Replies

http://www.eurekalert.org/pub_releases/2009-02/nsfc-nsp021709.php

Public release date: 17-Feb-2009

Contact: Sarah DeWitt
sarah.l.dewitt@nasa.gov
301-286-0535
NASA/Goddard Space Flight Center

NASA study predicted outbreak of deadly virus

An early warning system, more than a decade in development, successfully predicted the 2006-2007 outbreak of the deadly Rift Valley fever in northeast Africa, according to a new study led by NASA scientists.

Rift Valley fever is unique in that its emergence is closely linked to interannual climate variability. Utilizing that link, researchers including Assaf Anyamba, a geographer and remote sensing scientist with the University of Maryland Baltimore County and NASA’s Goddard Space Flight Center in Greenbelt, Md., used a blend of NASA and National Oceanic and Atmospheric Administration measurements of sea surface temperatures, precipitation, and vegetation cover to predict when and where an outbreak would occur.

The final product, a Rift Valley fever “risk map,” gave public health officials in East Africa up to six weeks of warning for the 2006-2007 outbreak, enough time to lessen human impact. The researchers described their findings in the Proceedings of the National Academy of Sciences.

The first-of-its-kind prediction is the culmination of decades of research. During an intense El Niño event in 1997, the largest known outbreak of Rift Valley fever spread across the Horn of Africa. About 90,000 people were infected with the virus, which is carried by mosquitoes and transmitted to humans by mosquito bites or through contact with infected livestock.

The 1997 outbreak provoked the formation of a working group—funded by the U.S. Department of Defense Global Emerging Infections Surveillance and Response System—to see if predictions of an outbreak could be made operational. Such predictions would not only aid mitigation efforts in the endemic countries and protect the global public, but would help protect American civilian and military personnel located and traveling overseas, ensure the safety of imported goods and animals, and prevent infected humans or mosquitoes from entering the United States.

“To do all that, we need to understand a disease in the endemic region,” Anyamba said.

The link between the mosquito life cycle and vegetation growth was first described in a 1987 Science paper by co-authors Kenneth Linthicum of the U.S. Department of Agriculture and Compton Tucker of NASA Goddard. Then, a subsequent 1999 Science paper described link between the disease and the El Niño-Southern Oscillation (ENSO). ENSO is a cyclical, global phenomenon of sea surface temperature changes that can contribute to extreme climate events around the world.

For some areas, the warm phase of ENSO brings drought, while in some areas like the Horn of Africa, ENSO leads to above-normal rainfall. Excessive, sustained rainfall awakens the eggs of mosquitoes infected with Rift Valley fever that can remain dormant for up to 15 years in dried-out dambos—shallow wetlands common in the region.

Building on that research, Anyamba and colleagues set out to predict when conditions were ripe for excessive rainfall, and thus an outbreak. They started by examining satellite measurements of sea surface temperatures. One of the first indicators that ENSO will bring an abundance of rainfall is a rise in the surface temperature of the eastern equatorial Pacific Ocean and the western equatorial Indian Ocean.

But perhaps the most telling indicator of a potential outbreak is a measure of the mosquito habitat itself. The researchers used a satellite-derived vegetation data set—processed at NASA Goddard and called the Normalized Difference Vegetation Index—that measures the landscape’s “greenness.” Greener regions have more than the average amount of vegetation, which means more water and more potential habitat for infected mosquitoes.

“Greenness describes habitat and represents life,” Anyamba said. “Without such systematic, continuous Earth system measurements from satellites, we would not be able to translate the information into outbreak predictions.”

The final product is a risk map for Rift Valley fever, showing areas of anomalous rainfall and vegetation growth over a three-month period. The forecast is updated and issued monthly as a means to guide ground-based mosquito and virus surveillance.

As early as September 2006, the monthly advisory from Anyamba and colleagues indicated an elevated risk of Rift Valley fever activity in East Africa. By November, Kenya’s government had begun collaborating with non-governmental organizations to implement disease mitigation measures—restricting animal movement, distributing mosquito bed nets, informing the public, and enacting programs to control mosquitoes and vaccinate animals.

“There is no human vaccine,” Anyamba said, “so prevention is critical.”

Between two and six weeks later—depending on the location—the disease was detected in humans.

“Satellite data is a valuable tool that allowed us to look remotely at large sections of land in Africa and understand what was happening on the ground,” Linthicum said.

After the 2006-2007 outbreak, Anyamba and colleagues assessed the effectiveness of the warning maps. They compared locations that had been identified as “at risk” with the locations where Rift Valley fever was reported.

