-
Social animals have been studied in the context of
complex systems especially in regards to the emergence of
collective solutions of problems involving cooperative behavior.
The standard example are ant colonies that can exhibit behavioral
patterns that are often associated with intelligence of the
colony. Individual ants, however, follow simple rules and do not
show signs of individual intelligence. Although they have a
sophisticated communication system they are not able to learn from
each other.
This is, however, what takes place among whales and dolphins,
whose individual intelligence is next to us humans and other
primates the most highly developed on our planet. Rendell &
Whitehead build a case for the claim that cetaceans (as well as
apes) satisfy the defining criteria for forming different cultures
that are robust (over several generations) and that can interact
with each others. They list a number of characteristics of
cultures that were introduced by different authors. Except for one
definition, that restricts the notion of culture exclusively to
the human species, the authors claim that whales and dolphins show
all the signs attributed to culture. Among them are the above
mentioned "social learning" that needs to be discriminated from
environmentally triggered individual learning. They assert that if
a novel behavior spreads in a population exponentially in time,
then this is strong evidence for social learning whereas
environmentally triggered individual learning would lead to a
spreading in the population that is only linear in time. The
authors present data for lobtail feeding of humpback whales that
seem to confirm exponential social learning. Other evidence for
culture is seen in the songs of humpback (and more recently
bowhead) whales that are shared between pods of whales that are as
far apart as Hawaii and Mexico. But these songs are not
(genetically) fixed but evolve slowly over the years. The purpose
for these songs is still a mystery as they have been shown to
neither attract females (only humpback males sing) nor to be used
for long-range communication or other purposes that have been
speculated for human music (see also:
Music On The Brain,ComDig 2000.22.11.4 ).
Rendell & Whitehead also mention one example where social
learning across species emerged in the cooperative fishing between
humans and dolphins that developed into a stable tradition that
lasted for numerous generations.
Editor's Note: I was invited to contribute a
commentary to the above paper by 11/20/00. I would like to invite
ComDig readers to send me e-mail related to this target article
(and complexity) and I will try to integrate those in my
commentary (with proper acknowledgements).
Study Finds Widespread Lying, Cheating Among U.S. Teens, CNN 
Different (human) cultures and social groups developed
different levels of tolerance towards lying and cheating. Whereas
in some cultures being caught in a lie implies "loosing face" and
considerable social consequences in other cultures learning how to
lie effectively as a child has strong correlations with later
success in economic and social standings in society.
Complications and confusions as consequence of not telling the
truth is considered funny and a continued source of entertainment
in US sitcom TV shows like "Seinfeld". Therefore it is no surprise
that recent studies show that this aspect of culture has a strong
representation in the US school system:
"Many U.S. high school students lie a lot, cheat a lot and
many show up for class drunk, according to preliminary results of
a nationwide teen character study released Monday.
Seven in 10 students surveyed admitted cheating on a test at
least once in the past year, and nearly half said they had done so
more than once, according to the nonprofit Joseph & Edna
Josephson Institute of Ethics. (…)
On the other hand, the results were not significantly worse
than on the last test in 1998 -- the first time that has happened
since the group began testing in 1992."
The topic of lying and cheating has been the focus of
complexity research in models like "Prisoner's Dilemma" where a
simple strategy "Tit-for-tat" was very successful but could be
beaten by strategies that would throw in an occasional extra
defection. Axelrod's "Norms" model discusses the roles of "honor
codes" and their level of enforcement.
-
Excerpt: "The study found "absolutely no
evidence" that playing Mozart or any other music for unborn
babies, infants, or toddlers ups their IQ. Hetland calls that idea
"totally bogus. It's motivated not by education but by a desire to
sell CDs. I feel sorry for parents who are duped by the hype."
The idea of Mozart as an easy path to greater intelligence
arose in 1993 when researchers at the University of Wisconsin
linked listening to 10 minutes of a Mozart sonata to an eight- to
10-point rise in IQ test scores. But the subjects were 36 college
students, and they were tested on paper folding not IQ. Students
who listened to the great Austrian composer did better on a test
that required them to visualize changes in shape produced by
cutting and folding pieces of paper.
