Preliminary work on computer testing of a generative phonology of Danish

No abstrac

Environmental Performance Evaluation of Ro-Ro Passenger Ferry Transportation

With increasing focus on the environmental performance of different transport modes (for example trucks, trains, ships and aircraft) it is of utmost importance that the different transport modes are compared on an equal basis so that the environmental impact, defined as energy demand and/or emissions per transport unit, is related to the same unit for the different transport forms. For Ro-Ro passenger ferries it can be difficult to find a suitable common transport unit, as they often transport a mix of cargo, such as passengers, passenger cars, trucks, lorries, busses and other rolling transport units. In this paper a method for determination of a common transport unit for Ro-Ro passenger ships will be described

Further work on computer testing of a generative phonology of Danish

No abstrac

TMB: Automatic Differentiation and Laplace Approximation

TMB is an open source R package that enables quick implementation of complex nonlinear random effect (latent variable) models in a manner similar to the established AD Model Builder package (ADMB, admb-project.org). In addition, it offers easy access to parallel computations. The user defines the joint likelihood for the data and the random effects as a C++ template function, while all the other operations are done in R; e.g., reading in the data. The package evaluates and maximizes the Laplace approximation of the marginal likelihood where the random effects are automatically integrated out. This approximation, and its derivatives, are obtained using automatic differentiation (up to order three) of the joint likelihood. The computations are designed to be fast for problems with many random effects (~10^6) and parameters (~10^3). Computation times using ADMB and TMB are compared on a suite of examples ranging from simple models to large spatial models where the random effects are a Gaussian random field. Speedups ranging from 1.5 to about 100 are obtained with increasing gains for large problems. The package and examples are available at http://tmb-project.org

Centuries-Old DNA from an Extinct Population of Aesculapian Snake (Zamenis longissimus) Offers New Phylogeographic Insight

The Aesculapian snake (Zamenis longissimus) is distributed in Central and Southern Europe, the Balkans, Anatolia, and Iran, but had a wider mid-Holocene distribution into Northern Europe. To investigate the genetic affinity of a Danish population that went extinct in historical times, we analysed three ethanol-preserved individuals dating back to 1810 using a silica-in-solution ancient DNA extraction method, combined with next-generation sequencing. Bioinformatic mapping of the reads against the published genome of a related colubrid snake revealed that two of the three specimens contained endogenous snake DNA (up to 8.6% of the reads), and this was evident for tooth, bone, and soft tissue samples. The DNA was highly degraded, observed by very short average sequence lengths (<50 bp) and 11–15% C to T deamination damage at the first 5′ position. This is an effect of specimen age, combined with suboptimal, and possibly damaging, molecular preservation conditions. Phylogeographic analyses of a 1638 bp mtDNA sequence securely placed the two Danish Aesculapian snakes in the Eastern (Balkan glacial refugium) clade within this species, and revealed one previously-undescribed haplotype. These results provide new information on the past distribution and postglacial re-colonization patterns of this species