“People have been discovering components of DNA in meteorites since the 1960′s, but researchers were unsure whether they were really created in space or if instead they came from contamination by terrestrial life,” said Dr. Michael Callahan of NASA’s Goddard Space Flight Center, Greenbelt, Md. “For the first time, we have three lines of evidence that together give us confidence these DNA building blocks actually were created in space.” Callahan is lead author of a paper on the discovery appearing in Proceedings of the National Academy of Sciences of the United States of America.

The discovery adds to a growing body of evidence that the chemistry inside asteroids and comets is capable of making building blocks of essential biological molecules. For example, previously, these scientists at the Goddard Astrobiology Analytical Laboratory have found amino acids in samples of comet Wild 2 from NASA’s Stardust mission, and in various carbon-rich meteorites. Amino acids are used to make proteins, the workhorse molecules of life, used in everything from structures like hair to enzymes, the catalysts that speed up or regulate chemical reactions.

In the new work, the Goddard team ground up samples of twelve carbon-rich meteorites, nine of which were recovered from Antarctica. They extracted each sample with a solution of formic acid and ran them through a liquid chromatograph, an instrument that separates a mixture of compounds. They further analyzed the samples with a mass spectrometer, which helps determine the chemical structure of compounds.

The team found adenine and guanine, which are components of DNA called nucleobases, as well as hypoxanthine and xanthine. DNA resembles a spiral ladder; adenine and guanine connect with two other nucleobases to form the rungs of the ladder. They are part of the code that tells the cellular machinery which proteins to make. Hypoxanthine and xanthine are not found in DNA, but are used in other biological processes.

Also, in two of the meteorites, the team discovered for the first time trace amounts of three molecules related to nucleobases: purine, 2,6-diaminopurine, and 6,8-diaminopurine; the latter two almost never used in biology. These compounds have the same core molecule as nucleobases but with a structure added or removed.

It’s these nucleobase-related molecules, called nucleobase analogs, which provide the first piece of evidence that the compounds in the meteorites came from space and not terrestrial contamination. “You would not expect to see these nucleobase analogs if contamination from terrestrial life was the source, because they’re not used in biology, aside from one report of 2,6-diaminopurine occurring in a virus (cyanophage S-2L),” said Callahan. “However, if asteroids are behaving like chemical ‘factories’ cranking out prebiotic material, you would expect them to produce many variants of nucleobases, not just the biological ones, due to the wide variety of ingredients and conditions in each asteroid.”

The second piece of evidence involved research to further rule out the possibility of terrestrial contamination as a source of these molecules. The team also analyzed an eight-kilogram (21.4-pound) sample of ice from Antarctica, where most of the meteorites in the study were found, with the same methods used on the meteorites. The amounts of the two nucleobases, plus hypoxanthine and xanthine, found in the ice were much lower — parts per trillion — than in the meteorites, where they were generally present at several parts per billion. More significantly, none of the nucleobase analogs were detected in the ice sample. One of the meteorites with nucleobase analog molecules fell in Australia, and the team also analyzed a soil sample collected near the fall site. As with the ice sample, the soil sample had none of the nucleobase analog molecules present in the meteorite.

Thirdly, the team found these nucleobases — both the biological and non-biological ones — were produced in a completely non-biological reaction. “In the lab, an identical suite of nucleobases and nucleobase analogs were generated in non-biological chemical reactions containing hydrogen cyanide, ammonia, and water. This provides a plausible mechanism for their synthesis in the asteroid parent bodies, and supports the notion that they are extraterrestrial,” says Callahan.

“In fact, there seems to be a ‘goldilocks’ class of meteorite, the so-called CM2 meteorites, where conditions are just right to make more of these molecules,” adds Callahan.

The team includes Callahan and Drs. Jennifer C. Stern, Daniel P. Glavin, and Jason P. Dworkin of NASA Goddard’s Astrobiology Analytical Laboratory; Ms. Karen E. Smith and Dr. Christopher H. House of Pennsylvania State University, University Park, Pa.; Dr. H. James Cleaves II of the Carnegie Institution of Washington, Washington, DC; and Dr. Josef Ruzicka of Thermo Fisher Scientific, Somerset, N.J. The research was funded by the NASA Astrobiology Institute, the Goddard Center for Astrobiology, the NASA Astrobiology: Exobiology and Evolutionary Biology Program, and the NASA Postdoctoral Program.

