F
Fighting for Air
Like a crystal hidden inside a rough
gray rock, the Homedale neighborhood on the west side
of Phoenix lies within an ugly concrete shell. The little group
of houses is completely surrounded by a perimeter of junkyards,
piles of scrap tires, and giant warehouses.
The neighborhood is demarcated by unmistakable landmarks.
On the southeast edge sits a truck stop, always filled with several
dozen idling tractor-trailer rigs. To the northwest, a hulking
power plant looms against the sky. Between truck stop and power
plant is splayed a group of 440 residential houses. Although
the area is increasingly spotted with sand lots and boarded up
windows, most of the homes are lovingly tended with soft green
lawns and bright f lowers.
Many of the current homeowners grew up in this neighborhood, and now work to raise their own families here. Unlike
many of the Phoenix metropolitan area’s fast-growing and
transient neighborhoods, Homedale is the kind of place where
people know each other. It is also the kind of place where they
will band together when something is wrong. In fact, banding
together is what they have had to do in 2002.
“Some of the community leaders think there are increased
health problems in the area,” says Sara Grineski, a doctoral
student in sociology at Arizona State University. Grineski works
with Homedale residents as part of a special research training
program for students. “There were a lot of bad smells in the
neighborhood. The residents were concerned about air
pollution,” she explains. “There’s a Circle K truck stop that
backs up into the neighborhood. The trucks idle all night long.”
Instead of merely speculating about the cause of their
problems, Homedale’s community leaders decided to find
answers. They brought their concerns to the attention of
environmental researchers at ASU. Their case made a perfect
workshop for the IGERT urban ecology program.
IGERT (Integrative Graduate Education and Research
Traineeship Program) is funded by the National Science
Foundation. The program is designed to provide students
an interdisciplinary research education in the life, earth,
and social sciences.
An IGERT fellow, Grineski leads a team of students who are
studying the Homedale neighborhood. The students are assisted
by faculty advisors from ASU’s sociology and environmental
engineering departments. The project gives Grineski and her
colleagues hands-on research experience. Homedale residents
will get scientific facts and quantifiable numbers to take before
the Phoenix City Council, if in fact problems are discovered.
The study consists of four parts. First, Grineski and her fellow
sociologists developed a resident survey to document health conditions, symptoms of illness, and other environmental concerns.
A team of students and residents canvassed the neighborhood
administering the surveys in both English and Spanish.
The second part of the study involves air quality monitoring.
The ASU team installed monitors inside and on rooftops of two
Homedale houses. The monitors measure levels of particulate
matter, elemental carbon, sulfate, and nitrate in the air.
Sulfate and nitrate are pollutants commonly released
during the burning of gasoline or diesel fuel by cars and trucks.
The same is true of elemental carbon. “Elemental carbon only
comes from human-made sources, mainly internal combustion
engines,” explains Justin Boreson, a graduate student in civil
and environmental engineering. “Although we can’t tell if the elemental carbon comes
from cars or trucks, we know that diesel engines emit significantly more elemental carbon
than do gasoline engines.”
The scientists also measure the concentration of particulate matter found in air samples.
They are looking for particulates less than 2.5 microns in diameter, which the EPA considers
most hazardous to human health. A micron is one millionth of a meter. For scale, consider
that a single fiber in a shag carpet is about 4 to 5 microns across. A human hair is about
25 to 100 microns wide. Tobacco smoke particles are between 0.01 and 1 micron.
Residents with air monitors installed on their homes are asked to record activities such
as cooking, burning wood, and using candles, all of which affect air content and quality.
The third part of the study involves recording ethnographic and historical data about
the neighborhood. Tim Collins is a doctoral student in geography. He is compiling the
“big picture” information. “I’ve been trying to conceptualize the neighborhood,” says
Collins. “I look at any and every news report on that area. I’m trying to develop a typology
of what issues keep coming up again and again.”
Collins’ research extends back to 1987, just before industrial growth in this area of
Phoenix really took off. “Heavy duty industrial development started there around the early
1990s,” he says. “Much of that had to do with the completion of Interstate 10. The west side
of Phoenix really began to be heavily developed at that time.”
The final phase of the project will include hazard mapping. The IGERT team will create
a map of what facilities exist in the area and how close they are to the homes, among other
things. Hazard maps are a common tool used by scientists to study environmental justice
issues, Collins’ area of specialization at ASU.
Not surprisingly, environmental risks often exist in or near low-income and minority
neighborhoods. For example, in the Homedale neighborhood, 88 percent of residents are
Latino and 36.5 percent live below the poverty line. But these people are not powerless.
