Sex with time-travellers might kill you.

When time travel finally becomes possible, we might want to think twice about getting it on. According to a new study on tiny shrimp (Artemia franciscana), sex with partners from a different time could kill you.

Researchers at the Center for Functional and Evolutionary Ecology (CEFE) in Montpellier, France, collected preserved brine shrimp eggs from various generations, and then reanimated them with water. Nicolas Rode and colleagues mated pairs of brine shrimp that had been reanimated from eggs preserved since 1985, 1996 and 2007, a period representing roughly 160 generations. They found that females that mated with males from the past or future died off sooner than those that mated with their own generation. The longer the time-shift, the earlier they died: The 22-year time difference shortened female lifetimes by 12 percent; the effect was 3 percent for the 11-year time-shift.

Interestingly, this didn’t affect the females’ reproductive success. Those that lived shorter lives produced the same average number of offspring, they just did it at a faster pace. “Females’ life histories are complex and are constantly adjusted,” explains study co-author Thomas Lenormand. These adjustments reflect the trade-offs between survival and reproduction in nature.

Brine shrimp are part of an interesting class of animal whose eggs can survive decades of drought in a form of dormancy known as cryptobiosis. Once the eggs are reintroduced to water—either in nature or in the lab—they hatch. The species therefore makes an ideal subject for a time-traveling experiment like this one.

What makes time-shifting sex hazardous to health is something called antagonistic coevolution, a way that different species (parasites and hosts, for example) or members of the same species (males and females) adapt to each other to promote their own individual reproductive interests. In nature’s sex wars, males campaign for more offspring—the proverbial seed-spreading—while females play hard-to-get because they bear most of the burden of reproduction and parenthood.

Evolutionary biologists say these conflicts are common in nature, and could occur either as an arms race, with each side’s weapons getting bigger and better, or as a fluctuation, where the two sides take turns dominating each other over time with novel adaptations.

If males and females coevolve their sex organs in tandem, mating with a partner from a different time could leave you unprepared—sort of like heading into modern war with 17th-century armor. The brine shrimp experiment shows just this.

Unfortunately, the researchers couldn’t determine whether there were arms-race-style or fluctuation-style adaptations at work in this experiment. They’d need a longer time-shift to figure that out, which would test the limits of brine shrimp cryptobiosis. They also don’t know what traits made the time-shifting males more deadly. Lenormand and Rode say they’d like to investigate these traits in the future. It could have something to do with amplexus, in which male brine shrimp grasp their partners for hours or even days after sex to keep them from mating with others. A byproduct of this so-called mate guarding is that the females can’t feed, which could shorten their lifetimes. The researchers would also like to flip the experiment on its head, studying the effects of time-shifting sex on males instead of females.

So what does shrimp sex have to do with us? Sexual conflicts and antagonistic coevolution are “probably central to understanding male/female behavior,” Lenormand says. In fact, it turns out that antagonistic coevolution is hard at work in humans today. I’ve previously written about the possible antidepressant properties of seminal fluid. But there’s a dark side to semen, too. Gordon Gallup, an evolutionary biologist as SUNY Albany explained it thus:

“At the level of semen chemistry and vaginal chemistry, there’s competition. The vagina is a very hostile environment for sperm. When a female is inseminated, the presence of the semen triggers an immune reaction, so semen—and particularly the sperm—are treated as pathogens. Male seminal plasma contains all kinds of chemicals that are designed to take this into account. Seminal plasma is alkaline, and a couple seconds after ejaculation the pH of the vagina approaches neutrality, which makes it a friendly environment for sperm. Sperm also contains a lot of immunosuppressants that suppress the female’s immune system and counteract this immune reaction to semen.”

The amazing fire ant.

Fire ants might be infuriating little beasts, an invasive species we’d all be pleased to see banished to its native Brazil, but it turns out a fire ant colony has some pretty amazing properties. In groups, they knit together, more like a fabric than anything else, and are waterproof, totally flexible, and nearly indestructible. A mechanical engineer describes these groups as behaving like a thick liquid.

Nobody has really bothered to study fire ants before, having been generally more interested in cursing at them and running quickly away from them, but a couple of mechanical engineers at the Georgia Institute of Technology noticed some pretty incredible properties upon examination. Turns out fire ants, when in groups, grasp onto each other using their mandibles, forming an intricate and precise pattern something like a Gore-Tex fabric.

This fabric-like bunching is even weirder than it sounds: The group of ants can be molded almost like a thick liquid (Wired compares it to honey or ketchup), and it will retain that shape even when manipulated. To undergo a waterproofing test, the engineers simply spun a bunch of ants in a cylinder, forming them into a near-perfect sphere in the same way you might form a meatball, if you used scientific equipment and not your hands while cooking. These ant-balls, with about 500-8,000 stinging bugs per ball, were dropped into a vat of water, where they assuredly did not drown.

Instead, the ant-ball almost instantly spread out into a raft, enhancing the ants’ already hydrophobic waterproofing. Ants can survive for days on the water in this way, never at risk of drowning. In fact, the engineers even poked this ant-raft with a stick (which would have been your first instinct too, don’t lie) and found that it was so hydrophobic that it merely bent the surface of the water rather than pushing the ants underneath it.

So how is this useful? Well, given how much we love biomimicry, we could easily see some of the properties of these ants used for commercial fabrics, but the engineers suggest military microbots could have a lot to learn from these ants as well.

Oh, and if you’re concerned about a bunch of engineers manhandling, poking, and doing their damnedest to drown these animals, don’t be. The fire ants, collected from the Georgia road-side, are a highly overpopulated invasive species in that region, and the engineers say they further “lost sympathy for them” after more than a few bites.