Systems biology is a holistic approach to the study of how a living organism emerges from the interactions of the individual elements that make up its constituent cells. Embracing a broad range of disciplines, this field of science that is just beginning to come into public prominence holds promise for advances in a number of important areas, including safer, more effective pharmaceuticals, improved environmental remediation, and clean, green, sustainable energy. However, the most profound impact of systems biology, according to one of its foremost practitioners, is that it might one day provide an answer to the central question: What is life?

Adam Arkin, director of the Physical Biosciences Division of the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory and a leading computational biologist, is the corresponding author of an essay in the journal Cell which describes in detail key technologies and insights that are advancing systems biology research. The paper is titled “Network News:Innovations in 21st Century Systems Biology.” Co-authoring the article is David Schaffer, a chemical engineer with Berkeley Lab’s Physical Biosciences Division. Both Arkin and Schaffer also hold appointments with the University of California (UC) Berkeley.

“System biology aims to understand how individual elements of the cell generate behaviors that allow survival in changeable environments, and collective cellular organization into structured communities,” Arkin says. “Ultimately, these cellular networks assemble into larger population networks to form large-scale ecologies and thinking machines, such as humans.”

In their essay, Arkin and Schaffer argue that the ideas behind systems biology originated more than a century ago and that the field should be viewed as “a mature synthesis of thought about the implications of biological structure and its dynamic organization.” Research into the evolution, architecture, and function of cells and cellular networks in combination with ever expanding computational power has led to predictive genome-scale regulatory and metabolic models of organisms. Today systems biology is ready to “bridge the gap between correlative analysis and mechanistic insights” that can transform biology from a descriptive science to an engineering science.

Discoveries in systems biology, the authors say, can generally be divided between those that relied on a “mechanistic approach to causal relationships,” and those that relied on “large-scale correlation analysis.” The results of these discoveries can also be categorized according to whether they primarily pertained to the principles behind cellular network organization, or to predictions about the behavior of these networks.

“As systems biology matures, the number of studies linking correlation with causation and principles with prediction will continue to grow,” Schaffer says. “Advances in measurement technologies that enable large-scale experiments across an array of parameters and conditions will increasingly meld these correlative and causal approaches, including correlative analyses leading to mechanistic hypothesis testing, as well as causal models empowered with sufficient data to make predictions.”

As the complete genomes of more organisms are sequenced, and measurement and genetic manipulation technologies are improved, scientists will be able to compare systems across a broader expanse of phylogenetic trees. This, Arkin and Schaffer say, will enhance our understanding of mechanistic features that are necessary for function and evolution.

“The increasing integration of experimental and computational technologies will thus corroborate, deepen, and diversify the theories that the earliest systems biologists used logic to infer,” Arkin says. “This will thereby inch us ever closer to answering the What is Life question.”

The systems biology research cited in this essay by Arkin and Schaffer was supported by DOE’s Office of Science (Biological and Environmental Research), and by the National Institutes of Health.

Walter and Eliza Hall Institute researchers have discovered how a key viral gene helps viruses evade early detection by the immune system. Their finding is providing new insights into how viruses are able to establish chronic infections, leading scientists to reevaluate their approaches to viral vaccine development.

Researchers from the institute’s Immunology division together with collaborators at the University of Cambridge (UK) have been studying how the immune system responds to viruses that cause persistent or chronic infections and why the immune system is unable to eliminate these infections.

Dr Gabrielle Belz, Dr Adele Mount and colleagues are particularly interested in immune system cells called dendritic cells and their interaction with viruses that cause chronic infections.

“Chronic infections are one of the greatest health challenges for the Western world, but currently we have very few ways of dealing with them,” Dr Belz said. “They require ongoing medical care and support due to an inability to treat infection effectively.

“We are trying to understand how chronic infections sneak past the usually highly effective immune armoury and covertly establish disease. If we can stop these infections establishing then we can eliminate, or substantially reduce, that societal burden.”

