The maximum extent of Arctic sea ice in winter 2007 was the second lowest on satellite record, narrowly missing the 2006 record, according to a team of University of Colorado at Boulder researchers.

The Arctic sea-ice extent, which is the area of ocean covered by at least 15 percent ice, was 5.7 million square miles in March 2007, slightly higher than the record low of 5.6 million square miles measured in March 2006.

Dr Alwyn Ruddock, a former reader in history at the University of London, was the world expert on John Cabot's discovery voyages from Bristol to North America (1496-98). What she was said to have found out about these voyages looked set to re-write the history of the European discovery of America. Yet, when Dr Ruddock died in December 2005, having spent four decades researching this topic, she ordered the destruction of all her research.

In an article published today in Historical Research, Alwyn Ruddock's extraordinary claims are explored by Dr Evan Jones of the University of Bristol.

Mating strategies are straightforward in bottlenose dolphins, or are they? Much of the work carried on male-female relationships in that species to date show that males tend to coerce females who are left with little choice about with whom to mate. This explains the complex relationships we observe in male bottlenose dolphins, which are only paralleled by human social strategies: the formation of alliances and alliances of alliances, also called coalitions. These alliances and coalitions are then used to out-compete other male bands to access females.

Horizon: My Pet Dinosaur was broadcast on BBC Two on 13 March at 21:00GMT. The idea behind the program is what would have happened if the dinosaurs hadn’t gone extinct? This sounds like a fantastic idea for a program and I am all for popularizing science, I believe public interest in scientific research is important. But some of these popularizations go to far; there are bound to be small anatomical mistakes in TV shows, even some hypotheses based on limited evidence, but what I hate is unreined wild speculation.

NGC 1672, visible from the Southern Hemisphere, is seen almost face on and shows regions of intense star formation. The greatest concentrations of star formation are found in the so-called starburst regions near the ends of the galaxy's strong galactic bar. NGC 1672 is a prototypical barred spiral galaxy and differs from normal spiral galaxies in that the spiral arms do not twist all the way into the centre. Instead, they are attached to the two ends of a straight bar of stars enclosing the nucleus.

HIV-positive people who say religion is an important part of their lives are likely to have fewer sexual partners and engage in high-risk sexual behavior less frequently than other people with the virus that causes AIDS, according to a study issued today by the RAND Corporation.

As a result, people with HIV who have stronger religious ties are less likely to spread the virus, according to the study by the nonprofit research organization.

J. B. S. Haldane once famously quipped that "God is inordinately fond of beetles." Results of a study by Mark A. McPeek of Dartmouth College and Jonathan M. Brown of Grinnell College suggest that this fondness was expressed not by making so many, but rather by allowing them to persist for so long. In a study appearing in the April issue of the American Naturalist, McPeek and Brown show that many insect groups like beetles and butterflies have fantastic numbers of species because these groups are so old.

Rabies, a relentless, ancient scourge, may hold a key to defeating another implacable foe: HIV. Scientists at Jefferson Medical College in Philadelphia have used a drastically weakened rabies virus to ferry HIV-related proteins into animals, in essence, vaccinating them against an AIDS-like disease. The early evidence shows that the vaccine – which doesn’t protect against infection – prevents development of disease.

Given the choice, many of us would opt for warmer climes during the bleak midwinter. However, most of us cannot afford to move abroad for a few months, so instead we pile on extra layers of clothing to keep warm. Arthropods face much the same dilemma, as they cannot migrate long distances to avoid low winter temperatures – so why are they not killed off by the cold? Dr Melody Clark, from the British Antarctic Survey, will present data on the fascinating ways two species of these animals combat the cold on Tuesday 3rd April at the Society for Experimental Biology’s Annual Meeting in Glasgow.

The story of some violent historic earthquakes may need to be revisited, according to a study published in the April issue of the Bulletin of the Seismological Society of America (BSSA). Seismologists rely on written accounts, mostly local newspaper articles, to judge how strongly the ground shook during earthquakes that predate the use of current instrumentation. Those news accounts have proven to be misleading, say scientists, and reliance upon them must be tempered when evaluating the size of past earthquakes.