1,325 research outputs found

    Quantitative estimation of plant characteristics using spectral measurement: A survey of the literature

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    Proving Craig and Lyndon Interpolation Using Labelled Sequent Calculi

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    We have recently presented a general method of proving the fundamental logical properties of Craig and Lyndon Interpolation (IPs) by induction on derivations in a wide class of internal sequent calculi, including sequents, hypersequents, and nested sequents. Here we adapt the method to a more general external formalism of labelled sequents and provide sufficient criteria on the Kripke-frame characterization of a logic that guarantee the IPs. In particular, we show that classes of frames definable by quantifier-free Horn formulas correspond to logics with the IPs. These criteria capture the modal cube and the infinite family of transitive Geach logics

    Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches

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    Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended

    Does Treewidth Help in Modal Satisfiability?

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    Many tractable algorithms for solving the Constraint Satisfaction Problem (CSP) have been developed using the notion of the treewidth of some graph derived from the input CSP instance. In particular, the incidence graph of the CSP instance is one such graph. We introduce the notion of an incidence graph for modal logic formulae in a certain normal form. We investigate the parameterized complexity of modal satisfiability with the modal depth of the formula and the treewidth of the incidence graph as parameters. For various combinations of Euclidean, reflexive, symmetric and transitive models, we show either that modal satisfiability is FPT, or that it is W[1]-hard. In particular, modal satisfiability in general models is FPT, while it is W[1]-hard in transitive models. As might be expected, modal satisfiability in transitive and Euclidean models is FPT.Comment: Full version of the paper appearing in MFCS 2010. Change from v1: improved section 5 to avoid exponential blow-up in formula siz

    Understanding the errors of SHAPE-directed RNA structure modeling

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    Single-nucleotide-resolution chemical mapping for structured RNA is being rapidly advanced by new chemistries, faster readouts, and coupling to computational algorithms. Recent tests have shown that selective 2'-hydroxyl acylation by primer extension (SHAPE) can give near-zero error rates (0-2%) in modeling the helices of RNA secondary structure. Here, we benchmark the method using six molecules for which crystallographic data are available: tRNA(phe) and 5S rRNA from Escherichia coli, the P4-P6 domain of the Tetrahymena group I ribozyme, and ligand-bound domains from riboswitches for adenine, cyclic di-GMP, and glycine. SHAPE-directed modeling of these highly structured RNAs gave an overall false negative rate (FNR) of 17% and a false discovery rate (FDR) of 21%, with at least one helix prediction error in five of the six cases. Extensive variations of data processing, normalization, and modeling parameters did not significantly mitigate modeling errors. Only one varation, filtering out data collected with deoxyinosine triphosphate during primer extension, gave a modest improvement (FNR = 12%, and FDR = 14%). The residual structure modeling errors are explained by the insufficient information content of these RNAs' SHAPE data, as evaluated by a nonparametric bootstrapping analysis. Beyond these benchmark cases, bootstrapping suggests a low level of confidence (<50%) in the majority of helices in a previously proposed SHAPE-directed model for the HIV-1 RNA genome. Thus, SHAPE-directed RNA modeling is not always unambiguous, and helix-by-helix confidence estimates, as described herein, may be critical for interpreting results from this powerful methodology.Comment: Biochemistry, Article ASAP (Aug. 15, 2011

    Chemically Related 4,5-Linked Aminoglycoside Antibiotics Drive Subunit Rotation in Opposite Directions

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    Dynamic remodelling of intersubunit bridge B2, a conserved RNA domain of the bacterial ribosome connecting helices 44 (h44) and 69 (H69) of the small and large subunit, respectively, impacts translation by controlling intersubunit rotation. Here we show that aminoglycosides chemically related to neomycin-paromomycin, ribostamycin and neamine-each bind to sites within h44 and H69 to perturb bridge B2 and affect subunit rotation. Neomycin and paromomycin, which only differ by their ring-I 6\u27-polar group, drive subunit rotation in opposite directions. This suggests that their distinct actions hinge on the 6\u27-substituent and the drug\u27s net positive charge. By solving the crystal structure of the paromomycin-ribosome complex, we observe specific contacts between the apical tip of H69 and the 6\u27-hydroxyl on paromomycin from within the drug\u27s canonical h44-binding site. These results indicate that aminoglycoside actions must be framed in the context of bridge B2 and their regulation of subunit rotation

    Management of the thrombotic risk associated with COVID-19:guidance for the hemostasis laboratory

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    Coronavirus disease 2019 (COVID-19) is associated with extreme inflammatory response, disordered hemostasis and high thrombotic risk. A high incidence of thromboembolic events has been reported despite thromboprophylaxis, raising the question of a more effective anticoagulation. First-line hemostasis tests such as activated partial thromboplastin time, prothrombin time, fibrinogen and D-dimers are proposed for assessing thrombotic risk and monitoring hemostasis, but are vulnerable to many drawbacks affecting their reliability and clinical relevance. Specialized hemostasis-related tests (soluble fibrin complexes, tests assessing fibrinolytic capacity, viscoelastic tests, thrombin generation) may have an interest to assess the thrombotic risk associated with COVID-19. Another challenge for the hemostasis laboratory is the monitoring of heparin treatment, especially unfractionated heparin in the setting of an extreme inflammatory response. This review aimed at evaluating the role of hemostasis tests in the management of COVID-19 and discussing their main limitations

    PENGEMBANGAN BUKU AJAR AKUNTANSI KAS BERBASIS SCIENTIFIC APPROACH PADA MATA PELAJARAN AKUNTANSI KEUANGAN KELAS XI DI SMK NEGERI SE SURABAYA

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    Penelitian pengembangan ini bertujuan untuk menghasilkan buku ajar akuntansi kas berbasis scientific approach pada mata pelajaran akuntansi keuangan kelas XI di SMK Negeri Se Surabaya agar dapat meningkatkan motivasi belajar, meningkatkan penguasaan konsep materi dan pemahaman siswa dalam proses pembelajaran materi yang bersangkutan. Selain itu, penelitian ini bertujuan untuk mengetahui kelayakan dan respon siswa terhadap buku ajar akuntansi kas berbasis scientific approach yang dikembangkan. Model pengembangan yang digunakan diadaptasi dari model pengembangan 4P yang terdiri dari empat tahapan yaitu tahap pendefinisisan, tahap perancangan, tahap pengembangan, dan tahap penyebaran sehingga menghasilkan buku ajar akuntansi kas berbasis scientific approach. Hasil pengembangan menunjukkan bahwa rata-rata kelayakan buku ajar sebesar 83,5%. Sedangkan respon siswa diperoleh persentase sebesar 88,7%. Dengan demikian, buku ajar akuntansi kas berbasis scientific approach dinyatakan sangat layak digunakan sebagai bahan ajar untuk meningkatkan penguasaan konsep materi dan pemahaman siswa kelas XI di SMK Negeri Se Surabaya pada mata pelajaran akuntansi keuangan materi akuntansi kas. Kata Kunci:&nbsp; Buku ajar, Scientific Approach, Akuntansi Ka
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