Dendritic cells, which are studied by Dr Belz, Dr Mount and colleagues, act as ‘sentinels’ of the immune system; they are critical for the early detection of invading bacteria and viruses and are one of the first cells to trigger the immune response. “Dendritic cells are called ‘antigen presenting cells’; they digest infectious agents into small fragments and shuttle these fragments to the outside of the cell where they are displayed to virus-specific killer T cells, helping to launch a full-blown immune response,” Dr Belz said.

The team has been investigating a virus called gamma herpesvirus-68, which establishes chronic infections in mice and provides a model of the workings of the human gamma herpesvirus Epstein-Barr Virus, commonly known to cause infectious mononucleosis, or ‘kissing disease’. Their results, which have been published in the Journal of Immunology, show that a viral gene called K3 rapidly disables the antigen-processing machinery normally used by dendritic cells to alert the immune system to infections.

“This gene quickly helps the virus to hide from the immune system by subverting normal antigen presentation to T cells, which have the critical task of destroying virally-infected cells,” Dr Belz said. “The virus carries out a top-secret operation. It shuts down the normal mechanisms that allow the immune system to recognise an infection and then boards the antigen-presenting cells which ferry the virus through the blood and tissues, allowing it to spread throughout the body and establish system infection.”

Dr Belz said the study could change conventional views on the best way to generate an immune response to combat chronic infections.

“Our research shows that viral evasion of the immune system in chronic infections happens incredibly early,” Dr Belz said. “Dendritic cells are compromised long before they have the chance to interact with T cells for the next phase of the immune response, so the T cells are never really activated properly. If we want to make an effective vaccine, we need to look at these early escape points used by the virus as the first target for trying to generate a more efficient immune response that will contain the virus and prevent it establishing a systemic infection.”

This work was supported by the National Health and Medical Research Council, the Wellcome Trust, the Swiss National Science Foundation, the Sylvia & Charles Viertel Charitable Foundation and the Howard Hughes Medical Institute.

Food should be delicious, healthy and sustainably produced. Researchers are working on new methods to use as many parts of plants as possible for nutrition. In the future, vegetable ingredients could replace animal raw materials. Lupin seeds, for instance, can be used to produce low-fat, exquisite sausage products.

In emerging countries such as China or Brazil, meat consumption is rising dramatically. Indeed, worldwide consumption of red meat has quadrupled since 1961. The United Nations Food and Agriculture Organization (FAO) expects increasing prosperity to lead to a doubling of global meat production by the year 2050. The question is whether our planet, with its limited farmland resources, will still be able to meet all of our needs into the future. Possible solutions for the brewing dilemma are familiar to Dr.-Ing. Peter Eisner of the Fraunhofer Institute for Process Engineering and Packaging IVV in Freising, Germany.

It takes a lot of land to produce meat. “Producing a kilogram of meat consumes between seven and 16 kilograms of grain or soybeans as animal feed,” Eisner reports. “As a result, in the US around 80 percent of grain is fed to livestock.”

Compared to meat production, the cultivation of plants as a food source is considerably less land-intensive. It takes 40 square meters to produce a kilogram of meat, yet that same space could produce 120 kilograms of carrots or 80 kilograms of apples instead. As the researcher points out: “Plants are a source of high-quality foodstuffs, but they can also provide raw materials for technological applications — and are a source of energy.” He demonstrates this in the case of sunflower seeds: up until now, they were used for oil production, their residues serving as low-grade livestock feed. As a result, a 2 ½ -acre parcel of land could be expected to yield around 950 euros. If all of the components were processed and converted to high-quality raw materials for the food, cosmetics and fuel industry, that same parcel would generate some 1770 euros in income.

Plant-based food ingredients can be expected to play a particularly important role as a substitute for raw materials derived from animals. Eisner presented a “milk substitute” made from lupin proteins and suitable as a basis for foods such as ice cream or cheese. It contains no lactose, has a neutral flavor, is cholesterol-free and rich in polyunsaturated fatty acids. Lupin seeds are also the basic ingredient in a new vegetable protein isolate with fat-like properties that has been developed by IVV researcher Daniela Sussmann. A special production method applied to the lupin seed yields a highly viscous protein suspension with a very creamy consistency.

