At the most fundamental level, the size of an animal's home range is determined by its energy needs. In the absence of confounding variables, home range size should therefore scale with body mass according to Kleiber's exponent for metabolic rate of 0.75. Comparative studies in a wide range of taxa have failed to confirm this prediction: home range size has commonly been found to scale with an exponent significantly >0.75. We develop a comparative measure of metabolic needs that incorporates both mass-specific metabolic rate and social-group size. We test the prediction that home range size in primates scales isometrically with this measure when an appropriate linear model is applied to data corrected for phylogenetic bias. Analyses using species values as data points indicate an exponent consistent with Kleiber's law. This result is misleading, however, because ecological factors confound the analysis, and the slopes within some ecologically homogeneous taxa are steeper. Accordingly, in analyses based on independent contrasts with reduced major axis, slopes are significantly greater than predicted by Kleiber's law. We examine the effects of other variables, and we find that systematic variation in substrate use, home range overlap, and diet account for the steeper than expected relationship between home range size and metabolic needs based on Kleiber's law. We therefore conclude that the scaling of home range size is subject to Kleiber's law but in combination with other factors. These results emphasize that the study of allometry requires detailed attention to statistical models and control of confounding variables.

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand the key element of all PQIP architectures is the beam splitter, which allows to coherently couple optical modes. Here we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time-bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long-distance quantum communications and quantum metrology.

This report describes the provision of an implant-supported hybrid overdenture in an 8-year-old child with mandibular anodontia. An interdisciplinary approach to treatment planning was employed. Two implant fixtures were placed in the canine regions and ball attachments connected to provide support and retention for the prosthesis. There was only one implant-related complication during the first follow-up year. Close follow-up during the child's growing years is essential for the maintenance of the peri-implant tissues and to replace the prosthesis as mandibular growth occurs.

No abstract