"Such results are difficult to quantify," Hetland comments.
"To make them more understandable, the researchers compared the
size of the effect to an eight- to 10-point rise in IQ."
The relative advantage lasted only 15 minutes, and other
researchers cannot always reproduce the Wisconsin effect. Last
year, Christopher Chabris, a psychologist at the Harvard Medical
School, analyzed 16 studies of the Mozart effect and found no real
change in comparative improvement. However, that hasn't stopped
several states from giving classical music CDs to all new mothers,
or the music industry from profiting from the idea.
Hetland has changed the tune of the controversy by
concluding that the effect does exist. She found that learning
music in school, as opposed to listening to it in the womb or in
diapers, can produce an effect on spatial reasoning. That's the
type of thinking that improves students' ability to manipulate
objects in their minds, understand graphs and maps, and find their
way in a new school or city.
What's more, learning to read musical notation produces a
stronger effect, no matter what style of music the student plays.
The finding doesn't translate into a recommendation that all
students should take piano or violin lessons in school, and learn
to read music to do better in other classes. Spatial skills can be
taught more directly using blocks, paper, and other objects.
"Strong spatial skills could give students an advantage in
subjects like geography or math, depending on how these subjects
are taught," notes Ellen Winner, a psychologist at Boston College
who worked on the Harvard study. "Sadly, however, many schools
offer few chances to apply spatial abilities."
The big mystery is why music affects spatial thinking at
all. Gottfried Schlaug, a neurologist at the Harvard Medical
School, discovered that musicians with perfect pitch have an area
on the left side of their brains that is larger than usual. The
area, known as the planum temporale, specializes in processing
music.
"Areas of the brain dealing with spatial orientation and
music may stimulate each other through brain-cell connections, or
both areas may be used together while making music," Hetland
speculates."
-
Excerpt: "New genetic research technologies, such
as DNA chips, enable scientists to evaluate simultaneously tissue
samples from several patients, expressing thousands of genes.
However, deciphering the vast amount of information derived,
consisting of anything from 100,000 to 1,000,000 genetic
"figures," requires highly sophisticated data processing tools.
Addressing this and similar challenges may soon be easier
thanks to Prof. Eytan Domany of the Weizmann Institute's Physics
of Complex Systems Department and doctoral students Gad Getz and
Erel Levine. The team has designed a unique mathematical system
for analyzing genetic data based on a computer algorithm that
"clusters" information into relevant categories. The algorithm
searches simultaneously for clusters of "similar" genes and
patients by evaluating the gene expression of tissue samples. (A
gene's "expression" refers to the production level of the proteins
it encodes.)
Reported in the October 17 issue of the Proceedings of the
National Academy of Sciences (PNAS), the algorithm's most powerful
feature is that it mimics unassisted learning. Unlike most
automated "sorting" processes, in which a computer must be
informed of the relevant categories in advance, the algorithm is
analogous to human intuition (such as the ability to intuitively
categorize images of animals and cars into proper classes). When
given a clustering task, it analyzes the data, computes the degree
of similarity among its components, and determines its own
clustering criteria.
The new method makes use of a previous application by Domany
and his colleagues based on a well-known physical phenomenon. When
a granular magnet such as a magnetic tape is warm, its grains are
highly disorganized. But upon cooling down, the magnet's grains
progressively organize themselves into well-ordered clusters.
Using the statistical mechanics of granular magnets, Domany
created an algorithm that can look for clusters in any data.
When applied in a cancer study using DNA chips, the new
algorithm proved highly effective, evaluating roughly 140,000
figures representing the cellular expression of 2,000 genes from
70 subjects. The algorithm categorized tissue samples into
separate clusters according to their gene expression profiles. For
example, one cluster consisted of cancerous tissues, while another
contained samples from healthy subjects. The new method also
distinguished among different forms of cancer and demonstrated
treatment effects, picking up differences in the gene expression
of leukemia patients that had received treatment versus those that
had not. The ability to monitor cell response to treatment and
understand the origin of disease in each patient may improve
future treatment protocols, which would be tailored to individual
pathologies.
