Connectivity and tree structure in finite graphs

Considering systems of separations in a graph that separate every pair of a given set of vertex sets that are themselves not separated by these separations, we determine conditions under which such a separation system contains a nested subsystem that still separates those sets and is invariant under the automorphisms of the graph. As an application, we show that the $k$-blocks -- the maximal vertex sets that cannot be separated by at most $k$ vertices -- of a graph $G$ live in distinct parts of a suitable tree-decomposition of $G$ of adhesion at most $k$, whose decomposition tree is invariant under the automorphisms of $G$. This extends recent work of Dunwoody and Kr\"on and, like theirs, generalizes a similar theorem of Tutte for $k=2$. Under mild additional assumptions, which are necessary, our decompositions can be combined into one overall tree-decomposition that distinguishes, for all $k$ simultaneously, all the $k$-blocks of a finite graph.Comment: 31 page

LpL^p-approximation of the integrated density of states for Schr\"odinger operators with finite local complexity

We study spectral properties of Schr\"odinger operators on \RR^d. The electromagnetic potential is assumed to be determined locally by a colouring of the lattice points in \ZZ^d, with the property that frequencies of finite patterns are well defined. We prove that the integrated density of states (spectral distribution function) is approximated by its finite volume analogues, i.e.the normalised eigenvalue counting functions. The convergence holds in the space $L^p(I)$ where $I$ is any finite energy interval and $1\leq p< \infty$ is arbitrary.Comment: 15 pages; v2 has minor fixe

Eigenvalue Bounds for Perturbations of Schrodinger Operators and Jacobi Matrices With Regular Ground States

We prove general comparison theorems for eigenvalues of perturbed Schrodinger operators that allow proof of Lieb--Thirring bounds for suitable non-free Schrodinger operators and Jacobi matrices.Comment: 11 page

LEA polypeptide profiling of recalcitrant and orthodox legume seeds reveals ABI3-regulated LEA protein abundance linked to desiccation tolerance

In contrast to orthodox seeds that acquire desiccation tolerance during maturation, recalcitrant seeds are unable to survive drying. These desiccation-sensitive seeds constitute an interesting model for comparative analysis with phylogenetically close species that are desiccation tolerant. Considering the importance of LEA (late embryogenesis abundant) proteins as protective molecules both in drought and in desiccation tolerance, the heat-stable proteome was characterized in cotyledons of the legume Castanospermum australe and it was compared with that of the orthodox model legume Medicago truncatula. RNA sequencing identified transcripts of 16 homologues out of 17 LEA genes for which polypeptides are detected in M. truncatula seeds. It is shown that for 12 LEA genes, polypeptides were either absent or strongly reduced in C. australe cotyledons compared with M. truncatula seeds. Instead, osmotically responsive, non-seed-specific dehydrins accumulated to high levels in the recalcitrant cotyledons compared with orthodox seeds. Next, M. truncatula mutants of the ABSCISIC ACID INSENSITIVE3 (ABI3) gene were characterized. Mature Mtabi3 seeds were found to be desiccation sensitive when dried below a critical water content of 0.4g H2O g DW–1. Characterization of the LEA proteome of the Mtabi3 seeds revealed a subset of LEA proteins with severely reduced abundance that were also found to be reduced or absent in C. australe cotyledons. Transcripts of these genes were indeed shown to be ABI3 responsive. The results highlight those LEA proteins that are critical to desiccation tolerance and suggest that comparable regulatory pathways responsible for their accumulation are missing in both desiccation-sensitive genotypes, revealing new insights into the mechanistic basis of the recalcitrant trait in seeds

REDUCED GENETIC DIVERSITY IN TWO INTRODUCED AND ISOLATED MOOSE POPULATIONS IN ALASKA

I examined indices of genetic diversity in 2 isolated moose (Alces alces) populations in Alaska that were founded by low numbers of individuals to determine effects of founding and infer whether subsequent gene flow has occurred with surrounding moose populations. Kalgin Island is a small, predator-free island in Cook Inlet that was founded by 6 moose (3 females) in the late 1950s; its population has since undergone dramatic fluctuations. Berners Bay is an isolated population along the coast of southeastern Alaska that was founded by 21 calves introduced in 1958-1960. Genetic attributes of those populations were compared to a population in Yukon Flats in central Alaska that served as an outbred control. Indices from 11 microsatellite markers indicated substantial effects of founding and subsequent isolation. Heterozygosity and allelic diversity, both of which are reduced by genetic bottlenecks, were significantly lower in the introduced populations than the Yukon Flats population. Kalgin Island diversity was significantly lower than that for Berners Bay, and was likely due to the smaller founding size and subsequent population fluctuations. Neither introduced population exhibited evidence of gene flow from surrounding populations. Managers should consider the isolation of those populations when assessing risks to population viability and crafting management strategies

