-
From NASA we know that rocket science deals with systems
that are inherently brittle: If one subsystem fails, the whole
mission is jeopardized. That is the reason NASA introduced triple
redundancy in critical systems just in case that one of them
fails. We also know from NASA that initial conditions like weather
and launch windows most be carefully chosen and the launch has to
be postponed if the conditions are not satisfied.
Warfare, on the other hand, deals with enemies that use all
their intelligence to emulate a complex system with high
unpredictability. The 100 Mio.$ test of Ballistic Missile Defense
system was held under unrealistic "rocket science" conditions:
Launch location, time, flight plan, target parameters were
precisely known to the experimenters. The test was further
"simplified" in that the target only released one decoy balloon,
which also happened to conveniently not inflate during the test.
Other than that, only a battery went bad and a signal was not sent
to separate the kill vehicle from the booster with the result that
the whole 100 Mio.$ test went down the drain.
The nature of complex systems is that one can never anticipate
every detail, here the separation of kill vehicle and booster was
not even on the checklist of the experiment. Assuming that all
participating rocket scientists and engineers are competent and
have given their best to make this experiment to succeed, we are
led to conclude that defensive systems in the 21st century need to
be based on robust, adaptive, complex systems and not on brittle
rocket science.
Excerpts:
"(...) Kadish: We had the launch of the target out
of Vandenberg and that operation appeared to be fairly
successful. We had an initial delay to the launch because of
some battery problems that we worked out on the target.
We had, as far as I know, only one anomaly with the
target launch in that we did not get the decoy balloon to
inflate, so it was an uninflated decoy.
Everything appeared to be on track with the launch in the
battle manager type systems, the integrated part of the system,
to work right. We launched the interceptor. But we failed to
have the kill vehicle separate from the booster second stage.
(...)
Q: General, with many experts claiming that this is a
possible $60 billion boondoggle, a system that won't work, you
now have two failures and one success. Doesn't that weaken your
position considerably?
Kadish: What it tells me is we have more engineering work
to do. And as we've said all along, this is a very difficult,
challenging job. This is rocket science, so there's a lot of
things that can happen in this process (...)
Q: General Kadish, of all the things that could have gone
wrong with this flight, was this at the very bottom of your
concern list?
Kadish: It wasn't even on my list. We had good confidence
in the reliability of this. It's worked very well before. And
to have the kill vehicle not separate was not something we
worried about. (...)"
- DoD
News Briefing,
Presenter: Lieutenant General Ronald Kadish, Director,
BMDO (Ballistic Missile Defense Organization), Defense
Link US DoD, Saturday, July 8, 2000 - 1:37 a.m.
EDT
- See also: Update
On National Missile Defense Intercept
Test, Defense Link US
DoD, July 8, 2000
Digitising Globalisation, World Link 
The International Monetary Fund defines globalisation
as "the growing economic interdependence of countries worldwide
through the increasing volume and variety of cross-border
transactions in goods and services and of international capital
flows, and also through the more rapid and widespread diffusion of
technology". The IMF omits some important factors and focuses on
the wrong central element. And like any definition of more than a
few years' vintage, it ignores the enormous impact of the Internet
on globalisation.
In addition to the IMF's points, globalisation entails
greater movement of people across national borders and the rise of
similar standards around the globe. The latter is driven by the
diffusion of technology and American popular culture and by the
dictates of industrial and commercial economic organisations. But
the central element of globalisation is that it is driven by
companies in their relentless search for market share and profits.
Companies are at the heart of globalisation. (…)
"Capitalism is a force that moves, but it does not know
where it is going. The simultaneous domination of the economy by
global finance and the coming of the information revolution make
this feature of capitalism even more pronounced. Indeed, there is
now a disjunction between the movements of finance and the
development of production and society. The former seem to move at
the speed of light. The latter moves at the speed of sound…
if not slower. In finance there is absolute fluidity and
everything is instantaneous. In material society there is
viscosity, an inevitable slowness, because people are the main
movers. This difference in speed gives rise to an increased risk
of ruptures and breakdown. Financial movements are too rapid for
the pace of the real economy. That is why financial movements must
be regulated, so that meaning is restored to these transactions.
