Home

Future Programme

2006 Meetings

2007 Meetings

2008 Meetings

Objectives

Constitution

 

 

2008 Meetings

April 2008

Bird Flu by Dennis Alexander 

At our meeting of 23 April we were treated to a very interesting and detailed presentation on BIRD FLU by Dr Dennis Alexander, a consultant virologist to the Veterinary Laboratories Agency.

Dr Alexander started by showing the structure of the flu virus and pointed out that each virus was typified by two different types of protein attached to its surface.  Glycoprotein Haemagglutinin denoted by H and Neuraminidase denoted by N were the substances in question.  At present 16 different H subtypes have been recognised (H1 to H16) and nine different N subtypes (N1 to N9) have been identified.  Each virus has one H and one N protein, in any combination.  Few of the 16 H and 9 N subtypes have been isolated from mammals, but all subtypes have been isolated from birds in most possible combinations.  There are enormous pools of influenza A viruses in wild bird, especially migratory waterfowl.

 Flu infections in humans are marked by the emergence of new viruses, now and again, that spread around the World causing severe pandemics.  In the 20th Century there were four pandemics of influenza due to the emergence of antigenically different strains in humans.  The pandemic of 1918 was due to H1N1, that of 1957 H2N2, 1968 H3N2 and that of 1977 H1N1.

 The RNA of influenza A virus is segmented into eight distinct genes and as a result genetic reassortment can occur in mixed infections with different viruses.  The 1957 and 1968 pandemic viruses differed from the preceding viruses in humans by the substitution  of some genes that came from avian viruses.  This indicated that pandemic viruses may arise by genetic reassortment of viruses of human and avian origin.

 Dr Alexander pointed out that simultaneous infection with both human and novel avian viruses raised the possibility of a hybrid form against which the human population would have no immunity.

 The session ended with a great deal of discussion on a topic which is obviously of great interest to most people.                                                                                                                                                                                                                                   

 

March 2008

Digital Electronics Unspun by Tony Allen

            Tony explained how everyday consumer products are becoming digital and thus the way they work becomes harder to understand. In order to follow the basis of digital processing it is necessary to start with the binary system of numbering, used almost universally by digital circuits. It is then possible to see how basic digital logic gates work and how common electronic circuits are derived from them.

            The talk briefly explored the concept and potential of Boolean Algebra before plunging into binary arithmetic and the circuitry that supports it. This led on to how negative numbers and fractions are stored, and how adders and subtractors work. Binary multiplication and division is an extension of addition and subtraction.

            Having dealt with the underlying concepts of digital electronics, the personal computer was used to show how a complete working system can be put together. The workings of a PC and its common components and peripherals were described in varying detail. The audience had the chance to practice binary arithmetic and to try out simple electronic circuits.

 

February 2008

Space Tourism by Peter Marshall

On Wednesday, 27th February 2008, Peter Marshall, satellite communications  expert, journalist and author, presented an extremely topical, informative talk about recent developments towards commercial  Space Tourism to Sherborne Science Cafe, at Sherborne House, Newland.

Peter worked for the BBC as a journalist and editor before becoming involved in developing the use of international satellites for worldwide TV news coverage and distribution.  He was the first Director of Broadcast Services at INTELSAT in Washington DC, before serving as a board member of the France Telecom subsidiary, Globecast.

After retirement he returned to the UK where he currently works as a writer and as a Director of the Arthur C. Clarke Foundation.

Using his considerable expertise, Peter explained how Space Travel, which hitherto has been government run, is being developed by the private sector.  Only five hundred astronauts and cosmonauts have travelled into space so far, but it is predicted that about five thousand civilians will go up there within the next five years.  Richard Branson’s Virgin Galactic project should start next year, when, for $200 000, after a day’s preparation, space tourists will travel 62 miles high and experience weightlessness.  In the next few years, it is forecast that the cost could reduce to about $40 000.

