Under the Microscope is a collection of videos that show glimpses of the natural and man-made world in stunning close-up. They are released every Monday and Thursday and you can see them here: www.io9.com/underthemicroscope Matthew Kuo: “I have a research interest in the geotechnical behaviour and biological origin of deep ocean clay crusts. These crusts are found in many areas that are of particular importance to offshore oil and gas developments, including the Gulf of Guinea, Gulf of Mexico and the Mediterranean Sea. I have discovered that sediments from these areas contain millions of tiny faecal pellets that have been produced by burrowing invertebrates (worms). These pellets, whose abundance in the sediment may range from 30% to 60% by dry mass, are robust and much stronger than undigested material. Their presence and mechanical behaviour can therefore explain the existence of the observed crusts. This video shows several pellets that have partially degraded over time adjacent to microfossils. I have discovered that when hot-oil pipelines are laid onto these pelletised sediments, the rough pipeline coatings cause the pellets to disintegrate. This in turn causes a reduction in friction between the pipeline and the seabed. I am therefore investigating how we can better understand this complicated soil-pipeline interaction. This research will help predict longer-term hot-oil pipeline behaviour, leading to safer and more economical designs." The pellets shown in this image are about 50 micrometers in diameter. This is about the same diameter as a human hair Many thanks to Professor Malcolm Bolton, Mr Andy Hill, Ms Anne Bahnweg, Mr Alan Heaver. More info: http://www-geo.eng.cam.ac.uk/directory/[email protected] Department of Engineering http://www.eng.cam.ac.uk Music by Peter Nickalls http://www.peternickalls.com Find more Cambridge research here: http://www.cam.ac.uk/research

Andrew Gamalski: “This video is a bright field environmental transmission electron microscopy video of silicon nanowires growing from gold catalyst particles. The dark crystalline shapes initially present in the video are the gold particles. Disilane, a silicon rich gas, feeds nanowire growth. The solid catalyst particles liquefy after being exposed to the disilane early in the video. Eventually, a solid silicon crystal forms in the now liquid catalyst particle. This crystal continues to grow as silicon is continuously deposited into the catalyst from the disilane gas. The new silicon crystal’s diameter is restricted by the size of the gold catalyst. This means the silicon can grow in one direction only, forming a nanowire.” Video courtesy of S. Hofmann, et al. Nature Materials 7, 372 - 375 (2008). Speaker in the video is Andrew D. Gamalski, a current graduate student studying nanowire growth under Dr. Stephan Hofmann in the Engineering Department at the University of Cambridge. Additional information about this group’s experiments involving germanium nanowires can be found at: http://nanotechweb.org/cws/article/tech/43377 Original Nature article: http://www.nature.com/nmat/journal/v7/n5/full/nmat2140.html Department of Engineering: http://www.eng.cam.ac.uk Music by Peter Nickalls: http://www.peternickalls.com Find more Cambridge research here: http://www.cam.ac.uk/research

Dr Andrew Gillis explains how an elephant fish embryo lives off a large yellow yolk sack for 7 to 10 months before hatching out as a fish. Dr Gillis: “This is a picture of an elephant fish embryo. Elephant fish are cartilaginous fishes, and are distant cousins of sharks, skates and stingrays. The elephant fish lives in deep water off the coasts of Australia and New Zealand, but migrates annually into shallow coastal bays to lay their eggs. I study the embryonic development of elephant fish, by collecting their eggs by SCUBA diving at their egg-laying grounds. Normally, an elephant fish embryo will live in their egg and feed off of their yolk supply for 7 to 10 months before hatching out as a completely self-sufficient juvenile. However, these embryos may also be cultured outside of their egg cases, as seen here. This allows us to observe and photograph the development and growth of this unusual fish.” The diameter of the petri dish in the elephant fish picture is 10cm. More info: http://www.pdn.cam.ac.uk/~jag93 Music by Peter Nickalls: http://www.peternickalls.com Many thanks: Graduate School of Life Sciences