The production of wealth must be geared to human
aims.(…)
" We fully recognise globalisation. But we do not see its
form as inevitable. We seek to create a regulatory system for the
world capitalist economy."(…)
We need to set up new regulatory systems for new networks
such as the Internet, so that we can influence the process of
globalisation and control its pace for the benefit of
society."(…)
The result in an era of lowered transaction costs will be a
rapid reshaping of firms and massive new horizontal mergers
calculated to take advantage of the benefits of global scale based
on common core competencies.(…)
"Fifth, the Internet is also the perfect mechanism to foster
and sustain democracy. Authoritarian governments last in part
because the state and its officials have more information than
anyone else. Not by chance did the Soviet Union spend vast
resources jamming radio broadcasts of countries hostile to
communism. China now seeks to control Internet access with the
rest of the world. But the Internet will not be controlled. There
are too many technological solutions to avoiding state control.
Any country that wants the immense benefits of global connectivity
- which Chinese leaders, for example, have made clear they believe
is essential for continued Chinese economic growth - will see a
shift in power. As their people connect, they will gain
information and with that information will come power. "
(…)
The Business Of Environment, World Link
"There is a fundamental change underway in the
interface between environment and business - an increasing
reliance on market mechanisms to produce the desired
sustainability outcomes for business and society.
Since the Earth Summit in Rio in 1992, there has also been
widespread acceptance of a sustainable development approach by
governments, by institutions such as the World Bank and the United
Nations, and corporations. Many environmentalists and regulators
have come to understand that while the market can be part of the
problem when economics is disconnected from environmental and
social concerns, it can also be a powerful tool for positive
outcomes when environmental and social goals are integrated with
commercial activity.
Green groups have traditionally looked to direct regulation
or controls to achieve environmental outcomes. They used to work
to ban activities that degraded the environment. Over time, it has
become apparent that a combination of direct control and measures
that are market based works better. Simple bans on mining have
tended to be replaced with arrangements that force mining
companies to internalise the full cost of their activities.
"(…)
There has been a huge shift in the macro-economic forces
driving corporate share ownership. Earlier, it was a limited
number of powerful and wealthy individuals who owned corporate
stocks. Today, the vast majority of share funds is owned by
pension funds, which generally represent the middle income working
investor. Members in the funds have an increasing say in how their
monies are invested, and have significant representation on the
trustee boards that make the investment decisions. The supply of
capital has thus shifted from a small group of powerful
individuals to a large group in society who appears to have
different values.
There are over $2.7 trillion in socially and environmentally
screened investment funds in the US alone, up from just over $1
trillion in 1997. More significantly, many of these funds are
outperforming the Standard and Poors 500 Index by large margins.
Dow Jones has even established a "Dow Jones Sustainability Index"
with Swiss asset manager SAM Sustainability Group. The index
comprises 225 stocks chosen for environmental, technological and
social performance. It is outperforming the Morgan Stanley
cumulative index. (…)
"(…) we tax wages and income, which discourages
employment. Germany, the UK and the Nordic countries are already
adopting a new tax structure that is performance-based. It taxes
pollution and waste. On a revenue neutral basis, we could
introduce taxes on pollution and remove taxes on payrolls and
savings. This provides a strong commercial incentive for
environmentally beneficial materials, energy efficiency,
employment and investment.(…)
Perhaps the simplest way of harnessing the markets is to
give consumers the greatest amount of information and the largest
range of products possible. The explosion of the Internet has
meant that information is available to all corners of the globe
within minutes. For business this means that there are no public
relations or advertising solutions to breaches of the public trust
in operations worldwide. From Bhopal to Brent Spar to Chernobyl,
the news gets out before damage control can be implemented.
(…)
For businesses wanting to capture market demand and
differentiate their products as "green", labelling is becoming
increasingly important. (…)
Third party certification of environmental and social
attributes is also becoming common. Eco-timber certified as "rain
forest safe" serves as one example. This information assists
consumers to make informed choices about the way they want their
capital to flow and enables visionary businesses to provide
products and services in a sustainable way, thereby benefiting
from their investments. "
Taming Combinatorial Explosion, PNAS
We can arrange five letters of the alphabet in more than
ten million ways so in principle we could - by properly redefining
the meaning of words- write Shakespeare's collected work down in a
single line. On the other hand, memorizing that one-liner (and its
meaning) would be just as hard as memorizing all of Shakespeare's
work.
