Today's Headlines

Rice Scientists Make First Nanoscale pH Meter
Novel Connection Found Between Biological Clock And Cancer
New Research May Reduce Global Need For Nitrogen Fertilizers
Satellite to Aid Education In Northeast India
First Global Lighting Study Is Released
Scientists Puzzled By Sand Bacteria

*Rice Scientists Make First Nanoscale pH Meter News Source: Rice University

Using unique nanoparticles that convert laser light into useful information, Rice University scientists have created the world's first nano-sized pH meter.

The discovery, which appears online this week in the jour nal Nano Letters, present s biologists with the first potential means of measuring accurate pH changes over a wide pH range in real-time inside living tissue and cells.

"Almost every biologist I speak with comes up with one or two things they'd like to measure with this," said lead researcher Naomi Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering, professor of chemistry and director of Rice's Laboratory for Nanophotonics (LANP).

For example, pH may be useful in determining whether or not some cancer tumors are malignant. With current methods, a piece of the tumor would need to be physically removed via biopsy - a painful and invasive procedure - and visually evaluated under a microscope. Halas said LANP's new nano-pH meter could be used instead as an "optical biopsy" to measure the pH inside the tumor with nothing more invasive than an injection.

Halas's LANP team created the pH sensor using nanoshells, optically tuned nanoparticles invented by Halas. Each nanoshell contains a tiny core of non-conducting silica that's covered by a thin shell of metal, usually gold. Many times smaller than living cells, nanoshells can be produced with great precision and the metal shells can be tuned to absorb or scatter specific wavelengths of light.

To form the pH sensor, Halas' team coated the nanoshells with pH-sensitive molecules called paramercaptobenzoic acid, or pMBA. When placed in solutions of varying acidity and illuminated, the nanoshell-molecule device provides small but easily detectable changes in the properties of the scattered light that, when "decoded," can be used to determine the pH of the nanodevice's local environment to remarkably high accuracy. Inspired by techniques normally applied to image recognition, the team formulated an efficient statistical learning procedure to produce the device output, achieving an average accuracy of 0.1 pH units.

The term "pH" was coined by the Danish chemist Søren Sørensen in 1909 as a convenient way of expressing a solution's acidity. pH ranges from one - the most acidic - to 14 - the most alkaline.

Co-authors on the paper include postdoctoral researchers Sandra Bishnoi, now an assistant professor at the Illinois Institute of Technology, and Muhammed Gheith; graduate students Christopher Rozell and Carly Levin; Bruce Johnson, distinguished faculty fellow of chemistry and executive director of the Rice Quantum Institute; and Don Johnson, J.S. Abercrombie Professor of Electrical and Computer Engineering and Statistics.

The research was supported by the Department of Defense's Congressionally Directed Medical Research Program, the Air Force Office of Scientific Research, the Keck Foundation, the Robert A. Welch Foundation and by Texas Instruments.

*Novel Connection Found Between Biological Clock And Cancer News Source: Dartmouth Medical School TOP^

Dartmouth Medical School geneticists have discovered that DNA damage resets the cellular circadian clock, suggesting links among circadian timing, the cycle of cell division, and the propensity for cancer.

Their work, reported June 29 in Science Express, the advance electronic publication of Science, implies a protective dimension for the biological clock in addition to its pacemaker functions that play such a sweeping role in the rhythms and activities of life.

"The notion that the clock regulates DNA-damage input and that mutation can affect the clock as well as the cell cycle is novel," says Jay Dunlap, professor and chair of genetics at DMS. "It suggests a fundamental connection among circadian timing, cell cycle progress, and potentially the origins of some cancers."

Dunlap is a co-author of the paper with DMS colleagues, Jennifer Loros, professor of biochemistry, graduate student Christopher L. Baker, and former students António M. Pregueiro and Qiuyun Liu.

The team of Loros and Dunlap were among to first to delineate the intricate web of clockwork genes, proteins and feedback loops that drive circadian rhythms, working chiefly in the classic genetic model organism Neurospora, the common bread mold.

