Anisotropy in Homogeneous Rotating Turbulence

The effective stress tensor of a homogeneous turbulent rotating fluid is anisotropic. This leads us to consider the most general axisymmetric four-rank ``viscosity tensor'' for a Newtonian fluid and the new terms in the turbulent effective force on large scales that arise from it, in addition to the microscopic viscous force. Some of these terms involve couplings to vorticity and others are angular momentum non conserving (in the rotating frame). Furthermore, we explore the constraints on the response function and the two-point velocity correlation due to axisymmetry. Finally, we compare our viscosity tensor with other four-rank tensors defined in current approaches to non-rotating anisotropic turbulence.Comment: 14 pages, RevTe

Cortical Folding Patterns and Predicting Cytoarchitecture

The human cerebral cortex is made up of a mosaic of structural areas, frequently referred to as Brodmann areas (BAs). Despite the widespread use of cortical folding patterns to perform ad hoc estimations of the locations of the BAs, little is understood regarding 1) how variable the position of a given BA is with respect to the folds, 2) whether the location of some BAs is more variable than others, and 3) whether the variability is related to the level of a BA in a putative cortical hierarchy. We use whole-brain histology of 10 postmortem human brains and surface-based analysis to test how well the folds predict the locations of the BAs. We show that higher order cortical areas exhibit more variability than primary and secondary areas and that the folds are much better predictors of the BAs than had been previously thought. These results further highlight the significance of cortical folding patterns and suggest a common mechanism for the development of the folds and the cytoarchitectonic fields.National Center for Research Resources (U.S.) (P41-RR14075)National Center for Research Resources (U.S.) (R01-RR16594-01A1)National Center for Research Resources (U.S.) (NCRR BIRN Morphometric Project BIRN002, U24 RR021382)National Institute of Biomedical Imaging and Bioengineering (U.S.) (R01 EB001550)National Institute of Biomedical Imaging and Bioengineering (U.S.) (R01 EB006758)National Institute of Neurological Disorders and Stroke (U.S.) (R01 NS052585-01)Mental Illness and Neuroscience Discovery (MIND) InstituteNational Institutes of Health (U.S.) (NIH Roadmap for Medical Research (grant U54 EB005149))Hermann von Helmholtz-Gemeinschaft Deutscher ForschungszentrenDeutsche Forschungsgemeinschaft (DFG)National Institutes of Health. National Institute for Biomedical Imaging and BioengineeringNational Institute of Neurological Disorders and Stroke (U.S.)National Institute of Mental Health (U.S.

Anomalous scaling of passively advected magnetic field in the presence of strong anisotropy

Inertial-range scaling behavior of high-order (up to order N=51) structure functions of a passively advected vector field has been analyzed in the framework of the rapid-change model with strong small-scale anisotropy with the aid of the renormalization group and the operator-product expansion. It has been shown that in inertial range the leading terms of the structure functions are coordinate independent, but powerlike corrections appear with the same anomalous scaling exponents as for the passively advected scalar field. These exponents depend on anisotropy parameters in such a way that a specific hierarchy related to the degree of anisotropy is observed. Deviations from power-law behavior like oscillations or logarithmic behavior in the corrections to structure functions have not been found.Comment: 15 pages, 18 figure

Preference-Based Monte Carlo Tree Search

Monte Carlo tree search (MCTS) is a popular choice for solving sequential anytime problems. However, it depends on a numeric feedback signal, which can be difficult to define. Real-time MCTS is a variant which may only rarely encounter states with an explicit, extrinsic reward. To deal with such cases, the experimenter has to supply an additional numeric feedback signal in the form of a heuristic, which intrinsically guides the agent. Recent work has shown evidence that in different areas the underlying structure is ordinal and not numerical. Hence erroneous and biased heuristics are inevitable, especially in such domains. In this paper, we propose a MCTS variant which only depends on qualitative feedback, and therefore opens up new applications for MCTS. We also find indications that translating absolute into ordinal feedback may be beneficial. Using a puzzle domain, we show that our preference-based MCTS variant, wich only receives qualitative feedback, is able to reach a performance level comparable to a regular MCTS baseline, which obtains quantitative feedback.Comment: To be publishe

AKARI's infrared view on nearby stars : Using AKARI Infrared Camera All-Sky Survey, 2MASS, and Hipparcos catalog

