More than 25% of the primary terrestrial productivity, and a significant portion of the food consumed by humans, is produced by plants that utilize C4photosynthesis to fix atmospheric CO2. Over decades many scientists have been working toward transferring the C4-abillity to C3 crops, Conservative estimates put the increase in crop yield, that this would give, at 50% and forecast considerable increases in water use efficiency and reduction in fertilizer requirements as a result of such a transfer. These benefits would be especially evident in, hot, dry environments. Crops like maize (Zea mays), sugarcane (Saccharum spp.) and several emerging bioenergy grasses exhibit high productivity levels under those conditions, primarily due to their ability to carry out C4 photosynthesis.
Up to now the ability to induce the more efficient form of photosynthesis in less efficient plants has eluded everyone working in the field. This is all about to change because researchers recently reported in Plant & Cell Physiology that they have pinned down the transcription factor, called SCARECROW, which regulates structural differentiation of the leaf anatomy, conferring the ability to carry out C4 photosynthesis on the plants in which it operates. Once the signal transduction pathway for this process has been completely characterized, researchers believe it will be possible to facilitate the transfer of the C4 trait into C3 crop species, including rice.
Pulsars are small stars, smaller than a large city but they are heavy stars, much heavier than our Sun and they spin very rapidly. While spinning they emit two beams of high energy electromagnetic waves that flash across the sensors of a variety of scientific recording instruments, like the beam of a lighthouse across the sea. First discovered in 1967 by Jocelyn Bell, now Dame (Susan) Jocelyn Bell Burnell DBE, FRS, FRAS and her thesis supervisor Anthony Hewish, they are enigmatic but, up to know, scientists knew they did not understand the fine detail of how these stars operated, but they felt they had a good grip on the general system.
All that has now been changed by a small team working at the University of Amsterdam. The team also included the University of Vermont’s Joanna Rankin (she has studied this pulsar, known as PSR B0943+10, for more than a decade), Wim Hermsen from SRON, (the Netherlands Institute for Space Research in Utrecht (the lead author on the new paper); Ben Stappers from the University of Manchester, UK; and Geoff Wright from Sussex University, UK.
To upset the pulsar apple cart they elicited the help of colleagues from institutions around the world to conduct simultaneous observations with the European Space Agency’s X-ray satellite (XMM-Newton), and two radio telescopes, the Giant Meter Wave Telescope (GMRT) (India) and the Low Frequency Array (LOFAR) (the Netherlands).
This pulsar was previously known to flip on and off every few hours alternating between bright (or strong) radio emissions and quiet (or weak) ones. Using the combined instrumentation the researchers found, to their surprise, that this pulsar exhibited the same behaviour, but in reverse, when observed at X-ray wavelengths. .Flipping between these two extremes – one dominated by X-ray pulses, the other by a highly organized pattern of radio pulses – was completely unexpected, according to Rankin. Neither of the leading models for pulsar emission predicts, or in fact explains such behaviour.
These observations will probably keep theoretical astrophysicists busy investigating possible physical mechanisms that could cause the sudden and drastic changes to the pulsar’s entire magnetosphere and result in such a curious flip in its emissions.
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Here is the table of contents for the November issue. Lots of well written, astronomy related stuff!
Gallery: Messier 83
From the Archimedes Archives
New on the bookshelf
For now, I am an Astronomer
Southern Milky Way
What a wonderful world
Astrophotography tutorial (Part 1)
Star names in Scorpius
A Supernova Indaba in Vela
When to photograph the zodiacal light
A star hop in Musca to NGC 4833
De Sterrennacht revisited
Plan an observing session using DOCdb
On the Web
Videos of the ASSA 2012 Symposium
Upcoming Moon–Jupiter occultations
The evening summer sky
Leprosy bacteria, Mycobacterium leprae, can reprogram cells to first revert to a stem-cell-like state and then to mature into completely different cell types. This is a new finding by Takeshi Masaki and associates in Cell152, 51–67 (2013). The team was researching the mechanism by which leprosy spreads around the body when they made this discovery. The exact mechanism by which the bacterium carries out the hijacking has not yet been elucidated but, once unravelled, it has the potential to become a major therapeutic strategy against the disease.
