943 research outputs found
An LP-Based Approach for Goal Recognition as Planning
Goal recognition aims to recognize the set of candidate goals that are
compatible with the observed behavior of an agent. In this paper, we develop a
method based on the operator-counting framework that efficiently computes
solutions that satisfy the observations and uses the information generated to
solve goal recognition tasks. Our method reasons explicitly about both partial
and noisy observations: estimating uncertainty for the former, and satisfying
observations given the unreliability of the sensor for the latter. We evaluate
our approach empirically over a large data set, analyzing its components on how
each can impact the quality of the solutions. In general, our approach is
superior to previous methods in terms of agreement ratio, accuracy, and spread.
Finally, our approach paves the way for new research on combinatorial
optimization to solve goal recognition tasks.Comment: 8 pages, 4 tables, 3 figures. Published in AAAI 2021. Updated final
authorship and tex
Service oriented architecture for scientific analysis at W7-X. An example of a field line tracer
Geological record and reconstruction of the late Pliocene impact of the Eltanin asteroid in the Southern Ocean
Using landscape topology to compare continuous metaheuristics: a framework and case study on EDAs and ridge structure
In this paper we extend a previously proposed randomized landscape generator in combination with a comparative experimental methodology to study the behavior of continuous metaheuristic optimization algorithms. In particular, we generate twodimensional landscapes with parameterized, linear ridge structure, and perform pairwise comparisons of algorithms to gain insight into what kind of problems are easy and difficult for one algorithm instance relative to another.We apply thismethodology to investigate the specific issue of explicit dependency modeling in simple continuous estimation of distribution algorithms. Experimental results reveal specific examples of landscapes (with certain identifiable features) where dependency modeling is useful, harmful, or has little impact on mean algorithm performance. Heat maps are used to compare algorithm performance over a large number of landscape instances and algorithm trials. Finally, we perform ameta-search in the landscape parameter space to find landscapes which maximize the performance between algorithms. The results are related to some previous intuition about the behavior of these algorithms, but at the same time lead to new insights into the relationship between dependency modeling in EDAs and the structure of the problem landscape. The landscape generator and overall methodology are quite general and extendable and can be used to examine specific features of other algorithms
Cyanophage MazG is a pyrophosphohydrolase but unable to hydrolyse magic spot nucleotides
Bacteriophage possess a variety of auxiliary metabolic genes (AMGs) of bacterial origin. These proteins enable them to maximise infection efficiency, subverting bacterial metabolic processes for the purpose of viral genome replication and synthesis of the next generation of virion progeny. Here, we examined the enzymatic activity of a cyanophage MazG protein â a putative pyrophosphohydrolase previously implicated in regulation of the stringent response via reducing levels of the central alarmone molecule (p)ppGpp. We demonstrate however, that the purified viral MazG shows no binding or hydrolysis activity against (p)ppGpp. Instead, dGTP and dCTP appear to be the preferred substrates of this protein, consistent with a role preferentially hydrolysing deoxyribonucleotides from the high GC content host Synechococcus genome. This showcases a new example of the fineâtuned nature of viral metabolic processes
Structure-Function insights of Jaburetox and Soyuretox: Novel intrinsically disordered polypeptides derived from plant ureases
Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) do not have a stable 3D structure but still have important biological activities. Jaburetox is a recombinant peptide derived from the jack bean (Canavalia ensiformis) urease and presents entomotoxic and antimicrobial actions. The structure of Jaburetox was elucidated using nuclear magnetic resonance which reveals it is an IDP with small amounts of secondary structure. Different approaches have demonstrated that Jaburetox acquires certain folding upon interaction with lipid membranes, a characteristic commonly found in other IDPs and usually important for their biological functions. Soyuretox, a recombinant peptide derived from the soybean (Glycine max) ubiquitous urease and homologous to Jaburetox, was also characterized for its biological activities and structural properties. Soyuretox is also an IDP, presenting more secondary structure in comparison with Jaburetox and similar entomotoxic and fungitoxic effects. Moreover, Soyuretox was found to be nontoxic to zebra fish, while Jaburetox was innocuous to mice and rats. This profile of toxicity affecting detrimental species without damaging mammals or the environment qualified them to be used in biotechnological applications. Both peptides were employed to develop transgenic crops and these plants were active against insects and nematodes, unveiling their immense potentiality for field applications.Fil: Grahl, Matheus V. Coste. Pontificia Universidade CatĂłlica do Rio Grande do Sul; BrasilFil: Lopes, Fernanda Cortez. Universidade Federal do Rio Grande do Sul; BrasilFil: Martinelli, Anne H. Souza. Universidade Federal do Rio Grande do Sul; BrasilFil: Carlini, CĂ©lia Regina R. S.. Pontificia Universidade CatĂłlica do Rio Grande do Sul; BrasilFil: Fruttero, Leonardo Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂmica ClĂnica e InmunologĂa; Argentin
Folksonomies and clustering in the collaborative system CiteULike
We analyze CiteULike, an online collaborative tagging system where users
bookmark and annotate scientific papers. Such a system can be naturally
represented as a tripartite graph whose nodes represent papers, users and tags
connected by individual tag assignments. The semantics of tags is studied here,
in order to uncover the hidden relationships between tags. We find that the
clustering coefficient reflects the semantical patterns among tags, providing
useful ideas for the designing of more efficient methods of data classification
and spam detection.Comment: 9 pages, 5 figures, iop style; corrected typo
Bloch-Wall Phase Transition in the Spherical Model
The temperature-induced second-order phase transition from Bloch to linear
(Ising-like) domain walls in uniaxial ferromagnets is investigated for the
model of D-component classical spin vectors in the limit D \to \infty. This
exactly soluble model is equivalent to the standard spherical model in the
homogeneous case, but deviates from it and is free from unphysical behavior in
a general inhomogeneous situation. It is shown that the thermal fluctuations of
the transverse magnetization in the wall (the Bloch-wall order parameter)
result in the diminishing of the wall transition temperature T_B in comparison
to its mean-field value, thus favouring the existence of linear walls. For
finite values of T_B an additional anisotropy in the basis plane x,y is
required; in purely uniaxial ferromagnets a domain wall behaves like a
2-dimensional system with a continuous spin symmetry and does not order into
the Bloch one.Comment: 16 pages, 2 figure
Reação de cultivares e linhagens promissoras de trigo ao AlumĂnio no solo.
O alumĂnio (Al) Ă© o principal responsĂĄvel pela baixa produtividade das culturas em solos ĂĄcidos
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