This is one example of the combinatorial explosion that would
make individual finite strings so improbable that it would not be
a good basis for a language.
The same is also true for the formation of bio-molecules from
individual monomers. A challenge in the theory of pre-biotic
evolution of life was to find constraining rules that would
dramatically cut down the number of combinations that were
possible based on the construction rules alone. This reduction of
degrees of freedom corresponds to the formation of order
parameters and attractors in non-linear dynamical systems. In the
context of the work of Morowitz et al. this is implemented in the
form of selection rules: molecules should have less than six
carbon atoms, be soluble enough in water, and they should not be
too combustible (i.e. the organic matter built from those
molecules should not contain too much more latent energy than the
elementary building bricks of H2O and
CO2).
Schuster gives details about how this can be accomplished and
concludes:
"(...) template-induced auto-catalytic processes
are excellent means for the taming of the combinatorial
explosion. (...)
If a system contains several catalytic cycles, selection
takes place between individual cycles and the result is again a
drastic reduction in the diversity of molecular species.
"
- Taming
Combinatorial
Explosion, Peter
Schuster,Proc. Natl. Acad. Sci. USA 97, 27 June 2000,
10.1073/pnas.150237097
- The
Origin Of Intermediary
Metabolism Morowitz, H.
J., Kostelnik, J. D., Yang, J. &Cody, G. D. (2000)
Proc. Natl. Acad. Sci. USA 97, 7704-7708.
-
Abstract: Self-adjusting, or adaptive, systems have
gathered much recent interest. We present a model for
self-adjusting systems which treats the control parameters of the
system as slowly varying, rather than constant. The dynamics of
these parameters is governed by a low-pass filtered feedback from
the dynamical variables of the system. We apply this model to the
logistic map and examine the behavior of the control parameter. We
find that the parameter leaves the chaotic regime. We observe a
high probability of finding the parameter at the boundary between
periodicity and chaos. We therefore find that this system exhibits
adaptation to the edge of chaos. (...)
Many of these studies show that adaptive systems will adapt
to a new state at the boundary of chaos and order, called the edge
of chaos. N.H. Packard [4] showed that this effect
occurred for a population of cellular automata rules evolving with
a genetic algorithm.
Pierre and Hubler [5] studied two competitive,
adaptive agents which used both control and modeling to predict
the behavior of the logistic map and found that, over time, the
agents use a control which places the logistic map at the edge of
chaos. The edge of chaos also occupies a prominent position
because it has been found to be not only an optimal setting for
control of a system [6], but also an optimal setting under
which a physical system can support primitive functions for
computation [7].
Controlling Spatiotemporal Dynamics in Excitable Systems, SFI Working-Papers
Abstract: Spatially extended excitable systems exhibit
a variety of spatiotemporal dynamics | from stable to chaotic.
These dynamics can change under pathological conditions and impair
normal functions. Thus being able to control the altered dynamics
for improved functioning has potential for wide ranging
applications in real and artificial
systems. Here we propose a simple and general method that
can be used to target the spatiotemporal dynamics, both globally
and in spatially-localized regions, in either direction - i.e.
towards the stable ("control") or unstable ("anti-control")
manifold - by simply changing the sign of an externally applied
perturbation or pinning. The method is applicable to both chaotic
and non-chaotic systems, with discrete and continuous local
dynamics, and for different topologies of interactions. We also
apply it to simulate an experiment on epileptogenic neuronal
activity in rat hippocampal tissue [1]. This unified
approach for differential targeting of global and local dynamics
promises to be useful for systems spanning large spatial scales
and having structural and functional heterogeneity.
Introduction: Along with homeostasis | periodic, complex and
even chaotic spatiotemporal dynamics are shown to be abundantly
present in a variety of natural and artificial systems. Examples
are arrays of semiconductors, lasers, plasmas, and chemical
reactors, fluid flow, and cardiac and neural tissues (...). Many
systemic or environmental factors can change the normal dynamics
and abnormalities or disease can set in. Few examples are
instabilities in lasers, charge density waves in plasmas, and
arrays of Josephson junctions [9]; desynchronization in
coupled chemical reactors [5]; defective biochemical
functions; cardiac arrhythmia, epileptogenic neural activity and
pathological physiology [10]; and, large population
uctuations and epidemics in metapopulation [11, 12].
