Archaeologists pulled a section of an ancient Egyptian pylon out of the Mediterranean seabed on Thursday in Alexandria.
The ruin was discovered 11 years ago by a Greek archaeological team, and dates back to around 30 B.C.. It is part of a late Ptolemaic-era temple near the tomb of Cleopatra.
Another important artifact will be brought to the surface in May.
Science & Technology
Skull fragments of prehistoric koalas from the Riversleigh rainforests of millions of year ago suggest they shared the modern koala's "lazy" lifestyle and ability to produce loud "bellowing" calls to attract mates and provide warnings about predators.
However, the new findings published as the featured cover article in the current issue of The Journal of Vertebrate Paleontology suggest that the two species of koalas from the Miocene (24 to five million years ago) did not share the uniquely specialized eucalyptus leaf diet of the modern koala (Phascolarctos cinereus).
The shift to a wholly eucalyptus diet by modern koalas was an adaptation that probably came later as Australia drifted north, causing its rainforests to retreat and Eucalypts to become the dominant tree of most Australian forests and woodlands.
However, the new findings published as the featured cover article in the current issue of The Journal of Vertebrate Paleontology suggest that the two species of koalas from the Miocene (24 to five million years ago) did not share the uniquely specialized eucalyptus leaf diet of the modern koala (Phascolarctos cinereus).
The shift to a wholly eucalyptus diet by modern koalas was an adaptation that probably came later as Australia drifted north, causing its rainforests to retreat and Eucalypts to become the dominant tree of most Australian forests and woodlands.
© University of Oregon
UO chemist Andrew Marcus has found that actin recruited by mitochondrial cells drive transport in budding yeast cells.
UO chemist Andrew Marcus has found that actin recruited by mitochondrial cells drive transport in budding yeast cells.
That movement -- documented in a paper appearing online the week of Dec. 14-18 ahead of regular publication in the Proceedings of the National Academy of Sciences -- appears to be coordinated by mitochondria's recruitment of actin-related proteins that rapidly assemble into extended fractal-like structures in a molecular chemical reaction known as polymerization. The coordinated movement of mitochondria is important for reproduction of identical daughter cells, and the sorting of mitochondrial DNA into the spinoff cells.
The research was done with a molecular fluorescence technology called Fourier imaging correlation spectroscopy that allows researchers using focused laser beams to see, measure and map the intermittent movement of mitochondria at micron scales. Marcus will discuss the technology, developed with funding from the National Institutes of Health and National Science Foundation, at the 2010 annual meeting of the American Physical Society in Portland, Ore., in March. It also was detailed in a paper published online in October by the journal Annual Reviews of Physical Chemistry.
Fierce competition over raw materials for new green technologies could become a thing of the past, thanks to a discovery by scientists from the University of Leeds.
Researchers from Leeds' Faculty of Engineering have discovered how to recover significant quantities of rare-earth oxides, present in titanium dioxide minerals. The rare-earth oxides, which are indispensable for the manufacture of wind turbines, energy-efficient lighting, and hybrid and electric cars, are extracted or reclaimed simply and cheaply from the waste materials of another industrial process.
If taken to industrial scale, the new process could eventually shift the balance of power in global supply, breaking China's near monopoly on these scarce but crucial resources. China currently holds 95 per cent of the world's reserves of rare earth metals in a multi-billion dollar global market in which demand is growing steadily.
Researchers from Leeds' Faculty of Engineering have discovered how to recover significant quantities of rare-earth oxides, present in titanium dioxide minerals. The rare-earth oxides, which are indispensable for the manufacture of wind turbines, energy-efficient lighting, and hybrid and electric cars, are extracted or reclaimed simply and cheaply from the waste materials of another industrial process.
If taken to industrial scale, the new process could eventually shift the balance of power in global supply, breaking China's near monopoly on these scarce but crucial resources. China currently holds 95 per cent of the world's reserves of rare earth metals in a multi-billion dollar global market in which demand is growing steadily.
DNA replication is a basic function of living organisms, allowing cells to divide and multiply, all while maintaining the genetic code and proper function of the original cell. The process, or mechanism, by which this is accomplished presents many challenges as the double helical (coil-shaped) DNA divides into two strands that are duplicated by different methods, yet both strands complete the replication at the same time.
New research by a team from UMDNJ-Robert Wood Johnson Medical School in conjunction with the University of Illinois and published in the Dec. 17 issue of Nature, has addressed this fundamental problem. The study identifies three essential ways the synthesis of the two strands is coordinated by enzymes, settling scientific deliberations on how the two DNA strands are copied in the same time span.
"DNA replication is a fundamental reaction required for the maintenance, survival, and propagation of living cells. It is also a very complex reaction that has been studied for decades without a clear understanding of how the two interwound strands are copied at the same time," says Smita Patel, PhD, professor of biochemistry at Robert Wood Johnson Medical School and lead author of the paper. "Our study explains how the replication is coordinated -- an important piece of the puzzle, because errors in DNA replication can cause disabilities and disease, such as cancer."
New research by a team from UMDNJ-Robert Wood Johnson Medical School in conjunction with the University of Illinois and published in the Dec. 17 issue of Nature, has addressed this fundamental problem. The study identifies three essential ways the synthesis of the two strands is coordinated by enzymes, settling scientific deliberations on how the two DNA strands are copied in the same time span.
"DNA replication is a fundamental reaction required for the maintenance, survival, and propagation of living cells. It is also a very complex reaction that has been studied for decades without a clear understanding of how the two interwound strands are copied at the same time," says Smita Patel, PhD, professor of biochemistry at Robert Wood Johnson Medical School and lead author of the paper. "Our study explains how the replication is coordinated -- an important piece of the puzzle, because errors in DNA replication can cause disabilities and disease, such as cancer."