Homedale residents are no strangers to collective action. Several years ago the community
successfully resisted expansion of the local power plant that would have increased local air
pollution. But environmental hazards still threaten the neighborhood. Industrial accidents,
fires, and other incidents plague the area regularly, causing concern among the residents.
The ASU researchers spent most of 2001 and 2002 collecting their data. They are now
tabulating the numbers. Those numbers tell interesting stories.
Based on survey findings, residents of the Homedale neighborhood appear to suffer
from a higher than normal rate of respiratory ailments. Survey results indicate that 16 percent
of Homedale adults and 16 percent of their children have been diagnosed with asthma.
That number compares with national averages of 7.2 percent for adults (Behavioral Risk Factor
Surveillance System Survey, 2000) and 7 percent for children (EPA Office of Children’s Health).
Homedale residents also report high rates of allergies, breathing problems, irritated eyes and
nose, congestion, and chronic cough.
Although the study results are not yet final, Homedale residents already see the fruits of
their efforts. They hosted an environmental conference in the community center that included
local government officials. As a result of that meeting, the neighborhood received a $90,000
Fight Back Grant from the City of Phoenix. (Phoenix provides one Fight Back grant per district
per year). The community can use the money as they see fit for neighborhood improvement.
Homedale is the first Phoenix neighborhood to use the grant for environmental purposes.
Diane Boudreau
FOR MORE INFORMATION ABOUT THE HOMEDALE PROJECT, CONTACT SARA GRINESKI, 480.965.3546.
SEND E-MAIL TO [email protected]
Note B ook
Allurin. It almost sounds like the latest scent fromACalvin
S U R EKlein.
S E A R CBut
H Myou
A G Awon’t
ZINE
find this scent among the lotions and potions at snazzy department stores
this holiday season. Check the local pond or swamp. Frogs like it just fine.
Allurin is a protein. And like perfume, it does have something to do with
male-female attraction, at the molecular level. A team of ASU biologists led
by Douglas Chandler discovered allurin in the jelly-like material that surrounds
eggs of the frog Xenopus laevis. Allurin is a sperm chemoattractant, a protein
that attracts sperm to an egg. The substance is the first sperm chemoattractant
to be isolated from a vertebrate animal.
Chandler thinks that allurin could be similar to sperm chemoattractants in
other vertebrates. He and his colleagues hope that understanding allurin will
be the gateway to understanding sperm chemoattraction in higher organisms
such as humans and other mammals.
Sperm chemoattraction plays an important role in fertilization, but human
sperm chemoattractant has never been isolated.
“For whatever reason, it’s proven very difficult to characterize,” says Chandler.
Once a human sperm chemoattractant is characterized, scientists can explore
possible clinical applications. Problems with chemoattraction could be the cause
of infertility in couples. Conversely, by chemically blocking the chemoattractant,
scientists might have the key to a new contraceptive.
MICHAEL HAGELBERG ILLUSTRATION
Froggy Allure
FOR MORE INFORMATION. CONTACT DOUGLAS E. CHANDLER, PH.D., BIOLOGY DEPARTMENT, 480.965.3571.
SEND E-MAIL TO [email protected].
Word Games
Ying-Cheng Lai’s research is not like playing a game of Scrabble
or completing a crossword puzzle. However, the work does give him new justification
for playing word games. Lai is an ASU professor of mathematics and electrical engineering.
He and his colleagues discovered that word association can link just about any two common
words in the English language.
Lai worked with industrial engineer Nong Ye and Partha Dasgupta, an associate professor
of computer science and engineering. The ASU researchers devised a method that uses
an average of three or four steps and follows the same “six degrees of separation” principle
known for connecting actor Kevin Bacon with other film stars.
The scientists presented results for the English language. However, Lai says their method
will work for other languages as well, because the fundamental role of any language
is the communication of ideas.
To build their conceptual network of language, the ASU scientists used an on-line English
thesaurus. The database had 30,000 entries and listed an average of more than 100 words
per entry. Lai’s team created 900,000 different word pairs from the original 30,000 words.
They then tried to link the words in each pair via a chain of related words. Lai defined two
words as being related if they expressed a similar concept—that is, if they were listed
together in any thesaurus entry.
“We constructed a conceptual network from the entries in the thesaurus. We considered
two words to be connected if they express similar concepts,” Lai explains. “The network
is clearly evolving and sparse. We believe and argue that these findings are important not
only for linguistics, but also for cognitive science.”
The secret to the idea of a conceptual network lies in words
with multiple meanings. Such words act as short cuts, connecting
remote concepts together. This reduces the number of steps
needed to get from one word to another.