Finally, one of the algorithm's most promising features is
that it enabled researchers to pinpoint a small group of genes
from within the 2,000 examined that can be used to accurately
distinguish among cellular cancerous processes.
In a sense, however, applying the new algorithm to DNA chips
is only a start. The new algorithm's inherent clustering capacity
makes it invaluable for use in data-heavy scientific and
industrial applications. It may be used to analyze financial
information and MRI data in brain research, or to perform "data
mining," the process by which specific details are culled from the
world's huge and ever-growing data banks, such as those generated
by the international Human Genome Project. The Institute's
technology transfer arm, Yeda Research and Development, has issued
a patent application for the algorithm. "
Effects Of Task Complexity And Experience On Learning And Forgetting, Human Factors
Abstract: This paper examines the effects of task
complexity and experience on parameters of individual learning and
forgetting. Three attributes of task complexity and experience are
addressed: the method, machine, and material employed. The task
involved a high-manual-dexterity skill taken from an operating
textile assembly plant; there were 2853 individual participant
learning/forgetting episodes. A parametric model of individual
learning and forgetting that allows the evaluation of worker
response to the attributes of task complexity and experience is
discussed. Results indicate that both task complexity and
experience significantly affect learning and forgetting rates.
Potential applications of this research include the allocation of
workers to tasks based on individual learning/forgetting
characteristics.
EEG Approximate Entropy Correctly Classifies The Occurrence Of Burst Suppression Pattern, Anesthesiology
Abstract: "Approximate entropy, a measure of
signal complexity and regularity, quantifies electroencephalogram
changes during anesthesia. With increasing doses of anesthetics,
burst-suppression patterns occur. Because of the high-frequency
bursts, spectrally based parameters such as median
electroencephalogram frequency and spectral edge frequency 95 do
not decrease, incorrectly suggesting lightening of anesthesia. The
authors investigated whether the approximate entropy algorithm
correctly classifies the occurrence of burst suppression as
deepening of anesthesia. METHODS: Eleven female patients scheduled
for elective major surgery were studied. After propofol induction,
anesthesia was maintained with isoflurane only. Before surgery,
the end-tidal isoflurane concentration was varied between 0.6 and
1.3 minimum alveolar concentration. The raw electroencephalogram
was continuously recorded and sampled at 128 Hz. Approximate
entropy, electroencephalogram median frequency, spectral edge
frequency 95, burst-suppression ratio, and burst-compensated
spectral edge frequency 95 were calculated offline from 8-s
epochs. The relation between burst-suppression ratio and
approximate entropy, electroencephalogram median frequency,
spectral edge frequency 95, and burst-compensated spectral edge
frequency 95 was analyzed using Pearson correlation coefficient.
RESULTS: Higher isoflurane concentrations were associated with
higher burst-suppression ratios. Electroencephalogram median
frequency (r = 0.34) and spectral edge frequency 95 (r = 0.29)
increased, approximate entropy (r = -0.94) and burst-compensated
spectral edge frequency 95 (r = -0.88) decreased with increasing
burst-suppression ratio. CONCLUSION: Electroencephalogram
approximate entropy, but not electroencephalogram median frequency
or spectral edge frequency 95 without burst compensation,
correctly classifies the occurrence of burst-suppression pattern
as increasing anesthetic drug effect."
-
Excerpt: "Quite a number of people who
watch these exorcism films will be affected and develop symptoms
of hysteria. These films will be a full-employment bill for
exorcists," said Elizabeth Loftus, a University of Washington
psychologist and memory expert.
