Bones are common sites for the spread, or metastasis, of breast cancer. Scientists here found that women treated for stage II/III breast cancer who also received a bone strengthening drug were less likely to have breast tumor cells growing in their bones after three months. The bone-strengthening drug used was zoledronic acid, a drug that decreases bone turnover and reduces bone fractures in patients with osteoporosis.

The findings will be reported June 3 at 11 a.m. CT at the 2008 American Society of Clinical Oncology Annual Meeting in Chicago.

"Tumor cells are continually being released from the primary tumor," says lead author Rebecca Aft, M.D., Ph.D., associate professor of surgery, faculty member of the Siteman Cancer Center and a Washington University breast surgeon at Barnes Jewish Hospital. "It is thought that the bone marrow harbors these cells and that these cells are likely to evolve into metastatic disease. We think that zoledronic acid changes the bone marrow so that cancer cells are unable to lodge there."

The researchers randomly assigned 120 women being treated for clinical stage II/III breast cancer to receive 4 milligrams of zoledronic acid intravenously every three weeks for one year, starting with their first cycle of chemotherapy, or to receive no zoledronic acid. Stage II/III cancer means the primary tumor has spread into lymph nodes or other areas near the breast.

At the time of diagnosis, none of the patients had evidence of metastatic disease on computed tomography (CT) and/or positron emission tomography (PET) scans. But bone marrow samples showed that about 40 percent of the patients had detectable breast tumor cells in the bone marrow.

Prior research has shown that women with even minuscule clusters of breast tumor cells — called micrometastases — in their bone marrow at the time of their diagnosis have an increased risk of developing large metastatic tumors later.

The researchers took bone marrow samples again three months and one year after treatment began. Only 23 percent of women who got zoledronic acid had tumor cells after three months compared to 36 percent of those who didn't get the drug. This result did not reach statistical significance.

Of women who started with no tumor cells in their bone marrow, 88 percent remained free of tumor cells in their bone marrow if they got zoledronic acid, compared to 70 percent of those who did not receive the drug. This result approached statistical significance. The one-year results are not yet available.

Aft says that women who receive chemotherapy for breast cancer have increased rates of bone turnover, which can release growth factors and produce a favorable environment for cancer cells. The suppression of bone turnover by zoledronic acid or other bisphosphonate drugs could make bones less friendly surroundings for cancer.

"We found that patients who are negative for tumor cells in bone marrow have a very good chance of staying negative if they take zoledronic acid," Aft says. "If longer follow up shows that women without tumor cells in their bones do not go on to develop metastatic disease, then it would be reasonable to say that bisphosphonates will likely benefit women with locally advanced breast cancer."

Everyone who has an e-mail account has probably received a forwarded chain letter promising good luck if the message is forwarded on to others--or terrible misfortune if it isn't. The sheer volume of forwarded messages such as chain letters, online petitions, jokes and other materials leads to a simple question--how do these messages reach so many people so quickly?

New research into these forwarded missives by Jon Kleinberg of Cornell University and David Liben-Nowell of Carleton College suggests a surprising explanation.

In the past three decades, as more and more individuals have come online and begun using e-mail, the number of these mass-forwarded messages has grown substantially, reaching more and more people each year. It had been assumed that the messages traveled to e-mail users in much the same way that a disease spreads in an epidemic--people received the messages and passed them on to those they came in contact with, who, in turn, spread them to people they encountered, and so on. In recent years, some scientists, as well as marketers, have used the term, "viral," to describe this pattern.

Kleinberg and Liben-Nowell decided to study exactly how some selected messages were disseminated through the Internet. In a research study supported by the National Science Foundation--along with Google, Yahoo and the MacArthur Foundation--the researchers looked at two e-mail petitions that circulated within the past 10 years. One petition in support of public radio began circulating in 1995, and the other, in opposition to the U.S. invasion of Iraq, originated in 2002. The messages had the common characteristic of being widely circulated--the researchers were able to find 316 copies of the public radio petition containing more than 13,000 signatures, and 637 copies of the Iraq petition with almost 20,000 signatures.