“The microscopic structure of this product resembles that of the fat particles in sausage meat. So you can use it to produce low-fat sausage products that taste just as good as the original,” the researcher added. In sensory tests she investigated whether adding lupin protein could improve the juicy and creamy impression of a low-fat sausage recipe. With success: “By adding 10 percent protein isolate, we were able to markedly improve the fat-like impression of low-fat liverwurst.”

Since sausage products are among the foods with the highest levels of fat, this would certainly be a step in the right direction. On average, a German eats 31 kilograms of sausage products each year. The result: An overweight population and cardiovascular disease. If some of the fat could be replaced with proteins derived from plants, every one would benefit: the consumer by eating less fat, the farmer through higher in come, and the environment because plants can be produced more sustainably than meat.

Researchers are creating a new type of solar cell designed to self-repair like natural photosynthetic systems in plants by using carbon nanotubes and DNA, an approach aimed at increasing service life and reducing cost.

“We’ve created artificial photosystems using optical nanomaterials to harvest solar energy that is converted to electrical power,”said Jong Hyun Choi, an assistant professor of mechanical engineering at Purdue University.

The design exploits the unusual electrical properties of structures called single-wall carbon nanotubes, using them as “molecular wires in light harvesting cells,” said Choi, whose research group is based at the Birck Nanotechnology and Bindley Bioscience centers at Purdue’s Discovery Park.

“I think our approach offers promise for industrialization, but we’re still in the basic research stage,” he said.

Photoelectrochemical cells convert sunlight into electricity and use an electrolyte — a liquid that conducts electricity — to transport electrons and create the current. The cells contain light-absorbing dyes called chromophores, chlorophyll-like molecules that degrade due to exposure to sunlight.

“The critical disadvantage of conventional photoelectrochemical cells is this degradation,” Choi said.

The new technology overcomes this problem just as nature does: by continuously replacing the photo-damaged dyes with new ones.

“This sort of self-regeneration is done in plants every hour,” Choi said.

The new concept could make possible an innovative type of photoelectrochemical cell that continues operating at full capacity indefinitely, as long as new chromophores are added.

Findings were detailed in a November presentation during the International Mechanical Engineering Congress and Exhibition in Vancouver. The concept also was unveiled in an online article (http://spie.org/x41475.xml?ArticleID=x41475) featured on the Web site for SPIE, an international society for optics and photonics.

The talk and article were written by Choi, doctoral students Benjamin A. Baker and Tae-Gon Cha, and undergraduate students M. Dane Sauffer and Yujun Wu.

The carbon nanotubes work as a platform to anchor strands of DNA. The DNA is engineered to have specific sequences of building blocks called nucleotides, enabling them to recognize and attach to the chromophores.

“The DNA recognizes the dye molecules, and then the system spontaneously self-assembles,” Choi said

When the chromophores are ready to be replaced, they might be removed by using chemical processes or by adding new DNA strands with different nucleotide sequences, kicking off the damaged dye molecules. New chromophores would then be added.

Two elements are critical for the technology to mimic nature’s self-repair mechanism: molecular recognition and thermodynamic metastability, or the ability of the system to continuously be dissolved and reassembled.

The research is an extension of work that Choi collaborated on with researchers at the Massachusetts Institute of Technology and the University of Illinois. The earlier work used biological chromophores taken from bacteria, and findings were detailed in a research paper published in November in the journal Nature Chemistry (http://www.nature.com/nchem/journal/v2/n11/abs/nchem.822.html).

However, using natural chromophores is difficult, and they must be harvested and isolated from bacteria, a process that would be expensive to reproduce on an industrial scale, Choi said.

“So instead of using biological chromophores, we want to use synthetic ones made of dyes called porphyrins,” he said.

The emerging tidal-energy industry is spawning another in its shadow: tidal-energy monitoring. Little is known about tidal turbines’ environmental effects and environmentalists, regulators and turbine manufacturers all need more data to allow the industry to grow.

Engineers at the University of Washington have developed a set of numerical models, solved by computers, to study how changing water pressure and speed around turbines affects sediment accumulation and fish health. They will present their findings this week at the American Geophysical Union’s meeting in San Francisco.

The current numerical models look at windmill-style turbines that operate in fast-moving tidal channels. The turbine blade design creates a low-pressure region on one side of the blade, similar to an airplane wing. A small fish swimming past the turbine will be pulled along with the current and so will avoid hitting the blade, but might experience a sudden change in pressure.