Loftus recently completed a demonic possession study that is
to be published in The Journal of Experimental Psychology:
Applied. She conducted the study with Giuliana Mazzoni, a Seton
Hall University psychology professor and a UW visiting scholar,
and Irving Kirsch, a University of Connecticut psychology
professor. The research demonstrated that nearly one-fifth of
those who previously said that demonic possession was not very
plausible and that as children they had not witnessed a possession
later said possession was more plausible and they may have
witnessed one. These changes in belief and memory were
accomplished in several steps. Subjects read several short
articles that described demonic possession and suggested it was
more common than believed. Later they were asked to list their
fears and then were told that witnessing a possession during
childhood caused those fears. (…)
The researchers conducted three experiments. In the first
and key experiment, students filled out questionnaires that rated
the plausibility of a number of events and asked about their life
experiences. Students were divided into three groups, two of which
were exposed to a plausibility manipulation a month later. The two
groups were given a series of 12 short articles to read. Among the
articles given to the first or "possession" group were three that
promoted the idea that demonic possession is quite common in Italy
and that many children witnessed such events. They also described
typical possession experiences. The second or "almost choked"
group was given three similar articles to read about choking. The
third or control group was not exposed to the manipulation.
A week later the first two groups filled out questionnaires
about their fears, such as being afraid of spiders. Then the
students were told that their individual "fear profiles" signaled
that they probably had witnessed a possession or had almost choked
in early childhood. After another week these students and the
control group filled out the original two questionnaires. The
researchers found that the manipulation not only increased
feelings of reality about an already plausible event, "almost
choked," but also of an initially implausible event "witnessed
possession." More important, according to Loftus, 18 percent of
the students now believed that the events had probably happened to
them. There was no change in the control group.
The other two experiments tested variations of the
manipulation.
Loftus said the three experiments tell a consistent story.
When people are exposed to a series of articles describing a
relatively implausible phenomenon, such as witnessing a
possession, they believe the phenomenon is not only more plausible
but also are less confident that they had not experienced it in
childhood.
"We are looking at the first steps on the path down to
creating a false memory," said Loftus. "There is controversy about
whether you can plant memories about events that are unlikely to
happen. As humans we are capable of developing memories of ideas
that other people think occurred. Just being exposed to credible
information can lead you down this path. This shows why people
watching Oprah or those in group therapy believe these kinds of
things happened to them. People borrow memories from others and
adopt them as their own experiences. It is part of the normal
process of memory." In addition, she said the study reinforces the
idea that therapists need to be careful in using potentially
suggestive procedures that could change a patient's perceived
likelihood of unremembered events. These include UFO abductions,
serious trauma suffered in a past life, or participating in or
witnessing satanic rituals (common elements in abuse claims).
"
The Theory And Practice Of Complexity Science, Systemexico
Some complexity researchers are endeavoring to find the
fundamental laws of complexity and explore how they apply to all
such systems (a theory of everything (TOE) if you like). Others,
particularly in the organizational science field, are looking to
utilize the concepts of complexity in a metaphorical sense. Still
others are exploring the epistemological implications of assuming
a complex universe.
These two papers fall into this final category. In these papers
the authors develop a practical complexity-based epistemology that
acknowledges the limitations that chaos, say, places on our
ability to 'know', and the roles of self-organization
(anti-chaos), history, etc. in the evolution of a complex system.
The resulting epistemology places paradigmatic pluralism and
critical thinking firmly at the heart of any analytical method
designed to examine complex systems.
In developing their epistemology the authors recognize the
contrast between the incompressible nature of complex systems and
our need to compress resulting from the category-based functioning
of the human mind in sense making. Also, they argue that linear
modeling and reductionism still have a lot to offer in the study
of complex systems. In a sense, the authors argue for a pragmatic
postmodern stance based on a quite Modernist analysis. Some of the
conclusions that are offered in these papers are:
- Complexity thinking both abhors and adores
institutionalism;
- Complexity thinking shifts our focus from the model to the
modeling process and the culture that supports that
process
- Complexity thinking problematises boundary recognition and
allocation;
- Complexity thinking legitimates pluralist thinking,
and;
- Complex thinking regards models as inspirational rather
than containers of truth.
- The
Theory And Practice Of Complexity Science -
Epistemological Implications For Military Operational
Analysis,K. A.
Richardson, G. Mathieson, And P. Cilliers,Systemexico,
1(2, 2000
- Complexity
Science: A 'Grey' Science For The 'Stuff In
Between',K. A.