--Results-- We found that the (B-V) v.s. (V-S9W) color-color diagram is useful to identify the stars with infrared excess emerged from circumstellar envelopes/disks. Be stars with infrared excess are well separated from other types of stars in this diagram. Whereas (J-L18W) v.s. (S9W-L18W) diagram is a powerful tool to classify several object-types. Carbon-rich asymptotic giant branch (AGB) stars and OH/IR stars form distinct sequences in this color-color diagram. Young stellar objects (YSOs), pre-main sequence (PMS) stars, post-AGB stars and planetary nebulae (PNe) have largest mid-infrared color-excess, and can be identified in infrared catalog. Finally, we plot L18W v.s. (S9W-L18W) color-magnitude diagram, using the AKARI data together with Hipparcos parallaxes. This diagram can be used to identify low-mass YSOs, as well as AGB stars. We found that this diagram is comparable to the [24] vs ([8.0]-[24]) diagram of Large Magellanic Cloud sources using the Spitzer Space Telescope data. Our understanding of Galactic objects will be used to interpret color-magnitude diagram of stellar populations in nearby galaxies which Spitzer Space Telescope has observed. --Conclusions-- Our study of the AKARI color-color and color-magnitude will be used to explore properties of unknown objects in future. In addition, our analysis highlights a future key project to understand stellar evolution with circumstellar envelope, once the forthcoming astronometrical data with GAIA are available.Comment: 14 pages, 11 figures, accepted for publication in A&A. High resolution version is available at: http://www.ir.isas.jaxa.jp/%7Eyita/allsky20100302.pdf (26Mb

BoostingTree: parallel selection of weak learners in boosting, with application to ranking

Boosting algorithms have been found successful in many areas of machine learning and, in particular, in ranking. For typical classes of weak learners used in boosting (such as decision stumps or trees), a large feature space can slow down the training, while a long sequence of weak hypotheses combined by boosting can result in a computationally expensive model. In this paper we propose a strategy that builds several sequences of weak hypotheses in parallel, and extends the ones that are likely to yield a good model. The weak hypothesis sequences are arranged in a boosting tree, and new weak hypotheses are added to promising nodes (both leaves and inner nodes) of the tree using some randomized method. Theoretical results show that the proposed algorithm asymptotically achieves the performance of the base boosting algorithm applied. Experiments are provided in ranking web documents and move ordering in chess, and the results indicate that the new strategy yields better performance when the length of the sequence is limited, and converges to similar performance as the original boosting algorithms otherwise. © 2013 The Author(s)

Mutation update for the GPC3 gene involved in Simpson-Golabi-Behmel syndrome and review of the literature

Simpson-Golabi-Behmel syndrome (SGBS) is an X-linked multiple congenital anomalies and overgrowth syndrome caused by a defect in the glypican-3 gene (GPC3). Until now, GPC3 mutations have been reported in isolated cases or small series and the global genotypic spectrum of these mutations has never been delineated. In this study, we review the 57 previously described GPC3 mutations and significantly expand this mutational spectrum with the description of 29 novel mutations. Compiling our data and those of the literature, we provide an overview of 86 distinct GPC3 mutations identified in 120 unrelated families, ranging from single nucleotide variations to complex genomic rearrangements and dispersed throughout the entire coding region of GPC3. The vast majority of them are deletions or truncating mutations (frameshift, nonsense mutations) predicted to result in a loss-of-function. Missense mutations are rare and the two which were functionally characterized, impaired GPC3 function by preventing GPC3 cleavage and cell surface addressing respectively. This report by describing for the first time the wide mutational spectrum of GPC3 could help clinicians and geneticists in interpreting GPC3 variants identified incidentally by high-throughput sequencing technologies and also reinforces the need for functional validation of non-truncating mutations (missense, in frame mutations, duplications)

Whose right to the city? An analysis of the mediatized politics of place surrounding alojamento local issues in Lisbon and Porto

In view of the proliferation of alojamento local (short-term vacation rentals) in the major Portuguese cities of Lisbon and Porto, along with the recent transformation of the historic city centre neighbourhoods, this study explores the mediatized politics of place by analysing data sets resulting from different, but interconnected, discursive practices. At the level of governance, we examine how legislation has enabled and facilitated this transformation. We then explore the media coverage of the issues surrounding these recent changes. Finally, we focus on individual and collective stakeholder voices by analysing the various rights claims and arguments found in social media communication channels. Framing our analysis initially in Lefebvre’s concept of ‘the right to the city’, often invoked as an argument for the promotion of justice, inclusion and sustainability in the face of urbanisation policies, we argue that a ‘rights in the city’ approach is better suited to gaining insight into the multiple tensions and conflicts brought about through the interlinking processes of regeneration, gentrification and touristification that affect neighbourhoods with high proportions of short-term rental accommodation, and conclude that there are many rights claimants within a seemingly unified group of stakeholders, invoking rights claims which are sometimes overlapping, but often conflicting.info:eu-repo/semantics/publishedVersio