A teenage girl with a chronic large posterior fossa tumor had primary position right-beating nystagmus with a constant-velocity slow phase. Smooth pursuit was normal to the left but absent to the right. Vestibuloocular move­ ments were present in both directions. The findings are analogous to downbeat and upbeat nystagmus, in which unidirectional pursuit palsies have been postulated as the path...

Horizontal or Lateral Gene Transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as ...

the gravity method is one of the first geophysical techniques used in oil and gas exploration. an algorithm is developed for a fast quantitative interpretation of gravity data generated by geometrically simple but also the estimated depths and other model parameters of a buried structure. following abdelrahman et al (1989). the general gravity anomaly expression produced by a sphere, an infinit...

abstract background and aim: considering the widespread development of implants in dental treatment plans, linear measurements on panoramic radiography are of especial importance. in the present study we investigated the effect of head misalignment up to 15° around vertical and horizontal axes on the magnification rate of digital panoramic radiography in each part of upper and lower jaws. mater...

In this note an attempt is made to create the necessary prerequisites for the development of a theory of ‘almost horizontal turbulence’. A system of simplified equations of ‘almost horizontal motions’ is proposed. These equations are affinely invariant, namely, one can independently modify the vertical and horizontal scales. It is shown that the simplification used does not prevent us from obta...

Horizontal gene transfer (HGT) is a major process in the evolution of bacteria and archaea (1–3) that is thought to be the principal source of functional innovation in microbial evolution (4, 5). The signal of vertical, tree-like evolution is detectable primarily among genes encoding components of information processing systems, whereas evolution of the operational genes (primarily, metabolic e...

We recall the contribution of Goguen and Burstall’s 1980 CAT paper and its powerful influence on theories of specification implementation that were emerging at about the same time, via the introduction of the notions of vertical and horizontal composition of implementations. We then give a different view of implementation which we believe provides a more adequate reflection of the rather subtle...