Using this data, the researchers mapped out how these messages traveled from recipient to recipient on a tree diagram. A careful analysis of the diagram challenges some of the common assumptions about how messages spread, including the viral contagion theory. Rather than spreading like a virus, with each message producing many direct "descendents" in the tree diagram, the data suggest that people are selective in forwarding messages to others in their social networks. For example, the researchers discovered that 90 percent of the time, the messages produced only a single descendent.

These messages also rarely took the most direct route between two inboxes, even when two people were connected by a few degrees of separation. "The chain letters themselves often got to people by highly circuitous routes," Kleinberg explains. "You could be six steps away from someone, and yet the chain letter could pass through up to 100 intermediaries before showing up in your inbox."

Many e-mail users know it is not uncommon to receive these types of messages multiple times from different people. The results of this study suggest that since most individuals belong to different social circles, it is not uncommon to receive a message more than once. For example, a college student may receive a petition about a tuition increase from a classmate one day, from the president of a fraternity or sorority the next day, and from a cousin the following day.

Kleinberg and Liben-Nowell's research suggests that these messages travel in a less direct and more diffuse pattern than was previously assumed. It also means that messages can reach some groups of people very quickly and take a relatively longer period of time to reach others, creating opportunities for the original message to be altered or abbreviated. This insight has potential implications for scholars in computer networking, sociology, marketing, political science and other fields. "All of this adds up," Kleinberg says, "to cause a much more complex picture of how this information flows though social networks."

Having visually distinct top-level domain names may help avoid confusion in navigating the ever-expanding Internet and combat fraud, by reducing the potential to create malicious look-alikes: .C0M with a zero instead of .COM, for instance.

Later this year, the Internet Corporation for Assigned Names and Numbers (ICANN) plans to launch the process for proposing a new round of “generic” top-level domains (gTLDs), strings such as .net, .gov and .org meant to indicate organizations or interests. In preparing for newly proposed gTLDs, ICANN reached out to various algorithm developers, including NIST’s Paul E. Black, as among those engaged to “provide an open, objective, and predictable mechanism for assessing the degree of visual confusion” in gTLDs.

Black’s algorithm compares a proposed gTLD with other TLDs and generates a score based on their visual similarities. For example, the domain .C0M scores an 88 percent visual similarity with the familiar .COM. The resulting scores may help indicate whether the newly proposed domain name looks too much like existing ones.

To make its assessments, the algorithm rates the degree of similarity between pairs of alpha-numeric characters. Some pairs, such as the numeral “1” and its dead-ringer, the lowercase letter “l,” are assigned the highest scores for visual similarity while other pairs, such as “h” and “n”, are given lower scores. The algorithm takes other considerations into account, for example how certain pairs of letters, like “c” and “l,” can join to look like a third letter (“d”), as in the case of “close” and “dose.” Employing these scores and considerations, the algorithm computes the “cost” of transforming one string of characters into another, such as “opel” into “apple.” Lower cost means higher visual similarity. The algorithm then adjusts for the relative lengths of the two strings (different lengths increase their distinctiveness) and converts the final cost into a percent similarity.

ICANN is considering future enhancements to the algorithm, such as having it check for visual confusion between existing domains and future planned Internet top-level domain names in scripts such as Cyrillic.

Salt causes the deterioration of historical artifacts
Scientists are fine-tuning the composition of cellulose poultices to maximize the extraction of salt from historical monuments.

The porosity of the various materials used throughout history to construct buildings and sculptures make them susceptible to salt absorption at rates which vary depending on geography, temperature, weather, and soil.

Salt carried by water and moisture are absorbed into the materials and deposited deep into the structures once the water evaporates. Over time, the salt reacts with the materials and compromises their strength and accelerates decay.

In a study of mice, where animals breathed air as polluted as the air in New York City, researchers showed that urban pollution may be as dangerous or even more dangerous than breathing second-hand smoke.