Teymour Javaherchi, a UW mechanical engineering doctoral student, says his model shows these pressure changes would occur in less than 0.2 seconds, which could be too fast for the fish to adapt.

If the pressure change happens too quickly the fish would be unable to control their buoyancy and, like an inexperienced scuba diver, would either sink to the bottom or float to the surface. During this time the fish would become disoriented and risk being caught by predators. In a worst-case scenario, severe pressure changes could cause internal hemorrhaging and death.

It’s too early to say whether tidal turbines could harm fish in this way, Javaherchi said. The existing model uses the blade geometry from a wind turbine.

“The competition between the companies is very tight and they are hesitant to share the designs,” Javaherchi said.

The researchers are open to working with any company that wants to use the technique to assess a particular turbine design.

Another set of numerical modeling looked at whether changes in speed of water flow could affect the settling of suspended particles in a tidal channel. Slower water speeds behind the turbine would allow more particles to sink to the bottom rather than being carried along by the current.

Javaherchi’s modeling work suggests this is the case, especially for mid-sized particles of about a half-centimeter in diameter, about two-tenths of an inch. This would mean that a rocky bottom near a tidal turbine might become sandier, which could affect marine life.

The UW research differs from most renewable energy calculations that seek to maximize the amount of energy generated.

“We are [also] interested in the amount of energy that can be extracted by the turbines, but we are aware that the limiting factor for the development of these technologies is the perception by the public that they might have a big environmental impact,” said Alberto Aliseda, a UW assistant professor of mechanical engineering and Javaherchi’s thesis adviser.

As to whether any negative effects discovered for tidal turbines would be preventable, Aliseda said, “Absolutely.”

“We need to establish what is the lowest pressure that the animals can sustain and the period of time that they need to adjust,” Aliseda said. “The blade can be shaped to minimize this effect.”

Aliseda says engineers in the wind-turbine industry are already adapting the UW work to look at interactions between wind turbines and bats, since high-frequency pressure changes are now thought to be responsible for the mysterious deaths of bats caused by wind turbines.

“Maybe the best turbine is not the one that extracts the most energy, but the one that extracts a reasonable amount of energy and at the same time minimizes the environmental effects,” he said.

The research was funded by a Department of Energy grant to the Northwest National Marine Renewable Energy Center. Joseph Seydel, a Boeing engineer and UW graduate in mechanical engineering, also contributed to the research.

The first in-depth national study of wild bees in the U.S. has uncovered major losses in the relative abundance of several bumble bee species and declines in their geographic range since record-keeping began in the late 1800s.

The researchers report that declining bumble bee populations have lower genetic diversity than bumble bee species with healthy populations and are more likely to be infected with Nosema bombi, an intracellular parasite known to afflict some species of bumble bees in Europe.

The new study appears this week in the Proceedings of the National Academy of Sciences.

“We have 50 species of bumble bees in North America. We’ve studied eight of them and four of these are significantly in trouble,” said University of Illinois entomology professor Sydney Cameron, who led the study. “They could potentially recover; some of them might. But we only studied eight. This could be the tip of the iceberg,” she said.

The three-year study analyzed the geographic distribution and genetic diversity of eight species of bumble bees in the U.S., relying on historical records and repeated surveys of about 400 sites. The researchers compiled a database of more than 73,000 museum records and compared them with current sampling based on intensive national surveys of more than 16,000 specimens.

The national analysis found that the relative abundances of four of the eight species analyzed have declined by as much as 96 percent and that their surveyed geographic ranges have shrunk by 23 to 87 percent. Some of these contractions have occurred in the last two decades.

Researchers have many hypotheses about what is causing the declines, but none have been proven, Cameron said. Climate change appears to play a role in the declines in some bumble bee species in Europe, she said. Habitat loss may also contribute to the loss of some specialist species, she said. Low genetic diversity and high infection rates with the parasite pathogen are also prime suspects.

“Whether it’s one of these or all of the above, we need to be aware of these declines,” Cameron said. “It may be that the role that these four species play in pollinating plants could be taken up by other species of bumble bees. But if additional species begin to fall out due to things we’re not aware of, we could be in trouble.”