Of the 1,088 cases reported in Kenya, Somalia, and Tanzania, 64 percent fell within areas delineated on the risk map. The other 36 percent of cases did not occur within “at risk” areas, but none were more than 30 miles away, leading the researchers believe that they had identified most of the initial infection sites.

The potential for mapping the risk of disease outbreaks is not limited to Africa. Previous research has shown that risk maps are possible whenever the abundance of a virus can be linked to extremes in climate conditions. Chikungunya in east Africa and Hantavirus and West Nile virus in the United States, for example, have been linked to conditions of rainfall extremes.

“We are coming up on almost 30 years of vegetation data from satellites, which provides us with a good basis for predicting,” Linthicum said upon returning from a Rift Valley fever workshop in Cairo, Egypt in January. “At this meeting, it was clear that using this tool as a basis for predictions has become accepted as the norm.”

###

http://www.nasa.gov/topics/earth/features/riftvalley_fever.html

Written By:
Kathryn Hansen
Goddard Space Flight Center

[Now it is “What is on my Strawberry?”...granny]

http://www.eurekalert.org/pub_releases/2009-02/asfh-mba021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606
American Society for Horticultural Science

Methyl bromide alternatives for California strawberry nurseries

Researchers find alternative fumigants effective in weed control

IMAGE: Testing alternatives to methyl bromide for controlling disease.
Click here for more information.

SALINAS, CA—Since around 1960, methyl bromide (MB) has been the foundation for soilborne disease and weed control in California strawberries. MB, classified as a Class I stratospheric ozone-depleting chemical, has been phased out since 2005, but is still being used in strawberry production under a critical-use exemption.

Strawberry production is important to California’s economy; the state leads the U.S. in strawberry production. In 2006, the fruit harvest yielded a value of $1.2 billion, and accounted for 79% of the total U.S. gross sales.

The diversity of climates in California along with the use of this fumigant, permits the production of high-quality runner plants, which are propagated in virus-free growing facilities called “screenhouses”. Plants are reared first in a low-elevation facility during the warm early season, and then moved to higher-elevation facilities for cool, late-summer conditions. This process ensures that strawberry plants will be ready to transplant into fruit fields by early fall.

A research study published in the American Society for Horticultural Science journal HortScience evaluated the effectiveness and cost efficiency for weed control in lower- and higher-elevation nurseries with MB-alternative fumigants.

Researchers Steven A. Fennimore, Milton J. Haar, Rachael E. Goodhue, and Christopher Q.Winterbottom noted that weed control in strawberry nurseries is more difficult than in fruiting fields. “Because weed control methods such as mulches used in fruit fields can’t be used in nurseries, fumigants are one of the most important weed control tools available for strawberry nursery fields”, the team explained.

Assessing weed control in the study consisted of three methods: weed seed viability, weed density counts, and timing of hand-weeding inputs by crews. Strawberry and weed seed samples were treated with the alternative fumigants to determine the potential for strawberry and weed seed to survive in the nursery fields. Fumigant effectiveness was studied in fields treated with the combination of MB plus Pic, iodomethane (IM) plus Pic, and control fields. Additional treatments tested were 1,3-dicloropropane (1,3-D) plus Pic followed by dazomet, and Pic followed by dazomet. Overall, there were few to no differences in weed control between IMPic, 1,3-D Pic followed by dazomet, Pic followed by dazomet, and MBPic. Relative to the control fields, hand-weeding times were reduced in all fields that had been fumigated.

The main difference between fumigating with the different methods was material cost. The researchers explained that, because current prices were used to calculate hand weeding and treatment costs, these prices will change over time and may become more equitable given different circumstances.

The study results showed that that fumigating with MB is currently much cheaper than using IM. On the basis of weed control, all of the alternative fumigant treatments were acceptable replacements for MB.

###

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/43/5/1495

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at: http://ashs.org

http://www.eurekalert.org/pub_releases/2009-02/asfh-ccb021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606
American Society for Horticultural Science
Controlling cucumber beetles organically
Pest numbers reduced, fruit yields increased using organic methods

FRANKFORT, KY—As the popularity of organic produce increases with consumers, growers need more options to manage pests naturally.

John D. Sedlacek and Gary R. Cline (retired) of the Land Grant Program at Kentucky State University led a research project designed to investigate options for reducing the presence of cucumber beetles. These pests damage crops by eating the roots, shoots, and flowers, and transmit the bacterial wilt pathogen. The study, published in the American Society of Horticultural Science journal HortTechnology, compares several practices in watermelon and muskmelon crops.

