Zebra pattern

Fig. 8. Top view of a 4.7 x 4.7 cm wafer whose surface is coated by a thin seed layer of copper deposited by evaporation. Above the seed layer is a zebra pattern of photoresist black indicates resist and white indicates exposed copper seed layer. (Originally presented at the Fall 1991 Meeting of the Electrochemical Society, Inc. [39]).

The summer pattern of circulation with the Segre River flowing above the Ebro River water has been pointed as providing optimal epilimnetic conditions for the growth of the zebra mussel [40]. 

Zebra mussel (Dreissena polymorpha) is a freshwater bivalve belonging to the Dreissenidae family. The common name, zebra, refers to the zebra stripes pattern on the shell and the scientific name, polymorpha, is derived from the many morphs or forms which occur in the shell color pattern, including albino and solid black or... 

Several animals have emerged as important model systems for the study of development, because they are easy to maintain in a laboratory and have relatively short generation times. These include nematodes, fruit flies, zebra fish, mice, and the plant Arabidopsis. This discussion focuses on the development of fruit flies. Our understanding of the molecular events during development of Drosophila melanogaster is particularly well advanced and can be used to illustrate patterns and principles of general significance. 

A biochemical switch) Zebra stripes and butterfly wing patterns are two of the most spectacular examples of biological pattern formation. Explaining the development of these patterns is one of the outstanding problems of biology see Murray (1989) for an excellent review of our current knowledge. 

Within the AL about 300 non-spiking interneurons modulate the output of the PNs. The resulting activity has been experimentally characterized as patterned on two time scales. There are fast 20 Hz local field potential (LFP) oscillations to which spikes of PNs are locked (Laurent et al. 1996 Wehr and Laurent 1996). The PNs are active in synchronized groups and these groups evolve over time in a slower, odor-specific pattern. The slow switching dynamics has been hypothesized to improve odor discrimination for very similar odors (Laurent et al. 2001 Rabinovich et al. 2001) and some experimental evidence for a decorrelation, and therefore presumably disambiguation, of similar patterns in the olfactory bulb of zebra fish has been observed experimentally (Friedrich and Laurent 2001). 

The same patterns, stripes and hexagons, appear in completely different physical systems and on different spatial scales. For instance, stripe patterns are observed in human fingerprints, on zebra s skin and in the visual cortex... 

With the advent of computers that which was difficult to solve (numerically) before, often became easy. Without computers, we would understand much less about dissipative structures, chaos theory, attractors, etc. These subjects are of a mathematical nature, but have a direct relation to physics and chemistry, and most of all to biology. The relation happens on remarkably different scales and in remarkably different circumstances from chemical waves in space rationalizing the extraordinary pattern of the zebra skin to population waves of lynxes and rabbits as functions of time. In all these phenomena non-linearity plays a prominent role. 

New immunohistochemical methods permit more precise analysis of patterns of prechondrogenesis in developing limbs of amphibians and for comparison in the paired fins of a teleost fish. The monoclonal antibody 3B3 was used to map the distribution of chondroitin-6-S04, a molecular marker of the prechondrogenic condensations. Thus we analysed early endoskeletal patterning of the paired fin buds in the zebra fish (Danio) and of the limb buds of two urodeles Salamandrella, a hynobiid basal urodele, and the axolotl, an advanced form) and of the anuran, Xenopus. The overall aim was to throw light on the developmental basis of tetrapod limb evolution. 

In the zebra fish, the fin bud endoskeleton development differs fundamentally both in its histology and its patterning process from that of tetrapods. A single proximal prechondrogenic plate subdivides twice to form the 4 major radial cartilages of the zebra fish pectoral fin. 

Figure 22.1 Definitive anterior paired fin and limb patterns in (a) a teleost (the zebra fish, Donio) (b) a dipnoan (Neocerotodus) (c) the osteolepiform Eusthenopteron (d) the panderichthyid Panderichthys , (e) a generalised tetrapod limb. Panderichthyiids are the sister-group to the tetrapods. Supposed metapterygial axis is marked (da=digital arch P=posterior). Partly from Coates (1995).

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