Spatiotemporal patterns

Clanis H. and Key B. (2001). Expression of glycoproteins in the vomero-nasal organ reveals a novel spatiotemporal pattern of sensory neurone maturation. J Neurobiol 46, 113-125. 

We carefully dissected rat tail arteries and loaded them with a Ca2+ indicator, Fluo-3. After a rectangular glass capillary was inserted into the lumen of the excised arteries, [Ca2+] in smooth muscle cells within the arterial wall was visualized using a confocal microscope. Brief electrical shocks were delivered at 5 Hz to the preparations to stimulate the sympathetic nerve network present in the adventitia. We found Ca2+ signals with diverse spatiotemporal patterns, Ca2+ waves and oscillations in individual smooth muscle cells during the sympathetic nerve stimulation (lino et al 1994). 

Pioneering efforts to understand the nature of olfactory coding were reported by Adrian (24-27). His work introduced the ideas that different odors activate ORCs in different regions of the olfactory epithelium and that spatiotemporal patterns of ORC firing would suffice to encode different odors. Subsequent studies by many investigators and involving various recording methods (reviewed in refs. 13 and 28) led to the conclusion that, at various levels of the pathway, the olfactory system uses distributed neural activity to encode information about olfactory stimuli. 

Gruber N, et al. (1999) Spatiotemporal patterns of carbon-13 in the global surface oceans and the oceanic Suess effect. Global Biogeochem Cycles 13 307-335 Gussone N, et al. (2005) Calcium isotope fractionation in calcite and aragonite. Geochim Cosmochim Acta 69 4485 494... 

In neural networks the interactions between neurons are highly nonlinear. Models based on the concept of dissipative structures can be constructed that account for spatiotemporal patterns in epileptic seizures. 

In the microscopic techniques discussed above, the challenge was to visualize the atomic detail. However, in catalysis one also encounters phenomena that occur on the scale of micrometers or millimeters which require imaging. In particular, these include the ordering of adsorbates in large islands and the development of spatiotemporal patterns in oscillating reactions [9]. This spectacular phenomenon has stimulated the exploration of imaging techniques that provide information on patterns on the micrometer to millimeter scale. 

The possibility for the formation of spatiotemporal patterns with heterogeneously catalyzed reaction systems was pointed out early (114-116). Here the following transport mechanisms may be responsible for spatial coupling ... 

Coupling between surface diffusion and reaction. If this mode is dominating [such as with the CO oxidation on Pt(100)], chemical waves propagating across the surface will give rise to spatiotemporal pattern formation. 

Figure 11.3 Spatiotemporal patterns of orthophosphate concentrations (mg PL-1) across an estuarine transect, from upper to lower Galveston Bay (USA) in August and October 1989. Texas Water Commission (TWC) data were collected a week prior to sampling by Santschi (1995). (Modified from Santschi, 1995.)...

Spatiotemporal pattern formation at the electrode electrolyte interface is described by equations that belong in a wider sense to the class of reaction-diffusion (RD) systems. In this type of coupled partial differential equations, any sustained spatial structure comes about owing to the interplay of the homogeneous dynamics or reaction dynamics and spatial transport processes. Therefore, the evolution of each variable, such as the concentration of a reacting species, can be separated into two parts the reaction part , which depends only on the values of the other variables at one particular location, and another part accounting for transport processes that are induced by spatial variations in the variables. These latter processes constitute a spatial coupling among different locations. 

The simplest model describing the active/passive oscillations is used by Birzu et al. [27-29] to model spatiotemporal patterns during metal dissolution (see Sec. 4.1). The homogeneous dynamics of the model reads ... 

The structural design of retinoic acid receptors explains, at least in part, the pleiotropy of this class of receptors. It is a consequence of the combinatorial possibilities offered by heterodimerization. The many different functional units that can be formed by heterodimerization make it understandable why so many different gene response elements can be recognized. This, and a distinct spatiotemporal pattern of expression, both in the developing embryo and in differentiated tissues, suggests that each RAR and RXR isoform and each heterodimer formed may have a unique function. Pierre Chambon has directed attention to the large repertoire of combinatorial arrangements. These combina-... 

Although nearly all cellular processes have spatiotemporal patterns and are timed in one way or the other, the outstanding example of a built-in clock is the cell cycle. The wheels and cogs of the clock that time the cell cycle are the cyclins and the cyclin-dependent kinases (Cdks). 

The most powerful approach to characterize the spatiotemporal patterns of proteins in cells would be to track individual proteins. This is difficult under most circumstances... 

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