In 2002, watermelon was grown on black plastic mulch with the exception of one group, which was grown on Al-plastic, an aluminum coated plastic mulch previously linked to reduced cucumber beetle densities on squash. Another plot of watermelons was planted with companion plants thought to repel cucumber beetles. A third group was planted with a different set of companion plants that seem to attract insects that prey on cucumber beetles. Sticky traps stationed among the plants collected cucumber beetles, which were counted and removed on a weekly basis. The watermelon yields were not adversely affected by the Al-plastic nor by the companion plants.

More beetles were collected in the control and Al-plastic groups than the companion plant groups. Similar numbers of beetles were trapped in repellent plant groups and beneficial insect-attracting plant groups, suggesting these plants may be more valuable as a physical barrier to the beetles’ movement than for their attractive or repellent properties.

In 2003, the study was replicated using muskmelons. Al-plastic was included again, but the companion plant groups were combined to include beetle-repelling radishes and predator-insect-attracting buckwheat. Other treatments included use of rowcovers and the organic insecticide PyGanic®. The separate Al-plastic and companion plant groups increased muskmelon yields of 75% and 66%, respectively, compared to the control. Rowcovers also significantly increased yield. The number of trapped beetles was significantly higher in the control group than in any other.

Then, in 2004, the study was repeated, but this time the insecticide group was replaced by a combination of Al-plastic and companion plants. Muskmelon weights varied significantly among all groups, with the greatest weights coming from the Al-plastic and companion plant combined groups with rowcovers. Weights in the Al-plastic-only group were greater than in the companion plant-only group.

All of the treatments, except for the insecticide, significantly increased yields compared to control groups. It appeared that some treatments, such as companion plants, may have reduced beetle populations by affecting adults, while others, such as the Al-plastic, may have affected beetle larvae still in the soil.

###

The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/18/3/436

http://www.eurekalert.org/pub_releases/2009-02/apa-wdi021709.php

Public release date: 17-Feb-2009

Contact: Audrey Hamilton
ahamilton@apa.org
202-336-5706
American Psychological Association

When dreaming is believing: Dreams affect people’s judgment, behavior

Dreams can carry more weight than conscious thoughts, say researchers

WASHINGTON – While science tries to understand the stuff dreams are made of, humans, from cultures all over the world, continue to believe that dreams contain important hidden truths, according to newly published research.

In six different studies, researchers surveyed nearly 1,100 people about their dreams. “Psychologists’ interpretations of the meaning of dreams vary widely,” said Carey Morewedge, an assistant professor at Carnegie Mellon University and the study’s lead author. “But our research shows that people believe their dreams provide meaningful insight into themselves and their world.”

The article appears in the February issue of the Journal of Personality and Social Psychology, published by the American Psychological Association.

In one study that surveyed general beliefs about dreams, Morewedge and co-author Michael Norton, an assistant professor at Harvard Business School, surveyed 149 university students in the United States, India and South Korea. The researchers asked the students to rate different theories about dreams. Across all three cultures, an overwhelming majority of the students endorsed the theory that dreams reveal hidden truths about themselves and the world, a belief also endorsed by a nationally representative sample of Americans.

In another study reported in the article, the researchers wanted to explore how dreams might influence people’s waking behavior. They surveyed 182 commuters at a Boston train station, asking them to imagine that one of four possible scenarios had happened the night before a scheduled airline trip: The national threat level was raised to orange, indicating a high risk of terrorist attack; they consciously thought about their plane crashing; they dreamed about a plane crash; or a real plane crash occurred on the route they planned to take. A dream of a plane crash was more likely to affect travel plans than either thinking about a crash or a government warning, and the dream of a plane crash produced a similar level of anxiety as did an actual crash.

Finally, the researchers wanted to find out whether people perceive all dreams as equally meaningful, or whether their interpretations were influenced by their waking beliefs and desires. In another study, 270 men and women from across the United States took a short online survey in which they were asked to remember a dream they had had about a person they knew. People ascribed more importance to pleasant dreams about a person they liked as compared to a person they did not like, while they were more likely to consider an unpleasant dream more meaningful if it was about a person they disliked.

“In other words,” said Morewedge, “people attribute meaning to dreams when it corresponds with their pre-existing beliefs and desires. This was also the case in another experiment which demonstrated that people who believe in God were likely to consider any dream in which God spoke to them to be meaningful; agnostics, however, considered dreams in which God spoke to be more meaningful when God commanded them to take a pleasant vacation than when God commanded them to engage in self-sacrifice.”

The authors say more research is needed to explore fully how people interpret their dreams, and in what cases dreams may actually reveal hidden information.. “Most people understand that dreams are unlikely to predict the future but that doesn’t prevent them from finding meaning in their dreams, whether their contents are mundane or bizarre,” said Morewedge.

###

Article: “When Dreaming Is Believing: The (Motivated) Interpretation of Dreams,” Carey K. Morewedge, PhD, Carnegie Mellon University, Michael I. Norton, PhD, Harvard University; Journal of Personality and Social Psychology, Vol. 96, Issue 2.