Richardson, P. Cilliers, And M. R. Lissack,Proceedings
Of The First International Conference On Systems
Thinking In Management, Pp 532-537,Geelong, Australia,
2000
- Contributed by
K.
A. Richardson
Interplanetary Network Detects Gigantic Gamma-Ray Burst, UC Berkeley/Science Daily
Excerpt: "The afterglow of a gamma-ray burst in
the southern constellation of Carina - more distant than any
high-energy flare ever observed - has been detected by a network
of spacecraft spread over the solar system, and has been traced
back to its original explosion about 11 billion years ago.
The observations, made by a cluster of interplanetary probes
called the Interplanetary Network, revealed that the burst
probably came from a gigantic dying star more than 30 times as
massive as the sun, when the universe was about one-tenth of its
present age, said Kevin Hurley, a physicist at the Space Sciences
Laboratory of the University of California, Berkeley, and
principal investigator of the gamma-ray burst experiment on board
NASA's Ulysses spacecraft. Ulysses is one of several spacecraft
studying the sun, and the only one that passes over the sun's
poles.
"Detection of gamma-ray burst GRB 000131 at an extremely
high red shift of 4.5 corresponds to a distance of about 11
billion light years away," said Hurley, whose results will be
reported today at the Science of Gamma-Ray Bursts conference in
Rome, an international colloquium on gamma ray bursts. "The light
from this gigantic flash had traveled 11 billion years before
reaching the Earth, and suggests that these explosive objects may
provide us with the longest yardsticks yet for detecting and
studying galaxies in the early universe."
Hurley's colleagues also will report details of the gamma
ray observations at a press briefing today in Rome. Results of the
observations will appear in a December issue of the European
science journal Astronomy and Astrophysics.
All objects in the universe are flying away from each other
as a result of the Big Bang. More distant galaxies recede faster
from Earth than nearby galaxies. This is observed as a Doppler
effect, best explained by the pitch of a train whistle, which
rises as the train approaches and diminishes as the train speeds
away. Similarly, if a galaxy is approaching the Earth, all of the
wavelengths in the galaxy's spectrum are shifted toward the blue
end of the spectrum. If the galaxy is receding from Earth, all
wavelengths in the spectrum are shifted toward the red end in what
is termed a "red shift." Observations of GRB 000131 revealed that
it is receding and its light is shifted toward the red end of the
spectrum by a factor of 4.5, which is a significant shift, Hurley
said.
Before these observations were recorded, the most distant
gamma-ray burst to be detected was GRB 971214, estimated to be
less than 9 billion light years away in the constellation Ursa
Major. A violent burst of gamma-ray radiation from this object was
recorded on December 14, 1997, by Italian and U.S. satellites,
including Ulysses. (...)"
Emulation As A Digital Preservation Strategy, D-Lib Magazine
Excerpt: "Many libraries and archives are in the
process of ‘going digital’. The advantages of digital
technology are well known and its adoption by libraries and
archives seems inevitable, inexorable and well-motivated. Yet the
fact remains that several key issues concerning the long term
preservation of digital technologies remain unsolved. Two key
problems are the fragility of digital media (its ‘shelf
life’ compared with, say, non-acidic paper is extremely
short) and, perhaps even more intractable, is the rate at which
computer hardware and software become obsolete. Many cases have
been cited in which valuable data has already been lost because of
obsolescence. Moreover, as of today no one knows how to ensure the
long-term preservation of multimedia documents nor how to ensure
the integrity of documents that may have many links to other
documents that may be anywhere in the world. For a brief overview
of some digital preservation issues see [1]
and [2].
These problems have, of course, been exercising the library and
archive communities for some time but as yet no one solution or
set of solutions has been reached. Solutions need to be found
urgently if we are not to sink in what Rothenberg [4]
calls ‘technological quicksand’."
-
Excerpt: "Smart" legs -- entire smart lower limbs
-- to replace those amputated from tens of thousands of Americans
yearly as a result of auto accidents, diabetes, or other causes
are expected to be on the market in two years.