Regularly drinking green tea could protect the brain against developing Alzheimer’s and other forms of dementia, according to latest research by scientists at Newcastle University.

The study, published in the academic journal Phytomedicine, also suggests this ancient Chinese remedy could play a vital role in protecting the body against cancer.

Led by Dr Ed Okello, the Newcastle team wanted to know if the protective properties of green tea — which have previously been shown to be present in the undigested, freshly brewed form of the drink — were still active once the tea had been digested.

Digestion is a vital process which provides our bodies with the nutrients we need to survive. But, says Dr Okello, it also means that just because the food we put into our mouths is generally accepted to contain health-boosting properties, we can’t assume these compounds will ever be absorbed by the body.

“What was really exciting about this study was that we found when green tea is digested by enzymes in the gut, the resulting chemicals are actually more effective against key triggers of Alzheimer’s development than the undigested form of the tea,” explains Dr Okello, based in the School of Agriculture, Food and Rural Development at Newcastle University.

“In addition to this, we also found the digested compounds had anti-cancer properties, significantly slowing down the growth of the tumour cells which we were using in our experiments.”

As part of the research, the Newcastle team worked in collaboration with Dr Gordon McDougall of the Plant Products and Food Quality Group at the Scottish Crop Research Institute in Dundee, who developed technology which simulates the human digestive system.

It is this which made it possible for the team to analyse the protective properties of the products of digestion.

Two compounds are known to play a significant role in the development of Alzheimer’s disease — hydrogen peroxide and a protein known as beta-amyloid.

Previous studies have shown that compounds known as polyphenols, present in black and green tea, possess neuroprotective properties, binding with the toxic compounds and protecting the brain cells.

When ingested, the polyphenols are broken down to produce a mix of compounds and it was these the Newcastle team tested in their latest research.

“It’s one of the reasons why we have to be so careful when we make claims about the health benefits of various foods and supplements,” explains Dr Okello.

“There are certain chemicals we know to be beneficial and we can identify foods which are rich in them but what happens during the digestion process is crucial to whether these foods are actually doing us any good.”

Carrying out the experiments in the lab using a tumour cell model, they exposed the cells to varying concentrations of the different toxins and the digested green tea compounds.

Dr Okello explained: “The digested chemicals protected the cells, preventing the toxins from destroying the cells.

“We also saw them affecting the cancer cells, significantly slowing down their growth.

“Green tea has been used in Traditional Chinese medicine for centuries and what we have here provides the scientific evidence why it may be effective against some of the key diseases we face today.”

The next step is to discover whether the beneficial compounds are produced during digestion after healthy human volunteers consume tea polyphenols. The team has already received funding from the Biotechnology and Biological Sciences Research Council (BBSRC) to take this forward.

Dr Okello adds: “There are obviously many factors which together have an influence on diseases such as cancer and dementia — a good diet, plenty of exercise and a healthy lifestyle are all important.”

Penguin biologists from around the world, who are gathered in Boston the week of September 6, warn that ten of the planet’s eighteen penguin species have experienced further serious population declines. The effects of climate change, overfishing, chronic oil pollution and predation by introduced mammals are among the major factors cited repeatedly by penguin scientists as contributing to these population drops. Prior to the conference, thirteen of these penguin species were already classified as endangered or threatened. Some penguin species may face extinction in this century.

More than 180 penguin biologists, government officials, conservation advocates, and zoo and aquarium professionals from 22 nations have convened in Boston for the five day International Penguin Conference, which is being hosted this year by the New England Aquarium. The conference is held every three to four years, and this is the first time that it has been held in the Northern Hemisphere.

Penguins are found exclusively in the Southern Hemisphere with a single species on the Galapagos Islands at the Equator to four Antarctic penguin species that are most well known to the public, yet 13 other species also live in South America, southern Africa, Australia, New Zealand, and on the many sub-Antarctic islands. Throughout their ranges, nearly all of penguin species are in significant decline or under duress due to a host of common factors.