Traditionally, the cleanliness of a beach is monitored by sampling the bathing water a few meters from shore. But since sand is an effective filter, it follows that fecal bacteria (those from sewage) may be concentrated in the sand as the tide flows and ebbs. Moreover, trapped bacteria are offered a large surface area for attachment, nourishment from nutrients in sand crevices, and protection from sunlight. These bacteria might be afforded greater survival opportunities and may even be nourished enough to replicate in the beach environment. Dr. Andrew Rogerson, formally of the Oceanographic Center of Nova Southeastern University, Florida, headed an Environmental Protection Agency study to determine the levels of fecal-derived bacteria in Florida beach sand and look for health implications. Early results showed that wet sand (in the intertidal zone) and dry sand above the intertidal zone had significantly more fecal bacteria than near-shore seawater. This lead to the question– do indicator bacteria survive longer in sand relative to open water? A series of laboratory experiments were conducted to answer this question and the results are presented in the May-June issue of Journal of Environmental Quality.

All the feces-derived bacteria (i.e. traditional indicators of sewage contamination) were capable of enhanced survival in sand and, more importantly, were capable of growth in the sand leading to much higher numbers. Conversely, in seawater the bacteria steadily decreased in number over time. Results also showed a rapid drop off in bacterial numbers in bathing water sampled close to the sand compared with 5, 10 or 20 m from shore. This indicates that the shoreline water is affected by bacterial run-off from the sand.

This has implications for beach managers since the number of bacteria from feces (fecal bacteria) in the water is used to assess the presence of sewages. A high count of these ‘indicator bacteria’ would require the beach to be closed, an action with financial consequences in tourist rich regions such as Florida. Any bacteria washed from the sand complicates the interpretation of counts in the water and could lead to unnecessary beach closures. On the other hand, high numbers of fecal-derived bacteria growing in the sand could constitute an increased health risk.

The authors suggest that water quality managers should consider sampling water further from shore than is routinely practiced (say 10 m from the swash zone) to avoid the complications of bacteria being washed from sand. However, further studies are required to determine whether these higher counts pose a health hazard to bathers. The results of a beach questionnaire designed to look for incidences of illness after beach use were inconclusive.

To prepare for a return to the moon, researchers with the National Space Biomedical Research Institute (NSBRI) are evaluating how dust deposits in the lungs in reduced gravity in order to assess the health risk of long-term exposure to the particles. The findings will influence the design of lunar bases and could also provide benefits for healthcare on Earth, such as improved delivery of aerosol medications to the lungs.

NSBRI Human Factors and Performance Team researcher Dr. Kim Prisk said there are major questions that need to be answered. “In the big picture, the questions are: How much goes into the lung? Where does it go? How long does it stay? And how nasty is the stuff?” said Prisk, who is an adjunct professor in the Department of Medicine at the University of California, San Diego.

During the Apollo lunar missions in the late 1960s and 1970s, the clingy particles were easily transported via spacesuits into the lunar lander following moonwalks. The amount of dust inside the vehicle was so great some astronauts reported they could smell it.

Even though there were no known illnesses due to exposure, lunar dust is a concern because it has properties comparable to that of fresh-fractured quartz, a highly toxic substance. However, the Apollo flights lasted only a few days. During the proposed return to the moon, astronauts will be exposed to lunar dust for longer periods of time, including missions that could last months.

Due to the moon’s reduced gravity and the size of its dust particles, the respiratory system’s process to remove unwanted matter may not work as efficiently as it does on Earth. “In the moon’s fractional gravity, particles remain suspended in the airways rather than settling out, increasing the chances of distribution deep in the lung, with the possible consequence that the particles will remain there for a long period of time,” Prisk said.

The lungs are a highly sensitive organ because of the large surface area that delivers oxygen molecules through a thin membrane directly to the blood. The health risk to astronauts increases as dust particles go deeper into the lungs.