© Getty Images
When scientists trapped samples of Staphylococcus aureus (shown here) in glass cages, the bacteria acted disturbed and "talked" to themselves.
When scientists trapped samples of Staphylococcus aureus (shown here) in glass cages, the bacteria acted disturbed and "talked" to themselves.
Humans in solitary confinement can go crazy, talking to themselves and trying to break free. Now scientists from New Mexico and New Hampshire are reporting that bacteria locked in solitary confinement know they are locked up, talk to themselves, and try to break free of their imprisonment.
The research could have important health implications, from how an individual bacterium can trigger full-blown infections to how a single human cancer cell can metastasize into a deadly tumor.
"There are many real-world situations where bacteria find themselves alone," said Jeff Brinker, a scientist at the University of New Mexico and co-author of a recent paper in the journal Nature Chemical Biology. "When the bacteria are confined they turn on these virulence pathways," causing infections.
© Google Images
A judge ruled Friday that Google must pay 300,000 euros ($430,000) in damages and interest to French publisher La Martiniere.
Google was also ordered to pay 10,000 euros per day until it removes extracts of the French books from its online database.
Google wants to scan millions of books and make them available online for its users.
This case will be seen as a success for critics who fear that Google will hold a monopoly over information.
Scientists at the Carnegie Institution, with colleagues, have found that a plant steroid prompts two genes to battle each other -- one suppresses the other to ensure that leaves grow normally in rice and the experimental plant Arabidopsis thaliana, a relative of mustard.
The results, published in the December 15, 2009, issue of The Plant Cell, have important implications for understanding how to manipulate crop growth and yield.
In plants, steroid levels reflect environmental and internal signals and control many processes. Steroid hormones called brassinosteroids (BRs) start their action on the surface of the cell and, through a molecular relay, send signals into the cell's nucleus to turn on or off specific genes, particularly those that are critical to regulating plant growth and development. Although a lot has been discovered about how the steroid affects genes in Arabidopsis, much less was known in crop plants such as rice.
The results, published in the December 15, 2009, issue of The Plant Cell, have important implications for understanding how to manipulate crop growth and yield.
In plants, steroid levels reflect environmental and internal signals and control many processes. Steroid hormones called brassinosteroids (BRs) start their action on the surface of the cell and, through a molecular relay, send signals into the cell's nucleus to turn on or off specific genes, particularly those that are critical to regulating plant growth and development. Although a lot has been discovered about how the steroid affects genes in Arabidopsis, much less was known in crop plants such as rice.
© McGill University
A McGill researcher has discovered a near-complete skull of a primitive "dugong" illuminating a virtually unknown period in Madagascar fossil history.
A McGill researcher has discovered a near-complete skull of a primitive "dugong" illuminating a virtually unknown period in Madagascar fossil history.
The discovery of a Middle Eocene (48.6-37.2 million years ago) sea cow fossil by McGill University professor Karen Samonds has culminated in the naming of a new species. This primitive dugong is among the world's first fully-aquatic sea cows, having evolved from terrestrial herbivores that began exploiting coastal waters. Within this ancient genus, the newly discovered species is unusual as it is the first species known from the southern hemisphere (its closest relatives are from Egypt and India), and is extremely primitive in its skull morphology and dental adaptations. The fossil is a pivotal step in understanding Madagascar's evolutionary history -- as it represents the first fossil mammal ever named from the 80-million-year gap in Madagascar's fossil record.
The research is to be published in the Journal of Vertebrate Paleontology on December 12.
Our cells' molecules form an intricate network of interactions. Today's techniques, however, can only be used to measure individual molecular reactions outside the cells. Since molecular concentrations are much higher in cells than in the laboratory, scientists suspect that the kinetics of molecular reactions in living cells differ substantially from external probes.
"We expected the cellular reaction speed to be higher," confirms LMU biophysicist Professor Dieter Braun. "However, our novel optical approach showed that -- depending on the length of the strands -- the coupling of DNA-strands inside living cells can be both faster and slower than outside." Data yielded from living cells are highly valuable for the development of models to understand the complex interactions as well as pathological processes in biological cells. Braun and his team now plan to probe a variety of molecular reactions in living cells, visualizing the heartbeat of cellular networks.
In their work, the scientists investigated the hybridization -- the coupling and de-coupling -- of two DNA-strands, which they introduced into living cells. To determine the reaction time constant they used an infrared laser to induce temperature oscillations of different frequencies in the cell and measured the concentration of the reaction partners, namely of coupled and de-coupled DNA. At low frequencies, these concentrations followed the temperature oscillations, whereas at higher frequencies they experienced a phase delay and oscillated with diminished amplitude. Both delay time and amplitude decrease, were evaluated to obtain the reaction time constant.
"We expected the cellular reaction speed to be higher," confirms LMU biophysicist Professor Dieter Braun. "However, our novel optical approach showed that -- depending on the length of the strands -- the coupling of DNA-strands inside living cells can be both faster and slower than outside." Data yielded from living cells are highly valuable for the development of models to understand the complex interactions as well as pathological processes in biological cells. Braun and his team now plan to probe a variety of molecular reactions in living cells, visualizing the heartbeat of cellular networks.
In their work, the scientists investigated the hybridization -- the coupling and de-coupling -- of two DNA-strands, which they introduced into living cells. To determine the reaction time constant they used an infrared laser to induce temperature oscillations of different frequencies in the cell and measured the concentration of the reaction partners, namely of coupled and de-coupled DNA. At low frequencies, these concentrations followed the temperature oscillations, whereas at higher frequencies they experienced a phase delay and oscillated with diminished amplitude. Both delay time and amplitude decrease, were evaluated to obtain the reaction time constant.