Engineering complex dynamics is also becoming increasingly useful
for improved functioning - for information transmission in
communication sciences [13], for mixing flows in physics
of fluids [14], and, in many branches of biological
sciences with medical applications such as, in the treatment of
cardiac and neural diseases [15]. Thus, possessing the
ability to modify or have control over the spatiotemporal dynamics
of systems have important applications. (...)
Analogy-Making as a Complex Adaptive System, SFI Working Papers
Abstract: This paper describes a computer program,
called Copycat, that models how people make analogies. It might
seem odd to include such a topic in a collection of papers mostly
on the immune system. However, the immune system is one of many
systems in nature in which a very large collection of relatively
simple agents, operating with no central control and limited
communication among themselves, collectively produce highly
complex, coordinated, and adaptive behavior. Other such systems
include the brain, colonies of social insects, economies, and
ecologies. The general study of how such emergent adaptive
behavior comes about has been called the study of "complex
adaptive systems".
The Copycat program is meant to model human cognition, and
its major contribution is to show how a central aspect of
cognition can be modeled as the kind of decentralized, distributed
complex system described above. In doing so it proposes principles
that I believe are common to all complex adaptive systems, and
that are particularly relevant to the study of immunology.
Copycat was developed by Douglas Hofstadter and myself, and
has been described previously. This paper summarizes these earlier
works, and makes explicit links to the immune system.
(...)
Analogy-making can be defined as "the perception of two or
more non-identical objects or situations as being the `same' at
some abstract level." We chose to focus on analogy-making because
of its centrality to every aspect of cognition. For example,
analogy-making is at the core of recognition and categorization.
Children learn to recognize instances of categories such as "dog"
or "cat". Even though different dogs look very different, children
perceive some essential sameness at an abstract level and can
differentiate a dog from a cat. Likewise, children learn to
recognize cats and dogs in books as well as in real life, even
though on the surface such images are very different from one
another and from the corresponding real-life creatures.
(...)
Editor's note: This paper is just like an evening of inspiring
conversations at El Farol (minus the loud music).
- Analogy-Making
as a Complex Adaptive
System, Melanie
Mitchell, SFI Working Papers 00-04-024, To appear in
L. Segel and I. Cohen (editors), Design Principles for
the Immune System and Other Distributed Autonomous
Systems. New York: Oxford University
Press,
WebWorld A Conceptual and Software Framework for Internet Alife, Preprint
Abstract: The Internet provides a rich environment
suitable for the development of true artificial life forms.
Internet Alife should be developed aggressively over the next few
years, both commercially and in academia. This will result in a
population of e-nimals living on the Net, providing useful
services, interacting with more complex Internet AI systems and
helping lead the Internet toward the next phase in its natural
evolution, the Global Brain. To support all this, the Alife
community needs to agree on standard protocols, systems and
languages for mediating Alife agent interactions.
The authors and their colleagues are currently designing a
system of this nature called WebWorld, which is briefly described
here.
Introduction: Artificial life, up until now, has basically
been about the creation of toy experimental systems, intended to
enhance our understanding of the mechanisms of life. There have
been very few all-out attempts to create viable new life forms in
the digital domain. A notable exception is Tom Ray's (1995)
Network Tierra experiment, a very ambitious and interesting,
albeit not altogether successful, attempt to create a distributed
Alife world rich enough to support the evolution of multicellular
life.
We suggest that the experimental, "bug world " phase of
Alife research is nearing its end or at least, should be. These
simple simulations with limitations on population size and
diversity, relatively sparse environments, limited communication
channels between actors, and immutable rules for such things as
mutation, crossover and learning have been useful for a variety of
experiments. Such experiments have produced a variety of
interesting dynamical and graphical results, but not a rich,
self-sustaining world of digital biota. It is time that Alife
moved into worlds with more diversity both in terms of types of
Alife actors and in terms of environmental stimuli. (...)
How We Perceive Vibrations, J. Neurosci.
Abstract: The flutter sensation is felt when
mechanical vibrations between 5 and 50 Hz are applied to the skin.
