Viral respiratory epidemics like the flu spike cyclically during autumn and winter - but only in the temperate regions of the globe's northern and southern hemispheres.

In the equatorial belt, they happen all year round, at lower levels.

A new numerical model hopes to provide insight. The authors find that both the prevalence and evolution of epidemics are strongly correlated with the amount of daily solar irradiation that hits a given location on the Earth at a given time of the year. 

In a classic "Charlie Brown" Halloween tale, one character believes in the pumpkin equivalent of an Easter Bunny or Tooth Fairy, but NGC  2292 and NGC  2293 are real. At 109,000 light-years across, the diameter of our Milky Way, they don't just form a Great Pumpkin, they form the greatest pumpkin of all.

What looks like two glowing eyes and a crooked carved smile is a snapshot of the early stages of a collision between the two galaxies. The "pumpkin’s" glowing "eyes" are the bright, star-filled cores of each galaxy that contain supermassive black holes. 

In February of 2020 there was a lot of confusion about how to contain the spread of SARS-CoV-2, the 2019 form of coronavirus that erupted in Wuhan, China. Much of the confusion was caused by political operatives and allied journalists. The federal government said we needed to restrict travel and that was deemed xenophobic, even racist, and epidemiologists were trotted out claiming that it would not work.

After clinical trials showed the safety and efficacy of Veklury (remdesivir) in adult and pediatric patients 12 years of age and older, the U.S. Food and Drug Administration has approved the antiviral drug for the treatment of severe COVID-19 - requiring hospitalization.

Veklury is the first treatment for COVID-19 to receive such FDA approval but it did get an Emergency Use Authorization (EUA) on May 1, 2020.

The approval of Veklury was supported by the agency’s analysis of data from three randomized, controlled clinical trials that included patients hospitalized with mild-to-severe COVID-19.

In early 2020 the U.S. government reacted to worrisome death figures for COVID-19, the SARS-CoV-2 form of coronavirus that erupted in Wuhan China in late 2019, and restricted air travel. This was xenophobia, political critics charged, and not based on evidence. Closing borders was not going to work anyway.

ome 250 million years ago, in the time when life was recovering from

The greatest mass extinction of all time, the Permian-Triassic mass extinction 250 million years ago, killed 95 percent of life, and the very few survivors faced a turbulent world, repeatedly hit by ice ages, rapid warming and ocean acidification cycles.

Through all of that, two main groups of tetrapods survived; the synapsids and archosaurs, ancestors of mammals and birds. And a new study find that the ancestors of both mammals and birds became warm-blooded at the same time.