Douglas Melton, Harvard University: "Stem Cell Challenges in Biology and Public Policy" - April 10,
Douglas Melton will discuss the biology and public policy challenges surrounding stem cell research. The potential of human embryonic stem cells for understanding human development and finding new therapies will be presented. Dr. Melton is a cell and molecular biologist as well as an advocate of embryonic stem cell research. His research focuses on the developmental biology of the pancreas. One of the primary goals of his work is to understand how human embryonic stem cells differentiate into pa
Virtual laboratories in Molecular and Cell Biology - Immuno-electron-microscopy
A virtual laboratory that includes immuno-gold labelling and transmission electron micrography (immuno-EM). It allows the student to study intracellular-traffic pathways of two cell-surface receptor molecules, following stimulation of the cells with their specific ligand, for different time periods. The programme first introduces the theory underlying the techniques and includes a video of EM work in a real laboratory. The student is then taken through a series of questions which requires them t
Virtual laboratories in Molecular and Cell Biology - SDS-PAGE
A protein analysis laboratory using SDS-PAGE, western-blotting and endoprotease digestion. The programme includes a section on the theory of the techniques, a video demonstration in a real laboratory, and a series of questions which guide the students through the structural analysis of model proteins (3 are included). Students go to the virtual laboratory and devise their own experiments in order to determine the molecular weight, subunit composition etc of the proteins. Results (gels and blots)
Molecular reaction dynamics
This package, written in 1998, includes interactive questions and demonstrations on the dynamics of chemical reactions. The aim is to show the effect of the potential energy surface, on reaction rates. It is intended for third or fourth year undergraduates in Chemistry. To download, click on View Download and follow the instructions. To uninstall, use the standard Windows option of “Add or Remove Programs”.
Fracture surface in a liquid crystalline polymer, oriented by a magnetic field
Above their melting point, liquid crystalline polymers exhibit a mesophase within which, although able to flow and are not arranged in a crystal, they exhibit long range orientational order. This molecular alignment can be exploited to make high strength and stiffness fibres such as Kevlar, or even mouldable thermotropics such as Vectra. Molecular alignment can also be controlled by an external applied field; a property exploited in liquid crystal displays. This polymer has been subjected to a m
Injection-moulded polystyrene (PS) case
The colours in the image are the result of birefringence and relate to the residual strain in the polystyrene. The pattern of strain is indicative of the flow of material during the injection process and it highlights the injection point (known as a 'sprue') which can also be identified by a small lump on the surface; the molecular alignment is greatest near this point. Towards the edges of the ruler and along its length, the material becomes more relaxed and as the molecular alignment falls, th
Injection-moulded polypropylene (PP) hinge
The colours in the image are the result of birefringence and relate to the residual strain in the polypropylene. The pattern of strain is indicative of the flow of material during the injection process and reveals the molecular alignment in the constriction which constitutes a hinge. The aligned molecules provide a fatigue resistant, flexible joint. A sprue which has been cut off is also visible in the top left-hand corner of the image.
Cu 21, Sn 79 (wt%), peritectic transformation
This microstructure is generated via a peritecticÃ¢â‚¬Â²s reaction (L+ÃŽÂµ = ÃŽÂ·), which bears some similarities to the more familiar eutectic reaction (L = ÃŽÂ±+ÃŽÂ²). Upon cooling from the liquid phase field, primary ÃŽÂµ is formed, which can be seen here as a slightly darker phase than the sheath of ÃŽÂ· surrounding it. The ÃŽÂ· sheath is the product of a peritectic reaction between ÃŽÂµ and liquid. The peritectic reaction rarely goes to completion, si
Optical Tweezers and Applications
Did you ever imagine that you can use light to move a microscopic plastic bead? Explore the forces on the bead or slow time to see the interaction with the laser's electric field. Use the optical tweezers to manipulate a single strand of DNA and explore the physics of tiny molecular motors. Can you get the DNA completely straight or stop the molecular motor?
2.1 Predictive medicine? Some experts now suggest that new knowledge of human genetics is likely to transform medical practice. They propose three main possibilities: Genetics will lead to the classification of diseases on the basis of the underlying genetics or biochemistry, rather than by symptoms. Genetic information will identify people who are likely to respond to drugs, or to be harmed by them (pharmacogenetics). Genetic variation will be
Some experts now suggest that new knowledge of human genetics is likely to transform medical practice. They propose three main possibilities:
Genetics will lead to the classification of diseases on the basis of the underlying genetics or biochemistry, rather than by symptoms.
Genetic information will identify people who are likely to respond to drugs, or to be harmed by them (pharmacogenetics).
Genetic variation will be
Physics in architecture
Developed in 1998 by Dr John Whittle (Department of the Built Environment) using Authorware, this package contains brief interactive notes on eight areas of physics in which architects need a working knowledge. However, it is also useful to others in science, engineering and social sciences looking for an introduction to the topics concerned. These topics are: Units of measurement; Scalar and vector quantities; Newton’s laws; Mass and weight; Action and reaction; Waves; Heat, work and energy;
Marketing of organic products