There are more than forty companies worldwide involved in the development of Space Tourism.  With over 30 billion dollars invested, space stations are big business.  INTELSAT, the intergovernmental body, was owned by 111 governments, so although it possessed much knowledge, many resources and engineers, it was so large that bureaucracy and wastefulness impeded progress. In Peter’s time there in the late 1980s, more money was being spent on conferences than on satellites!  It was recently privatised, demonstrating that commercial enterprise tends to be more efficient, so Peter is convinced that Space Tourism will become a reality when run by the private sector.

Peter then gave a brief potted history of the development of space travel to date.  During WW2, Werner Von Braun developed the V2 rocket. His team gave Hitler a demonstration in 1943.  Hitler was so impressed, he ordered 10 000 to be built.  They were fired to a height of 50 miles loaded with heavy warheads.  Our troops headed north after D-Day to take out these rocket sites.  Many people were unaware that 2000 V2s fell on SE England with thousands of casualties.

Post war, Von Braun went to America, becoming a US citizen.  He became one of their  key scientists, being involved in space and moon travel in the 1950s and 60s.  Interestingly, some of Von Braun’s original team joined the Russian space development programme, so much early space research,  on both sides of the Atlantic, was derived from that original rocket work in Germany.

Peter then praised the role of Arthur C. Clarke as a great scientist, who predicted the arrival of rockets capable of launching geostationary satellites and providing global microwave transmission as early as 1944.

Fast forward to the present day, when the audience were shown ideas for concept rocket ships, shuttles and even inflatable space hotels where people will be able to relax while undertaking their holiday in space.  European engineers are designing an eight seater spacecraft which will take off and land conventionally, but it will convert to rocket power once airborne.  In the future maybe supersonic destination flights via space will be possible, extending the idea started with Concorde: or even a trip round the moon. All that will be needed will be plenty of cash! 

There were many questions after this truly fascinating talk.  It was very thought provoking.

 

January 2008

GM - Boon or Bane?

Sherborne Science Café was treated to an interesting and informative talk on GM Crops by Professor Dixon, who was very well qualified to do so, having worked either as a professor or as a specialist researcher in many of the educational and research organisations of the UK.

He started by considering the differing roles that natural and man made evolution played in the development of plants, paying particular attention to the brassicas, which started in Africa, but took slightly different paths is Europe and Asia. Before serious work could start on selective breeding it was necessary know and understand about sex in plants. Although the Greeks were aware of this issue, they did not know enough and development had to await the Renaissance, the Reformation and the Enlightenment, when much more work was done, driven by trade and commerce. In the seventeenth century there developed a division between botanists, who went for purity in species, and plant breeders, who experimented with hybrids.

Professor Dixon then went on to briefly discuss the work of Carolus Linnaeus (1707-78), the Swedish botanist, who travelled around Europe collecting and describing new plant species, and by 1735 he had named and described about 100 new species. It was Linnaeus, who, in 1749, announced the binomial system of naming plants – one name for the genus and one for the species – which is still in use today.

This led on to a discussion of the work of Charles Darwin (1809-82) and Alfred Russell Wallace (1823-1913) on evolutionary theory by natural selection. Professor Dixon also mentioned the important work of Johann Gregor Mendel (1822-84) on the laws of inheritance. This work was ignored during Mendel’s lifetime, but they were rediscovered in 1900 by Bateson and de Vries. These laws led to a completely new understanding of genetics and opened up the possibility of further developments in the application of genetics to plant breeding. The year 1905 saw the use of single gene inheritance for disease resistance and this was applied to Yellow Rust in wheat and Blight and Wart in potatoes.

The next great leap forward in genetics came with the working out of the structure of DNA in 1953 by Francis Crick (1916-2004) and James Watson (1928- ), building on the work of Maurice Wilkins (1916- ) and Rosalind Franklin (1920-58). This work brought in a completely new age for plant breeding, as it was now possible to alter the characteristics of plants at the level of the actual genes. Professor Dixon explained how this was done by inserting parts of the genes from one organism into the genetic makeup of another. Much of the rest of the meeting was devoted to the advantages, and also the possible disadvantages, of manipulating the genetic ingredients of plants to make them more disease resistant and to produce species that had a higher yield per hectare.