Some more pure science from guest blogger LisaJ:

Everyone seems to love a little Sonic Hedgehog around here. Whenever PZ discusses another function that this fascinating gene is capable of, much excitement ensues in the comment posts. So I thought I would take this opportunity to talk a bit about what I study, and how my seemingly unrelated favourite protein pathway is also connected to the Shh gene.

The main protein that I study was originally identified through studies of a pediatric eye cancer, called Retinoblastoma, as loss of function of this protein (termed the Retinoblastoma protein, or pRb for short) was found to be causative in the formation of this tumour type. What we know now is that pRb is required to control normal cell division in all cell types; its functional loss leads to the formation of many types of tumours, and is thought to be involved in the development of at least half of all human cancers. Not only is pRb essential in preventing uncontrolled cell division that can lead to cancer, but it is also essential for embryonic development, as mice deficient for the Rb gene die by about the 15th day of gestation, about 5 days before they would be born.

To explain how pRb functions in the cell, I thought that I could easily pull out a figure from a review paper that diagrams a simplified cell cycle pathway and the protein interactions that take place. But instead, I’m going to show you this beautiful piece of work that a few of my talented previous lab mates created for me one day, as a means of cheering me up after a year’s worth of protein purifications and binding assays did not give me the result I was hoping for. Although a simplistic depiction of cell cycle regulation, I think it really drives home the point well of how pRb functions.

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Imagine you’re a paleontologist, digging through the Sahara desert looking for dinosaur bones and you stumble, instead, upon this wondrous find:

That’s exactly what happened to Paleontologist Paul Sereno and his team back in 2000, and they have announced their findings from their excavations of this region in Northern Niger in National Geographic this week. This team unexpectedly unearthed 200 human burials on the shores of a long dried up lake, representing two very distinct cultures spanning 5000 years (between 4500 to about 9000 years ago). The image shown above is of their ‘most striking discovery’, and depicts a woman and two children, ages 5 and 8, holding hands. They also found pollen in the grave, suggesting that they may have been laid on a bed of flowers. Very cool stuff. These researchers have located the remnants of two human tribes that are thought to have lived in the Sahara during the Holocene period, when environmental factors culminated in a ‘greening’ of the desert, which attracted human inhabitants.

Here’s a video featuring an interview with Paul Sereno and some nice shots of their excavation sites. They give a really nice overview of what they have discovered about the two distinct colonies found, and how they may have lived. You can also read the whole story in National Geographic, if you’re so inclined, where you will also find a link to additional photos of the site and their excavations, which are quite amazing.

Here’s a link to the study’s paper appearing in the current issue of PLoS ONE.

From guest blogger LisaJ

Here’s an awesome video of the most recent solar eclipse that took place a couple of weeks ago. This group was lucky enough to witness the eclipse from their airplane seats! You can see the eclipse pretty much from start to finish. Wait it out until the end, because it’s an amazing view when the sun comes back out. (Posted by LisaJ).

Here’s the open thread for comments about the Evolve episode on the History Channel-or anything else you’d like to chat about.

And here’s a classic post by PZ on the subject of vertebrate jaw evolution, just to get you warmed up. Enjoy!

~Danio

PZ has been live-blogging the new “Evolve” series on the History Channel since it began a few weeks ago. This week’s episode is on the evolution of jaws, and should be a good one. Alas, none of the Minions will be able to live-blog the program, but I will post an ‘Evolve’ open thread in time for the East Coast airing at 10 PM Tuesday night, in case anyone is interested in commenting as they watch.

Danio, for the collective.

Posted by LisaJ

Now this is a super cool new Science story. Have you ever wanted to make yourself invisible? Ever said “man, I wish I could just run away or hide and make everyone go away”? Maybe as a young 8 year old, trying to hide from those bullies on the playground. Or perhaps you’d like to saunter into mass inconspicuously one Sunday morning to grab one of those delicious wafers without starting a riot. Well, if this sounds like you, then your lucky day is (almost) here. Dr. Xiang Zhang and his group from the University of California have reportedly “created a material that could render people and objects invisible”. They are announcing this week, in a pair of articles to be published in Nature and Science, their generation of a 3D metamaterial that exhibits a negative refractive index (thanks negentropyeater). ‘Metamaterials’ are apparently a manmade mixture of metal and ceramic or Teflon like materials (anyone who knows anything about this field is welcome to clarify this!) that function to bend visible light waves quite aptly. These researchers have harnessed this unusual property of the metamaterial they have created to redirect light around 3D objects to effectively disguise or ‘cloak’ them.

This new study represents a major progression in the field, as previously this technology could only be used to cloak very thin 2D objects. Now I’m assuming that the 3D objects they effectively made invisible in these studies were probably pretty small too, we’ll have to wait until the end of the week to find out, but this is a big step closer to allowing humans to obtain their own invisibility cloaks.

This article explains that this ‘new work moves scientists a step closer to hiding people and objects from visible light, which could have broad applications, including military ones. ‘ Which is a pretty cool application, I guess (but also a very frightening one when you think about it). I think it’s pretty obvious what the greatest potential of this new technology really is: to make millions of Harry Potter fans very, very happy. You make a real invisibility cloak and you’ve hit a goldmine with that fanbase.

Now I am by no means a mechanical engineer, materials scientist, or an expert in this particular field. So if anyone would like to add any additional info on how this technology works it would be much appreciated. It sounds very cool, and I’d like to learn more.

Hi all! This is LisaJ, and I’ll also be guestblogging here on Pharyngula for the next 10 days or so. I’m very much looking forward to the opportunity to chat it up with you fine folks here on Pharyngula, and I hope I can do my part to keep everyone stimulated and satisfied.

I would first like to echo MAJeff and Danio’s sentiment and send a big thanks to PZ for inviting me to participate as a guestblogger. I too was very surprised and flattered to be asked. What a nice guy that PZ is! Just to briefly introduce myself: I’m a 3rd year PhD student studying novel functions for the pRb/E2F tumour suppressor pathway in nervous system development. Although this is my favourite protein pathway, largely because it takes up most of my waking thoughts and, you know, these proteins are just so awesome and multifunctional, I will likely be contributing various Science related posts during my time here, among other topics that will just come as I go!

I’m also a pretty proud Canadian girl, currently living in Ottawa, our beautiful capital city. Since alot of the posts here on Pharyngula center around the news, politics, crazy christian crusades, etc, going on in PZ’s fine country, the US of A, I thought that for my first post I would lead a little discussion on what makes its Northern neighbour such a special place… but also, not really that different at all in some respects.

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MAJeff here, and I’ll be one of your guestbloggers for the next several days. I’d first like to thank PZ for asking me to do this. I was more than a little surprised to get an email the other day inviting me, and I hope I can keep up the quality people have come to expect from the place.

I’m not sure of everything I’ll be posting about yet. But, I’ll probably be doing some of what I do when I teach, and that is asking questions. Y’all are a chatty bunch, so I probably won’t need to do much asking. Sometimes, though, I just like to get to know folks better, to move beyond argument and talk. As a sociologist, I study people. I don’t always understand them, but I do find them fascinating. Opportunities to get to know what drives folks are never to be turned down.

So, here goes: What is it about science that so enthuses all of you?

My brief answer–it’s not Boobies; not that there’s anything wrong with that, w00t–is below the fold….
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I’m wondering how this works. VADLO is a web search engine for biologists, and my first attempts at using it…it worked surprisingly well. I looked up a few techniques I’ve been using, and actually turned up some useful articles.