(Full text of the article is available from the APA Public Affairs Office and at http://www.apa.org/journals/releases/psp962249.pdf)

Contact Carey Morewedge by e-mail at morewedge@cmu.edu; his phone number is 617-308-7033.

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world’s largest association of psychologists. APA’s membership includes more than 150,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting human welfare.

http://www.eurekalert.org/pub_releases/2009-02/asfh-apa021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606

American Society for Horticultural Science

Apple peel appeal
Using software to measure variances in ‘honeycrisp’ apple peels

IMAGE: Computer measures amount of blush or stripe in peel of “honeycrisp “ apple.
Click here for more information.

ST. PAUL, MN—Apples have long been associated with good health, including lower risks of cancer and cardiovascular disease. Apples also contain anthocyanins, important antioxidants that give the peels their red coloring. Redness is one of the most important factors consumers consider when buying apples.

One variety of apple called ‘Honeycrisp’ has peel pigment that takes on one of two patterns—”striped” or “blushed.” A single ‘Honeycrisp’ tree can produce both striped and blushed apples, a phenomenon unique to this variety. In terms of marketability, consumers in some regions prefer striped apples, while others prefer blushed, but overall redder is better.

Adriana Telias, Emily Hoover, and Diego Rother of the University of Minnesota published a research study in the American Society for Horticultural Science journal HortScience comparing the coloring of ‘Honeycrisp’ apples. From 2005 the team studied the fruit of trees grown from buds on branches with exclusively striped or blushed fruit. The apples were separated as either striped or blushed, and color and stripe intensity were measured, and then the fruits were photographed. The researchers developed color-analyzing software to automatically separate the apples from the background in the photos and measure statistics such as mean color in large areas of the fruit peel.

It was found that blushed trees produced more blushed fruit than striped trees. Likewise, the markings on striped fruit were more intense on striped trees than blushed trees.

Position on the tree may also be related to the pattern, as it was observed that northeast-facing branches produced 13% blushed fruit compared to only 6% on southwest-facing branches. Southwest branches also produced more intensely striped fruit than northeast branches. And, within clusters of fruit, the apples were more likely to have similar coloring.

Each year, blushed fruit was found to be redder than striped fruit. “Given that blushed fruit are redder than striped ones, the goal should be to increase blushed fruit production when target markets prefer redder fruit,” stated the researchers. They added; “This may prove difficult given that even the top blushed-producing trees never yielded more than 50% blushed fruit over all 3 years.”

Because higher crop loads were associated with lower percentage of blushed fruit, the study suggests regulating the crop load to increase the number of blushed fruits, and that growing trees from buds of blushed fruit branches, should result in higher blushed fruit yields. This is based on indications that both genetic and environmental factors affect peel pigmentation.

The software developed to evaluate peel color in the study is available for community use.

###

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/43/5/1441

http://www.eurekalert.org/pub_releases/2009-02/asfh-pwg021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606

American Society for Horticultural Science

Protecting wine grapes from heat and drought

Winemakers may see benefits using foliar particle film

IMAGE: Particle film used to protect wine grapes from heat and drought.
Click here for more information.

PARMA, ID—Deficit irrigation is an agricultural technique used to achieve a variety of results depending on the crop. For white wine grapes, it balances the crop load by limiting the canopy size so there aren’t too many leaves shading the grapes. For red wine grapes, deficit irrigation again limits canopy size, but also affects berry components associated with wine quality.

A drawback of this canopy-limiting process is that fruit can become sunburned, especially under sunny, arid conditions, which can adversely affect productivity and fruit maturity. A particle film, which increases light reflection and reduces leaf temperature, has been tested on several crops. It acts as a sunscreen by reflecting the harmful ultraviolet rays off of the leaves and fruit, but still allows the right radiation for photosynthesis through to nourish the plant.

Krista Shellie of the U.S. Department of Agriculture led a study to learn more about foliar particle film’s effects on wine grapes when the grapes were grown under varying levels of water stress. The study, published in the American Society for Horticultural Science journal HortScience, also noted particle film’s effect on grape yield and maturity. Grapes were grown according to commercial practice with the exception of the watering schedule and application of the particle film. Film effectiveness was monitored by measuring the amount of leaf gas exchange, but particle film’s influence on this process seemed to differ depending on the amount of water stress the vine was experiencing.

Particle film did not prevent sunburn on exposed fruit when vines were under the most stressful growing conditions, but did increase the weight of a red-skinned wine grape by 7% and increased a white-skinned wine grapes’ soluble solids concentration by 11%. But, the weight of white-skinned wine grape and the soluble solids concentration of the red-skinned grape were unaffected. Other factors pertaining to yield, including grape maturity, were not influenced by particle film.

