Biometrics: Unlocking Doors With Your Eyes

Research by Ms Phang, from QUT's Faculty of Built Environment and Engineering, is helping to remove one of the final obstacles to the everyday application of iris scanning technology.

Ms Phang said the pattern of an iris was like a fingerprint in that every iris was unique. "Every individual iris is unique and even the iris pattern of the left eye is different from the right. The iris pattern is fixed throughout a person's lifetime" she said.

"By using iris recognition it is possible to confirm the identity of a person based on who the person is rather than what the person possesses, such as an ID card or password.

"It is already being used around the world and it is possible that within the next 10 to 20 years it will be part of our everyday lives."

Ms Phang said although iris recognition systems were being used in a number of civilian applications, the system was not perfect. "Changes in lighting conditions change a person's pupil size and distort the iris pattern," she said.

"If the pupil size is very different, the distortion of the iris pattern can be significant, and makes it hard for the iris recognition system to work properly."

To overcome this flaw, Ms Phang has developed the technology to estimate the effect of the change in the iris pattern as a result of changes in surrounding lighting conditions. "It is possible for a pupil to change in size from 0.8mm to 8mm, depending on lighting conditions," she said.

Ms Phang said by using a high-speed camera which could capture up to 1200 images per second it was possible to track the iris surface's movements to study how the iris pattern changed depending on the variation of pupil sizes caused by the light. "The study showed that everyone's iris surface movement is different."

She said results of tests conducted using iris images showed it was possible to estimate the change on the surface of the iris and account for the way the iris features changed due to different lighting conditions.

"Preliminary image similarity comparisons between the actual iris image and the estimated iris image based on this study suggest that this can possibly improve iris verification performance."

Adapted from materials provided by Queensland University of Technology

Genetic Engineering - Intro

Biotechnology is technology based on biology, especially when used in agriculture, food science, and medicine. The United Nations Convention on Biological Diversity has come up with one of many definitions of biotechnology.

Biotechnology is often used to refer to genetic engineering technology of the 21st century, however the term encompasses a wider range and history of procedures for modifying biological organisms according to the needs of humanity, going back to the initial modifications of native plants into improved food crops through artificial selection and hybridization. Bioengineering is the science upon which all Biotechnological applications are based. With the development of new approaches and modern techniques, traditional biotechnology industries are also acquiring new horizons enabling them to improve the quality of their products and increase the productivity of their systems.

Before 1971, the term, biotechnology, was primarily used in the food processing and agriculture industries. Since the 1970s, it began to be used by the Western scientific establishment to refer to laboratory-based techniques being developed in biological research, such as recombinant DNA or tissue culture-based processes, or horizontal gene transfer in living plants, using vectors such as the Agrobacterium bacteria to transfer DNA into a host organism. In fact, the term should be used in a much broader sense to describe the whole range of methods, both ancient and modern, used to manipulate organic materials to reach the demands of food production. So the term could be defined as, "The application of indigenous and/or scientific knowledge to the management of (parts of) microorganisms, or of cells and tissues of higher organisms, so that these supply goods and services of use to the food industry and its consumers.

Closest Look Ever At Native Human Tissue

"This is a real breakthrough in two respects," says Achilleas Frangakis, group leader at EMBL. "Never before has it been possible to look in three dimensions at a tissue so close to its native state at such a high resolution. We can now see details at the scale of a few millionths of a millimetre. In this way we have gained a new view on the interactions of molecules that underlie cell adhesion in tissues -- a mechanism that has been disputed over decades."

So far, the only information available about a protein's position and interactions in a cell was based on either light microscopy images at poor resolution or techniques that remove proteins from their natural context. Frangakis and his group have been developing a technique called cryo-electron tomography, with which a cell or tissue is instantly frozen in its natural state and then examined with an electron micro-scope.

Electron microscopy normally requires tissue to be treated with chemicals or coated in metal, a procedure that disturbs the natural state of a sample. With cyro-electron tomography, images are taken of the untreated sample from different directions and assembled into an accurate 3D image by a computer.

