Sunday, 12 August 2012

Biology stuff from the fortnight 30/7 - 12/8/12

C0nc0rdance - The Science Of Human Race (43 mins 18 secs in total)
Part 1:
Part 2:
Racism is wrong not because it means 'judging people' but because races are nonsense - they are not science.

'A flash of light changes cell activity - and understanding of disease'
Blue light has been used to manipulate the shape and motility of cells, by combining photo-receptive proteins from plants with enzymes in the cell's outer membrane.
This formed a 'complex', by which the behaviour could be influenced, by the influence of the enzymes, by the influence of the incidental light.
But this is more than just playing with cells in a lab, saying "ooh, look - it goes this way, and now it goes this way - it goes this way, and now it goes this way..."
The cell membrane plays a large part in the functioning of cells, and malfunction is associated with cancer, many diseases, diabetes, and neurodegenerative diseases.
Many forms of dementia involve the physical degredation of the myelin sheath which protects the axon of the neurons from harm, and increases the integrity of the charge flow.
Basically, if light can be used to influence the way cell membranes behave, then there is an avenue of research by which treatments for these kinds of conditions might be found.

In another story, this week, light has been used to change the activity of brain cells:
'Light-activated brain cells boost monkey skills'
The team identified the region of the brain used by monkeys, while doing a spot-identifying activity - the arcuate sulcus.
They then inserted a gene that makes photoreceptive proteins, to work in conjunction with the neurons there, so that light would influence their activity.
Using thin needles, they guided light striaght to the arcuate sulcus, and boserved the changes that happened.
"During the treatment, they were able to locate the dot on the screen about 10 per cent faster than before."
Just like in the cell-membrane study, this is just a proof-of-principle experiment, so this might or might not lead to a useful application in medicine.

[video] It's that gene again - FOXP2.
'Of mice and melodies: Research on language gene seeks to uncover the origins of the singing mouse'
Scotinomys teguina is a species of mouse that uses vocalisations, much like most birds do, to communicate over (relatively) long distances.
Unlike birds, however, they utilise only one note, so although it bears a similarity to birdsong, the difference is obvious - no tune.
The FOXP2 gene has been identified, in humans, and now in singing mice, to play an important role in developing the ability to vocalise.
In humans, people with FOXP2 variations often have difficulty forming sounds with their mouths, as well as understanding grammar.
The reason FOXP2 has such a broad effect, is that it encodes how other genes are expressed - it is a transcription factor - and because it has influence through a variety of other genes, it is effectively pleiotropic.
The researchers noted that regions containing FOXP2 lit up, when the mice were listening to songs of their own species, indicating that it is involved in recognition of and integration if audio information.
Further research should provide deeper insight to the mechanics of language and language learning.

Scientists at the Smithsonian have found that females of the giant wood spider - Nephila pilipes - 'bung themselves up', to avoid unwanted and excessive copulation from males.
The giant wood spider is a polyandrous species - many males compete for a few females - and it is common practice for males to deliberately lose their genitals, to prevent other males from mating with her.
By plugging themselves up, females enduring sexual conflict can opt out.
Also observed in spiders, is that female spiders who cannibalise her male partners, produce more robust egg cases, than those that don't.

15% of 136 sampled plectropomus leopardus, otherwise known as the common coral trout, have dark lesions on their skin. And now we know that they are indeed melanomas - the first verified case of skin cancer in fish.
"In the lab, hybridised fish were found to be more susceptible to UV radiation due to exposure of the so-called 'Xmrk' gene. In the case of coral trout cross-breeding – or hybridisation – may also be occurring and play a role in the coral trout's susceptibility to the disease."

[video] Marinologist Stephanie Bush has observed the squid species Octopoteuthis deletron, apparently deliberately detaching its tentacles, in order to escape.
The blue-tailed skink is a well-known example of a land vertebrate that can detach its tail, to occupy predators while it flees. No squid had previously been observed doing this.

No comments:

Post a Comment