The study’s findings support a classification of these grapes as anisohydric, meaning the plant is affected by the amount of soil moisture available and is unable to restrict its own water loss under dry soil conditions. This is also known as a “drought-avoiding” classification.

Particle film may increase the yield potential of the vines, but it did not protect against sun damage when vines were grown under deficit irrigation. The cost-benefit of particle film must be decided by growers and wine makers and its potential benefit of more uniform fruit maturity, increased yield, and berry size.

###

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/43/5/1392

http://www.eurekalert.org/pub_releases/2009-02/asfh-srs021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606

American Society for Horticultural Science

Select roses survive with minimal care
Rose research shows best performers for low-maintenance gardens

IMAGE: Belinda’s Dream, one of the original EarthKind Roses.
Click here for more information.

DALLAS, TX—Roses have long been a favorite of gardeners, but they often require a lot of work to thrive. And the emphasis on organics has more home gardeners concerned about the environment and reluctant to use pesticides.

W. A. Mackay of Texas A&M University led a study comparing several varieties of roses to determine which grow best with minimal care under certain conditions. The results were published in the American Society for Horticultural Science journal HortTechnology.

Flower number, flower size, visual estimate of flowering percentage, plant vigor and overall plant performance were rated for 116 varieties of roses from Spring 2000 through 2002. No pesticides or fertilizers were used to grow the roses. Four plants represented each variety, and only varieties with three or four plants surviving the experiment were used in the statistical analysis.

Additional tests were run on a subset of rose varieties to assess their nutrient levels. Monthly recordings were also taken to rate each variety’s disease resistance by noting symptoms of petal blight, powdery mildew, and black spot, some of the most common ailments of roses. Plants that were grown on their own roots had significantly better appearance ratings and survival rates than plants that were grafted.

‘RADrazz’ (Knock Out™) was the best-performing rose overall, which the study contributes to its “vigorous growth and attractive foliage.” Trumpeter® was the worst-performing rose. Out of all the roses that performed well in the study, 15 are recommended as low-maintenance for growing in Texas.

The study also found differences in performance between classes of roses, with Polyanthas being best in overall performance and Hybrid Tea roses being worst. Based on the results of this study, selected varieties were chosen for an expanded nationwide study to develop the EarthKind™ collection of roses.

###

The complete study is available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/18/3/417

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education and application. More information at: ashs.org

http://www.eurekalert.org/pub_releases/2009-02/asfh-cml021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606

American Society for Horticultural Science

Capillary mats labor-saving, economical alternative to hand watering
Retail nurseries can recoup investment in one year

TUCSON, AZ—Capillary mats are popular in the retail nursery industry and with many home gardeners. The uniquely designed mats provide automated irrigation to a variety of plants, conserve water, and reduce the need for labor-intensive hand-watering.

Made with absorbent fabric lined with polyethylene film on the bottom and covered on top with perforated polyethylene or similar material, the mats help minimize evaporation while allowing water to move from the bottom of the mat up into the containers on top.

One advantage of capillary mats is that plants of different size and water requirement can be placed on the same mat without under- or over- watering individual containers. Other reasons mats are preferred to overhead sprinklers are that mats leave less water on the floor of the retail area, and staff don’t have to spend as much time watering plants. The downside: capillary mats can be an expensive system to set up and maintain.

In a study published in the American Society of Horticultural Science journal HortTechnology, a research team from the University of Arizona used capillary mats and overhead sprinkler irrigation in a simulated retail environment to maintain annual and perennial plants in containers for various time periods during both summer and winter.

The researchers combined the results from both seasons and concluded that four species with dense canopies had larger canopy sizes when maintained on the capillary mats. Three species requiring more drainage had larger canopies with overhead irrigation, and five species were unaffected by irrigation systems. Additionally, substrate electrical conductivity was higher for some species in winter for plants on capillary mats, thus conserving fertilizer compared with overhead irrigation. Plants maintained on capillary mats required 71% less water in summer and 62% less in winter compared to the plants watered using overhead irrigation systems.

The study also included an economic analysis component comparing the investment required for setup and maintenance of plants in a retail situation using hand-watering, overhead sprinkler, or capillary mat irrigation. “The economic analysis indicates that capillary mats are a labor-saving alternative to hand-watering in a retail nursery and will compensate for the higher initial investment within less than one year”, noted lead author Ursula K. Schuch.

Summarizing the research results, Schuch found that “overhead sprinklers were the most cost-effective system of the three because of less costly initial set-up and maintenance than the capillary mats”, but added that sprinklers are not a true alternative to hand-watering in a retail situation because they interfere with customer traffic and retail workers.