A few word pairs, however, can’t be linked very closely. For
example, Lai says that it took eight steps to get from “octagonal”
to “appendectomy” using the link: octave, tone, purity, sterility,
birth control, and vasectomy.
Even though the ASU study focused on the meanings of words,
Lai says that building the conceptual network of language
required an interdisciplinary approach. “Our conceptual network
involves physics, language, biology, and computer science,”
he says. “It’s not just about studying the English language.
Our work examines a person’s memory or ability to remember
the links of words and their meanings.”
Human memory is associative. Lai says this means that
information can be retrieved by connecting similar concepts.
“From the standpoint of the retrieval of information in an
associative memory, the small-world property of the network
represents a maximization of efficiency,” Lai says. “Similar pieces
of information are stored together due to the high clustering,
which makes searching by association possible.
“However, even very different pieces of information are
never separated by more than a few links, which guarantees
a fast search,” he adds. “We speculate that associative memory
has arisen in humans partly because of a maximization of
efficiency in the retrieval by natural selection.” Manny Romero
THE “SMALL-WORLD AND GROWING NETWORK” STUDY WAS SUPPORTED BY THE DEPARTMENT
OF DEFENSE CRITICAL INFORMATION PROTECTION PROGRAM. FOR MORE INFORMATION,
CONTACT YING-CHENG LAI, PH.D., MATHEMATICS DEPARTMENT, 480.965.6668.
SEND E-MAIL TO [email protected]
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Diane Boudreau
FOR MORE INFORMATION, VISIT HTTP://CES.ASU.EDU/ASULICHENS/SONORAN/SONORAN.HTML
OR CONTACT THOMAS NASH PH.D., DEPARTMENT OF PLANT BIOLOGY, 480.965.3414.
SEND E-MAIL TO [email protected]
< 50 MICROMETERS >
A
Likin’ Lichen Like a layer of paint, lichens add color
to the landscape without calling attention to themselves.
Hikers marvel at cacti and wildf lowers. Rarely do their eyes
linger on the rough blue-green crust that carpets rocks and tree
trunks. However, these understated plants are important, hardy,
and even beautiful when one stops to notice them.
“They’re the most important organisms in some ecosystems,
such as the coastal areas of Baja California,” says Thomas Nash,
an ASU plant biologist.
Lichens are very sensitive to air pollution. As a result,
scientists rely on them as bioindicator species, a sort of natural
early warning system.
“Lichens produce unique secondary metabolites, some of
which are important in the pharmaceutical industry as anticancer agents,” adds Nash. “They’re also important in breaking
down rocks and holding soil in place.”
Lichens are actually made up of two plants—an alga and
a fungus—living in a symbiotic relationship. In the desert,
lichens dry out completely and remain dormant until rain or
dewfall provides enough moisture to make them active again.
This ability allows lichens to survive some of the harshest
environments on the planet.
The Sonoran Desert and surrounding regions are home to
more than 40 percent of the lichens known to North America.
Until now, these species have never been catalogued in one place.
Volume I of the Lichen Flora of the Greater Sonoran Desert Region
covers nearly 600 species of lichen in more than 140 genera.
The volume is co-edited by Nash, Bruce D. Ryan, Corinna Gries,
and Frank Bungartz. It is largely based on collections in the ASU
lichen herbarium, which boasts more then 90,000 specimens.
The book offers identification keys and descriptions for each
species treated, as well as maps showing species distribution.
For the past 30 years, Nash has collected lichens extensively
throughout the region, which includes all of Arizona, the desert
regions of southeast California, and coastal Californian areas
as far north as San Francisco. In Mexico it includes Baja California,
Sonora, Sinaloa, and the Sierra Madre area of western Chihuahua.
The book will ultimately be part of a three-volume set. Nash
says the second volume should be published by summer 2003.
SCANNING ELECTRON MICROGRAPH SHOWS A SECTION THROUGH THE FRUITING BODY AND THE THALLUS
OF THE LICHEN BUELLIA DISPERSA. IN THIS MICROGRAPH, FUNGAL HYPHAE HAVE BEEN ARTIFICIALLY
COLORED AS BROWN. THE FRUITING BODY IS A DARKER BROWN. THE SYMBIOTIC ALGAE ARE GREEN.
BOTTOM LEFT–TELOSCHISTES CRYSOPHTHALMUS IS A BRIGHT ORANGE, SHRUB-LIKE EPIPHYTE
GROWING ON OCOTILLO, FOUQUIERIA DIGUETII, ALONG THE COAST OF BAJA CALIFORNIA.
