Multiple landmarks

From the notion that animals form an overall representation of an experienced spatial environment, at least three implications have been drawn. One is that animals use multiple landmarks to locate important places by computing their distance and direction from these landmarks. A second implication is that animals can use the cognitive map to infer new routes or shortcuts through space that would be to their advantage. The third implication to be discussed is the suggestion that by exploring a spatial environment, an animal can form a topological map of that environment. 

The diagrams in Figure 2.8 show how bees make use of multiple landmarks. Bees learned to search for sucrose at fixed distances from three equally spaced landmarks, as shown in Diagram A. Variation in the size... 

Note Added in Proof This is nicely illustrated by the landmark publication of Protasiewicz et al. [94] who describe derivative (122), the first conjugated polymers featuring phosphorus-phosphorus multiple bonds (Scheme 33). The di-phosphene-PPV (122) exhibits an extended 71-conjugated system as shown by the optical HOMO-LUMO gap that is close to that of related PPV [94]. 

In the natural world, animals may sometimes be able to use beacons to navigate toward a goal. The location of food, water, or an animal s home might be at the base of a tree or near a large rock. On many other occasions, however, important sites may be located in an open, homogeneous field that offers no beacons. Nevertheless, animals are able to use cues only distantly related to the goal site to precisely track its position. The use of multiple cues to define a specific location in space is called piloting. We turn to some mechanisms by which animals may learn to use landmarks to pilot to a precise position. 

To say this is not to detract from Liljenroth s paper, which is a landmark of the chemical engineering literature it is just to notice a matter of style and the point at which a mathematical model is bom. For in the next papers on the question of multiple steady states, those of Wagner (1945), Denbigh (1944, 1947), Denbigh el al. (1948) and Van Heerden (1953) we do find more general structures. 

The classic landmark paper on parametric sensitivity in nonisothermal chemical reactors is by Bilous and Amundson (1956). A more recent example of multiple stationary states in packed catalytic tubular reactors is discussed by Pedernera et al. (1997). 

Figure 4 The Anthropometric Landmark Data from Multiple Subjects Is Displayed in the Form of Data Qouds. The simultaneous view of the data allows for rapid assessment of control location and adjustment questions. Courtesy Dr. Jerry Duncan, John Deere Corporation)...

The electrocardiogram (ECG) is a weU-known pattern of electrical activity. For present purposes, a simplified approach can be adopted, with focus falling on just one of the multiple intervals that can be identified on an ECG. Figure 3.1 is a stylistic representation of an ECG waveform, with the landmarks and interval of interest identified. These are the onset of the QRS complex, the offset of the T-wave, and the distance between these two points, known as the QT interval. Given that drug-induced prolongation of the QT interval is of considerable importance in the book s discussions, a stylistic representation of QT interval prolongation is shown in Fig. 3.2. 

Publication of the results of the landmark Vitamin Intervention for Stroke Prevention (VISP) Trial is the first evidence from a large randomized controlled trial of the effect of lowering total Hey via folic acid-based multiple B vitamin supplementation on the incidence of hard clinical events, such as recurrent stroke, in patients with recent ischemic stroke (Spence et al. 2001 Toole et al. 2004). Hankey and Eikelboom (2004) believed that Hey hypothesis of ather-othrombotic vascular disease in general, and stroke in particular, remains viable. Two studies using different methods yield consistent results in support of the hypothesis (He et al. 2004 Wald et al. 2002). 

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