To listen to more of Martin Raff’s stories, go to the playlist: https://www.youtube.com/watch?v=YxaSzxT5Uns&list=PLVV0r6CmEsFwhzamH0DHsJ8SS5tgH4A_8
Born in 1938, Martin Raff is a Canadian-born neurologist and research biologist who has made important contributions to immunology and cell development. He has a special interest in apoptosis, the phenomenon of cell death. He retired from active science in 2002. [Listener: Christopher Sykes]
TRANSCRIPT: So he’s been treated with testosterone for a year and a half now and because this is all being controlled by a clinic at Stanford, he’s psychologically tested every few months. And so interestingly, I mean, even though this is now sex hormones being given to an adult, his brain is clearly changing dramatically so his ability in space… spatial ability is increasing. It’s… males do this better than females, where his verbal abilities, females do this better than males, is decreasing with time.
So it got me interested in this whole question of sex hormones and brain plasticity, and so the history here is quite remarkable. It was believed until the early 1970s that the brain of a male and a female is the same in a mammal, like us, and that the reason our behaviour is so different is that, you know, the external genitals are different and social influences affect your behaviour. So the first clue that that wasn’t right was in 1971 where someone in Britain discovered that the female rat brain is quite different, at least in one area, from the male rat brain and now… this has now been shown in many animals and it’s been shown in humans and there are many differences between the male and female brain.
And then in 1990 I believe Dick Swaab in the Netherlands showed that homosexual men, their brain in this one particular area, in one part of the brain has twice as many nerve cells as males that are not homosexual, that are heterosexual. And then a year later someone else in the States found a different nucleus where in homosexuals it’s different, it’s like a female, so that’s rather remarkable. And then in 1995 the same guy who made the first discovery about homosexual differences in the brain looked at transsexuals, male to female transsexuals, and showed that yet a different region of the brain is different in these males. They, in this region, look like females.
So it’s quite a remarkable thing and the… the second thing that’s I think quite interesting is that there’s a very big difference between your sexual identity and your sexual orientation. So Ben Barres is a transsexual; from as long as he can remember he never felt like a girl, even though he looks entirely female… always felt male. He never felt comfortably in his body and that’s true of all transsexuals, but their sexual orientation can be heterosexual, homosexual, bisexual, asexual. So Ben is now homosexual because always has been attracted to men and still is attracted to men. So your sexual orientation is quite different from your sexual identity, and it turns out it’s different parts of the brain that are doing it.
So how does all this happen, and how much of it is genetic, and how much of it is hormonal, and how much of it is behavioural? So it turns out that a hell of a lot of it is hormonal and it sort of works like this: we are born… earlier… not born. A fertilised egg as it develops can become either a female or a male. It depends on one gene sitting on one chromosome, the Y chromosome. So the male has an X and a Y, the female has two Xs. On the Y chromosome there’s one gene. If you have that, you develop as a male. You put that one gene into a female embryo and, bang, it becomes a male.
Read the full transcript on [https://www.webofstories.com/play/martin.raff/11].
This site provides links to random videos hosted at YouTube, with the emphasis on random.
The original idea for this site actually stemmed from another idea to provide a way of benchmarking the popularity of a video against the general population of YouTube videos. There are probably sites that do this by now, but there wasn’t when we started out. Anyway, in order to figure out how popular any one video is, you need a pretty large sample of videos to rank it against. The challenge is that the sample needs to be very random in order to properly rank a video and YouTube doesn’t appear to provide a way to obtain large numbers of random video IDs.
Even if you search on YouTube for a random string, the set of results that will be returned will still be based on popularity, so if you’re using this approach to build up your sample, you’re already in trouble. It turns out there is a multitude of ways in which the YouTube search function makes it very difficult to retrieve truly random results.
So how can we provide truly random links to YouTube videos? It turns out that the YouTube programming interface (API) provides additional functions that allow the discovery of videos which, with the right approach, are much more random. Using a number of tricks, combined some subtle manipulation of the space-time fabric, we have managed to create a process that yields something very close to 100% random links to YouTube videos.
YouTube is an American video-sharing website headquartered in San Bruno, California. YouTube allows users to upload, view, rate, share, add to playlists, report, comment on videos, and subscribe to other users. It offers a wide variety of user-generated and corporate media videos. Available content includes video clips, TV show clips, music videos, short and documentary films, audio recordings, movie trailers, live streams, and other content such as video blogging, short original videos, and educational videos. Most content on YouTube is uploaded by individuals, but media corporations including CBS, the BBC, Vevo, and Hulu offer some of their material via YouTube as part of the YouTube partnership program. Unregistered users can only watch videos on the site, while registered users are permitted to upload an unlimited number of videos and add comments to videos. Videos deemed potentially inappropriate are available only to registered users affirming themselves to be at least 18 years old.
YouTube and selected creators earn advertising revenue from Google AdSense, a program which targets ads according to site content and audience. The vast majority of its videos are free to view, but there are exceptions, including subscription-based premium channels, film rentals, as well as YouTube Music and YouTube Premium, subscription services respectively offering premium and ad-free music streaming, and ad-free access to all content, including exclusive content commissioned from notable personalities. As of February 2017, there were more than 400 hours of content uploaded to YouTube each minute, and one billion hours of content being watched on YouTube every day. As of August 2018, the website is ranked as the second-most popular site in the world, according to Alexa Internet, just behind Google. As of May 2019, more than 500 hours of video content are uploaded to YouTube every minute.
YouTube has faced criticism over aspects of its operations, including its handling of copyrighted content contained within uploaded videos, its recommendation algorithms perpetuating videos that promote conspiracy theories and falsehoods, hosting videos ostensibly targeting children but containing violent and/or sexually suggestive content involving popular characters, videos of minors attracting pedophilic activities in their comment sections, and fluctuating policies on the types of content that is eligible to be monetized with advertising.