One gene (period-4) was identified over 25 years ago by a mutation that affects two clock properties, shortening the circadian period and altering temperature compensation. For this study, the researchers cloned the gene based on its position in the genome, and found it was an important cell cycle regulator. When they eliminated the gene from the genome, the clock was normal, indicating that the mutation interfered in some way with the clock, rather than supplying something that the clock normally needs to run.

Biochemically, the mutation results in a premature modification of the well understood clock protein, frequency (FRQ). The investigators demonstrated that this was a direct result of action by an enzyme, called in mammals checkpoint kinase-2 (CHK2), whose normal role is exclusively in regulating the cell division cycle. CHK2 physically interacts with FRQ; the mutation makes this interaction much stronger. However, a mutant enzyme that has lost its activity has no effect on the clock.

Normally CHK2 is involved in the signal response pathway that begins when DNA is damaged and results in a temporary stoppage of cell division until the damage is fixed. The researchers found that the resetting effect of DNA damage requires the period-4 clock protein, and that period-4 is the homolog, the Neurospora version, of the mammalian checkpoint kinase.

Moreover, the clock regulates expression of the period-4 gene. This closes a loop connecting the clock to period-4 and period-4 to the clock and the cell cycle. The clock normally modulates expression of this gene that encodes an important cell cycle regulator, and that cell cycle regulator in turn affects not only the cell cycle but also the clock.

Recent evidence in mammalian cells shows that other cell cycle regulators physically interact with clock proteins. Loss of at least one clock protein (mammalian period-2) is known to increase cancer susceptibility. The coordination of the clock and cell division through cell cycle checkpoints, supports the clock's "integral role in basic cell biology," conclude the researchers." Their work can help advance understanding of cancer origins as well as the timing of anti-cancer treatment.

*New Research May Reduce Global Need For Nitrogen Fertilizers News Source: Biotechnology and Biological Sciences Research Council
 

Research published June 29 in the journal Nature reveals how scientists at the John Innes Centre (JIC), Norwich and Washington State University, USA have managed to trigger nodulation in legumes, a key element of the nitrogen fixing process, without the bacteria normally necessary. This is an important step towards transferring nodulation, and possibly nitrogen fixation, to non-legume crops which could reduce the need for inorganic fertilizers.

The researchers, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the Royal Society and the US National Science Foundation, have used a key gene that legumes require to establish the interaction with the nitrogen-fixing bacteria to trigger the growth of root nodules, even in the absence of the bacteria.

The fixation of nitrogen by some plants is critical to maintaining the health of soil as it converts the inert atmospheric form of nitrogen into compounds usable by plants. Legumes, as used in this study, are an important group of plants as they have the ability to fix nitrogen – which they owe to a symbiotic relationship with nitrogen-fixing bacteria in root nodules. Legumes are often used as a rotation crop to naturally enhance the nitrogen content of soils. Scientists have been working for a number of years to understand the symbiosis between legumes and rhizobial bacteria, with the hope that one day they can transfer this trait to crop plants, the majority of which cannot fix nitrogen themselves.

Intensive crop agriculture depends heavily on inorganic fertilisers that are often used to provide nutrients particularly nitrogen that are critical for plant growth. The production of nitrogen fertilisers requires a large amount of energy and is estimated to constitute approximately 50 per cent of the fossil fuel usage of the modern agricultural process. Inorganic fertilizers also cause environmental problems associated with leeching into our water systems.

Dr Giles Oldroyd is the research leader at JIC. He said: “We now have a good understanding of the processes required to activate nodule development. The nodule is an essential component of this nitrogen fixing interaction as it provides the conditions required for the bacteria. Nodules are normally only formed when the plant perceives the presence of the bacteria. The fact that we can induce the formation of nodules in the plant in the absence of the bacteria is an important first step in transferring this process to non-legumes. If this could be achieved we could dramatically reduce the need for inorganic nitrogen fertilizers, in turn reducing environmental pollution and energy use. However, we still have a lot of work before we can generate nodulation in non-legumes.”

Professor Julia Goodfellow, Chief Executive of BBSRC, commented: “BBSRC is the principal funder of fundamental plant research in the UK and commits millions of pounds a year to furthering our understanding of basic plant biology. Such fundamental research may seem disconnected from the every day world for many people but this project shows how potentially important such science is. The findings have the potential to lead to a practical application with substantial economic impact for the UK.”