###

The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/18/2/250

http://news.illinois.edu/news/09/0213nature.html

The science suggests access to nature is essential to human health

2/13/09

Diana Yates, Life Sciences Editor
217-333-5802; diya@illinois.edu
Kuo
Click photo to enlarge
Photo by L. Brian Stauffer

Frances Kuo, a professor of natural resources and environmental science and psychology at Illinois, studies how environmental factors, such as access to nature, may influence social, psychological and physical health.

CHAMPAIGN, Ill. — Elderly adults tend to live longer if their homes are near a park or other green space, regardless of their social or economic status. College students do better on cognitive tests when their dorm windows view natural settings. Children with ADHD have fewer symptoms after outdoor activities in lush environments. Residents of public housing complexes report better family interactions when they live near trees.

These are only a few of the findings from recent studies that support the idea that nature is essential to the physical, psychological and social well-being of the human animal, said Frances Kuo, a professor of natural resources and environmental science and psychology at the University of Illinois. Kuo will present her own and other findings on the subject at the annual meeting of the American Association for the Advancement of Science in Chicago on Feb. 13.

“Humans are evolved organisms and the environment is our habitat,” Kuo said. “Now, as human societies become more urban, we as scientists are in a position to look at humans in much the same way that those who study animal behavior have looked at animals in the wild to see the effect of a changing habitat on this species.”

Humans living in landscapes that lack trees or other natural features undergo patterns of social, psychological and physical breakdown that are strikingly similar to those observed in other animals that have been deprived of their natural habitat, Kuo said.

“In animals what you see is increases in aggression, you see disrupted parenting patterns, their social hierarchies are disrupted,” she said.

Considerable research has found that violence and aggression are highest in urban settings devoid of trees and grass, for example.

Kuo has studied how access to nature influences crime and conflict resolution among residents of public housing facilities in Chicago. These facilities provide an ideal laboratory for studying the “green effect,” she said, because their occupants are randomly assigned to standard housing units, some of which have grass and trees nearby.

In a 2001 study of the Robert Taylor Homes (recently demolished), Kuo and her colleague, U. of I. landscape architecture professor William Sullivan, found that those who lived in housing units with no immediate view of or access to nature reported a greater number of aggressive – including violent – conflicts with partners or children than their peers who lived near trees and grass.

In another 2001 study, Kuo and Sullivan looked at two years of crime statistics in relation to specific addresses in the Ida B. Wells public housing facility in Chicago. After controlling for other factors, the researchers found that crime rates were highest for residences with little or no proximity to nature. Identical units with views of grass and trees were associated with significantly less crime.

“Roughly 7 percent of the variation in crime that can’t be accounted for by other factors can be accounted for by the amount of trees,” Kuo said.

Humans suffer a variety of negative social effects when living in barren landscapes. Kuo and her colleagues have shown that these effects include decreased civility, less supervision of children outdoors, more illegal activity, more aggression, more property crime, more loitering, more graffiti and more litter.

“We might call some of that ‘soiling the nest,’ which is not healthy,” she said. “No organisms do that when they’re in good shape.”

Certain psychological problems are also likely to appear more often in those lacking access to nature, she said.

“In our studies, people with less access to nature show relatively poor attention or cognitive function, poor management of major life issues, poor impulse control,” she said.

Other researchers have found that access to nature positively influences a person’s mood, life and work satisfaction, she said.

Kuo has seen such psychological effects in children with ADHD. In a 2001 study, she and her colleagues asked parents of children with ADHD which after-school activities worsened – and which soothed – their children’s symptoms. The parents consistently reported that outdoor activities in natural settings lessened their children’s ADHD symptoms more than activities conducted indoors, or in built environments outdoors.

In a 2008 study, Kuo and a colleague, Illinois postdoctoral researcher Andrea Faber Taylor, studied children with ADHD who went on field trips in green or manmade environments. After the trips, other researchers (who didn’t know where the kids had been) tested their concentration. Children with ADHD had significantly better concentration after a walk in a park than in an urban setting. The difference was comparable to what is achieved with standard ADHD medication, Kuo said, although “no one knows how long the green effect will last.”

More recent studies by various teams in Japan, the Netherlands, the United Kingdom and the U.S., are showing that access to nature – or lack thereof – can also have significant physical effects. A large-scale study in the Netherlands found that general health is predicted by the amount of green space within a 1-mile or 3-mile radius, Kuo said. Another study found that elderly Japanese adults lived longer when their homes were within walking distance of a park or other green space. These effects were independent of their social or economic status.