Neurons with rapidly adapting properties in the somatosensory
system of primates are driven very effectively by periodic flutter
stimuli; their evoked spike trains typically have a periodic
structure with highly regular time differences between spikes. A
long-standing conjecture is that, such periodic structure may
underlie a subject's capacity to discriminate the frequencies of
periodic vibrotactile stimuli and that, in primary somatosensory
areas, stimulus frequency is encoded by the regular time intervals
between evoked spikes, not by the mean rate at which these are
fired. We examined this hypothesis by analyzing extracellular
recordings from primary (S1) and secondary (S2) somatosensory
cortices of awake monkeys performing a frequency discrimination
task. We quantified stimulus-driven modulations in firing rate and
in spike train periodicity, seeking to determine their relevance
for frequency discrimination. We found that periodicity was
extremely high in S1 but almost absent in S2. We also found that
periodicity was enhanced when the stimuli were relevant for
behavior. However, periodicity did not covary with psychophysical
performance in single trials. On the other hand, rate modulations
were similar in both areas, and with periodic and aperiodic
stimuli, they were enhanced when stimuli were important for
behavior, and were significantly correlated with psychophysical
performance in single trials. Thus, the exquisitely timed,
stimulus-driven spikes of primary somatosensory neurons may or may
not contribute to the neural code for flutter frequency, but
firing rate seems to be an important component of it.
The Emergence Of Visual Objects In Space-Time, Proc. Natl. Acad. Sci.
Abstract: It is natural to think that in perceiving
dynamic scenes, vision takes a series of snapshots. Motion
perception can ensue when the snapshots are different. The
snapshot metaphor suggests two questions: (i) How does the visual
system put together elements within each snapshot to form objects?
This is the spatial grouping problem. (ii) When the snapshots are
different, how does the visual system know which element in one
snapshot corresponds to which element in the next? This is the
temporal grouping problem. The snapshot metaphor is a caricature
of the dominant model in the field - the sequential model -
according to which spatial and temporal grouping are independent.
The model we propose here is an interactive model, according to
which the two grouping mechanisms are not separable. Currently,
the experiments that support the interactive model are not
conclusive because they use stimuli that are excessively
specialized. To overcome this weakness, we created a new type of
stimulus - spatiotemporal dot lattices- which allow us to
independently manipulate the strength of spatial and temporal
groupings. For these stimuli, sequential models make one
fundamental assumption: if the spatial configuration of the
stimulus remains constant, the perception of spatial grouping
cannot be affected by manipulations of the temporal configuration
of the stimulus. Our data are inconsistent with this assumption.
Human Immunity To A Virus Using A Plant-Based, Edible Vaccine, Cornell Univ, Cornell Univ /Science Daily
Human immunity to a virus has been triggered for the
first time by a vaccine genetically engineered into a potato. The
specific virus involved is the pervasive Norwalk virus -- the
leading cause of food-borne illness in the United States and much
of the developed world.
Scientists from the Boyce Thompson Institute (BTI) for Plant
Research at Cornell University and the University of Maryland
School of Medicine at Baltimore report on the success of the first
human clinical trials of the plant-based vaccine in the latest
issue (July 2000) of the Journal of Infectious Diseases.
"This plant-based vaccine could be the first one readily
accepted in the developed world. It's very exciting," says Charles
Arntzen, president and chief executive of BTI. "It's likely that
in the United States, this Norwalk virus vaccine could easily be
the first licensed product based on our plant biology research."
Arntzen and his colleagues previously conducted a successful
clinical trial in triggering immune response in humans to the
bacterium Escherichia coli through a transgenic potato vaccine.
The result were published in Nature Medicine in 1998.
The first of three stages of human clinical trials for the
Norwalk virus plant-based vaccine began in April 1999 and was
conducted at the Center for Vaccine Development at the University
of Maryland. Volunteers ate two or three doses of BTI-developed
transgenic, raw potato containing the viral antigen. Overall, 19
of the 20 volunteers (95 percent) who ate the transgenic potatoes
developed an immune response to the Norwalk virus. Before eating
the potatoes, the volunteers were tested for Norwalk antibodies,
and all indicated previous exposure to the virus.
The Centers for Disease Control and Prevention in Atlanta
estimates that more than 23 million people in the United States
are infected annually by the Norwalk virus, or by Norwalk-like
viruses. That compares to 79,000 cases resulting from E. coli
contamination, 2,500 cases of listeriosis and 1.4 million cases of
illness from salmonella.