*Satellite to Aid Education In Northeast India  Agartala, India (IANS) Jun 30, 2006 TOP^

Students in India's northeast will soon have satellite-based educational facilities available. Three states - Tripura, Mizoram and Nagaland - will be included in the first phase of the hi-tech facilities using the services of EDUSAT, a dedicated satellite for education launched in 2004.

In the first phase, the project will cover government-run schools and it will be subsequently introduced in private schools.

"Educational programmes through satellite would reach some of the most interior and inaccessible hilly areas of Tripura, Mizoram and Nagaland through video-conferencing," said K.C. Bhattacharya, director of the Northeastern Space Application Center.

There will be a hub and a studio each in the three states.

Tripura and Nagaland will each have 30 satellite educational facilities and Mizoram 31.

"These resource centers will be located in blocks, higher secondary and middle schools, district institutes of education and training," Bhattacharya told IANS.

Reception terminals will be installed in each center.

The EDUSAT services will be made available in the remaining states of the region - Assam, Manipur, Meghalaya, Arunachal Pradesh and Sikkim - by the end of March 2007.

NESAC is coordinating with the ISRO for the launch of the project.

There will be specialized teachers at the uplink station or the hub and lessons taught would reach hundreds of students in the remote centers through satellite signals.

"The teachings in the studio can be seen and heard in the classrooms on large screens or big television sets with cameras and audio equipment available at both ends for communication," said Krishna Dhan Nath, director of the State Council for Educational Research and Training.

"The teachers will be able to hear the students who will be visible to all the other learners in various centers, creating an atmosphere of a virtual classroom," he said.

The new venture is expected to bring down the dropout rate among school students in the region, besides helping teachers to enhance their knowledge base.

The Indira Gandhi National Open University and ISRO have been jointly working to develop a satellite-based educational network since 1993. The EDUSAT was launched in 2004 by the Geosynchronous Satellite Launch Vehicle.

The project is being funded and coordinated by the human resource development ministry and the department of space and technology.

*First Global Lighting Study Is Released TOP^

Paris (UPI) Jun 30, 2006

The first global survey of lighting uses and costs suggests the world's electric bill would greatly decrease with a switch to efficient lighting systems. The Paris-based International Energy Agency, which conducted the study, said it found lighting is a major source of electricity consumption.

Paul Waide, a senior IEA policy analyst and one of the report's authors, told the BBC: "Nineteen percent of global electricity generation is taken for lighting. That's more than is produced by hydro or nuclear stations, and about the same that's produced from natural gas."

The study notes the incandescent light bulb -- developed about 125 years ago -- still produces nearly half of the light used in homes around the world. But, scientists say, incandescent bulbs are very inefficient, converting only about five percent of the energy they receive into light.

However the biggest consumers of electricity are the fluorescent tube, the efficiency of which can vary between 15 percent and 60 percent, and halogen lighting, which the IEA says is the least efficient of all commonly used lighting systems.

The study concludes new lighting policies and individual action could slash 38 percent from the world's lighting bill by 2030.

*Scientists Puzzled By Sand Bacteria TOP^

Mount Pleasant (UPI) Jun 30, 2006

U.S. scientists say bacteria forcing the closure of many beaches may not be coming from people, animals, or sewage -- but might be produced in the sand. Researchers at Central Michigan University say they have found E. coli can live and thrive in beach sand without a warm-blooded host. While not necessarily a threat to human health, E. coli has been used as an indicator of other pathogens in excrement, such as viruses, the Duluth (Minn.) News Tribune reported.

But Central Michigan University Microbiologist Elizabeth Alm says E. coli has been found in Lake Huron sand with no fecal matter from people, birds or animals.

Alm says her finding means scientists need to create a new indicator for harmful pathogens in water and might also indicate dangerous organisms are thriving in beach sand.

"Geese and gulls and diapers may still be sources of some fecal matter and some E. coli, but we clearly can have E. coli without any of them," She said. "We need to do a lot more research to see what else may be naturalized in the sand."

The findings appear in the Journal of Great Lakes Research.