To conduct the research, scientists take measurements during flights on NASA’s Microgravity Research Aircraft. These airplanes are used to provide short periods of reduced- and zero-gravity during a series of steep climbs and descents.

“During the portions of the flight in which gravity is reduced to levels seen on the lunar surface, we inject particles into a mouthpiece through which the study participants breathe,” Prisk said. “Subjects breathe in and out, and we measure how the particles behave and how many end up inside the lung.”

Prisk said the research flights have been beneficial so far. “With the reduced-gravity flights, we’re improving the process of assessing environmental exposure to inhaled particles,” he said. “We’ve learned that tiny particles (less than 2.5 microns) which are the most significant in terms of damage, are greatly affected by alterations in gravity.”

The next step is to investigate the risks and determine ways to limit exposure. The severity of the risks will determine the level of engineering work needed to limit exposure to lunar dust, which also can cause problems for equipment.

As for benefits on Earth, the research could give scientists a better understanding of how the lungs work, improving the understanding of how particles distribute within the lungs.

“If we learn how to target drugs to specific areas inside the lung, it will be possible to achieve optimal results with small quantities of drugs delivered to exactly the right place in the lung, and it will minimize side effects,” Prisk said.

These processes are implicated in diseases such as cancers and autophagy has recently been shown to be involved in degenerative neurological disorders such as Alzheimer's and Huntington's diseases. The discovery will fill gaps in basic knowledge about the workings and evolutionary origins of the living cell and provide new avenues to explore in linking these fundamental processes to human disease.

The study was led by Stephen Michnick, a Université de Montréal biochemistry professor and Canada Research Chair in Integrative Genomics, along with Université de Montréal co-first authors: Kirill Tarassov, Vincent Messier, Christian Landry and Stevo Radinovic. Collaborators from McGill’s Department of Biology included Canadian genomics pioneer Prof. Howard Bussey and Prof. Jackie Vogel.

“Our team systematically analyzed the interactions of proteins of bakers yeast, a unicellular organism confirmed to provide insight into fundamental processes shared by most living cells including those of humans,” explained Prof. Michnick.

The examination of protein complexes was made possible by a unique technology developed by Prof. Michnick with his post-doctoral fellows and graduate students. The novel technology allows interactions between proteins to be studied in their nearly natural state in the cell. With this technology, the scientists performed approximately 15 million pair-wise tests to identify about 3,000 interactions between protein pairs.

Since protein-to-protein association largely defines their function, this is a major advancement towards scientific understanding of the inner life of human cells. Thanks to Prof. Michnick’s technology, the researchers also uncovered the architecture of protein complexes – key information necessary to determine how proteins work together to orchestrate complex biochemical processes.

“The technologies and resources developed for this study can be applied to investigate protein networks in more complex organisms including crop plant and human cells,” said Prof. Michnick. “They may also be used to link multiple genes implicated in complex human diseases to common cellular processes. What’s more, applications to diagnostic tests and the development of drugs and antibodies against human cancers can be readily envisioned.”

Artist's impression of HD 189733b

By identifying the "chemical fingerprints" -- organic molecules found in a planet's environment -- scientists can begin to locate "habitable zones" in exoplanets (planets outside our solar system). These zones are defined by their chemical composition, temperature, and pressure, all of which are necessary for the possibility of life.

The detection of water and methane in the atmosphere of the Jupiter-sized gas giant, HD 189733 b, may open the door to a deeper and more localized analysis of other more promising exoplanetary environments, scientists say.

In the Cerrado region of Brazil, four dogs trained to detect animal feces by scent are helping researchers monitor rare and threatened wildlife such as jaguar, tapir, giant anteater and maned wolf in and around Emas National Park, a protected area with the largest concentration of threatened species in Brazil.

The researchers analyze feces found by the dogs to learn about where and how the threatened mammals live. Data such as numbers, range, diet, hormonal stress, parasites and even genetic identity contribute to a study of how the mammals use environments inside and outside the park, especially on privately owned lands of the region.

