1,347 research outputs found
Ising Spin Glasses on Wheatstone-Bridge Hierarchical Lattices
Nearest-neighbor-interaction Ising spin glasses are studied on three
different hierarchical lattices, all of them belonging to the Wheatstone-Bridge
family. It is shown that the spin-glass lower critical dimension in these
lattices should be greater than 2.32. Finite-temperature spin-glass phases are
found for a lattice of fractal dimension (whose unit cell is
obtained from a simple construction of a part of the cubic lattice), as well as
for a lattice of fractal dimension close to five.Comment: Accepted for publication in Physics Letters
Using causal knowledge to improve retrieval and adaptation in case-based reasoning systems for a dynamic industrial process
Case-based reasoning (CBR) is a reasoning paradigm that starts the reasoning process by examining past similar experiences. The motivation behind this thesis lies in the observation that causal knowledge can guide case-based reasoning in dealing with large and complex systems as it guides humans. In this thesis, case-bases used for reasoning about processes where each case consists of a temporal sequence are considered. In general, these temporal sequences include persistent and transitory (non-persistent) attributes. As these sequences tend to be long, it is unlikely to find a single case in the case-base that closely matches the problem case. By utilizing causal knowledge in the form of a dynamic Bayesian network (DBN) and exploiting the independence implied by the structure of the network and known attributes, this system matches independent portions of the problem case to corresponding sub-cases from the case-base. However, the matching of sub-cases has to take into account the persistence properties of attributes. The approach is then applied to a real life temporal process situation involving an automotive curing oven, in which a vehicle moves through stages within the oven to satisfy some thermodynamic relationships and requirements that change from stage to stage. In addition, testing has been conducted using data randomly generated from known causal networks. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .T54. Source: Masters Abstracts International, Volume: 45-01, page: 0366. Thesis (M.Sc.)--University of Windsor (Canada), 2006
User's Guide for ERB 7 SEFDT. Volume 1: User's Guide. Volume 2: Quality Control Report, Year 1
The Nimbus-7 ERB SEFDT Data User's Guide is presented. The guide consists of four subsections which describe: (1) the scope of the data User's Guide; (2) the background on Nimbus-7 Spacecraft and the ERB experiment; (3) the SEFDT data product and processing scenario; and (4) other related products and documents
Enterohemorrhagic Escherichia coli colonization of human colonic epithelium in vitro and ex vivo
Enterohemorrhagic E. coli (EHEC) are important foodborne pathogens causing gastroenteritis and more severe complications such as hemorrhagic colitis and hemolytic uremic syndrome. Pathology is most pronounced in the colon, but to date there is no direct clinical evidence showing EHEC binding to colonic epithelium in patients. In this study, we investigated EHEC adherence to the human colon by using in vitro organ culture (IVOC) of colonic biopsies and polarized T84 colon carcinoma cells. We showed for the first time that EHEC colonized human colonic biopsies by forming typical attaching/effacing (A/E) lesions which were dependent on EHEC type III secretion (T3S) and binding of the outer membrane protein intimin to the Translocated intimin receptor (Tir). A/E lesion formation was dependent on oxygen levels and suppressed under oxygen-rich culture conditions routinely used for IVOC. In contrast, EHEC adherence to polarized T84 cells occurred independently of T3S and intimin and did not involve Tir translocation into the host cell membrane. Neither colonization of biopsies nor T84 cells was significantly affected by expression of Shiga toxins. Our study suggests that EHEC colonize and form stable A/E lesions on the human colon which is likely to contribute to intestinal pathology during infection. Furthermore, care needs to be taken when using cell culture models as they might not reflect the in vivo situation
Geometry and Topology of Escape I: Epistrophes
We consider a dynamical system given by an area-preserving map on a
two-dimensional phase plane and consider a one-dimensional line of initial
conditions within this plane. We record the number of iterates it takes a
trajectory to escape from a bounded region of the plane as a function along the
line of initial conditions, forming an ``escape-time plot''. For a chaotic
system, this plot is in general not a smooth function, but rather has many
singularities at which the escape time is infinite; these singularities form a
complicated fractal set. In this article we prove the existence of regular
repeated sequences, called ``epistrophes'', which occur at all levels of
resolution within the escape-time plot. (The word ``epistrophe'' comes from
rhetoric and means ``a repeated ending following a variable beginning''.) The
epistrophes give the escape-time plot a certain self-similarity, called
``epistrophic'' self-similarity, which need not imply either strict or
asymptotic self-similarity.Comment: 15 pages, 9 figures, to appear in Chaos, first of two paper
Multi-utility Learning: Structured-output Learning with Multiple Annotation-specific Loss Functions
Structured-output learning is a challenging problem; particularly so because
of the difficulty in obtaining large datasets of fully labelled instances for
training. In this paper we try to overcome this difficulty by presenting a
multi-utility learning framework for structured prediction that can learn from
training instances with different forms of supervision. We propose a unified
technique for inferring the loss functions most suitable for quantifying the
consistency of solutions with the given weak annotation. We demonstrate the
effectiveness of our framework on the challenging semantic image segmentation
problem for which a wide variety of annotations can be used. For instance, the
popular training datasets for semantic segmentation are composed of images with
hard-to-generate full pixel labellings, as well as images with easy-to-obtain
weak annotations, such as bounding boxes around objects, or image-level labels
that specify which object categories are present in an image. Experimental
evaluation shows that the use of annotation-specific loss functions
dramatically improves segmentation accuracy compared to the baseline system
where only one type of weak annotation is used
Constipation in children
Constipation remains a frequent presentation to paediatricians, with significant health resource implications. We present a practical guide to the management of paediatric constipation and evaluate the current evidence for treatment regimens, to help the clinician in treating a condition that can be distressing and has a significant impact on affected families
Direct Visualization of Asymmetric Behavior in Supported Lipid Bilayers at the Gel-Fluid Phase Transition
AbstractWe utilize in situ, temperature-dependent atomic force microscopy to examine the gel-fluid phase transition behavior in supported phospholipid bilayers constructed from 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1,2-dipentadecanoyl-sn-glycero-3-phosphocholine, and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine. The primary gel-fluid phase transition at Tm occurs through development of anisotropic cracks in the gel phase, which develop into the fluid phase. At ∼5°C above Tm, atomic force microscopy studies reveal the presence of a secondary phase transition in all three bilayers studied. The secondary phase transition occurs as a consequence of decoupling between the two leaflets of the bilayer due to enhanced stabilization of the lower leaflet with either the support or the water entrained between the support and the bilayer. Addition of the transmembrane protein gramicidin A or construction of a highly defected gel phase results in elimination of this decoupling and removal of the secondary phase transition
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