In this video Dr Sungjune Jung shows us the fluid structures produced by the impact of two liquid jets. Dr Jung: “This video shows the evolution of the flow structures generated from the collision of two liquid jets each with a radius of 420um. The jets were ejected from parallel cylindrical nozzles with an internal diameter of 0.85mm. The collision of the jets resulted in various systems of behaviour which depend on the jet velocities and the liquid properties. We focus on the system where the impinging jets form a liquid sheet which then breaks up into a regular succession of ligaments and droplets, a so-called "fishbone" pattern. This high-speed imaging reveals a fish-like formation for the fluid: the oval sheet with rims correspond to the fish head, the drops on thin ligaments to its body, and bigger free drops at the end to its tail. We are particularly interested in this fluid formation, because the fishbone phenomenon provides a simple and visual tool to evaluate the properties of inkjet printing fluids, with which the fishbone structure sensitively varies." Many thanks to Prof Ian Hutchings, Dr Graham Martin and Dr Steve Hoath at Inkjet Research Centre, Department of Engineering. More info: Dr Jung's profile: http://www.oe.phy.cam.ac.uk/people/oepdras/sjj37.htm Inkjet Research Centre http://www.ifm.eng.cam.ac.uk/pp/inkjet/ Department of Engineering http://www.eng.cam.ac.uk/ Music by Intercontinental Music Lab http://www.intercontinentalmusiclab.com

This is a beautiful image of human brain cells, which can now be grown from adult skin cells. Yichen Shi: "Brain neural stem cells derived from human skin cells: these stem cells express typical marker genes of brain neocortical stem cells, such as Pax6 (Red fluorescent labeled), and form a rosette structure resembling the transection of the neural tube." The entire image is about 250 μm across (a really thick bit of human hair). More info: http://www.cam.ac.uk/research/news/brain-cells-created-from-patients-skin-cells Picture taken by Yichen Shi in the Livesey Lab http://www.gurdon.cam.ac.uk/~liveseylab/fjlhome/index.html Voice over by Fred Lewsey. Music by Peter Nickalls: http://www.peternickalls.com

PhD student Paola Cognigni shows us this beautiful image of a fruit fly’s brain and gut. Paola Cognigni: “This video shows the anatomical and functional connection between the brain and the gut in the fruit fly, Drosophila melanogaster. This work is carried out in Dr Irene Miguel-Aliaga's lab in the Department of Zoology as part of a research project that aims to find and explain the interactions between internal organs and their importance in growth and health.” The brain is about 700 microns wide (the entire image is something like 1600 microns across): about the size of a pencil tip. The image was taken in the Zoology Dept Imaging Facility on a Leica SP5 confocal system. More info and images: http://www.zoo.cam.ac.uk/zoostaff/miguel-aliaga/main.html Music by Intercontinental Music Lab http://www.intercontinentalmusiclab.com

Here we can see the underside of mouse tail skin. Claire Cox: "The epidermis, which is the outer layer of mammalian skin, is maintained by numerous stem cell populations. The identification of the factors involved in controlling these populations and thus epidermal maintenance is highly valuable. Not only will it provide information as to how a complex tissue is organised and controlled, the principles that are learnt can be applied to other tissues. Through the work that I am completing, I hope that I can also gain a perspective as to what goes wrong in disease processes such as skin cancer. Skin cancer is one of the most prevalent cancers in the world, and understanding what goes wrong and the factors involved could potentially lead to new ideas as to prevention and treatment." The image is 700µm in width - this is about the size of the full stop in this sentence. About 5000 cells would fit on the surface of a full stop. Many thanks to: Dr Michaela Frye, Frye Lab members, Peter Humphreys, Margaret McLeish. More info: Wellcome Trust Centre For Stem Cell Research http://www.cscr.cam.ac.uk Department of Physiology Development and Neuroscience http://www.pdn.cam.ac.uk/ Claire Cox's profile: http://www.cscr.cam.ac.uk/research/researchers-by-group/frye-lab/claire-cox Graduate School of Life Sciences and its annual Poster and Image Competitions http://www.biomed.cam.ac.uk/gradschool/comp/2011/index.html Music by Peter Nickalls: http://www.peternickalls.com Find more Cambridge research here: http://www.cam.ac.uk/research