Climate Change Concerns

The effects of climate change on different penguin species has been the topic of many of the scientists’s papers and presentations. Many penguin species are highly dependent on small schooling fish for food. These masses of anchovies, sardines and other small finfish are seasonally brought to many penguin habitats by cold water currents. In years with El Nino events in the Pacific, there has been a dramatic warming of sea surface temperatures which effectively blocked cold water currents coming up the western coast of South America. Consequently, Galapagos penguins and Humboldt penguins, which are found on the coasts of Peru and Chile, have suffered due to reduced food availability, which principally affects the survival of the young. Galapagos penguins stand a 30% probability of becoming extinct in this century and Humboldt penguins have been classified by the Peruvian government as endangered.

Earlier this year, African penguins, found in Namibia and South Africa, were reclassified internationally as endangered as many breeding colonies in the western part of their range have disappeared. Important food bearing cold water currents have shifted and are now routinely found much further offshore. The increased roundtrip commuting distance for African penguins to obtain food has been devastating to their population.

Scientists are closely watching the potential effects on several Antarctic penguin species that are highly dependent on the presence of sea ice for breeding, foraging and molting. Emperor penguins, which were the subject of “March of the Penguins,” could see major population declines by 2100, if they do not adapt, migrate and change the timing of their growth stages.

Adelie penguin colonies in the Antarctic’s Ross Sea have coped for several years with two super-sized icebergs that have grounded there and created an enormous physical barrier. It has resulted in lower breeding rates and the migration of many animals out of the area.

Sea ice also creates an important nursey cover for juvenile krill which feed on ice algae. Krill is the primary fuel at the base the Antarctic food chain. Reduced sea ice cover has led to a dramtic decline in krill and will likely lead to a decline in many wildlife populations further up the food chain that relies on krill as its foundation food source.

The effects of climate change on penguins are very real. Many environmental conditions are changing and much less predictable. For penguins living in harsh conditions, the ability to properly time when to migrate, nest, mate and seek food are critical decisions often with a very small margin for error, both for both individual animals and entire species.

Overfishing and Bycatch

As fishing efforts around the globe have multipled several fold over the last few decades, penguins are now competing with people for enough food. The large scale harvesting of anchovy and sardine stocks have directly reduced the prey available to many penguin species including Macaroni and Chinstrap penguins in the South Atlantic. Combined with the effects of climate change on the locations of fish stocks, reduced food availability leads to higher starvation rates, increased vulnerabilty to disease and lower breeding success.

Thousands of penguins are also killed annually when caught in fixed fishing nets.

Chronic Oiling

Large scale oil spills make worlwide headlines, but chronic petroleum pollution has killed thousands of penguins particularly off the coasts of South America and South Africa. The most common sources are illegal operational dumping from ships, long term leaks from sunken ships and some land-based discharges. Better legislation and law enforcement efforts can yield positive results. The incidence of oiling of Magellanic penguins off the coast of Argentina has decline signficantly in recent years due to increased public awareness and enforcement.

Introduced Mammalian Predators

Many penguin species evolved in extremely remote settings devoid of any mammal predators.. Prior to the arrival of humans, New Zealand’s only mammals were bats. Now, introduced weasels have had a large impact on the the small populations of Yellow-Eyed and Fiordland penguins. In Australia and Argentina, the arrival of foxes have had impacts while feral cats in the Galapagos have reduced penguin populations there.

The goal of the 7th International Penguin Conference is to present ongoing research, identify current and emerging conservations issues and create action plans that will help create a strategic global effort on behalf of these threatened species.

Trypanosomes are parasites responsible for many human and animal diseases, primarily in tropical climates. One disease these parasites cause, African sleeping sickness, results from the bite of infected tsetse flies, putting over 60 million Africans at risk in 36 sub-Saharan countries. The recent 1998-2001 sleeping sickness epidemics in South Sudan, Angola, Democratic Republic of Congo and Uganda killed tens of thousands of people and resulted in over a half million infected individuals.

A team of researchers at the University of Georgia and Glasgow University has now shown, for the first time, just how one species of these parasites evades the human innate defenses. The finding could open the way for new classes of drugs and more in-depth studies about how parasites manage to kill so many and cost governments billions of dollars to fight.

“We believe this research represents a paradigm shift and causes us to think more broadly about how pathogens avoid host defense mechanisms,” said Stephen Hajduk, professor and head of the department of biochemistry and molecular biology at UGA and one of the leaders of the research. “It turns out that African trypanosomes have evolved a diversity of ways to avoid human innate and acquired immune systems.”