Norwalk virus received its name in 1968 when nearly 100
students in a Norwalk, Ohio, school simultaneously came down with
nausea, vomiting, stomach cramps and diarrhea. It was not until
four years later that scientists realized the pathogen was a
virus.
Until 1990, scientists and doctors routinely blamed common
food-borne disease symptoms on bacterial pathogens. Microbiologist
Mary K. Estes and others at the Baylor College of Medicine in
Houston cracked the Norwalk virus's genetic code 10 years ago, and
scientists routinely began testing for it.
The BTI/University of Maryland report, "Human Immune
Responses to a Novel Norwalk Virus Vaccine Delivered in Transgenic
Potatoes," was authored by Arntzen; Estes;; Hugh S. Mason, a
senior scientist at BTI; and by Drs. Genevieve Losonsky, Carol O.
Tacket, and Myron M. Levine, of University of Maryland School of
Medicine.
The research was funded in part by the National Institute of
Allergy and Infectious Diseases of the National Institutes of
Health.
Microscopic Life At The South Pole?, NSF/Science Daily
In a finding that may extend the known limits of life
on Earth, researchers supported by the National Science Foundation
(NSF) have discovered evidence that microbes may be able to
survive the heavy doses of ultraviolet radiation and the extreme
cold and darkness of the South Pole.
The team's findings, published in Applied and Environmental
Microbiology, the journal of the American Society for
Microbiology, indicate that a population of active bacteria, some
of which have DNA sequences that align closely with species in the
genus Deinococcus, exists at the South Pole in the austral summer.
A similar species lives elsewhere in Antarctica, but the discovery
of microbes at the Pole may mean that the bacteria have become
uniquely adapted to the extreme conditions there, including a
scarcity of liquid water.
A species in the genus Deinococcus was first discovered in
cans of irradiated meat in the 1950's, and is able to withstand
extreme dryness and large doses of radiation. It is possible that
the related bacteria from the South Pole may also possess these
characteristics.
"While we expected to find some bacteria in the South Pole
snow, we were surprised that they were metabolically active and
synthesizing DNA and protein at local ambient temperatures of -12
to -17 Celsius (10.4 to 1.4 degrees Fahrenheit)," said Edward J.
Carpenter, of the State University of New York at Stony Brook, who
headed the research team. "Before attempting to publish the
results, we wanted to be certain that the data were correct and
were able to duplicate the observations in a second field season
during January 2000."
Antarctica was once part of a supercontinent called
Gondwanaland and drifted into its present position only about 60
million years ago. Deinococcus, however, is thought to be one of
the earlier branches in the bacterial tree, and is much older than
Antarctica in its present location. It is therefore unlikely that
it evolved in Antarctica.
If the team's conclusions prove true, the discovery not only
has important implications for the search for life in other
extreme environments on Earth, but also for the possibility that
life -- at least at the microscopic level -- may exist elsewhere
in the solar system. Furthermore, the snow bacteria may possess
unique enzymes and membranes able to cope with a subzero
existence.
The team was careful to take samples at the edge of the
clean-air sector at Amundsen-Scott South Pole Station to prevent
contamination of the samples by bacteria from human habitation.
The containers of bacteria were flown, still frozen, within 24
hours to the Albert P. Crary Science and Engineering Center at
NSF's McMurdo Station for analysis. In examining the snowmelt, the
researchers found coccoid and rod-shaped bacteria, some of which
appeared to be dividing.
The findings by Carpenter and his colleagues, Senjie Lin, of
the University of Connecticut, and Douglas Capone, of the
University of Southern California, also may be significant because
a separate team of NSF-supported investigators reported that ice
cores taken at Lake Vostok, deep in the Antarctic interior,
indicate the presence of microbes in what is suspected to be a
vast pool of liquid water thousands of meters below the Antarctic
ice sheet. That finding may have similar implications for
extending the known limits of life.
Structural Genomics, NY Times
Editor's Note
So the new effort, known as structural genomics,
aims to determine the three-dimensional structures of thousands
upon thousands of proteins, much as the genome project
determined gene sequences en masse.
"It's basically the next step after the Human Genome
Project," said Dr. Helen M. Berman, a professor of chemistry at
Rutgers University and director of the Protein Data Bank, a
federally financed database of protein structures. "Instead of
a list of letters, we'll understand biology in a
three-dimensional way."