The information helps develop conservation and development strategies that meet the needs of both the animals and local farmers. The dogs are rewarded for their good work with tennis balls to chase and chomp.

The project is led by Carly Vynne of the Center for Conservation Biology at the University of Washington as part of her doctoral thesis, in partnership with Conservation International (CI) Brazil.

After a brief pilot study in 2004, research began in 2006 in a 3,000-square-kilometer (equivalent to 300,000 soccer fields) area in the western portion of Emas National Park and surrounding farms in Mato Grosso do Sul state and Goiás state.

Now nearing conclusion, the project’s analysis of feces samples shows that all the species studied use the area surrounding the park, but that farms with less than 30 percent of natural vegetation cover have fewer endangered mammals. Jaguar, however, rarely moved outside the protected park into the more deforested surrounding farmland, as they require the healthy ecosystems of conserved environments. According to Vynne, preservation of open grasslands should be a priority for maned wolf, giant anteater and giant armadillo since these species prefer open areas of park but there is very little open area under protection outside the park.

“The data and results serve as a warning to develop conservation strategies for the restoration of degraded areas in the region, both to conserve healthy ecosystems and biodiversity,” Vynne said.

Brazil’s Cerrado region, a wooded grassland that is one of the world’s 34 biodiversity hotspots, already has lost 60 percent of its original area to deforestation and continues to disappear at twice the rate of the neighboring Amazon forest. Such deforestation leaves protected national parks as savanna islands surrounded by agricultural fields, noted Ricardo Machado, director of the Cerrado-Pantanal Program of CI-Brazil. Using the sniffing dogs to locate trails of endangered species is instrumental in identifying and establishing key areas as corridors to connect isolated areas of native vegetation. That means working with rural landowners to help threatened species survive.

“If we wish to speak of sustainable development, we have to establish incentives and strategies for farmers to maintain native species in agricultural landscapes,” Machado said.

In addition to CI-Brazil, the project is supported by the University of Brasilia, the Jaguar Conservation Fund, and the Chico Mendes Institute for Conservation of Biodiversity, the entity responsible for management of the Emas National Park.

The dogs are trained in the same manner as those trained to sniff out drugs. When the dogs find the feces, the accompanying researcher marks the location with a GPS (Global Positioning System) and collects the samples. With the aid of satellite images, the sample data are correlated with the environments where the samples were found.

Prof. Jader Marinho Filho of the University of Brasilia, a sponsor of the project, said sniffing dogs can collect data that otherwise would only be available through radio telemetry and other expensive and labor-intensive techniques. Tracking dogs also are non-intrusive, collecting biological material without capturing or sedating animals, and the information they help gather is essential.

“The levels of stress hormones in the animals’ feces are important indicators in the evaluation of their capacity to reproduce in a given environment,” Marinho Filho said. “These data allow us to estimate which mammals would be able to reproduce or if they would be destined to disappear from the region.”

Researchers at the University of Leicester are now looking for first-year University of Leicester students who use Facebook to help their pioneering research into this issue.

They should not be too difficult to recruit. Student use of the online networking site Facebook is running at a phenomenal level, with almost 10,000 present and past students and staff participating.

Currently, 95 per cent of 16-18 year olds intending to go to university are using social networking sites like Facebook and MySpace.

“Yet we know little about how this phenomenon impacts on the student experience and, in particular, if and how it helps them integrate into university life,” commented Jane Wellens, Education Developer in the University of Leicester’s Staff Development Centre.

“The expectations and online experience of the latest and next generations of students requires universities to think carefully about how, and whether, to use these new technologies and meeting spaces to enhance the social aspects of student integration into university life.”

Dr Wellens is working with Dr Clare Madge, of the Department of Geography, Tristram Hooley, of CRAC, the Career Development Organisation, and Julia Meek, an independent evaluation consultant.

Academic and social integration into university life are key factors influencing individual students’ experiences and the likelihood of their withdrawing from their student courses. Until now most research in the field has concentrated on academic support rather than integration into the wider social world of the university.