The research, published in the Proceedings of the National Academy of Sciences, was a joint effort between UGA and a group led by Annette Macleod at the University of Glasgow in Scotland. Other authors of the paper include Rudo Kieft, a research professional in Hajduk’s lab at UGA; Paul Capewell and Nicola Veitch in the Macleod lab in Wellcome Center for Molecular Parasitology in Glasgow; and Michael Turner of the Biomedical Research Center at the University of Glasgow. The department of biochemistry and molecular biology at UGA is part of the Franklin College of Arts and Sciences. Hajduk also is a member of the Center for Tropical and Emerging Global Diseases at UGA.

The need for a clearer understanding of how these parasites evade human immune systems is at the heart of a serious public health problem, Hajduk said. During the recent epidemics of African sleeping sickness, as many as half the occupants in some African villages were infected with trypanosomes. The geographical isolation of these villages and ongoing civil wars contributed to what many believe were the worst epidemics of sleeping sickness in five decades.

This led to the realization that many of the existing therapies now available to fight African sleeping sickness are often ineffective and have extreme toxicity, frequently causing death. Additionally, there is increasing evidence that while new therapeutics may cure the disease, long-lasting neurological damage can be caused by infection.

The World Health Organization reports that the recent introduction of aggressive population screening in rural areas and distribution of more effective drugs has dramatically reduced the number of deaths, however.

Several species of African trypanosomes infect non-primate mammals and cause important veterinary disease yet are unable to infect humans. The trypanosomes that cause human disease, Trypanosoma brucei gambiense and T. b. rhodensiense, have evolved mechanisms to avoid the native human defense molecules in the circulatory system that kill the parasites that cause animal disease.

Two of the major challenges faced by scientists studying human sleeping sickness have been the identification of the naturally occurring human defense molecules that are active against the trypanosomes causing animal disease, and the identification of the strategies used by the human sleeping sickness parasites to avoid the action of these molecules.

Human innate immunity against most African trypanosomes is mediated by a subclass of HDL (high density lipoprotein, which people know from blood tests as “good cholesterol”) called trypanosome lytic factor-1, or TLF-1. This minor subclass of human HDL further contains two proteins, apolipoprotein L-1 and haptoglobin-related protein, which are only found in primates. These proteins work together, in the lipid environment of the HDL particle, as a specific and highly active toxin against the trypanosomes that infect non-primate mammals. Despite its activity against some African trypanosomes, the toxin is completely nontoxic to the human sleeping sickness parasites.

The parasite that causes fast-onset, acute sleeping sickness in humans, T. b. rhodensiense, is able to cause disease because it has evolved an inhibitor of TLF-1 called Serum Resistance Associated (SRA) protein. Another species, T. b. gambiense, causes slow onset, chronic sleeping sickness and is responsible for over 95 percent of the human deaths caused by these parasites. Until the just-published research by Hajduk, Macleod and their colleagues, nothing was known about TLF-1 resistance in T. b. gambiense. Hajduk and Macleod report, for the first time, that T. b. gambiense resistance to TLF-1 is caused by a marked reduction of TLF-1 uptake by the parasite.

So how is this happening?

To survive in the bloodstream of humans, these parasites have apparently evolved mutations in the gene encoding a surface protein receptor. These mutations result in a receptor with decreased TLF-1 binding, leading to reduced uptake and thus allow the parasites to avoid the toxicity of TLF-1.

“Humans have evolved TLF-1 as a highly specific toxin against African trypanosomes by tricking the parasite into taking up this HDL because it resembles a nutrient the parasite needs for survival,” said Hajduk, “but T. b. gambiense has evolved a counter measure to these human ‘Trojan horses’ simply by barring the door and not allowing TLF-1 to enter the cell, effectively blocking human innate immunity and leading to infection and ultimately disease.”

The parasite may pay a price for blocking the uptake of a nutrient, but still the strategy works and the parasite can infect humans. Now that researchers know how the parasite survives, this may provide an intervention target that could keep the parasites from evading the human defense system. The result could be a newly strengthened innate defense system that halts the parasites in their paths.

The research was supported by grants from the National Institutes of Health and the Burroughs-Wellcome Fund.