Wednesday, December 5, 2007

Cell Signaling

Cell Signaling - part of a complex system of communication that governs cellular activities and coordinates cell actions. The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, and immunity as well as normal tissue homeostasis. Errors in cellular information processing are responsible for diseases. By understanding cell signaling, diseases can be treated and artificial tissue could potentially be built. Types of cell signaling include: cell-to-cell and gap junctions.

Passive Transport - moving of biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve chemical energy. Passive transport is dependent on the permeability of the cell membrane, which, in turn, is dependent on the organization and characteristics of the membrane lipids and proteins. The four main kinds of passive transport are diffusion, facilitated diffusion, filtration and osmosis.





Continuous Spatial Automata - Have a continuum of locations. The state of a location is a finite number of real numbers. Time is also continuous, and the state evolves according to differential equations. One important example is reaction-diffusion textures, differential equations proposed by Alan Turing to explain how chemical reactions could create the stripes on zebras and spots on leopards.[citation needed] When these are approximated by CA, such CAs often yield similar patterns. MacLennan [1] considers continuous spatial automata as a model of computation.

Membranes

A cell wall is a fairly rigid layer surrounding a cell, located external to the cell membrane, which provides the cell with structural support, protection, and acts as a filtering mechanism. The cell wall also prevents over-expansion when water enters the cell. They are found in plants, bacteria, archaea, fungi, and algae.

A cell membrane regulates what enters and exists the cell.
Active transport - Requires energy to push particles through the membrane. Passive transport - Occurs spontaneously in order to randomly distribute particles through the system and to achieve equilibrium.

The Metapolis Dictionary For Advanced Architecture defines a Membrane as: a thin layer of organic, elastic and resistant tissue which separate two cavities or envelops an organ.


Molecular structure of the primary cell wall in plants.


Scanning electron micrographs of diatoms showing the external appearance of the cell wall


Another video by Terreform titled FUTURE CITY

Tuesday, October 23, 2007

"The Wreck of Hope"

A beautifully haunting image by Caspar David Friedrich, titled
The Sea of Ice (c. 1823-1825)



A reinterpretation by Gottfried Helnwein (1998)



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Sunday, October 21, 2007

Interpreting Geologic Sections

The field of Geology studies the various forms of matter that constitute the Earth. Cross sections and maps of specific areas can be analyzed to discover patterns and history of environmental events.

There are two basic tools for interpreting these sections:
1. Superposition - Generally sedimentary rocks are deposited one on top of the other.
2. Crosscutting relations - rock units are often cut across by faults that break the existing rocks, folds that bend them, and igneous intrusions that get squeezed into other rocks.

Here are examples of a fault:






Here are examples of folds and an intrusion:




A Sudden Origin

The theory of evolution, according to Darwin is a slow gradual process. Darwin wrote, "…Natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps." Thus, Darwin conceded that, "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." Such a complex organ would be known as an irreducibly complex system.

It would seem that the theory of natural selection is accurate. Evidence has shown throughout the generations that organism adapt to their environments over time and pass the traits on to the dominant species. Evolution is a supposed "descent with modification" where complex creatures evolve from more simplistic ancestors naturally over time. This could be said not only for individual organisms but entire species and cultures, from a single cell to a whole civilization.

But the Darwinian idea that organisms adapt to their environment through constant small gene mutations disagrees with basic cell biology. Molecular biologist Michael Denton wrote, "Although the tiniest bacterial cells are incredibly small, each is in effect a veritable micro-miniaturized factory containing thousands of exquisitely designed pieces of intricate molecular machinery, made up altogether of one hundred thousand million atoms, far more complicated than any machinery built by man and absolutely without parallel in the non-living world." Furthermore, it is known that cells are protected by an army of proteins, making them very resistant to change. Only extreme stresses can overcome these defenses and cause mutations in the cells. This resistance to change means that evolution is more likely to occur in bursts triggered by extreme environmental conditions.

These irreducibly complex systems are composed of multiple parts, all of which are necessary for the system to function. If one component is missing, the entire system will fail. Each individual part is integral. A system such as this could not evolve slowly, piece by piece. Even Darwin confessed, "To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree."

To better understand how these complex systems function, we should consider the idea of an organisms’ morphogenetic variation across phylogeny. This concept is a natural phenomenon that can be observed throughout several areas of organic as well as computational existence. Patterns on sea -hells and migrating flocks of birds are examples of real life autonomous agency and cellular automata. Both of these terms define processes that produce spectacularly complex results from system rules and instruction from nearby neighbors. Perhaps the most incredible instances of automata exist in cellular biology. Task such as cell signaling and cell transport exemplify complex actions carried out based on rules and responses to external stimuli without global governing. Cells are independent and self-regulating, but communicate with each other to produce marvelous results.

A single cell is more complex than anything ever created by man. The future of responsive architecture is not mechanic it is organic. Used wisely, the tool of programming can be incredibly powerful and influential. However, technology is excelling at such a rapid rate that we are struggling to fully understand how to utilize it. We are approaching an era when the positive effects of technology are outweighed by its consequences. Since the industrial revolution, technology has made our society inextricably tied the planets limited resources in order to propel civilization into the future. A necessary balance must exist. Technology and nature should maintain mutual relationship in which both aid to better understand and evolve the other.

And so it has become clear that we must challenge ourselves to rethink and redefine how we interact with the environment in order to preserve the longevity of society. By observing systems in nature such as cellular biology and fossil finds, we can begin to develop a better understanding of what it takes to create a superior and sustainable civilization. Through an evolution of form we can begin to envision the future of the metropolis and present a new understanding of social spaces and built structures. If we challenge ourselves to analyze the evolution of systems from a new perspective, I believe we can reevaluate and better understand the principles of our world. Through an evolutionary leap of form, we will discover an evolution of consciousness.