While none of these studies proves conclusively that nature is essential to optimal functioning in humans, Kuo said, the body of evidence strongly points in that direction.

“So when people say: ‘As a scientist, would you say that we know this now? Do we know that people need nature?’ I say: ‘As a scientist I can’t tell you. I’m not ready to say that,’ ” Kuo said. “ ‘But as a mother who knows the scientific literature, I would say, yes.’ ”

Editor’s note: To reach Frances Kuo, call: 217-244-0393; e-mail: fekuo@illinois.edu.

http://news.illinois.edu/news/09/0212virus.html

NEWS INDEX Archives 2009 February

Research on viral origins suggests new definition of virus may be needed

2/12/09
Cotesia wasp
Click photo to enlarge
Rights-protected photo courtesy Alex Wild (myrmecos.net)
A parasitic Cotesia wasp preparing to oviposi onto a Manduca caterpillar.

Diana Yates, Life Sciences Editor
217-333-5802; diya@illinois.edu

CHAMPAIGN, Ill. — The strange interaction of a parasitic wasp, the caterpillar in which it lays its eggs and a virus that helps it overcome the caterpillar’s immune defenses has some scientists rethinking the definition of a virus.

In an essay in the journal Science, Donald Stoltz, a professor of microbiology and immunology at Dalhousie University, in Halifax, Nova Scotia, and James Whitfield, a professor of entomology at the University of Illinois, report that a new study also appearing in Science shows how the diverse ways in which viruses operate within and among the organisms they encounter may not be fully appreciated. The study, from a team of researchers led by the Université François Rabelais, in Tours, France, found that the genes that encode a virus that helps wasps successfully parasitize caterpillars are actually integrated into the wasps’ own chromosomes. These genes, which they show to be related to those from another known group of viruses, are an indivisible part of the wasp’s genetic heritage; they are passed down from one generation to another of parasitoid wasps.

While it is not unusual for virus DNA to become embedded in the chromosomes of their hosts, in this case the wasp is not the only “host” of the virus. The viral genes do replicate (copy themselves) inside the wasp (the permanent host), but they actually target – and act upon – the immune system of the caterpillar (a more transient host).
Whitfield
Click photo to enlarge
Photo by L. Brian Stauffer
Entomologist James Whitfield suggests a new definition of viruses is needed, based on research on parasitic wasps.

“The unique thing about these viruses is that the organism into whose DNA their genes are embedded in is not the same one that their genes are actually targeted to operate on,” Whitfield said. “So it’s sort of like having two hosts, except that there’s not a complete life cycle in either host.”

The virus is beneficial to the wasp and depends on the wasp for its own survival, suggesting a kind of obligate mutualism that is not normally seen in viruses, Whitfield said.

Researchers have known for about 40 years that some species of parasitoid wasps inject these viruses, known as polydnaviruses, into the body cavities of caterpillars at the same time that they lay their eggs in the caterpillars. Because these “virus-like particles” have become an integral part of the wasp genome, some researchers have suggested they should no longer be considered viruses.

“It’s true that the wasp DNA and the viral DNA are now combined into the same genome, so maybe it’s not productive to think of them as separate entities,” Whitfield said. “But on the other hand, if you really want to understand them well, it does help to know where things come from.”

Whitfield and Stoltz have each spent decades studying the interplay of parasite and pathogens that makes up the life cycle of the parasitoid wasps. In their essay, they suggest that taxonomists of viruses take a new look at how viruses are defined.

“Many virology texts won’t even mention polydnaviruses,” Whitfield said. “The issue we bring up is: Do we want to call these viruses? And if not, why not? Because they certainly started out as viruses. And if so, then we have to change the definition of viruses to somehow specify what it is that a virus has to contain, and what it has to do, to be considered a virus.”

Editor’s note: To reach James Whitfield, call 217-778-9944; e-mail jwhitfie@illinois.edu.

To reach Don Stoltz, call 902-494-3587; email dstoltz@dal.ca.

http://www.eurekalert.org/pub_releases/2009-02/asfh-sta021709.php

Public release date: 17-Feb-2009

Contact: Michael W. Neff
mwneff@ashs.org
703-836-4606
American Society for Horticultural Science

Sweet potato takes a ride on space shuttle

Study shows roots can regenerate in microgravity

TUSKEGEE, AL—Because of the distinct lack of grocery stores in outer space, scientists are looking for ways to provide food for long-term space missions.

Desmond G. Mortley and colleagues from the Center for Food and Environmental Systems for Human Exploration of Space, G.W. Carver Agricultural Experiment Station, and the Kennedy Space Center undertook a study on microgravity’s effects on sweetpotato. The study findings were published in the Journal of American Society for Horticultural Science.

