Rett syndrome (RTT) is a severe neurodevelopmental disorder affecting females almost exclusively and is characterized by a wide spectrum of clinical manifestations. Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene have been found in up to 95% of classical RTT cases and a lesser proportion of atypical cases. Recently, mutations in another X-linked gene, CDKL5 (cyclin-dependent kinase-like 5) have been found to cause atypical RTT, in particular the early onset seizure (Hanefeld variant) and one female with autism. In this study we screened several cohorts of children for CDKL5 mutations, totaling 316 patients, including individuals with a clinical diagnosis of RTT but who were negative for MECP2 mutations (n = 102), males with X-linked mental retardation (n = 9), patients with West syndrome (n = 52), patients with autism (n = 59), patients with epileptic encephalopathy (n = 33), patients with Aicardi syndrome (n = 7) and other patients with intellectual disability with or without seizures (n = 54). In all, seven polymorphic variations and four de novo mutations (c.586C>T [p.S196L]; c.58G>C [p.G20R]; c.2504delC [p.P835fs]; deletion of exons 1 - 3) were identified, and in all instances of the latter the clinical phenotype was that of an epileptic encephalopathy. These results suggest that pathogenic CDKL5 mutations are unlikely to be identified in the absence of severe early-onset seizures and highlight the importance of screening for large intragenic and whole gene deletions.

Much ink has been spilled over the future prospects of a Northern native economy based on a mix of hunting, trapping and wage work. Information on the mixed economy appeared during debates over Northern pipeline development which raged during the 1970s; though the native lifestyle came under close scrutiny during that period, sceptics remain unconvinced of the very existence, let alone the viability, of a native mixed economy. In their view a way of life based on harvesting ‘country foods’ is moribund and should give place as soon as possible to a full-fledged wage economy; those who think otherwise, including the authors of pipeline inquiries, are misguided romantics. This paper re-examines the debates over the prospects for a native hunting economy, and comes down on the side of its proponents. The author concludes that, given proper institutional support, a mixed economy should persist into the next century, and shows that the critics of the bush economy have underestimated its contribution to the welfare of Northern natives.

The feeding behaviour of stage I–III phyllosoma of the spiny lobsters Jasus edwardsii and Jasus verreauxi was recorded to determine the sequence of events and sensory mechanisms involved in the feeding process. All phyllosoma exhibited a characteristic tumbling behaviour prior to making contact with an individual Artemia and feeding behaviour was similar between the two species. Tactile contact with pereiopods 1 or 2 was necessary to initiate a prey capture response which involved spearing of Artemia, using the terminal dactyl present on these two pereiopods and then passing the prey forward to the mouth with the maxillipeds.

Scanning electron microscopy (SEM) of the pereiopods revealed two morphologically distinct receptors present on the distal segments. These receptors are suggested to have tactile and chemoreceptive roles.