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July 1, 2011
· Growing crops on other planets
· Broccoli may be key to beating Alzheimer’s
· Canada seeks to breed a better honey bee
· EU E. coli may have Egyptian seed link
Growing crops on other planets
(space.com) – Science fiction lovers aren't the only ones captivated by the possibility of colonizing another planet. Scientists are engaging in numerous research projects that focus on determining how habitable other planets are for life.
Mars, for example, is revealing more and more evidence that it probably once had liquid water on its surface, and could one day become a home away from home for humans.
"The spur of colonizing new lands is intrinsic in man," said Giacomo Certini, a researcher at the Department of Plant, Soil and Environmental Science (DiPSA) at the University of Florence, Italy. "Hence expanding our horizon to other worlds must not be judged strange at all. Moving people and producing food there could be necessary in the future."
Humans traveling to Mars, to visit or to colonize, will likely have to make use of resources on the planet rather than take everything they need with them on a spaceship. This means farming their own food on another planet that has a very different ecosystem than Earth's.
Certini and his colleague Riccardo Scalenghe from the University of Palermo, Italy, recently published a study in Planetary and Space Science that makes some encouraging claims. They say the surfaces of Venus, Mars and the moon appear suitable for agriculture. [Best Space Foods of All Time]
Know your (space) soil
Before deciding how planetary soils could be used, the two scientists had to first explore whether the surfaces of the planetary bodies can be defined as true soil.
"Apart from any philosophical consideration about this matter, definitely assessing that the surface of other planets is soil implies that it 'behaves' as a soil," said Certini. "The knowledge we accumulated during more than a century of soil science on Earth is available to better investigate the history and the potential of the skin of our planetary neighbors."
One of the first obstacles in examining planetary surfaces and their usefulness in space exploration is to develop a definition of soil, which has been a topic of much debate.
"The lack of a unique definition of 'soil,' universally accepted, exhaustive, and (one) that clearly states what is the boundary between soil and non-soil makes it difficult to decide what variables must be taken into account for determining if extraterrestrial surfaces are actually soils," Certini said.
At the proceedings of the 19th World Congress of Soil
Sciences held in
On Earth, five factors work together in the formation of soil: the parent rock, climate, topography, time and biota (or the organisms in a region such as its flora and fauna). It is this last factor that is still a subject of debate among scientists.
A common, summarized definition for soil is a medium that enables plant growth. However, that definition implies that soil can only exist in the presence of biota. Certini argues that soil is material that holds information about its environmental history, and that the presence of life is not a necessity.
"Most scientists think that biota is necessary to
produce soil," Certini said. "Other
scientists, me included, stress the fact that important parts of our own
planet, such as the
The researchers of this study contend that classifying a material as soil depends primarily on weathering. According to them, a soil is any weathered veneer of a planetary surface that retains information about its climatic and geochemical history.
On Venus, Mars and the Moon, weathering occurs in different ways. Venus has a dense atmosphere at a pressure that is 91 times the pressure found at sea level on Earth and composed mainly of carbon dioxide and sulphuric acid droplets with some small amounts of water and oxygen.
The researchers predict that weathering on Venus could be caused by thermal process or corrosion carried out by the atmosphere, volcanic eruptions, impacts of large meteorites and wind erosion.
Mars is currently dominated by physical weathering caused by meteorite impacts and thermal variations rather than chemical processes.
According to Certini, there is no active volcanism that affects the martian surface but the temperature difference between the two hemispheres causes strong winds. Certini also said that the reddish hue of the planet's landscape, which is a result of rusting iron minerals, is indicative of chemical weathering in the past.
On the moon, a layer of solid rock is covered by a layer of loose debris. The weathering processes seen on the Moon include changes created by meteorite impacts, deposition and chemical interactions caused by solar wind, which interacts with the surface directly.
Some scientists, however, feel that weathering alone isn't enough and that the presence of life is an intrinsic part of any soil.
"The living component of soil is part of its unalienable nature, as is its ability to sustain plant life due to a combination of two major components: soil organic matter and plant nutrients," said Ellen Graber, researcher at the Institute of Soil, Water and Environmental Sciences at The Volcani Center of Israel's Agricultural Research Organization.
One of the primary uses of soil on another planet would be to use it for agriculture—to grow food and sustain any populations that may one day live on that planet. Some scientists, however, are questioning whether soil is really a necessary condition for space farming.
Soilless farming – It's not science fiction
Growing plants without any soil may conjure up images from a "Star Trek" movie, but it's hardly science fiction. Aeroponics, as one soilless cultivation process is called, grows plants in an air or mist environment with no soil and very little water. Scientists have been experimenting with the method since the early 1940s, and aeroponics systems have been in use on a commercial basis since 1983.
"Who says that soil is a preconditiospace-farming-on-other-planets-101125.htmln for agriculture?" asked Graber. "There are two major preconditions for agriculture, the first being water and the second being plant nutrients. Modern agriculture makes extensive use of 'soilless growing media,' which can include many varied solid substrates."
In 1997, NASA teamed up with AgriHouse and BioServe Space Technologies to design an experiment to test a soilless plant-growth system on board the Mir Space Station. NASA was particularly interested in this technology because of its low water requirement. Using this method to grow plants in space would reduce the amount of water that needs to be carried during a flight, which in turn decreases the payload.