Seeds of several crops have been grown in microgravity, but this was the first test for plants grown from cuttings. Cuttings grow roots faster than do seeds, and sweetpotato cuttings regenerate very easily. This made them ideal for the study, half of which took place on a 5-day space mission on the shuttle Columbia.

The other half of the cuttings remained on earth as the ground-based control group at Kennedy Space Center in Florida. Conditions were similar for both growing environments.

Both environments resulted in similar root growth development, though the microgravity roots tended to grow perpendicular to the cuttings. The number of roots was almost the same in both samples. However, the length of roots grown in microgravity was significantly greater. Microgravity cuttings contained significant accumulation of soluble sugars and higher starch concentration than ground cuttings; the starch grains appeared smaller in microgravity samples.

Despite these differences, the study was successful in showing that stem cuttings, at least those started in normal gravity conditions, can regenerate roots in microgravity. “This suggests that the space flight environment has no negative effect on the ability of vegetative cuttings to form roots and that use of cuttings should be an acceptable means for propagating sweetpotato for future space applications,” summarized the researchers.

The next step will be to experiment over longer space missions to test root cuttings’ ability to grow plants.

###

The complete study and abstract are available on the ASHS J. Amer. Soc. Hort. Sci. electronic journal web site: http://journal.ashspublications.org/cgi/content/abstract/133/3/327

http://www.aftau.org/site/News2?page=NewsArticle&id=8731

Tiny “Lab-on-a-Chip” Can Detect Pollutants, Disease and Biological Weapons
Tuesday, February 17, 2009

TAU scientists develop highly accurate nano-scale biomonitoring solution

Photo: Prof. Yosi Shacham-Diamand, Tel Aviv University
Prof. Yosi Shacham-Diamand

For centuries, animals have been our first line of defense against toxins. A canary in a coalmine served as a living monitor for poisonous gases. Scientists used fish to test for contaminants in our water. Even with modern advances, though, it can take days to detect a fatal chemical or organism.

Until now. Working in the miniaturized world of nanotechnology, Tel Aviv University researchers have made an enormous — and humane — leap forward in the detection of pollutants.

A team led by Prof. Yosi Shacham-Diamand, vice-dean of TAU’s Faculty of Engineering, has developed a nano-sized laboratory, complete with a microscopic workbench, to measure water quality in real time. Their “lab on a chip” is a breakthrough in the effort to keep water safe from pollution and bioterrorist threats, pairing biology with the cutting-edge capabilities of nanotechnology.

“We’ve developed a platform — essentially a micro-sized, quarter-inch square ‘lab’ — employing genetically engineered bacteria that light up when presented with a stressor in water,” says Prof. Shacham-Diamand. Equipment on the little chip can work to help detect very tiny light levels produced by the bacteria.

Instead of using animals to help detect threats to a water supply, Prof. Shacham-Diamand says, “Our system is based on a plastic chip that is more humane, much faster, more sensitive and much cheaper.”

Tiny Lab-on-Chip Boosts Accuracy

“Basically, ours is an innovative advance in the ‘lab on a chip’ system,” says Prof. Shacham-Diamand. “It’s an ingenious nano-scale platform designed to get information out of biological events. Our solution can monitor water with never-before-achieved levels of accuracy. But as a platform, it can also be used for unlimited purposes, such as investigating stem cell therapies or treating cancer.”

According to published literature, Tel Aviv University is one of the top five universities in the world pioneering the “lab on a chip” concept. The nanolabs can be used to evaluate several biological processes with practical applications, such as microbes in water, stem cells, or breast cancer development. Prof. Shacham-Diamand’s active lab group publishes a major paper about once a month in this field, most recently in the journal Nano Letters.

Environmental, Medical and Defense Uses for “Mini-Labs”

Partnering with other Israeli scientists, Tel Aviv University is currently building and commercializing its water-testing mini-labs to measure and monitor how genetically engineered bacteria respond to pollution such as E. coli in water. Cities across Israel have expressed interest in the technology, as has the state of Hawaii.

But other uses are being explored as well. Funded by a $3 million grant from the United States Department of Defense Projects Agency (DARPA), the new lab-on-a-chip could become a defensive weapon that protects America from biological warfare. His system, Prof. Shacham-Diamand says, can be also modified to react to chemical threats and pollution. With some tweaking here and there, it can be updated as new threats are detected.

Prof. Shacham-Diamond’s research has also attracted the interest of cancer researchers around the world. He recently addressed 400 physicians at a World Cancer Conference who are seeking new devices to measure and monitor cancer and pharmaceuticals. “They need sensors like Tel Aviv University’s lab on a chip. It’s a hot topic now,” says Prof. Shacham-Diamond.