Galaxies and Malaria and Other Cool Science Stuff

A sampling of recent science news:

Hubble Finds a Galaxy With Almost No Dark Matter

Since the 1960s, astrophysicists have postulated that in addition to all the matter that we can see, the Universe is also filled with a mysterious, invisible mass. Known as “Dark Matter,” its existence was proposed to explain the “missing mass” of the Universe, and is now considered a fundamental part of it. Not only is it theorized to account for 26.8% of the Universe’s mass, it is also believed to have played a vital role in the formation and evolution of galaxies.

However, a recent finding may throw this entire cosmological perspective sideways. Based on observations made using the NASA/ESA Hubble Space Telescope and other observatories around the world, astronomers have found a nearby galaxy (NGC 1052-DF2) that does not appear to have any dark matter. This object is unique among galaxies studied so far, and could force a reevaluation of our predominant cosmological models.


What If A Drug Could Make Your Blood Deadly To Mosquitoes?

Ivermectin was developed in the early 1980s as a drug to fight parasites that cause river blindness and elephantiasis. Smit and his colleagues hope it can also help eradicate malaria. {Deborah points out that ivermectin is used to prevent heartworm in dogs.)

In their study, the researchers demonstrate that three high doses of ivermectin make human blood deadly to mosquitoes for up 28 days after the third treatment. This high dose of ivermectin was also well-tolerated with few side effects. “The most exciting result was the fact that even one month after [the subjects took] ivermectin, their blood was still killing mosquitoes,” Smit says. “That’s much longer than we thought.


NGC 247 and Friends 

Many background galaxies are visible in this sharp galaxy portrait, including the remarkable string of four galaxies just below and left of NGC 247 known as Burbidge’s Chain. Burbidge’s Chain galaxies are about 300 million light-years distant. The deep image even reveals that the two leftmost galaxies in the chain are apparently interacting, joined by a faint bridge of material. NGC 247 itself is part of the Sculptor Group of galaxies along with the shiny spiral NGC 253.


Macular Degeneration, Genes, and Vitamins

A study published in 2001 reported the finding that antioxidants and zinc supplements slow the progression of age-related macular degeneration (AMD). Based on this study, eyecare providers routinely recommend these supplements to patients with AMD. Since then we have learned a great deal about the genetics of macular degeneration.  Genes play a major role in the risk of developing AMD and in the progression of AMD.  Numerous genes have been identified.

A group of investigator has published research promoting the assertion that the standard combination of antioxidants and zinc may result in sub-optimal outcomes for AMD patients with specific genetic fingerprints. If their assertions are true, genetic testing would be necessary to ensure that patients are receiving the optimal combination of supplements. A second group of investigators has performed their own analyses, criticized the methods of the first group, and vociferously challenged their recommendations. This debate has become quite contentious, and played out in numerous articles, counter articles, and letters to editors.

This debate has tremendous public health implications. The prevalence of AMD is so high that even small incremental changes in outcome affects the lives of millions of patients. (Click through to read more on the arguments pro and con…)


Is there life adrift in the clouds of Venus?

In a paper published online today (March 30, 2018) in the journal Astrobiology, an international team of researchers led by planetary scientist Sanjay Limaye of the University of Wisconsin-Madison’s Space Science and Engineering Center lays out a case for the atmosphere of Venus as a possible niche for extraterrestrial microbial life.

“Venus has had plenty of time to evolve life on its own,” explains Limaye, noting that some models suggest Venus once had a habitable climate with liquid water on its surface for as long as 2 billion years. “That’s much longer than is believed to have occurred on Mars.”

On Earth, terrestrial microorganisms — mostly bacteria — are capable of being swept into the atmosphere, where they have been found alive at altitudes as high as 41 kilometers (25 miles) by scientists using specially equipped balloons, according to study co-author David J. Smith of NASA’s Ames Research Center.

There is also a growing catalog of microbes known to inhabit incredibly harsh environments on our planet, including the hot springs of Yellowstone, deep ocean hydrothermal vents, the toxic sludge of polluted areas, and in acidic lakes worldwide.



Galaxies and Malaria and Other Cool Science Stuff — 5 Comments

  1. As we concluded at dinner the other night, in order for ivermectin to be effective, the mosquito still has to bite a person—which doesn’t really solve the problem. Sure, they won’t be likely to bite you again, but once they feed on you the first time, they’re usually not going to be coming back for seconds in any case (being more preoccupied at that point with laying eggs and such).

    Now if we had a mass, longterm program of inoculation over the entire world population, which caused a permanent alteration in mosquito DNA to mark the scent of human respiration as deadly (sort of the way birds know to avoid certain caterpillars and bugs), then this might have some promise. But I really doubt that’s feasible. Face it: mosquitos just aren’t that smart.

    Only very thirsty.

    • Well, even if the mosquito bites one person once and then dies, it’s still progress on several fronts.
      On a trivial level: I’ve been bitten 3 or 4 times by one mosquito in one night before I managed to kill it, so that if it died after the first bite it might still save me from several more itchy bumps.
      On a more important level, if a mosquito bites a carrier for some blood-borne illness and then dies, it can’t bite someone else and spread the illness.
      So if you could give the Ivermectin to malaria-carriers (along with their usual malaria treatments) to make sure any mosquito that bites them can’t spread the illness, that would create a big improvement in the health environment for their families and neighbors.

      • True. The malaria-prevention aspect does hold promise.

        But, but—won’t someone please think of the bats!

        • I don’t think the bats are real mosquito specialists. They could eat lots of other flying insects, couldn’t they? Any kind of (small) fly that doesn’t drink blood would not be affected. Though if those suddenly get predated more, that might impact the plant species that are pollinated by little flies…
          Messing with ecologies is just one unintended consequence after another, isn’t it?

          But as you pointed out, not all mosquitoes will disappear, only those that bite protected malaria sufferers. So that might teach them to avoid that scent, or to prefer livestock to humans, or something like that.

          One unintended consequence of this, that I’ve just thought of, is what livestock farmers will do with this knowledge. Will they put their livestock on Ivermectin to diminish weight loss from mosquito irritation? Of course they will if it seems economically feasible and there’s no law against it. What will that do to Ivermectin resistance (nothing good, as we’ve seen from antibiotic resistance arising from overuse in livestock), and what will Ivermectin-poisoned blood do to vampire bats, vultures, or humans if they eat meat still tainted with the residuals?

  2. There are thousands of species of mosquitoes, almost none of which bite humans. So this drug probably would not make a noticeable dent in the population of little flying insects which bats and birds and other animals need to feed on.

    Hard to guess what might happen if livestock were treated with ivermectin. That’s a really interesting question. I doubt the amount of ivermectin in the meat would be significant for animals that eat it, considering that much higher doses are pretty safe for dogs and humans. Vampire bats, hmm. They might get exposed to much higher levels of ivermectin. If this causes trouble for them, farmers might not mind, considering that apparently vampire bats are fairly dangerous to cattle in some areas:

    I could imagine sudden strong pressure for resistance to ivermectin might cause some changes in the mosquito populations. One very possible change might be that the mosquitoes that now bite cows stop. Many mosquito species are extremely specific about what hosts they select to bite, so it’s quite possible the species would just switch hosts rather than rearranging their metabolism in some funky way.