Sensors and chips will be developed by the Department of
Energy's Sandia National Laboratories. Materials work and testing
will be performed by, strangely, the Russian nuclear weapons
laboratory Chelyabinsk 70. Technical requirements for the limb
will be set by the Seattle Orthopedic Group (SOGI).
"This is about making a leg that is more like a missing limb
than a collection of components ever can be," says Diane Hurtado
of the Smart Integrated Lower Limb (SILL) project team. "This limb
will have a digital control system to make it smart."
Says Ivan Sabel, president of Hangar, of which SOGI is a
division, "This is taking us -- an industry that has gone in 30
years from plastic to carbon fibers -- to the next generation."
The advance should enable otherwise competent amputees to
maintain active lives rather than be confined to wheelchairs or
rest homes.
The leg is intended to simulate a human gait whether on
uphill, downhill, or even irregular terrain. To do so, a
microprocessor-controlled module implanted in the leg will respond
to sensor input from multiple sources. The microprocessor will
control hydraulic joints and piezoelectric motors that power the
ankle, knee and socket.
The leg socket will also adjust to the changing diameter of
an amputated stump over the course of a day, thus reducing sores,
improving comfort, and increasing time of use. "
Links & Snippets
1 Modeling At The Political Science Dept. Of The U. Of Mich, Announcement
The Political Science Department of the University of
Michigan now has an upgraded Program in Modeling. There are
three new faculty members who have modeling as one of their
major reserach interests: Jenna Bednar, James Morrow, and Scott
Page. In terms of computational modeling, Scott Page joins
Robert Axelrod and Kenneth Kollman who do agent-based
modeling.
This gives Michigan's Political Science Department unusual
depth in all types of modeling, with particular strength in
computational modeling.
2 Social Games In A Social Network, arXiv
Abstract: We study an evolutionary version of the
Prisoner's Dilemma game, played by agents placed in a
small-world network. Agents are able to change their strategy,
imitating that of the most successful neighbor. We observe that
different topologies, ranging from regular lattices to random
graphs, produce a variety of emergent behaviors. This is a
contribution towards the study of social phenomena and
transitions governed by the topology of the community.
3 Experimental Verification Of Decoherence-Free Subspaces, Science
Excerpts: The viable development of quantum
computers will depend on the implementation of procedures to
overcome the problem of decoherence, where the superposition of
the quantum states is lost due to disturbances from the
environment. Recent theoretical work has suggested that the
existence of decoherence-free subspaces can be created--a
particular subset of quantum states can be chosen that will be
robust to certain perturbations and not decohere. By subjecting
the quantum system, in this case a pair of entangled photons,
to collective decoherence, Kwiat et al. (p.
498) present experimental evidence for the existence
of such decoherent-free states. The use of decoherence-free
subspaces can help reduce the burden of quantum
error-correction schemes in quantum information
processing.
4 Learning-Induced LTP In Neocortex, Science
Excerpts: Learning a complex motor task in rats has
now been shown to increase synaptic efficacy in motor cortex.
Rioult-Pedotti et al. (p.
533) also found that this increase is accompanied by
an occlusion in long-term potentiation (LTP) and a simultaneous
increase in the capacity for long-term depression in the same
synapses. Their findings indicate that the learning-produced
synaptic potentiation reflects a shift in efficacy within the
normal range for modifications of excitability. These data
provide the strongest evidence to date that LTP and
learning-related changes in synaptic efficacy share a common
mechanism.
5 Building A Disease-Fighting Mosquito, Science
Excerpts: With resistance against insecticides on
the rise and a U.N.-backed push to phase out DDT, several labs
have embarked on the most ambitious and futuristic of all
approaches to combat malaria: They hope to replace billions and
billions of mosquitoes in the world's endemic areas with new
strains, created in the lab, that would be "refractory," or
unable to transmit Plasmodium, the parasite that causes the
disease. The idea is not that farfetched, these researchers
claim.
6 Glacial/Interglacial Variations In Atmospheric Carbon Dioxide, Nature
Excerpts: Twenty years ago, measurements on ice
cores showed that the concentration of carbon dioxide in the
atmosphere was lower during ice ages than it is today. As yet,
there is no broadly accepted explanation for this difference.
