Academy warning of bunker-buster risks leaves US unmoved

A nuclear weapon designed to strike at targets deep underground would be likely to cause unacceptable civilian casualties, according to a study released by the US National Academy of Sciences.

Since 2002, the Bush administration has advocated the study and possible development of earth-penetrating nuclear weapons. Administration officials contend that such bombs would be the best way to strike at deeply buried targets — but other studies show that the bombs would spew out clouds of radioactive material that could harm civilians (see Nature 423, 469; 2003).

The academy study shows that a nuclear weapon powerful enough to destroy a facility hundreds of metres below ground could kill up to a million people on the surface. It suggests that conventional weapons might be just as effective, without causing such devastating casualties.

Despite the new findings, administration officials are continuing to lobby for $8.5 million for a study of the new weapon.

Wildfires add to growing problem of vanishing forest

To cope with an increasing amount of land in need of reforestation, the US Forest Service should prioritize the issue and change the way it collects data. That's the conclusion of a report issued on 27 April by the Government Accountability Office.

Wildfires and other natural disturbances, such as insect infestations and diseases, have left 360,000 hectares in need of planting. If historically forested lands are not reforested, competing vegetation can take over, raising the risk of wildfires even further.

Forest Service officials acknowledge that changes need to be made, and say a new data tracking system is being developed. But they add that funding has not kept pace with the growing need for reforestation.

Dash for cash raises nanotech patent fears

A "gold-rush mentality" towards patenting could inhibit the development of nanotechnology, warn US analysts.

The New York-based nanotech consultancy Lux Research analysed 1,084 nanotech patents, just under a third of those issued so far in the United States. The patents, which related to five different materials including carbon nanotubes and nanowires, often overlapped, leaving little space for new claims.

The report, issued late last month, adds that overly broad claims could be withdrawn by the courts, as has happened with numerous biotechnology patents.

But Stephen Maebius, a nanotech specialist in the Washington office of law firm Foley & Lardner, which co-authored the report, says that even though nanotech companies should be more careful about how they define claims, they should still aim to patent developments as soon as possible. "While some litigation is inevitable, those who have patents will have some leverage with which to avoid a self-destructive intellectual-property war," he says.

Judges rule in favour of 'saviour sibling' babies

Rejecting a challenge from an anti-abortion group, judges in the UK House of Lords ruled unanimously last week that the creation of babies through in vitro fertilization to help cure sick siblings is lawful. The decision marks the end of a lengthy battle in the courts about whether the nation's reproductive watchdog, the Human Fertilisation and Embryology Authority (HFEA), can allow couples to screen their embryos to find tissue matches for their seriously ill children.

Lawmakers backed the 2003 Court of Appeal ruling that gave the HFEA the authority to grant Raj and Shahana Hashmi a licence to screen their embryos for this purpose. The Hashmis' son Zain suffers from the rare blood disorder thalassaemia major, and requires daily drugs and monthly blood transfusions. A transplant of stem cells from the umbilical cord of a 'saviour sibling' baby with the correct tissue match could cure his condition.

Advocates of reproductive rights have applauded the decision. "Families facing this critical situation will now have another treatment option," says Laura Riley, director of the Progress Educational Trust, a UK charity that monitors issues relating to assisted reproduction and genetics.

Big bangs spark toad death explosion

Speculation is running wild over harrowing scenes near a small pond in Hamburg, Germany. Three weeks ago passers-by first reported the sight of toads inflating like balloons and exploding. Since then, more than 1,000 toad corpses have been found, emptied of their innards, while scientists, the press and conspiracy theorists puzzle about the mass bursting.

Bacterial infections, environmental toxins, and a lethal fungus from a nearby race track have been blamed. But none of these has been confirmed by researchers at Hamburg's Institute for Hygiene and Environment, who are investigating cadavers and water samples. "We are facing a mystery", says Janne Klöpper, a spokesman for the institute.

NASA told to make space for Earth science

Having watched with alarm as NASA axed or threatened to cut several key Earth-science missions as a result of budget shortfalls, a National Academy of Sciences panel has accused the agency of putting its decades-long Earth-science programme "at substantial risk".

NASA/TERRA/MODIS

The committee, which is setting priorities for the next decade of Earth observations from space, recommended last week that two missions — Global Precipitation Measurement, and Atmospheric Soundings from Geostationary Orbit — be reinstated immediately. It added that four more — Ocean Vector Winds, Landsat Data Continuity, Glory, and technology for a Wide-Swath Ocean Altimeter — be "urgently reconsidered".

NASA's head of space science, Al Diaz, stated in a congressional hearing that the agency has "no intention of abandoning Earth science", and said that not all the cancellations were final. For example, the agency intends to transfer some sensors to a new generation of weather satellites due to start flying in 2009, he explained.