Welcome to the first of a new monthly blog series highlighting the best content from Royal Society Publishing’s Research Journals. Together our journals cover the whole of the life sciences, physical sciences and interdisciplinary research.
This month we have flying machines modelled on jellyfish, why fever could be good for you, icebergs on the increase in Greenland, resilient painted turtles and not so resilient elephant seals.
Published in Journal of the Royal Society Interface, Leif Ristroph and Stephen Childress of New York University have built the first flying machine capable of stable hovering using flapping wings alone. Previous designs for ornithopters, or flapping-wing aircraft, have mimicked the wing motions of insects – a scheme that is now known to be inherently unstable – and thus must rely on either active control systems or high-drag tails and sails for stabilization. They implement a new type of flapping-flight mechanism that resembles the motions of swimming jellyfish more so than any insect or bird. Their prototype takes advantage of wing flexibility to generate enhanced lift and, most importantly, has an intrinsic ability to keep upright and recover from disturbances during hovering and in other manoeuvring modes. These results show the promise of considering strategies for flying that may not have been explored by biological evolution.
Fever induction reduces tumours
Peregrine Laziosi (1265–1345), an Italian priest, became the patron saint of cancer patients when the tumour in his left leg miraculously disappeared after he developed a fever. It has been known that in rare cases tumours can regress spontaneously at elevated body temperature; however, the underlying mechanisms are only slowly emerging. Tumour cells accumulate broken chromosomes but fail to repair them due to a local increase in temperature inside the cancer. This repair defect can lead to the death of the malignant cells while normal cells are protected. Malignancies such as prostate cancer have successfully been treated with heat-based techniques. In this intriguing review published in Open Biology, researchers from Bangor University describe how heat casts a spell on the DNA damage surveillance systems which protect normal cells but can eliminate cancerous cells.
The tip of the iceberg
The International Ice Patrol records show an increase in the number of Greenland icebergs passing latitude 48°N, off Newfoundland over the past century. This Proceedings A paper uses a combination of modelling techniques on this data to show that these records are strongly related to the rate of iceberg calving from the Greenland Ice Sheet. From these results, they infer that the underlying causes of this are a combination of warming sea surface temperatures encouraging increases in calving and declining sea ice allowing increased iceberg mobility. This results in a larger number of icebergs reaching this point from western and northwestern Greenland adding to those originating from southern Greenland.
Female painted turtles don’t go with the flow
This Biology Letters paper uses an impressive long-term dataset, collected from a site along the Mississippi River, to study the effects of multiple extreme environmental events on a population of adult female painted turtles. Interestingly, the data show that that these individuals exhibit great resilience to flooding, even after major events just prior to the nesting season. These types of comprehensive datasets are likely to become increasingly useful as the number of extreme environmental events is expected to increase as a result of climate change.
More ice; fewer elephant seals
Southern elephant seal numbers at Macquarie Island have continuously decreased over the past 50 years. In an article published in Proceedings B, Australian scientists, led by the Australian Antarctic Division, have now found that annual variation in sea-ice duration affects numbers of females breeding at the island. Their analysis shows that in a long sea-ice season, adult female seals could be excluded from highly productive Antarctic shelf waters for longer than usual. As a result, mothers are unable to store sufficient fat reserves to ensure their pups’ survival. Decreases in seal numbers correlated best with increased sea-ice duration and extent. According to the authors, the news is not all bad for elephant seals, with populations on the West Antarctic peninsula increasing as sea ice in that region declines. However, it is still too early to say whether elephant seals will be climate change winners or losers.