PHOTOS COURTESY FRANK BUNGARTZ
Planting Water-Wise Laziness is a virtue. At least, it can be when it comes
to maintaining your yard. For desert plants, less work can be better in terms of efficient
water use, says ASU plant biologist Linda Stabler. Efficient water use is important to
the environment, especially in the desert. Improving your yard’s water efficiency can also
save you money, time, and effort. Stabler studies the effects of irrigation and pruning
on a plant’s water use efficiency. She took a close look at two shrubs popular in desert
landscapes: Texas sage and oleander.
In the Phoenix area, these shrubs are planted densely and pruned frequently. Landscapers
often trim Texas sage into square or rounded shapes. Keeping these shapes neat requires
a lot of maintenance. Oleander is often used as a natural fence between properties because
it grows very tall. The plants are placed close together to create a “living wall.” Both of these
plants require little water. But Stabler found that many people get caught in a cycle of heavy
watering and pruning. Plants that are watered heavily need to be pruned often to control
size. Those that are pruned frequently use water less efficiently.
As part of her study, Stabler set up 14 simulated residential landscapes at the Desert
Botanical Garden in Phoenix’s Papago Park. Each 100 meter by 100 meter plot includes trees,
shrubs, and ground covers. The distribution and density of the plants mimics what commonly
exists around homes throughout the Phoenix area. The plots are divided according to pruning
frequency: every six weeks, every six months, once a year, or never. Water use efficiency
is measured in growth per unit of water applied. Plants that score high in water use efficiency
can grow more per unit of water applied than low-scoring plants.
“We found that plants given low volumes of irrigation water and left unpruned had
high water use efficiency,” Stabler says. “The plants given high volumes and pruned often
had very low water use efficiency.”
Why is this so?
“A fully mature leaf is good at using the sun’s energy to make the plant grow,” the
scientist explains. “Immature leaves require a lot more energy to grow. If you’re constantly
pruning a plant it never develops a lot of good mature leaves to provide energy for the rest
of the plant. Also, it’s stressful on the plant to constantly shear it.”
But this does not mean that all pruning is bad. “Pruning is a rejuvenating process,”
Stabler adds. “Very mature tissue isn’t very efficient either, so occasional pruning is helpful.”
Stabler says that people often buy new houses and program their irrigation systems
Note B ook
Improving Language Skills By age 5, most children are ready
to head off to kindergarten. The real question is whether
A S U R or
E S Enot
A R Cthey
H Mare
A G Aready
ZINE
to learn. Jeanne Wilcox directs ASU’s Infant Child Research Program. She and her
colleagues work with teachers to better develop language skills in at-risk
preschoolers. The idea is to provide children with the language tools necessary
for success in school.
Much of learning is based on language, says Wilcox, a professor of speech
and hearing science. Beyond vocabulary, people need language to describe
and understand the worlds around them. Abstract thinking is a language-based
skill. So are concepts such as understanding sequences and the ability to describe
and explain events. Without adequate language skills, a child may have a difficult
time making it through school.
Wilcox says that children most at risk are from lower income families, and
those learning English as their second language. Since 1997, Wilcox has focused
on teachers working in 26 Head Start classrooms throughout the Phoenix
metropolitan area. The goal is to devise methods that improve the language
learning environment for children.
To date, the ASU researchers have developed a series of language-based
activities that are integrated within typical preschool activities. They also
created a teacher self-assessment to help identify and monitor implementation
of classroom language goals. The next stage will be to put the program into
action in more schools. Gary Campbell
THE PROJECT IS SUPPORTED BY THE SCOTTSDALE-BASED VIRGINIA G. PIPER CHARITABLE TRUST. FOR MORE INFORMATION,
CONTACT JEANNE WILCOX, PH.D., SPEECH AND HEARING SCIENCE, 480.965.9397. SEND E-MAIL TO [email protected]
for young trees and plants, which require more water than established plants. Then they
forget to change these levels once the plants mature. While wasting water, these people may
also be harming their plants, causing problems such as root rot. “When people see a plant
failing they immediately think, ‘More water!’ But that might not be the solution,” she says.
Distribution is another important part of the equation. Many people position plants so close
together they don’t have room to spread out. As a result, the plants require more pruning.
A water-efficient yard is also a low-maintenance yard, says Stabler. “Around here you
always see landscapers out with their power hedgers and leaf-blowers,” she says. These
are quick and easy from a business standpoint, but not very good for the environment
or for the customer’s pocketbook, Stabler notes. “Fallen leaves are good for your yard.
