 rad m^-2 for the latter two sources. These are lower than what is expected of CSOs (several 1000 rad m^-2) and, depending on the path length of the Faraday screens, require magnetic fields from 0.03 to 6 \mu G. These CSOs may be more heavily affected by Doppler boosting than their unpolarized counterparts, suggesting that a jet-axis orientation more inclined towards the line of sight is necessary to detect any polarization. This allows for low RMs if the polarized components are oriented away from the depolarizing circumnuclear torus. These observations also add a fourth epoch to the proper motion studies of J0000+4054 and J1826+1831, constraining their kinematic age estimates to >610 yrs and 2600 \pm 490 yrs, respectively. The morphology, spectrum, and component motions of J1915+6548 are discussed in light of its new classification as a CSO candidate, and its angle to the line of sight (~50\deg) is determined from relativistic beaming arguments.Comment: 29 pages, including 9 figures; Accepted by Astrophysical Journal, 16 Feb 0

    Feno de cunhã (Clitoria ternatea L.) para acabamento de cordeiros.

    Get PDF
    Resumo: Foram utilizados 32 cordeiros, mestiços, durante setenta dias em estudo na Embrapa Caprinos, em Sobral, CE, para determinar a influência do nível de concentrado em dietas para acabamento de cordeiros em confinamento. Os tratamentos foram as seguintes relaçoes forragem:concentrado: 100%:0% (T1), 85%:15% (T2), 70%:30% (T3) e 55%:45% (T4). A forragem fornecida era feno de cunha e o concentrado era composta de 75% de milho e 25% de farelo de soja. 0 ajuste das proporçoes foi feito diariamente, corn base no consumo de volumoso, servido ad libitum. Corn o aumento do nível de concentrado na dieta dos animais, observou-se incrementos lineares (PO,05) quanto aos tratamentos. Conclui-se que todas as raçoes testadas podem ser utilizadas para terminação de cordeiros em confinamento. Cunhã hay (Clitoria ternatea L.) for finishing of lambs. ABSTRACT - Thirty two crossbred lambs were used in a 70 day study at Embrapa Caprinos, in Sobral, CE, Brazil to evaluate the influence of concentrate levels on finishing diets under confinement. The treatments were the following roughage to concentrate relations: 100% to 0% (T1), 85% to 15% (T2), 70% to 30% (T3) and 55% to 45% (T4). The roughage was cunhã hay (Clitoria ternatea L), and the concentrate was composed of corn (75%) and soybean meal (25%). The adjustments of the proportions were made daily, based on the roughage intake, served ad libitum. It was observed that the total dry matter intake increased, the forage intake decreased, the feed efficiency improved and the daily weight gain increased (P0.05) among treatments. It was concluded that any of the diets studied can be used for finishing lambs

    An evolutionary perspective on the kinome of malaria parasites

    Get PDF
    Malaria parasites belong to an ancient lineage that diverged very early from the main branch of eukaryotes. The approximately 90-member plasmodial kinome includes a majority of eukaryotic protein kinases that clearly cluster within the AGC, CMGC, TKL, CaMK and CK1 groups found in yeast, plants and mammals, testifying to the ancient ancestry of these families. However, several hundred millions years of independent evolution, and the specific pressures brought about by first a photosynthetic and then a parasitic lifestyle, led to the emergence of unique features in the plasmodial kinome. These include taxon-restricted kinase families, and unique peculiarities of individual enzymes even when they have homologues in other eukaryotes. Here, we merge essential aspects of all three malaria-related communications that were presented at the Evolution of Protein Phosphorylation meeting, and propose an integrated discussion of the specific features of the parasite's kinome and phosphoproteome

    Avaliação preliminar de clones de seringueira em Mazagão-AP.

    Get PDF
    Para indicar germoplasma adaptados e de elevada produtividade, esta sendo deselvolvido um ensaio de competição com 15 clones de seringueira de diferentes origens.bitstream/item/65107/1/AP-1989-avaliacao-preliminar-clones-seringueiras.pd

    Dark matter from cosmic defects on galactic scales?

    Full text link
    We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We emphasize that the more standard defects (such as Goto-Nambu strings) are unsuitable for this task, but show that more general models (such as transonic wiggly strings) could in principle have a better chance. In any case, we show that observational data severely restricts any such scenarios.Comment: Submitted to Phys. Rev. D (Brief Reports). v2: Reference added and some typos corrected, matches published versio
    corecore