Dr Andrew Gillis shows us an embryonic skate head and explains how the red denticles dotted all over it have very similar properties to human teeth. Dr Gillis: "This is a picture of the head of an embryonic skate (Leucoraja erinacea). A skate is a cartilaginous fish, closely related to sharks and stingrays. This embryo has been stained with dyes that colour the skeleton - cartilage is blue, and mineralised tissue is red - and then cleared with chemicals to make it transparent. The result is a specimen that shows the complex shape and arrangement of different skeletal tissues during embryonic development. I use this staining procedure to visualise the skeleton following experimental manipulation. This allows me to investigate how different genes and proteins are involved in controlling the formation and growth of different skeletal tissues in these fishes". The skate image is approximately 3cm across. More info: http://www.pdn.cam.ac.uk/~jag93 Music by Peter Nickalls: http://www.peternickalls.com With thanks: Graduate School of Life Sciences and its annual Poster and Image Competitions http://www.biomed.cam.ac.uk/gradschool/comp/2011/index.html

Matt Benton shows us nuclei moving inside a beetle egg as a beetle embryo forms. Matt Benton: “For my PhD I am studying the embryonic development of the beetle, Tribolium castaneum. During development in this beetle, a large number cells must move together at a certain location of the egg to form the embryo proper. At the same time, other cells move to overlap the forming embryo, to protect it and help it grow. Currently, we only have a basic understanding of how these different groups of cells move. In my work I am trying to extend this understanding, and to learn how the movements of different groups of cells are controlled and coordinated. Together with the group of Michalis Averof, I am developing methods to allow the movements of these cells to be seen in live embryos. The beetle shown in this video has been genetically modified so that the nucleus of each cell is labelled with a fluorescent protein. By using a certain microscope, I am able to record the movements of these cells in 3D, as the embryo develops. Many thanks to Michalis Averof for creating the nuclear-green fluorescent protein transgenic line shown in the movie, and to my PhD supervisor, Michael Akam, for supporting my work.” The width of this egg is 300 micrometres, and the length is 600 micrometres (1 metre is 1,000,000 micrometres). So the width of this egg is roughly 3 times the width of a human hair. The time span of the movie is about 5.5 hours. Matt Benton’s profile: http://www.zoo.cam.ac.uk/zoostaff/akam/benton.html Music by Sophie Smith: http://www.sophieasmith.co.uk

In this video Dr Ingrid Graz shows us a thin layer of gold on top of rubber. Cracks in the gold allow it to stretch and we can use this for stretchable electronics. Dr Graz: “Imagine a future mobile phone that can be wrapped around your wrist or an MP3 player that is integrated in your T-shirt. Stretchable electronics is a new evolution of electronics - the idea behind is to create electronic devices that can be rolled, flexed, deformed and even stretch like a rubber band. To enable stretchable electronics we use rubber such as silicone coated with a very thin layer of gold. The gold serves as stretchable conductor and can be elongated to twice its original length without electrical failure. The secret behind the stretchability lies within the microstructure. Tiny cracks in the film open up when it is stretched without damaging the film. This image shows a silicone rubber with a gold layer and an additional silicone layer to protect the electrode.” The image is about 3x3mm. Nanoscience Centre, University of Cambridge: http://www.nanoscience.cam.ac.uk Department of Engineering: www.eng.cam.ac.uk Music by Peter Nickalls: http://www.peternickalls.com

In this video we see a killer T cell of the immune system attacking a cancer cell. Professor Gillian Griffiths: “Cells of the immune system protect the body against pathogens. If cells in our bodies are infected by viruses, or become cancerous, then killer cells of the immune system identify and destroy the affected cells. Cytotoxic T cells are very precise and efficient killers. They are able to destroy infected or cancerous cells, without destroying healthy cells surrounding them. The Wellcome Trust funded laboratory of Professor Gillian Griffiths, at the Cambridge Institute for Medical Research, investigates just how this is accomplished. By understanding how this works, we can develop ways to control killer cells. This will allow us to find ways to improve cancer therapies, and ameliorate autoimmune diseases caused when killer cells run amok and attack healthy cells in our bodies.” Cytotoxic T cells are just 10 microns in length: approximately one-tenth the width of a human hair. These movies are 92 times real time. The original footage shown was made by Alex Ritter, a PhD student on the NIH-OxCam programme, in the laboratory of Professor Gillian Griffiths at the Cambridge Institute for Medical Research and the Department of Medicine of the Clinical School of the University of Cambridge. The images were acquired using an Andor Revolution spinning disk system with an Olympus microscope. Professor Griffiths is a Wellcome Trust Principal Research Fellow. Links for more information: http://www.cimr.cam.ac.uk http://www.immunology.cam.ac.uk/about Music by Intercontinental Music Lab http://www.intercontinentalmusiclab.com