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Mars spacecraft spots signs of ancient ocean
Presently, Martian surface is a barren, arid desert but the European Space Agency's Mars Express spacecraft has provided strong evidence that an ocean may have covered parts of the red planet billions of years ago.
Using radar, the orbiter has detected sediments reminiscent of an ocean floor within the boundaries of previously identified, ancient shorelines on Mars. The MARSIS radar was deployed in 2005 and has been collecting data ever since.
Jeremie Mouginot of University of California, Irvine, and colleagues have analysed more than two years of data and found that the northern plains are covered in low-density material.
“We interpret these as sedimentary deposits, maybe ice-rich,” said Dr Mouginot.
“It is a strong new indication that there was once an ocean here.” The existence of oceans on ancient Mars has been suspected before and features reminiscent of shorelines have been tentatively identified in images from various spacecraft. But it remains a controversial issue.
Two oceans have been proposed: 4 billion years ago, when warmer conditions prevailed, and also 3 billion years ago when subsurface ice melted following a large impact, creating outflow channels that drained the water into areas of low elevation.
The sediments revealed by MARSIS are areas of low radar reflectivity. Such sediments are typically low-density granular materials that have been eroded away by water and carried to their final destination.
Metabolic breathalyser may detect disease early
The future of disease diagnosis may lie in a “breathalyser”- a non-invasive and sensitive technology, which may help in early detection and diagnosis of the disease.
New research demonstrates a simple but sensitive method that can distinguish normal and disease-state glucose metabolism by a quick assay of blood or exhaled air. Many diseases, including diabetes, cancer, and infections, alter the body’s metabolism in distinctive ways. The new work shows that these biochemical changes can be detected much sooner than typical symptoms would appear – even within a few hours.
“With this methodology, we have advanced methods for tracing metabolic pathways that are perturbed in disease,” said senior author Fariba Assadi-Porter, a University of Wisconsin-Madison biochemist and scientist at the Nuclear Magnetic Resonance Facility at Madison.
“It’s a cheaper, faster, and more sensitive method of diagnosis.” The researchers studied mice with metabolic symptoms similar to those seen in women with polycystic ovary syndrome (PCOS), an endocrine disorder that can cause a wide range of symptoms including infertility, ovarian cysts, and metabolic dysfunction. PCOS affects approximately 1 in 10 women but currently can only be diagnosed after puberty and by exclusion of all other likely diseases – a time-consuming and frustrating process for patients and doctors alike.
“The goal is to find a better way of diagnosing these women early on, before puberty, when the disease can be controlled by medication or exercise and diet, and to prevent these women from getting metabolic syndromes like diabetes, obesity, and associated problems like heart disease,” Assadi-Porter said.
The researchers were able to detect distinct metabolic changes in the mice by measuring the isotopic signatures of carbon-containing metabolic by-products in the blood or breath.
Mediterranean seagrass is the world’s oldest living organism
Scientists say a swathe of seagrass in the Mediterranean could be the oldest known living thing on Earth.
Carlos Duarte of the University of Western Australia in Perth and his team sequenced the DNA of Posidonia oceanica at 40 sites spanning 3500 kilometres of seafloor, from Spain to Cyprus.
They found that one patch off the island of Formentera was identical over 15 kilometres of coastline. Like all seagrasses, Posidonia oceanica reproduces by cloning, so meadows spanning many kilometres are genetically identical and considered one organism.
On the basis of the plant’s annual growth rate the team calculated that the Formentera meadow must be between 80,000 and 200,000 years old, making it the oldest living organism on Earth. It beats a Tasmanian seagrass, Lomatia tasmanica, believed to be 43,600 years old.
However, Duarte says, the patch of P. oceanica is now threatened by climate change.
The Mediterranean is warming three times faster than the world average, and each year P. oceanica meadows decline by around 5 per cent.
