Hormone replacement therapy (HRT) had been used to treat menopausal estrogen deficiency  for decades but the 2002 publication of a major study, the Women's Health Initiative (WHI), indicated increased risk for certain outcomes in older women, without increasing longevity.

This sparked debate regarding potential benefits and harm of HRT.

A new article published in The American Journal of Medicine conducted a meta-analysis of the available data using Bayesian methods and concluded that HRT almost certainly decreases mortality in younger postmenopausal women. 

An explosion detected on April 23 by NASA's Swift satellite was more than 13 billion light-years from Earth, representing an event that occurred 630 million years after the Big Bang, when the Universe was only four percent of its current age of 13.7 billion years.

Astronomers turned telescopes from around the world to study the blast, dubbed GRB 090423.  National Science Foundation's Very Large Array (VLA) first looked for the object the day after the discovery, detected the first radio waves from the blast a week later, then recorded changes in the object until it faded from view more than two months later.

Researchers say they have discovered how to transform human embryonic stem cells into germ cells, the embryonic cells that ultimately give rise to sperm and eggs, an advance that will allow researchers to observe previously inaccessible human germ cells in laboratory dishes.

"This achievement opens a new window into what was only recently a hidden stage of human development," said Susan B. Shurin, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that provided funding for the study. "Laboratory observation of human germ cells has the potential to yield important clues to the origins of unexplained infertility and to the genesis of many birth defects and chromosomal disorders."

A recent article addressed the issue of children being frightened of costumed characters and some of the other fears they might experience.  In some cases, this fear escalated into a phobia.

However, comments like "fears likely helped our ancestors survive" generate more alarm than comfort to me. Besides being pretty obvious, it raises the question of why fear should be considered such a bad thing, especially for children.

I can certainly understand that an unreasonable fear that has escalated all of out proportion and become debilitating can be problematic. I suspect that the vast majority of fears and phobias don't actually fall into that category.

After yesterday's cliffhanger, I suppose I should explain what it means for a squid to fly. Can they control their aerial trajectory? Can they gain altitude, once airborne, which is the definition of "true" flight?

Speaking of cephalopods which have surprised by not being too heavy to fly after all, I was reminded of one little cuttlefish who is actually too heavy to swim: Metasepia pfefferi, or Pfeffer's Flamboyant Cuttlefish. With the scientist's charming penchant for repurposing ordinary adjectives, biologists describe the body of this little fellow as "robust," which means that it is chubby in all dimensions. It may sound insulting to keep calling it heavy and chubby, but actually these features make for a very cool trick.

The Flamboyant doesn't swim and hover midwater like other cuttlefish. Instead, it crawls on the seafloor like an octopus.

My statistics page depressingly shows that a large fraction of readers who visit this site do so for an average of 30 seconds. Maybe they were looking for something different, or maybe they do not like the content offered here. In any case, I have decided that my long, detailed articles about particle physics are not exactly meeting the demand of the audience. I am not going to change my writing style because of that, of course, but I will try to also offer some thirty-seconds physics bits here, every once in a while. So let me make a dry run, using a recent result by the CDF collaboration. The clock may start.

NASA's Fermi Gamma Ray Space Telescope has captured more than one thousand discrete sources of gamma rays in its first year, including a measurement that provided experimental evidence about the very structure of space and time, unified as space-time in Einstein's theories.

Your Jack-o'-Lantern may scare away more than just birds - the skin of that pumpkin contains a substance that could put a scare into microbes that cause millions of cases of yeast infections in adults and infants each year, says a new study in the Journal of Agricultural and Food Chemistry.

Kyung-Soo Hahm, Yoonkyung Park and colleagues note that some disease-causing microbes are becoming resistant to existing antibiotics so scientists worldwide are searching for new antibiotics. Past studies had hinted that pumpkin, long used as folk medicine in some countries, might have antibiotic effects.