(…) Others propose that the biological pump was more
efficient during glacial times because of more complete
utilization of nutrients at high latitudes, where much of the
nutrient supply currently goes unused. We present a version of
the latter hypothesis that focuses on the open ocean
surrounding Antarctica, involving both the biology and physics
of that region.
7 Molecular Emission From Single-Bubble Sonoluminescence, Nature
Excerpts: Ultrasound can drive a single gas bubble
in water into violent oscillation; as the bubble is compressed
periodically, extremely short flashes of light (about 100 ps)
are generated with clock-like regularity. This process, known
as single-bubble sonoluminescence, gives rise to featureless
continuum emission in water. (…)
Here we report a series of polar aprotic liquids that
generate very strong single-bubble sonoluminescence, during
which emission from molecular excited states is observed.
Previously, single-bubble sonoluminescence from liquids other
than water has proved extremely elusive.
8 Cooler Winters As A Possible Cause Of Mass Extinctions At The Eocene/Oligocene Boundary, Nature
Excerpts: The Eocene/Oligocene boundary, at about
33.7 Myr ago, marks one of the largest extinctions of marine
invertebrates in the Cenozoic period. (…). Here we report
stable oxygen isotope measurements of aragonite in fish
otoliths-ear stones-collected across the Eocene/Oligocene
boundary. (…) These seasonal data suggest that winters
became about 4 °C colder across the Eocene/Oligocene
boundary. We suggest that temperature variability, rather than
change in mean annual temperature, helped to cause faunal
turnover during this transition.
9 Isolation Of A 250 Million-Year-Old Halotolerant Bacterium From A Primary Salt Crystal, Nature
Excerpts: Bacteria have been found associated with
a variety of ancient samples, however few studies are generally
accepted due to questions about sample quality and
contamination. (…) Here we report the isolation and growth
of a previously unrecognized spore-forming bacterium (Bacillus
species, designated 2-9-3) from a brine inclusion within a 250
million-year-old salt crystal from the Permian Salado
Formation. Complete gene sequences of the 16S ribosomal DNA
show that the organism is part of the lineage of Bacillus
marismortui and Virgibacillus pantothenticus.
Editor's Note: The 250 Million year old bacteria were found
in the construction site for long term storage of nuclear waste
(WIPP in New Mexico) that was selected because of its
geological stability.
10 Involuntary Orienting To Sound Improves Visual Perception, Nature
Excerpts: To perceive real-world objects and
events, we need to integrate several stimulus features
belonging to different sensory modalities. Although the neural
mechanisms and behavioral consequences of intersensory
integration have been extensively studied, the processes that
enable us to pay attention to multimodal objects are still
poorly understood. (…)
Here we provide psychophysical evidence that a sudden
sound improves the detectability of a subsequent flash
appearing at the same location. These data show that the
involuntary orienting of attention to sound enhances early
perceptual processing of visual stimuli.
11 Denoising Human Speech Signals Using Chaoslike Features, Phys Rev Lett.
Abstract: A local projective noise reduction scheme,
originally developed for low-dimensional stationary
deterministic chaotic signals, is successfully applied to human
speech. This is possible by exploiting properties of the speech
signal which resemble structure exhibited by deterministic
dynamical systems. In high-dimensional embedding spaces, the
strong inherent nonstationarity is resolved as a sequence of
many different dynamical regimes of moderate
complexity.
12 'Strange Attractors': Controlled Chaos Theory, NYtimes
A NAME="12.12">
Excerpts: "Strange Attractors" begins with a tangy,
slightly nightmarish prelude. It continues with a first part
that is lushly romantic like its score by Michael Nyman and put
together with subtle, exquisite precision.
The title "Strange Attractors" comes from chaos theory
and its probing of how apparently random behavior can occur in
a world governed by deterministic laws. Program notes define a
strange attractor as "a moving and magnetic focal point in a
seemingly chaotic field." Mr. Petronio has found the perfect
analogy for his own approach to choreography.
