HAMNET Report 29th December 2019

For all you post-Christmas couch-potatoes out there, I have bad news for you. Writing in Medical X-press, the American Cancer Society provides fairly hard evidence that recommended levels of physical activity can lower your risk of 7 different types of cancer.

A pooled analysis of nine prospective studies involving more than 750 000 adults finds that recommended amounts of leisure-time physical activity were linked to a lower risk for seven cancers. The study was led by investigators at the National Cancer Institute, the American Cancer Society, and the Harvard T.H. Chan School of Public Health, and appears in the Journal of Clinical Oncology.

While it’s long been known that physical activity is associated with a lower risk of several cancers, less clear has been the shape of the relationship and whether recommended amounts of physical activity are associated with lower risk. Updated guidelines for activity now state that people should aim for 2.5 to 5 hours/week of moderate-intensity activity or 1.25 to 2.5 hours/week of vigorous activity.

The investigators found engaging in recommended amounts of activity was associated with a statistically significant lower risk of seven of the 15 cancer types studied, with the reduction increasing with more exercise hours. Physical activity was associated with a lower risk of colon cancer in men, breast cancer and  endometrial cancer in women, kidney cancer, myeloma, liver cancer, and non-Hodgkin lymphoma (particularly in women).

The analysis had some limitations. However, the authors conclude: “These findings provide direct quantitative support for the levels of activity recommended for cancer prevention and provide actionable evidence for ongoing and future cancer prevention efforts.”

“Physical activity guidelines have largely been based on their impact on chronic diseases like cardiovascular disease and diabetes,” said Alpa Patel, Ph.D., senior scientific director of epidemiology research at the American Cancer Society. “These data provide strong support that these recommended levels are important to cancer prevention, as well.”

So, folks, it’s time to put the remote down, put on your exercise outfit, and take your beloved dog out for a run. Both of you need it!

Phys.Org notes that sky watchers from Saudi Arabia and Oman to India and Singapore were treated to a rare “ring of fire” solar eclipse on Thursday (Boxing Day).

Annular eclipses occur when the Moon is not close enough to the Earth to completely obscure the Sun, leaving a thin ring of the solar disc visible.

While these types of eclipses occur every year or two, they are only visible from a narrow band of Earth each time and it can be decades before the same pattern is repeated.

Depending on weather conditions, this year’s astronomical phenomenon was set to be visible from the Middle East across southern India and Southeast Asia before ending over the northern Pacific.

Hundreds of amateur astronomers and photographers set up by Singapore’s harbour for what some described as a “once in a lifetime” event.

“The next one will happen in about 40 years I think,” said Jason Teng, 37, who took the day off work to photograph the eclipse.

In southern India, people gathered on the beaches in Tamil Nadu to watch the event.

The eclipse even affected cricket, with play delayed by two hours in a first-class match between Mumbai and Rajkot.

The eastern state of Odisha declared a public holiday, with all government offices, courts, schools and colleges closed.

The next annular eclipse in June 2020 will be visible to a narrow band from Africa to northern Asia, and the following one in June 2021 will only be seen in the Arctic and parts of Canada, Greenland and the remote far-east of Russia.

Writing in Science News, Christopher Crockett reports that a new satellite devoted to gazing at planets orbiting other stars has just launched into space.

At 3:54 a.m. Eastern time on December 18, the European Space Agency’s CHEOPS satellite lifted off from Kourou, French Guiana. CHEOPS — an abbreviation of “Characterizing Exoplanet Satellite” — is the first ESA-led mission dedicated solely to the study of planets outside the solar system. The launch was originally scheduled for December 17 but was called off shortly before take-off due to a glitch with the rocket.

Unlike many other exoplanet missions, CHEOPS is not setting out to look for new planets. Rather, it will gather data on exoplanets already found, helping researchers figure out how these worlds were built.

While orbiting Earth, CHEOPS will spend 3½ years looking beyond our solar system for exoplanetary transits: subtle dips in starlight that occur when a planet crosses in front of its sun. The bigger the planet, the more starlight it blocks. By measuring how much the star darkens, researchers will be able to deduce the planet’s girth.

The focus will be to measure precisely the sizes of roughly 500 planets orbiting relatively bright stars. By combining the sizes with measurements of mass — obtained by ground-based telescopes that record how fast a host star gets whipped around by a planet’s gravity — astronomers will be able to calculate each planet’s density, a key metric for figuring out what these planets are made of. Astronomers will also look for hints of atmospheres by tracking how quickly the starlight dims just before and after a transit.

And there’s always the chance that some unexpected planets will wander in front of their stars while CHEOPS is watching.

Transit-hunting is the same technique used by the now-defunct Kepler spacecraft, and the ongoing TESS mission, though CHEOPS has the advantage of knowing exactly when to look for a transit. While the worlds found by Kepler orbit stars that are too faint for CHEOPS to follow up, many planets discovered by TESS are just right, and the two teams are partnering up.

Finally, this is the season to be merry, but it is also the season to do silly things, and so the pleasure resorts, safe bathing beaches, hiking routes, and mountains to be climbed are full to overflowing with holidaymakers. Most of the people holidaying don’t know the areas they are in very well, and accidents abound, waiting to happen. The country is full of volunteer rescuers, from lifeguards, to search and rescue teams, to sea rescue institute crews, as well as all the governmental agencies, who are rushed off their feet at this time of year, saving people from themselves.

HAMNET heartily encourages you, Mr Man or Woman-in-the-street, to volunteer your help in responding to local needs, becoming part of the solution, and not part of the problem. And if you can’t find a cause to support, create one yourself, by cleaning out the local vlei, or trimming vegetation along your road that obstructs vision, or making contact with your local animal rescue agency, and offering to walk the dogs, or brush the cats, or asking at your local supermarket for scrap cardboard or newsprint which can be used to line the kennels of the sick animals. Above all, have a meaningful and productive 2020.

From all of us in HAMNET, this is Dave Reece ZS1DFR wishing you a happy and healthy New Year.