5,331 research outputs found
Radiosynthesis of 1-[2-[18F]Fluoro-1-(hydroxymethyl)-Ethoxy]methyl-2-Nitroimidazole([18F]FENI)
開始ページ、終了ページ: 冊子体のページ付
Verifying Temporal Regular Properties of Abstractions of Term Rewriting Systems
The tree automaton completion is an algorithm used for proving safety
properties of systems that can be modeled by a term rewriting system. This
representation and verification technique works well for proving properties of
infinite systems like cryptographic protocols or more recently on Java Bytecode
programs. This algorithm computes a tree automaton which represents a (regular)
over approximation of the set of reachable terms by rewriting initial terms.
This approach is limited by the lack of information about rewriting relation
between terms. Actually, terms in relation by rewriting are in the same
equivalence class: there are recognized by the same state in the tree
automaton.
Our objective is to produce an automaton embedding an abstraction of the
rewriting relation sufficient to prove temporal properties of the term
rewriting system.
We propose to extend the algorithm to produce an automaton having more
equivalence classes to distinguish a term or a subterm from its successors
w.r.t. rewriting. While ground transitions are used to recognize equivalence
classes of terms, epsilon-transitions represent the rewriting relation between
terms. From the completed automaton, it is possible to automatically build a
Kripke structure abstracting the rewriting sequence. States of the Kripke
structure are states of the tree automaton and the transition relation is given
by the set of epsilon-transitions. States of the Kripke structure are labelled
by the set of terms recognized using ground transitions. On this Kripke
structure, we define the Regular Linear Temporal Logic (R-LTL) for expressing
properties. Such properties can then be checked using standard model checking
algorithms. The only difference between LTL and R-LTL is that predicates are
replaced by regular sets of acceptable terms
Morphological aspects of male and female hands
This is an electronic version of an article published in Annals of Human Biology, 1996, 23(6), 491-494. Annals of Human Biology is available online at informaworldTM http://www.informaworld.com/smpp/content~content=a739339013~db=all~order=pageThis journal article discusses a series of hand radiographs from Gwynedd, North Wales, which were assessed for frequencies in digital and metacarpal formulae between the genders
Novel electronic wave interference patterns in nanographene sheets
Superperiodic patterns with a long distance in a nanographene sheet observed
by STM are discussed in terms of the interference of electronic wave functions.
The period and the amplitude of the oscillations decrease spatially in one
direction. We explain the superperiodic patterns with a static linear potential
theoretically. In the k-p model, the oscillation period decreases, and agrees
with experiments. The spatial difference of the static potential is estimated
as 1.3 eV for 200 nm in distance, and this value seems to be reasonable in
order that the potential difference remains against perturbations, for example,
by phonon fluctuations and impurity scatterings. It turns out that the
long-distance oscillations come from the band structure of the two-dimensional
graphene sheet.Comment: Published as a LETTER in J. Phys.: Condens. Matter; 8 pages; 6
figures; Online version at
http://www.iop.org/EJ/S/3/1256/0hJAmc5sCL6d.7sOO.BtLw/abstract/0953-8984/14/3
6/10
Metacarpophalangeal pattern profile analysis of a sample drawn from a North Wales population
This is tha author's PDF version of an article published in Annals of human biology© 2001. The definitive version is available at http://www.tandf.co.uk/journalsSexual dimorphism and population differences were investigated using metacarpophalangeal pattern profile (MCPP) analysis. Although it is an anthropmetric technique, MCPP analysis is more frequently used in genetic syndrome analysis and has been under-used in the study of human groups. The present analysis used a series of hand radiographics from Gwynedd, North Wales, to make comparisons, first, between the sexes within the sample and then with previously reported data from Japan. The Welsh sexes showed MCPP analyses that indicated size and shape differences but certain similarities in shape were also evident. Differences with the Japanese data were more marked. MCPP anlysis is a potentially useful anthropmetric technique but requires further statistical development
DAP12 (KARAP) amplifies inflammation and increases mortality from endotoxemia and septic peritonitis
DAP12 (KARAP) is a transmembrane signaling adaptor for a family of innate immunoreceptors that have been shown to activate granulocytes and monocytes/macrophages, amplifying production of inflammatory cytokines. Contrasting with these data, recent studies suggest that DAP12 signaling has an inhibitory role in the macrophage response to microbial products (Hamerman, J.A., N.K. Tchao, C.A. Lowell, and L.L. Lanier. 2005. Nat. Immunol. 6:579–586). To determine the in vivo role for DAP12 signaling in inflammation, we measured the response of wild-type (WT) and DAP12−/− mice to septic shock. We show that DAP12−/− mice have improved survival from both endotoxemia and cecal ligation and puncture–induced septic shock. As compared with WT mice, DAP12−/− mice have decreased plasma cytokine levels and a decreased acute phase response during sepsis, but no defect in the recruitment of cells or bacterial control. In cells isolated after sepsis and stimulated ex vivo, DAP12 signaling augments lipopolysaccharide-mediated cytokine production. These data demonstrate that, during sepsis, DAP12 signaling augments the response to microbial products, amplifying inflammation and contributing to mortality
Magneto-transport in periodic and quasiperiodic arrays of mesoscopic rings
We study theoretically the transmission properties of serially connected
mesoscopic rings threaded by a magnetic flux. Within a tight-binding formalism
we derive exact analytical results for the transmission through periodic and
quasiperiodic Fibonacci arrays of rings of two different sizes. The role played
by the number of scatterers in each arm of the ring is analyzed in some detail.
The behavior of the transmission coefficient at a particular value of the
energy of the incident electron is studied as a function of the magnetic flux
(and vice versa) for both the periodic and quasiperiodic arrays of rings having
different number of atoms in the arms. We find interesting resonance properties
at specific values of the flux, as well as a power-law decay in the
transmission coefficient as the number of rings increases, when the magnetic
field is switched off. For the quasiperiodic Fibonacci sequence we discuss
various features of the transmission characteristics as functions of energy and
flux, including one special case where, at a special value of the energy and in
the absence of any magnetic field, the transmittivity changes periodically as a
function of the system size.Comment: 9 pages with 7 .eps figures included, submitted to PR
A deeply branching thermophilic bacterium with an ancient acetyl-CoA pathway dominates a subsurface ecosystem
<div><p>A nearly complete genome sequence of <em>Candidatus</em> ‘Acetothermum autotrophicum’, a presently uncultivated bacterium in candidate division OP1, was revealed by metagenomic analysis of a subsurface thermophilic microbial mat community. Phylogenetic analysis based on the concatenated sequences of proteins common among 367 prokaryotes suggests that <em>Ca.</em> ‘A. autotrophicum’ is one of the earliest diverging bacterial lineages. It possesses a folate-dependent Wood-Ljungdahl (acetyl-CoA) pathway of CO<sub>2</sub> fixation, is predicted to have an acetogenic lifestyle, and possesses the newly discovered archaeal-autotrophic type of bifunctional fructose 1,6-bisphosphate aldolase/phosphatase. A phylogenetic analysis of the core gene cluster of the acethyl-CoA pathway, shared by acetogens, methanogens, some sulfur- and iron-reducers and dechlorinators, supports the hypothesis that the core gene cluster of <em>Ca.</em> ‘A. autotrophicum’ is a particularly ancient bacterial pathway. The habitat, physiology and phylogenetic position of <em>Ca.</em> ‘A. autotrophicum’ support the view that the first bacterial and archaeal lineages were H<sub>2</sub>-dependent acetogens and methanogenes living in hydrothermal environments.</p> </div
- …