Vibrations in robot action, both in the arm control system and arm itself, and in the transported load, are a serious problem in the development of high speed systems. The paper discusses the typical causes of vibration resulting from the motion command in path controlled robots and those due to the failure of a system to meet the specified command through power and performance limitations. Experimental results illustrating such phenomena are presented. Methods of reducing the magnitude or occurrence of such vibrations through the improved design of motion commands, which take account of the vibratory nature of the system and load, are presented.

Background. The human serotonin transporter gene (5-HTT) is a strong candidate for involvement in the pathogenesis of mood disorders. Two common polymorphisms have been identified in the gene: a VNTR in intron 2 and a functional deletion/insertion in the promoter region. In previous studies we proposed that allele 12 of the VNTR might increase susceptibility for bipolar disorder.

Methods. We have genotyped 122 parent–offspring trios of British Caucasian origin where the proband had DSM-IV Bipolar I disorder (BPI). The results were analysed with the transmission/disequilibrium test (TDT), which examines whether particular alleles are preferentially transmitted from heterozygous parents to affected offspring.

Results. The 12 repeat in the VNTR in intron 2 was transmitted 72 times and not transmitted 56 times (χ2 = 2·0, 1 df, P=0·16). If we exclude 24 families in which the proband was a case in our published case–control studies (Collier et al. 1996a; Rees et al. 1997), the excess transmission of allele 12 reaches conventional levels of statistical significance: χ2 = 3·85, 1 df, P<0·05. The deletion/insertion polymorphism in the promoter region was not associated with BPI: 66 parents transmitted the inserted (L) allele and 59 parents transmitted the deleted (S) allele (χ2 = 0·39, 1 df, P=0·53).

Conclusions. The 12 repeat of the VNTR in intron 2 of the serotonin transporter gene might be a susceptibility factor in bipolar affective disorder. The genetic effect, if true, is likely to be small, and requires confirmation in further studies using parental controls.

Although meningiomas represent 15 per cent of tumours of the central nervous system, they rarely metastasize. A case is presented in which metastasis to a cervical lymph node occurred, together with local recurrence, nine years after initial diagnosis and treatment. This case serves to illustrate that malignant meningioma is a rare cause of a neck mass.

Unfortunately, there is as yet no direct observation of a forming galaxy, nor of a manifestly “young” galaxy. It is not even clear what such galaxies might look like. There are, however, some lines of attack that will yield indirect information about the environment in which galaxies formed. There is no lack of theories of galaxy formation, many of which provide quite different scenarios for the birth-process. the hope is that theories of galaxy formation may indicate what young galaxies ought to look like and thus guide us in our search for such objects.