Your front lawn is not your kitchen floor—it doesn’t have to be spotless.” Diane Boudreau
WATER EFFICIENCY RESEARCH IS SUPPORTED BY THE INTERNATIONAL SOCIETY FOR ARBORICULTURE, CAP-LTER,
AND THE
IGERT FELLOWSHIP. FOR MORE INFORMATION, SEND E-MAIL TO LINDA STABLER AT [email protected]
Xeriscape Facts
Xeriscaping is a type of landscaping designed to use water
efficiently. ASU plant biologist Linda Stabler says that many people create desert-looking
landscapes and believe they are xeriscaping. “Putting out a bunch of gravel and installing
a drip irrigation system is not xeriscaping,” she says. “True xeriscape is a practice, not a style,
and it is founded on seven basic principles.”
The principles, created by the Denver Water Department, are:
PLAN AND DESIGN FOR WATER CONSERVATION AND BEAUTY FROM THE START.
CREATE PRACTICAL TURF AREAS OF MANAGEABLE SIZES, SHAPES AND APPROPRIATE GRASSES.
SELECT LOW WATER REQUIRING PLANTS AND GROUP PLANTS OF SIMILAR WATER NEEDS TOGETHER.
USE SOIL AMENDMENTS SUCH AS COMPOST OR MANURE AS NEEDED
BY THE SITE AND TYPE OF PLANTS USED.
USE MULCHES, SUCH AS WOODCHIPS, TO REDUCE EVAPORATION AND KEEP THE SOIL COOL.
IRRIGATE EFFICIENTLY WITH PROPERLY DESIGNED SYSTEMS—
APPLY THE RIGHT AMOUNT OF WATER AT THE RIGHT TIME.
MAINTAIN THE LANDSCAPE PROPERLY BY MOWING, WEEDING, PRUNING, AND FERTILIZING PROPERLY.
FOR MORE INFORMATION ON XERISCAPING, VISIT XERISCAPE COLORADO! INC. (HTTP://WWW.XERISCAPE.ORG/)
OR VISIT THE ARIZONA DEPARTMENT OF WATER RESOURCES (HTTP://WATER.AZ.GOV/DEFAULT.HTM).
Light Transport Generations of Star Trek fans
grew up watching the transporter system on the starship
Enterprise beam crew members from ship to planet surface
and back again. Quick as a beam of light they winked in
and out from place to place. Modern medical researchers
are not yet ready to beam up Scotty and his pals, but they
are looking at beams of light as a propulsion system.
Scientists would like to use ultra small nano-scale tubes to push
tiny amounts of drugs dissolved in water to exactly where they are
needed in the human body. The roadblock has been the challenge
of building pumps small enough to do the job. The engineering
challenge of building a nano-scale pump is tough enough.
But there are other complications. Biological molecules can clog
valves small enough to fit inside a channel the size of bacteria.
Scientists at Arizona State University have a solution.
They created a system that does not rely on mechanical parts.
The ASU researchers developed a technique to pull water up a
tube tinier than a straw by shining a beam of light on the surface
of the tube. The process is called photocapillarity. The process
might be useful in future nanotechnology applications, such as
the targeted distribution of medicine in the body.
“As the size of capillaries or channels in devices shrinks,
it becomes very difficult to control the movement of ‘liquid,’
says Antonio Garcia, an ASU bioengineering professor.
“The everyday use of mechanical valves and pumps becomes
difficult in nanotechnology because making them tinier is
a manufacturing challenge. Also, any real-life application would
be prone to operational problems, such as clogging of the pump
or valve by tiny molecules.”
Garcia works with Devens Gust and Mark Hayes, professors
in the department of chemistry and biochemistry. While studying
light responsive molecules, they found a way of attaching the
molecules to the surface and structuring the surrounding surface
to control the spread of water.
“When we shine light just beyond the visible range, the light
responsive molecules attract water and trigger the advancement
of water through the channel,” Garcia explains.
The ASU team also developed a science lab demonstration kit.
By the end of the year, students and teachers can order
inexpensive glass tubes and a laboratory guide to exploring
the phenomena. “By providing the lab kit, we hope to stimulate
the creativity of the next generation of scientists and engineers.
They will be the ones who routinely design new products
using nanotechnology,” Garcia says.
THE RESEARCH IS SUPPORTED BY THE NATIONAL SCIENCE FOUNDATION. FOR MORE INFORMATION,
CONTACT ANTONIO GARCIA, PH.D., BIOENGINEERING DEPARTMENT, 480.965.8798.
SEND E-MAIL TO [email protected]
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