Category: Science (page 2 of 103)

under the sea on ecstasy – octopuses on MDMA

 

octopus on ecstasy

An octopus explores its surroundings. After receiving ecstasy, octopuses become more social.

Have you ever wondered what would happen to an octopus on ecstasy? If you have, then you aren’t alone. Gul Dolen, a neuroscientist a Johns Hopkins University School of Medicine, had wondered the same thing.

She and Eric Edsinger, conducted a study on the effects of the drug ecstasy, also known as (+/−)-3,4-methylendioxymethamphetamine or MDMA, on the brains and behaviors of octopuses. They placed octopuses  a chamber and allowed them to explore on their own. The chamber was connected to two others, one containing a hidden octopus and another containing a strange object. They then compared the time the octopus spent with either the object or the second octopus. The octopus tended to gravitate toward the other animal but only if it was a female. If the second octopus was a male, it avoided the second creature. This was true for bothe male and female octopuses placed into the chamber.

Then they gave the octopus a hit of MDMA, by dunking it into a solution containing the drug to allow it to soak in through its gills. While on the drug they spent way more time with male octopus. Describing their behavior, Dolen says”

“They mashed themselves against one wall, very slowly extended one arm, touched the [other animal], and went back to the other side. But when they had MDMA, they had this very relaxed posture. They floated around, they wrapped their arms around the chamber, and they interacted with the other octopus in a much more fluid and generous way. They even exposed their [underside], where their mouth is, which is not something octopuses usually do.”

This was very unusual behavior for octopuses, which are known to live in solitude. MDMA appeared to make the animals more social in a way that mimics its effects in humans. After studying serotonin transporter proteins in humans and octopuses, the researchers found that the sequences had a 50% match. It is especially similar in the part of the protein where MDMA binds, and that is why they believe they see similar effects in behavior.

But, some scientists remain unconvinced. The researchers always administered the drug after the control, so their more exploratory behavior could just be due to them being more comfortable in their surroundings. Other scientists suggest that ecstasy may just be interfering with the animal’s ability to detect chemical information from potential mates.

 

airport trays are full of germs

airport tray germs

Trays at airport security stations are loaded with microbes. A new study shows they can contain more viruses than toilets.

Air travel is a well known culprit in the spread of infectious diseases, such as the common cold and the flu. We can now add another potential mechanism for the spread of these types of infections, thanks to a new study published in BMC Infection Diseases last month.

Scientists from the University of Nottingham in England and the Finnish National Institute for Health and Welfare swabbed the trays and other airport surfaces after peak travel times, then identified traces of common respiratory viruses that were found in those samples. They looked at a variety of surfaces including toilets, pay machines, hand rails and luggage trays. Of all of the surfaces that they sampled, the luggage trays contained the most identifiable traces of respiratory viruses. Out of the 8 tray samples, 4 of them were positive for respiratory viruses like rhinovirus, which causes the common cold, and influenza, or the flu. Out of the 14 samples from the toilet flush button, zero gave positive results.

We know that objects that are frequently handled or manipulated with our hands tend to be laden with bacteria. Mobile phones, tv remotes and computer keyboards have been identified as having high bacterial counts. It now appears that the same applies to airport trays.

One caveat of the study is that although traces of viral DNA were found on various surfaces, this does not necessarily mean that they were contagious or able to infect humans. However, viruses and microbes have been known to survive for a few days on surfaces.

What can you do to minimize your risk of infection? The best advice still applies:  Wash your hands!

the persistent myth of the super sperm

sperm egg fertilization

Fertilization occurs when a sperm cell fuses with an egg.

Over at AeonRobert D Martin debunks a persistent myth of biology. Many people, including scientists, believe that during fertilization, sperm are in competition, racing to be the first to fertilize an egg. Because sperm competition is observed in chimpanzees and other mammals closely related to humans, people think that the same holds true for men. But Robert points out all the evidence against this theory.

First, human sperm contains a higher proportion of deformed or abnormal sperm compared to chimpanzees. If sperm were in competition to fertilize an egg, you would expect for there to be fewer nonmotile sperm than are observed. Chimpanzees, have relatively few abnormalities in their sperm cells.

Secondly, much of the sperm’s transport to the ovary is achieved passively. Through the womb and oviducts, a wafting and pumping motions propel sperm through the female tract. And in fact much of the selection of intact sperm is happens because of  environment in the woman’s vagina and cervix.

Many sperm do not even make it into the neck of the womb (cervix). Acid conditions in the vagina are hostile and sperm do not survive there for long. Passing through the cervix, many sperm that escape the vagina become ensnared in mucus. Any with physical deformities are trapped. Moreover, hundreds of thousands of sperm migrate into side-channels, called crypts, where they can be stored for several days. Relatively few sperm travel directly though the womb cavity, and numbers are further reduced during entry into the oviduct. Once in the oviduct, sperm are temporarily bound to the inner surface, and only some are released and allowed to approach the egg.

Robert continues from there, explaining what happens when too many sperm reach an egg and how cervical mucus can contain and release viable intact sperm for up to 5-10 day. The essay is quite interesting and well worth a read, so I won’t spoil it all. It’s an interesting counterargument to the manly notion that the best sperm gets the egg.

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