2,622 research outputs found
Detecting Determinacy in Prolog Programs: 22nd International Conference, ICLP 2006, Seattle, WA, USA, August 17-20, 2006. Proceedings
In program development it is useful to know that a call to a Prolog program will not inadvertently leave a choice-point on the stack. Determinacy inference has been proposed for solving this problem yet the analysis was found to be wanting in that it could not infer determinacy conditions for programs that contained cuts or applied certain tests to select a clause. This paper shows how to remedy these serious deficiencies. It also addresses the problem of identifying those predicates which can be rewritten in a more deterministic fashion. To this end, a radically new form of determinacy inference is introduced, which is founded on ideas in ccp, that is capable of reasoning about the way bindings imposed by a rightmost goal can make a leftmost goal deterministic
On low temperature kinetic theory; spin diffusion, Bose Einstein condensates, anyons
The paper considers some typical problems for kinetic models evolving through
pair-collisions at temperatures not far from absolute zero, which illustrate
specific quantum behaviours. Based on these examples, a number of differences
between quantum and classical Boltzmann theory is then discussed in more
general terms.Comment: 25 pages, minor updates of previous versio
First Report of Alternaria Black Spot Disease Caused by Alternaria alternata on the Invasive Weed Solanum rostratum in Xinjiang, China
Solanum rostratum is a noxious weed, native to Mexico and the USA, which has invaded Liaoning, Jilin, Hebei, Inner
Mongolia, Shanxi, Xinjiang and Beijing, China (Eminniya et al., 2013). In August 2015, foliar symptoms of yellowish to black
spots were observed on plants of S. rostratum nearby an agricultural plantation in Changji, Xinjiang. The following year, about
17% of the 206 plants surveyed on about 0.2 ha of deserted farmland were infected from July-September (at 19-35°C under
29-97% RH)
Incompatibility Systems in Switchgrass
Switchgrass (Panicum virgatum L.), a cross-pollinated perennial, produces very little or no seed when self-pollinated, indicating the presence of self-incompatibility mechanisms. Knowledge of self-incompatibility mechanisms is required to use germplasm effectively in a breeding program. The objective of this study was to characterize features of the incompatibility systems in switchgrass. Seed set and seed characteristics of reciprocal matings of tetraploid, octaploid, and tetraploid x octaploid plants were used as measures of incompatibility. Both bagged mutual pollination and manual emasculation and pollination methods were used to make crosses. The percentages of self-compatibility in the tetraploid and octaploid parent plants were 0.35 and 1.39%, respectively. Prefertilization incompatibility in switchgrass is apparently under gametophytic control, since there were significant differences in percentage of compatible pollen as measured by percentage of total seed set between reciprocal matings within ploidy levels. Results indicated that the prefertilization incompatibility system in switchgrass is similar to the S-Z incompatibility system found in other members of the Poaceae. A postfertilization incompatibility system also exists that inhibits intermatings among octaploid and tetraploid plants. In these interploidy crosses, two very distinctive types of abnormal seed were found. When the female parent was the tetraploid plant, the resulting seed was small and shriveled, while when the female parent was the octaploid, small seed with floury endosperm was obtained. These results are similar to those obtained for endosperm incompatibility due to the endosperm balance number system found in other species
Patterning the neuronal cells via inkjet printing of self-assembled peptides on silk scaffolds
The patterning of neuronal cells and guiding neurite growth are important for neuron tissue engineering and cell-based biosensors. In this paper, inkjet printing has been employed to pattern self-assembled I3QGK peptide nanofibers on silk substrates for guiding the growth of neuron-like PC12 cells. Atomic force microscopy (AFM) confirmed the dynamic self-assembly of I3QGK into nanofiber structures. The printed self-assembled peptide strongly adheres to regenerated silk fibroin (RSF) substrates through charge-charge interactions. It was observed that in the absence of I3QGK, PC12 cells exhibited poor attachment to RSF films, while for RSF surfaces coated or printed with peptide nanofibers, cellular attachment was significantly improved in terms of both cell density and morphology. AFM results revealed that peptide nanofibers can promote the generation of axons and terminal buttons of PC12 cells, indicating that I3QGK nanofibers not only promote cellular attachment but also facilitate differentiation into neuronal phenotypes. Inkjet printing allows complex patterning of peptide nanofibers onto RSF substrates, which enabled us to engineer cell alignment and provide an opportunity to direct axonal development in vitro. The live/dead assay showed that printed I3QGK patterns exhibit no cytotoxicity to PC12 cells demonstrating potential for future nerve tissue engineering applications
Distribution of spectral weight in a system with disordered stripes
The ``band-structure'' of a disordered stripe array is computed and compared,
at a qualitative level, to angle resolved photoemission experiments on the
cuprate high temperature superconductors. The low-energy states are found to be
strongly localized transverse to the stripe direction, so the electron dynamics
is strictly one-dimensional (along the stripe). Despite this, aspects of the
two dimensional band-structure Fermi surface are still vividly apparent.Comment: 10 pages, 11 figure
Continuous-distribution puddle model for conduction in trilayer graphene
An insulator-to-metal transition is observed in trilayer graphene based on
the temperature dependence of the resistance under different applied gate
voltages. At small gate voltages the resistance decreases with increasing
temperature due to the increase in carrier concentration resulting from thermal
excitation of electron-hole pairs. At large gate voltages excitation of
electron-hole pairs is suppressed, and the resistance increases with increasing
temperature because of the enhanced electron-phonon scattering. We find that
the simple model with overlapping conduction and valence bands, each with
quadratic dispersion relations, is unsatisfactory. Instead, we conclude that
impurities in the substrate that create local puddles of higher electron or
hole densities are responsible for the residual conductivity at low
temperatures. The best fit is obtained using a continuous distribution of
puddles. From the fit the average of the electron and hole effective masses can
be determined.Comment: 18 pages, 5 figure
Classical and Thermodynamic Stability of Black Branes
It is argued that many non-extremal black branes exhibit a classical
Gregory-Laflamme instability if, and only if, they are locally
thermodynamically unstable. For some black branes, the Gregory-Laflamme
instability must therefore disappear near extremality. For the black -branes
of the type II supergravity theories, the Gregory-Laflamme instability
disappears near extremality for but persists all the way down to
extremality for (the black D3-brane is not covered by the analysis of
this paper). This implies that the instability also vanishes for the
near-extremal black M2 and M5-brane solutions.Comment: 21 pages, LaTeX. v2: Various points clarified, typos corrected and
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