Localization criteria for Anderson models on locally finite graphs

We prove spectral and dynamical localization for Anderson models on locally finite graphs using the fractional moment method. Our theorems extend earlier results on localization for the Anderson model on \ZZ^d. We establish geometric assumptions for the underlying graph such that localization can be proven in the case of sufficiently large disorder

On the negative spectrum of two-dimensional Schr\"odinger operators with radial potentials

For a two-dimensional Schr\"odinger operator $H_{\alpha V}=-\Delta-\alpha V$ with the radial potential $V(x)=F(|x|), F(r)\ge 0$, we study the behavior of the number $N_-(H_{\alpha V})$ of its negative eigenvalues, as the coupling parameter $\alpha$ tends to infinity. We obtain the necessary and sufficient conditions for the semi-classical growth $N_-(H_{\alpha V})=O(\alpha)$ and for the validity of the Weyl asymptotic law.Comment: 13 page

IP Management – Key Skills in a Knowledge Economy

Intellectual property (IP) is an important element in the knowledge economy. Through focused appropriation strategies, companies can use intellectual property to generate profits from the investments they make in new knowledge. To do so, it is necessary for various subsystems of the knowledge economy to be combined at an interdisciplinary level. To support the success of the company, IP management can help to optimize appropriation mechanisms. A consideration of the economic properties of intangible assets and an interdisciplinary background of those involved are required for this. With the management of IP, new competences and skills are entering the knowledge economy. By understanding the generation of wealth in the knowledge economy and the IP exploitation mechanisms, the need for new training approaches becomes clear

The Fernald Envoy Program: How face-to-face public involvement is working

In March 1994, the Fernald Environmental Management Project (FEMP), initiated the Fernald Envoy Program as a tool for strengthening public involvement in the restoration of the Fernald site, a former US Department of Energy uranium processing facility which ceased operation in 1989 and became an environmental restoration site. Based on the concept that opinion leaders play a key role in the flow of information, the Envoy Program was developed to link Fernald with opinion leaders in community groups. In February and March 1995, the University of Cincinnati Center for Environmental Communication Studies, under contract with the Fernald Environmental Restoration Management Corporation, conducted an evaluation to determine how the Envoy Program was functioning in relation to the original Envoy Plan. A quasi-experimental design was applied using telephone surveys of opinion leaders in groups with envoy representation and in groups without representation. Findings validated the effectiveness of the program and also identified areas for program improvement

The Thresher : lucky imaging without the waste

JAH acknowledges funding from the Science and Technology Facilities Council of the United Kingdom.In traditional lucky imaging (TLI), many consecutive images of the same scene are taken with a high frame-rate camera, and all but the sharpest images are discarded before constructing the final shift-and-add image. Here, we present an alternative image analysis pipeline – The Thresher – for these kinds of data, based on online multi-frame blind deconvolution. It makes use of all available data to obtain the best estimate of the astronomical scene in the context of reasonable computational limits; it does not require prior estimates of the point-spread functions in the images, or knowledge of point sources in the scene that could provide such estimates. Most importantly, the scene it aims to return is the optimum of a justified scalar objective based on the likelihood function. Because it uses the full set of images in the stack, The Thresher outperforms TLI in signal-to-noise ratio; as it accounts for the individual-frame PSFs, it does this without loss of angular resolution. We demonstrate the effectiveness of our algorithm on both simulated data and real Electron-Multiplying CCD images obtained at the Danish 1.54-m telescope (hosted by ESO, La Silla). We also explore the current limitations of the algorithm, and find that for the choice of image model presented here, non-linearities in flux are introduced into the returned scene. Ongoing development of the software can be viewed at https://github.com/jah1994/TheThresher.Publisher PDFPeer reviewe