OBJECTIVE To study the source of non-outbreak legionnaires' disease, particularly the role of cooling towers, by comparing the locations of patients' homes in relation to the location of cooling towers. DESIGN Retrospective, descriptive study of a case series of patients with legionnaires' disease ill between 1978 and 1986 and, for comparison, a case series of patients with lung cancer. A pro...

Objective: To determine whether there is an increased cancer incidence and mortality in populations exposed to radiofrequency radiations from TV towers. Design: An ecological study comparing cancer incidence and mortality, 1972-1990, in nine municipalities, three of which surround the TV towers and six of which are further away from the towers. (TV radiofrequency radiation decreases with the sq...

In the Twin Towers of Hanoi version of the well known Towers of Hanoi Problem there are two coupled sets of pegs. In each move, one chooses a pair of pegs in one of the sets and performs the only possible legal transfer of a disk between the chosen pegs (the smallest disk from one of the pegs is moved to the other peg), but also, simultaneously, between the corresponding pair of pegs in the cou...

Executive dysfunction (ED) is a characteristic of Huntington disease (HD), but its severity and progression is less understood in the prodromal phase, e.g., before gross motor abnormalities. We examined planning and problem-solving abilities using the Towers Task in HD mutation-positive individuals without motor symptoms (n = 781) and controls (n = 212). Participants with greater disease progre...

We consider a set of static towers with communication capabilities, but not within range of each other due to distance and obstacles. The goal is to achieve connectivity among the towers through a set of robots positioned in a way to act as gateways among the towers. The autonomous mobile robots are initially randomly deployed without necessarily being within range of each other, nor of the st...

Packed towers are widely used for distillation processes due to their higher separation efficiency and capacity in comparison to tray towers. The separation efficiency of the tower strongly depends on the liquid flow behaviour inside the packing, which becomes more complex with the appearance of a second liquid phase. Such flow behaviour can be observed in the three-phase distillation process i...

Modular towers, a notion due to M. Fried, are towers of Hurwitz spaces, with levels corresponding to the characteristic quotients of the p-universal Frattini cover of a fixed finite group G (with p a prime divisor of |G|). The tower of modular curves X1(pn) (n>0) is the original example: the group G is then the dihedral group Dp. There are diophantine conjectures on modular towers, inspired by ...

The HEGRA experiment is a hybrid installation characterized by four diierent types of detectors (scintillator counters, open Cerenkov counters, Cerenkov telescopes and Geiger towers) located within one detector array. The Geiger towers are built with the objective to measure the local energy deposition and to reconstruct and identify muon tracks. In addition each tower may serve as an independe...

Many open problems and important theorems in low-dimensional topology have been formulated as statements about certain 2–complexes called gropes. This paper describes a precise correspondence between embedded gropes in 4–manifolds and the failure of the Whitney move in terms of iterated 'towers' of Whitney disks. The 'flexibility' of these Whitney towers is used to demonstrate some geometric co...

Towers of function fields (resp., of algebraic curves) with positive limit provide examples of curves with large genus having many rational points over a finite field. It is in general a difficult task to calculate the genus of a wild tower. In this paper, we present a method for calculating the genus of certain Artin–Schreier towers. As an illustration of our method, we obtain a very simple an...