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This paper presents an extension to the the Ivanoff–Merzbach renewal process. The Ivanoff–Merzbach process is a natural analogue to the one-dimensional renewal process. Restricting our attention to two dimensions, the focus of the current paper will be formation of this extension, which we will refer to as a Markov renewal process, as well as simulation, estimation and applications to data sets in ecology and forestry. Copyright © 2010 John Wiley & Sons, Ltd.

A sample of 111 12-year-old children in Salford, UK was examined in 1988, and the findings compared with those of a survey carried out in 1960 of 12-year-old children in the same city. Between 1960 and 1988, the mean DMFT of the boys fell from 6.04 to 2.34 and that of the girls from 6.54 to 3.40. All types of teeth were affected by caries in 1960 but in 1988 none of the canines and mandibular lateral incisors were affected. In 1960 the permanent first molars contributed 57% of the boys' and 54% of the girls' total DMFT while in 1988 they contributed 87% of the boys' and 73% of the girls' DMFT. Jackson's Treatment Index showed that the dental services were making a greater impact in 1988; for the boys it rose from 29.5 to 63.2 and for the girls from 27.8 to 62.3.

Benzyl chlorides and bromides are shown to undergo copper-promoted coupling with a variety of terminal alkynes including, for the first time, electron-poor acetylenes such as methyl propiolate. The reaction permits easy access to a wide range of (functionalized) benzyl-substituted propiolates (as well as several related alkynes) from commercially available benzyl halides. These products should in turn function as useful building blocks for the synthesis of previously inaccessible (functionalized) benzyl-substituted heterocycles.

This paper demonstrates how to apply the Ivanoff–Merzbach renewal process (Ivanoff and Merzbach, 2006; Ivanoff, 2008) to the modelling of environmental and other forms of point process data. The model is explored via simulation, focusing on two special cases. Maximum likelihood estimation of model parameters is described and demonstrated for these cases. The methods are applied to a point pattern related to human settlement patterns and to a point pattern describing the locations of a species of pine. Copyright © 2009 John Wiley & Sons, Ltd.

The configuration and dynamics of six Bathyergus suillus and one Cryptomys hottentotus burrow systems in coastal fynbos vegetation was studied for a year by monitoring mound production and excavating burrows. Bathyergus suillus is a large solitary mole-rat and C. hottentotus is smaller and social. Our results are compared with those for other subterranean rodents. Most B. suillus burrows (15–22 cm in diameter) were 40–65 cm below ground to prevent their collapse in the seasonally softer and drier surface sand; the burrows were consequently situated deeper than most food plants. Cryptomus hottentotus burrows were narrower (5–7 cm) and shallower (