Intro: Was treatment the right way to go?

The amount of new cases of HIV have been more or less stable the last decade, but I wonder – how would it look if we didn´t treat the infected? There are about 50 million HIV positive people on the planet today, and a large part of them are people undergoing a strict antiretroviral drug regiment – costing the public billions of dollars each year. And the treatment give the infected up to 20 years longer before they develop AIDS, if they develop it at all. But the problem is this, then they have 20 or so more years with the ability to infect others.

The way to get rid of dangerous deceases like HIV/AIDS isn´t to keep it in check, but to let the infected die out or find a cure. If treatment never started, and we focused the funds given to research for these regiments on how to prevent infections, the world-wide numbers would be way down.

I´ll continue this when I´ve done a bit more research, but I actually think that treatment was the wrong way to go. Call me brutal, but the only way to eradicate deadly deceases is to cure or let the infected die – though I do get why someone infected with HIV wants to live as long as possible, but that doesn´t make it the right strategy for eradicating the illness.

Three new AIDS advances embolden the medical community

After three decades, major developments in HIV treatment and prevention are finally moving forward at a steady pace – two studies and one extraordinary patient have captured the attention of doctors and scientists, and made the idea of a cure less fantastical.

Doctors say American Timothy Ray Brown was indeed cured of HIV in Germany. The “Berlin Patient” was being treated for leukemia when he was given a bone marrow transplant using the stem cells of a HIV resistant donor. More than two years after the transplant, his bloodstream is now free of HIV even though he´s not taking antiretroviral drugs.

Many of us view this as a unique case that´s not relatable to people doing very well on medications, says Peter Anton, a professor of medicine at the University of California, Los Angeles. However, it does provide proof that it´s possible to eradicate HIV from the body. Until now we haven´t had that proof because of concerns that there are hidden reservoirs of HIV as well as low levels of HIV replication we cannot detect.

There is also much excitement over microbicides, a new type of prevention method in the form of a gel applied vaginally or rectally to prevent infection, especially after last year´s announcement that a vaginal gel containing the antiretroviral drug tenofovir had a 39% success rate among South African women. Further advances could boost those numbers, and more studies are under way. Human trials of rectal microbicide will likely begin in two to three years.

If you go to a bar nad ask how many people know what a microbicide is, most people won´t raise their hand, Anton says. We want to change that.

Another breakthrough came out of a study on pre-exposure prophylaxis, PrEP. Results showed that regular doses of the antiretroviral pill Truvada cut HIV infection rate by 44% among a group of HIV-negative, specially men and transgender women who have sex with men. While Anton is heartened by the findings, he offers caveats, specially about people preemptively taking PrEP without further confirmation of its success. The second major PrEP worry involves those who contract HIV while taking the regimen – there´s a chance they could become resistant to other antiretroviral drugs.

There are so many people who do not know their diagnosis, Anton says. If they end up taking prevention medicines but are already HIV-positive, they could be utilizing single-drug therapy, which is a big NO-NO. To avoid drug resistance, HIV-positive people need combination-drug therapy.

As studies on PrEP continues, regiment refinement is likely on the horizon.

One of the efforts on the PrEP side was to study preventive use in a controlled setting so we could document whether you need it daily or weekly, Anton says. This is going to be looked at further so we can give more informed guidelines than those out now.

Note: Mutations protect against development of AIDS

One out of about 300 infected with the HIV virus never developes full-blown AIDS. They are in some way able to keep the virus under control.

An international team of researchers have now found five mutations in the protein HLA-B which makes it easier for the immune system to identify the HIV virus and attack it. This may be a clue to finding the flaws of the virus and help in finding a cure.

Related stories:
Norwegian gay men – not safe enough!
HIV, a thing of the past?

The largest black hole ever measured

A universal heavyweight champion was crowned this morning at the 217th meeting of the American Astronomical Society in Seattle: A giant black hole weighing a staggering 6.6 billion suns accepted the title of the most massive black hole for which a precise mass has been determined.

That’s not to say it’s necessarily the largest black hole in the universe by any means, but we haven’t measured a bigger one. Located at the heart of the galaxy M87 some 50 million light years away in the direction of Virgo, the black hole is so big it could swallow our solar system hole easily. Its event horizon – the boundary at which nothing, not even light, can escape the monster’s gravitational pull – is four times as large as the orbit of Neptune, our sun’s outermost planetary satellite.

Previous estimates of M87’s black hole mass registered at some 3 billion suns, still 1,000 times the size of the Milky Way’s welterweight black hole. The new measurements were acquired using the adaptive optics capabilities on the 26.6-foot Frederick C. Gillett Gemini Telescope on Mauna Kea, Hawaii, which can compensate for the distorting effects of Earth’s atmosphere. This allowed astronomers to gauge just how fast the stars in M87 are orbiting the black hole, and from that they could determine the mass.

If one simply compares the old measurements of M87’s black hole to it’s current massive size, it might beg the question: Is M87 juicing? Indeed, astronomers think the black hole did get some outside help beefing up over the course of its lifetime. Aside from feasting on gas and stars, M87’s champion is likely the result of a series of black hole mergers, the last of which may have happened in the not too distant past.

Whether M87’s black hole achieved its mass fairly or not, it may not hold the heavyweight title for very long anyhow. Over the next decade astronomers plan to hook up telescopes all over the world to create a whole Earth submillimeter array that will vastly increase their ability to locate event horizons and characterize the size of black holes throughout the universe.