Posts Tagged TED
How good would this be? According to a recent TED talk by Mark Kendall it could soon become reality (http://www.ted.com/talks/mark_kendall_demo_a_needle_free_vaccine_patch_that_s_safer_and_way_cheaper.html).
Instead of using a needle and syringe the vaccine is applied via a patch that is placed on the skin. The patch contains thousands of projections that release the vaccine into the top layers of the skin. As well as being pain free the administration of the vaccine into the skin, rather than the muscle, also generates a more powerful immune response. This means that much less vaccine is required (up to one hundredth of the traditional dose) lowering the cost and decreasing the possibility of undesirable side effects.
The vaccine that coats the patch is in a dry form. Therefore, it does not need to be refrigerated, unlike traditional vaccines, and will retain its potency at 23 C for up to a year. This makes it much more feasible to use in countries where electricity and refrigeration are difficult to guarantee, such as Papua New Guinea which has only 800 refrigerators. Patch trials are due to start there soon.
Dr. F. Bunny
Recently I watched a TED talk by Suzana Herculano-Houzel (http://www.suzanaherculanohouzel.com/lab) entitled, “What is so special about the human brain?” (http://www.ted.com/talks/suzana_herculano_houzel_what_is_so_special_about_the_human_brain.html). In this presentation she makes the intriguing assertion that our brain is as large as it is, at least in part, because we cook our food.
Size, as in brain size, is not as important as neuron number when it comes to intelligence. Although the elephant brain is three times as large as the human brain it contains 23 billion neurons, compared with 86 billion in the human brain (http://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons).
Unfortunately the human brain is incredibly expensive to run, 25% of the energy consumed daily goes to fuel the brain. It costs around 6 kCal to run one billion neurons per day. Despite great apes being physically larger than us, their brains are smaller. Herculano-Houzel proposes that this is because they cannot consume enough calories on a daily basis to run a bigger brain. They do have a fairly low energy diet consisting predominantly of high fibre plant material with a few fruits and, in the chimpanzee’s case, some meat. This may be why the chimpanzee can afford to run 5.5 to 6.2 billion cerebral cortical neurons compared with the gorilla’s 4.3 billion.
However, humans maintain between 19 and 23 billion cerebral cortical neurons. Herculano-Houzel believes we can feed this number because of cooking, which effectively predigests our food releasing more energy and allowing us to more completely absorb our food. She depicts a graph, which correlates the increase in brain size of our ancestors with the invention of cooking.
Paradoxically we are now moving away from cooking and processing back to a more unprocessed diet because we appear to have overdone it, consuming too many calories and becoming extremely obese in the process. If we could only divert all those extra calories to our brains instead of our bodies imagine how incredibly intelligent we could become.
Dr. F. Bunny
I was watching yet another presentation about the possibility of reviving extinct life forms (http://www.ted.com/talks/hendrik_poinar_bring_back_the_woolly_mammoth.html). Now that we appear to have the technology, at least in theory, to extract DNA from long dead animals and place it in currently extant species there seem to be more and more articles about how terrific it would be to bring them back from oblivion. This particular talk concerned reviving the woolly mammoth but I have seen similar ones suggesting restoring the thylacine, or Tasmanian tiger, to life.
Technology has been astonishingly uninspiring when it comes to saving the world’s current long list of endangered species. While there have been a few cases of successful artificial insemination or an embryo from an endangered species being reared to term by a surrogate (http://www.scientificamerican.com/article.cfm?id=cloning-endangered-animals), the majority of effective conservation programs have relied on natural breeding to create enough animals to sustain a population, along with addressing the causes why the species became endangered in the first place. There are too many unknowns when it comes to artificially breeding wild animals: how best to harvest the eggs and collect sperm, how to freeze gametes and embryos, synchronising reproductive cycles, carrying a foreign species to term, providing appropriate milk, etc, etc. All these difficulties, and more, apply to the resurrection of extinct species.
If we are able to successfully impregnate a surrogate that takes the pregnancy to term, then what? We have a single individual being reared by an individual of a different species. If this works what do we then do with our mammoth or thylacine? Apparently appropriate mammoth habitat exists in Siberia. But what would our solitary mammoth do in such a place? We would need to produce at least 50 mammoths (probably more like 500: http://www.eoearth.org/article/Minimum_viable_population_size?topic=58074), to create a self-sustaining population. Given the paucity of genetic material available to play with, these mammoths would be virtual clones with very little genetic diversity. All conservation programs seek to maximise genetic diversity to avoid the problems that now occur in inbred populations e.g. Tasmanian devils and their contagious cancer.
What would be the point of bringing back one species? The mammoth will be no more than a curio, devoid of any real value, unless you bring back its entire ecosystem. This ecosystem would need to include not just all the extinct animals but also all the plants it shared its former existence with.
There is more logic in restoring the thylacine as it only became extinct in the 1930s, not 4000 years ago, but even there the Tasmanian ecosystem has changed in the past 70 years. Would it not make more sense to invest all that time, money and expertise into preventing other species from heading down the same extinction path, instead of wasting it on frivolous projects whose only purpose seems to be to let scientists marvel at their own cleverness?
Dr. F. Bunny