The researchers applied this technique to observe proteins that are crucial for the integrity of tissues and organs like the skin and the heart, but also play an important role in cell proliferation. These proteins, called cadherins, are anchored in cell membranes and interact with each other to bring cells close together and interlink them tightly.

"We could see the interaction between two cadherins directly, and this revealed where the strength of human skin comes from," says Ashraf Al-Amoudi, who carried out the work in Frangakis' lab. "The trick is that each cadherin binds twice: once to a molecule from the juxtaposed cell, and once to its next-door neighbour. The system works a bit like specialised Velcro and establishes very tight contacts between cells."

The new insights into the cadherin system broadens the understanding of structural aspects of cell adhesion and shed light on other crucial processes such as cell proliferation. The technical advances achieved in cryo-electron tomography of frozen sections open up new possibilities to study more systems at native conditions with molecular resolution.

Adapted from materials provided by European Molecular Biology Laboratory

Global Climate Change: The Impact Of El Niño On Galápagos Marine Iguanas

According to the authors, recurring El Niño events provide an ideal system to study the impact of human-mediated climate change on ecosystems worldwide, by allowing observation of changes in populations associated with individual events.

"Since global warming is expected to cause an increase in the strength and frequency of El Niño events, it is important to evaluate the impact of El Niño on natural populations and their capacity to respond to environmental stresses," said Gisella Caccone, senior research scientist in ecology and evolutionary biology at Yale, and senior author of the paper published recently in the Public Library of Science One.

In this study, the researchers investigated the effect of sea surface warming associated with the single, intense El Niño event of 1997 to 1998 on genetic diversity in Galápagos marine iguana populations. They found that populations within the same species responded very differently.

Collaboration between German scientists who fortuitously collected and archived samples between 1991 and 1993 and Yale researchers who sampled the iguanas in 2004 enabled these unique before-and after comparisons. More than 800 samples from 11 Galápagos marine iguana populations were evaluated.

The researchers looked for changes in levels of genetic variation in nuclear microsatellite DNA and mitochondrial DNA markers of samples collected before and after this El Nino event. Changes in microsatellite frequency are sensitive enough to detect low population sizes before there is a significant loss of diversity in a population, whereas mitochondrial markers only show losses of diversity.

Caccone said that although some populations had mortality rates of up to 90%, only one population from a single island showed strong evidence of a "genetic bottleneck," suggesting that the El Niño-induced disturbance affected populations very differently even within the same species.

"Our study points out that there was a low population size on the island of Marchena during the same period in which there was serious volcanic activity as well as the El Nino," said Yale graduate student Scott Glaberman, a principal author of the study. "Since both of these forces could have acted on the population, it shows the importance of knowing the major forces influencing survival and reproduction to best interpret the results of genetic tests.

"The most striking result of our study is that although marine iguanas on some islands had a rather high mortality due to El Niño, the genetic consequences were mostly absent," said author Sebastian Steinfartz a postdoctoral fellow. "This unique study shows that natural populations may be able to balance even severe short term climatic disturbances, and that such fluctuations will not necessarily have long-term negative consequences on the population structure."

"Basic surveys and ecology of organisms are not the most glamorous aspects of research, but if used together with the exciting genetic approach in our study, they make for a very powerful approach," said Glaberman.

"This underscores the importance of having baseline studies for any population of interest, and the value of archiving samples for the use of future research," Caccone said. "It sets the basis for future research to determine which environmental and biological factors make specific populations more vulnerable than others."

Other authors on the study are Deborah Lanterbecq at Yale, Cruz Marquez at the Charles Darwin Research Station, Santa Cruz, Galápagos, Ecuador and Kornelia Rassmann in Germany. Granting from the National Geographic Society, the German Research Community, the Belgian American Educational Foundation, and the Yale Institute for Biospheric Studies supported the research.

Citation: Public Library of Science (PLoS): December 12, 2007.

Adapted from materials provided by Yale University