The dopamine D4 receptor structurally and pharmacologically resembles the dopamine D2 and D3 receptors. Clozapine, an atypical antipsychotic that is relatively free of the adverse effects of drug-induced parkinsonism and tardive dyskinesia, binds to the D4 receptor with an affinity 10 times higher than to the D2 and D3 receptors. This may explain clozapine's atypical properties. Here we report the existence of at least three polymorphic variations in the coding sequence of the human D4 receptor. A 48-base-pair sequence in the putative third cytoplasmic loop of this receptor exists either as a direct-repeat sequence (D4.2), as a fourfold repeat (D4.4) or as a sevenfold repeat (D4.7). Two more variant alleles were detected in humans. Expression of the complementary DNA for the three cloned receptor variants showed different properties for the long form (D4.7) and the shorter forms (D4.2, D4.4) with respect to clozapine and spiperone binding. To our knowledge, this is the first report of a receptor in the catecholamine receptor family that displays polymorphic variation in the human population. Such variation among humans may underlie individual differences in susceptibility to neuropsychiatric disease and in responsiveness to antipsychotic medication.

The purpose of our study was to evaluate the individual variations of the foramen transversarium of the seventh cervical vertebra. This foramen sometimes has the same dimensions as the foramina of the other cervical vertebrae, but it can also be smaller, or absent. In cases where a foramen is present in the seventh cervical vertebra, vascular or nerve structures (or both) can be occasionally observed within. When the transverse foramina are found to contain none of the above structures, what then is to be found within this space? According to our results, the transverse foramina of the seventh cervical vertebra almost always contains vascular and nerve branches as well as fibrous and adipose tissues. This report concerns the results of the macroscopic and microscopic studies concerning the contents of the transverse foramina of the sixth and seventh cervical vertebrae. The comparative study was completed at the Department of Anatomy of the Faculty of Medicine, University Laval.

Abstract-The brushless doubly-fed induction machine (BDFIM) has been extensively researched over approximately 30 years, but a related machine, the brushless doubly fed reluctance machine (BDFRM), has not. This was mainly due to the fact that reluctance rotor designs were not capable of generating saliency ratios large enough to make the BDFRM competitive with other machines. However recent developments in reluctance rotors, spurred on by research into synchronous reluctance machines, has resulted in high saliency ratio rotors that are economic to build. This, together with the promise of higher efficiency and simpler control compared to the BDFIM, means that further investigation of the BDFRM is warranted. A relatively limited amount of work to date has been published on the BDFRM. This paper attempts to fill this void by presenting a theoretical analysis of some of the important control properties of the ideal BDFRM.

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