Aeroponically-grown crops also can be a source of oxygen and drinking water for space crews.
"I would suspect that if and when humankind reaches the stage of settling another planet or the Moon, the techniques for establishing soilless culture there will be well advanced," Graber predicted.
Alien soil: Key to the past and future
The surface and soil of a planetary body holds important clues about its habitability, both in its past and in its future. For example, examining soil features have helped scientists show that early Mars was probably wetter and warmer than it is currently.
"Studying soils on our celestial neighbors means to individuate the sequence of environmental conditions that imposed the present characteristics to soils, thus helping reconstruct the general history of those bodies," Certini said.
In 2008, NASA's Phoenix Mars Lander performed the first wet chemistry experiment using martian soil. Scientists who analyzed the data said the Red Planet appears to have environments more appropriate for sustaining life than was expected, environments that could one day allow human visitors to grow crops.
"This is more evidence for water because salts are
there," said
Researchers found traces of magnesium, sodium, potassium and chloride, and the data also revealed that the soil was alkaline, a finding that challenged a popular belief that the martian surface was acidic.
This type of information, obtained through soil analyses, becomes important in looking toward the future to determine which planet would be the best candidate for sustaining human colonies.
Broccoli may be key to beating Alzheimer’s
(mailonline.co.uk) – Broccoli could hold the key to beating Alzheimer’s.
Scientists believe that a chemical derived from the vegetable could help keep the brain sharp into old age.
They hope that sulforaphane, which is also made in the body from a compound found in rocket, Brussels sprouts and cabbages, will kick-start the body’s natural defenses.
This will protect vital brain cells from being attacked and destroyed by free radicals - dangerous oxygen molecules produced when food is turned into energy.
Anti-oxidants, such as vitamins C and E, can ‘mop up’ the attackers, but are of limited use in the brain.
The
It is hoped that chemical, which is made when we eat green vegetables, will succeed where other approaches have failed.
They believe that taking the chemical in pill form is likely to be more beneficial than simply eating bowl after bowl of broccoli.
This is because not everyone makes the same amount of sulforaphane, with some people making 10 times less than other despite eating the same amount of greens.
Dr Sharkey said: ‘For some people, eating large amounts of broccoli may have the biological effects we are looking for. But for many people, it won’t.
In a two-year study, Dr Sharkey, an expert in the underlying causes of degenerative brain conditions, plans to see whether the chemical slows, or even halts, the progression of Alzheimer’s in mice genetically engineered to develop the disease.
The preliminary nature of the work means that even if it is successful, any sulforaphane-based drug is at least a decade from the market.
Similar drugs could also help tackle Parkinson’s disease, stroke and even cancer.
Dr Sharkey, who is funded by the charity Alzheimer’s
Research
Alzheimer’s other forms of dementia affect more than 800,000 Britons and the number expected to double in a generation as the population ages.
Existing pills such as Aricept can delay the progress of Alzheimer’s, but their failure to tackle the underlying cause in the brain means that their effect quickly wears off and the disease soon takes its devastating course.
Deborah Bunn’s, whose mother, Patricia, was diagnosed with Alzheimer’s seven years ago, said: ‘Mum is prescribed Aricept and that has really helped her but I would dearly love to see a treatment that could stop the disease in its tracks.’
Canada
(physorg.com) – Following a massive bee die-off in parts of the world, two Canadian universities on Wednesday launched an effort to breed honey bees resistant to pests and diseases.
Led by the universities of
It will also screen new products for pest and disease control, and try to come up with new ways of managing pollination colonies that face risks that include parasites, bacterial infections and pesticides resulting from the impact of human activities on the environment.
The goal is to "help beekeepers secure sustainable honey harvests and provide essential pollination services to the fruit and vegetable industry," the government said in a statement.
Honey bee colony declines in recent years have reached 10 to
30 percent in Europe, 30 percent in the
Honey bees are critical to global agriculture. They pollinate more than 100 different crops, representing up to $83 billion in crop value world wide each year and roughly one-third of the human diet.
"We're looking for bees (for the breeding program) that
are resistant to mites and with a greater tolerance to viruses because these
appear to be the two main factors behind colony loss," Rob Currie, entomology
professor at the
"Hopefully we can keep our bees going by making them stronger."
Currie said the university has had success so far in keeping bee losses down to 40 percent in tests exposing them to diseases, down from 75 percent.
"It's not a total success, but it's a significant improvement and that makes quite a lot of economic difference," he added.
In Ontario, beekeepers' association spokesman Les Eccles said that as part of the research his group would vary the kinds and amounts of food given to bees, as well as the way bees are transported to farms across Canada for pollination, to study how best to care for them.
EU E. coli may have Egyptian seed link
The
The report said "fenugreek seeds imported from
However, further investigation was necessary, said the report.
The death toll in
In
The report said that a 2009 lot of fenugreek seeds appeared
to be implicated in the outbreak in
Many questions were still unanswered about the source of the E. coli.
A further 119 cases have been reported in a total of 15
other countries. The source has been traced to a vegetable sprout farm in
northern
The World Health Organization said it considers an outbreak
in
The report said the clinical picture of the French cases was similar to that of German cases.
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