We describe a set of ∆−1 slopes that are universal for 1-bend planar drawings of planar graphs of maximum degree ∆ ≥ 4; this establishes a new upper bound of ∆− 1 on the 1-bend planar slope number. By universal we mean that every planar graph of degree ∆ has a planar drawing with at most one bend per edge and such that the slopes of the segments forming the edges belong to the given set of slop...

This article discusses estimation of multilevel/hierarchical linear models that include cluster-level random intercepts and random slopes. Viewing the models as structural, the random intercepts and slopes represent the effects of omitted cluster-level covariates that may be correlated with included covariates. The resulting correlations between random effects (intercepts and slopes) and includ...

The Energetic Equivalence Rule (EER) is a controversial issue in ecology. This rule states that the amount of energy that each species uses per unit of area is independent of its body size. Here, we perform a meta-analytical procedure to combine and compare the slopes of population density and body size relationships across independent studies of mammals and birds. We then compared a distributi...

We investigate slope distributions in the northern hemisphere of Mars from topographic profiles collected by the Mars Orbiter Laser Altimeter. Analysis of the region from about 12øS to 82øN, over diverse geologic units, indicates that the range of regional-scale slopes is small, generally < 3 ø. Surface smoothness is most distinctive in the vast northern hemisphere plains, where slopes are typi...

This paper introduces nonparametric U-statistics for testing the curvature (e.g., linearity, concavity, or convexity) of an unknown regression function. The U-statistics are based on pairwise slopes in the data. No choice of smoothing parameters is required for the global version of the statistics or their (asymptotic) standard errors, making them simple to compute. The proposed tests are analo...

We present a suite of extensions for ARCVIEW GISTM (ESRI) that allows to map the spatial distribution of first-order mechanical slope-properties in hard rock terrain, e.g. for large slope areas like water reservoir slopes. Besides digital elevation data, this expert-system includes regional continuous grid-based data on geological structures that might act as potential sliding or cutoff planes ...

Sandpile models with randomized updating rules are studied. The randomness is not quenched, but set dynamically by the dissipation events (avalanches) in the system. Relaxation from fixed updating rules is here a consequence of medium anisotropy and motivated by the behavior of various driven physical systems. A one-dimensional sandpile model in which the critical slope at a site varies as the ...

The A–polynomial of a manifold whose boundary consists of a single torus is generalised to an eigenvalue variety of a manifold whose boundary consists of a finite number of tori, and the set of strongly detected boundary curves is determined by Bergman’s logarithmic limit set, which describes the exponential behaviour of the eigenvalue variety at infinity. This enables one to read off the detec...

Quasi-simultaneous optical/near-IR photometry is presented for a sample of 37 luminous optically selected QSOs drawn from the Large Bright QSO Survey. Most of the QSOs have decreased in brightness since discovery; this is expected in flux-limited samples. The continuum shape of most of the QSOs can be represented by a power-law of the form F (ν) ∝ ν, but a few have softer (redder) continuum slo...

In response to the paper by Keown andJochemsen in which the latest empirical data concerning euthanasia and other end-of-life decisions in the Netherlands is discussed, this paper discusses three points. The use of euthanasia in cases in which palliative care was a viable alternative may be taken as proof of a slippery slope. However, it could also be interpreted as an indication of a shift tow...