Students are now so used to using social networking sites that one university in the US has actually been running sessions to encourage students to build up face-to-face networks. One aspect of the Leicester project is to explore whether there are differences in the longevity and nature of university friendships that students establish face-to-face compared with those they make online through social networking sites.

The Leicester project builds on internationally acclaimed work the University has already started on teaching and learning online. “We recently used Facebook as a means of encouraging students on an online module to get to know one another,” Jane Wellens said. “This raised many issues such as where the boundary between public and private space is, and how comfortable students (and staff) of different ages feel regarding the use of such technology.”

The Leicester project also draws on internationally recognised expertise by this specific team of researchers in online research methodologies. As Clare Madge of the Department of Geography at the University of Leicester stated: “This project will be using both an online questionnaire and virtual interviews, and will innovate in the use of Facebook itself as a site to conduct virtual interviews”.

What Dr Wellens and her colleagues hope to establish from the new research project is how Leicester students are using Facebook as part of their social and learning experience and whether joining the University’s Facebook network before they come to Leicester helps students to settle down more easily to university life.

They will also be looking to see if there is any way that university support services and academic departments can use the online social networking sites to help students integrate into university life, and how the sites might be re-shaping our everyday lives in terms of the importance of place-based versus virtual networking.

Research results are expected to influence university policies at Leicester and beyond. “It may affect the way the University uses its Facebook network,” said Dr Wellens. “One outcome might be that the University would use these sites to bring new students together before their arrival, or to bring together current and new students to provide peer support. It will also ascertain students’ views about the ways in which the University and its staff should, or shouldn’t, use Facebook for academic purposes.”

The discovery suggests that the tiny motor protein is much more important than previously thought – and for humans it may even hold a key to understanding potentially fatal conditions such as aneurisms.

Says Professor Knight of the University’s Faculty of Biological Sciences: “This is an astonishing discovery. Myosin 2’s function is to make the smooth muscle in internal organs tense and relax involuntarily. These creatures have completely different regulatory mechanisms: the myosin in a turkey’s gizzards allows it to ‘chew’ food in the absence of teeth, while that in a scallop enables it to swim. Yet they have exactly the same structure.”

Myosin molecules generate tension in smooth muscle by adhering to form a filament, which grabs hold of a neighbouring filament, and relaxes by letting go. When the muscle is in a relaxed state, myosin molecule folds itself up into a compact structure.

This folded structure allows the smooth muscles to adjust to being different lengths so they can operate over a large distance, such as the bladder or the uterus expanding and contracting. In contrast, skeletal muscles operate over a narrow range, defined by how much joints can move.

Professor Knight says: “We were puzzled to find that the scallop’s myosin 2 had retained its ability to fold and unfold, as they don’t need to accommodate a large range of movement. After all, the scallop only moves its shell a little when it swims.

“In evolution, if something is not essential to the survival of an organism, it is not conserved. The fact that the scallop has retained all the functions of its myosin 2 over hundreds of millions of years tells us that this folding is of fundamental functional importance in muscle and that we don’t know as much about it as we need to know.”

In humans, any changes in the composition of myosin within the muscles can be fatal. For example, a swelling in the walls of an artery can cause a brain aneurism, while an enlarged heart can lead to cardiac arrest in a young, fit person.

Says Professor Knight: “Because these malfunctions occur in our internal organs, we are often unaware of what is going wrong until it’s too late. Learning how to control myosin, how to move it around without disturbing the delicate balance between filaments and individual molecules, is an emerging area and one we are only just beginning to tackle.”

Scientists have enlisted the public's help in the photo identification of whale sharks, the world's largest fish. Divers are encouraged to submit any photos they take of whale sharks to a Web site (whalesharks.org) that tracks the endangered whale sharks around the world. Despite their giant size, whale sharks are harmless to divers and snorkelers. The patterns of spots on their backs are unique to each individual.