It appears that the prime targets of Mycobacterium leprae are Schwann cells, which are part of the peripheral nervous system. The bacterial cells wrap around the nerve cells and prevent the electric signals from passing through. This causes the characteristic loss of tactile sensation in peripheral parts of the body.
Further investigation revealed that the bacterium changed mature Schwann cells into a stem-like state by turning off genes associated with maturity and turning on embryonic or developmental ones. The reprogrammed stem cells are able to migrate to different body areas, carrying the bacteria with them. Whatever the destination, the infected cells integrate with that tissue’s cells and spread the bacteria.
Dense clouds of gas and dust in the depths of space are recognized as the birthplace of new stars. At the wavelengths of the electromagnetic spectrum, which humans can see, the dust clouds are dark and effectively obscure the background stars. William Herschel, help observing such a cloud in Scorpius remarked, “Hier ist wahrhaftig ein loch im Himmel!”
To truly come to grips with the processes involved in star formation, a method is required that will enable astronomers to see into and beyond these clouds. The Atacama Pathfinder Experiment (APEX) on the Chajnantor Plateau in the Chilean Andes, is the largest single-dish submillimetre-wavelength telescope operating in the southern hemisphere, and is exactly what the doctor or at least the astronomers ordered, for studying the birthplace of stars..
The subject of this investigation is the Orion Molecular Cloud Complex situated 1500 light-years away from Earth, which makes it the closest region of massive star formation to Earth. The new image in the article can be compared to an older image from the NASA/ESA Hubble Space Telescope at (http://www.spacetelescope.org/images/opo0010a/). The region in this image is located about two degrees south of Messier 42, the well-known Orion Nebula.
Dr Robert Braun, Chief Scientist at CSIRO Astronomy and Space Science says their results represent the most precise measurement ever made of the cooling of the Universe during its 13.77 billion year history,
“Our results verify the prediction of the Big Bang Theory, that the Universe of several billion years ago was a few degrees warmer than it is now,” said the leader of the research team, Dr Sebastian Muller of Onsala Space Observatory at Chalmers University of Technology in Sweden.
The DailyGalaxy recently featured an article with the dramatic heading “We’re on the Threshold of Unravelling the Biggest Mystery in Modern Physics“. As it turns out this statement originates from Maria Spiropulu. She is professor of Physics at the California Institute of Technology and also works on experiments at the Large Hadron Collider She is also a former fellow at the Enrico Fermi Institute. Professor Spiropulu’s remark refers to the encouraging outcomes of the meeting held in mid-October 2012, when more than 100 cosmologists, particle physicists and astrophysicists got together at the National Academy of Sciences’ Beckman Center in Irvine, California. The theme of the meeting was “Dark Matter Universe: On the Threshold of Discovery“. Their main objective was to overview all the latest theories and findings about dark matter and, once that was done, to assess just how close scientists really were to detecting Dark Matter. Their second objective was to generate cross-disciplinary discussions and collaborations with the specific purpose of resolving the dark matter enigma.
Michael S. Turner – Rauner Distinguished Service Professor and Director of the Kavli Institute for Cosmological Physics at the University of Chicago is quoted as having said: “Figuring out what dark matter is, has become a problem that astrophysicists, cosmologists and particle physicists all want to solve, because dark matter is central to our understanding of the universe. We now have a compelling hypothesis, namely that dark matter is comprised of WIMPs (Weakly Interacting Massive Particle), particles that don’t radiate light and interact rarely with ordinary matter. After decades of trying to figure out how to test the idea that dark matter is made up of WIMPs, we now have three ways to test this hypothesis. Best of all, is that all three methods are closing in on being able to either confirm or falsify the WIMP-hypothesis.”
Our guest from Oslo, the capital of Norway, landed at Cape Town International airport on the 29th December, 2012 for her first visit to South Africa. The prime objective of her 13 day stay was kite surfing and she was fortunate to have favourable conditions for most of her stay. She contacted ELF Astronomy to arrange a wine tasting tour for the penultimate day of her visit and, after discussing the options with her, she opted for a fairly leisurely day with only three estates on the itinerary At the last moment she asked us to cancel the first tasting of the day, the chocolate and wine tasting at Seidelberg, as she wanted more time to pack her kites and boards that morning, so we were left with only Fairview and Backsberg.
Lynnette and I picked her up in the Vito on Wednesday the 09th at 10:00 and headed north for our first appointment in the Beryl Back Master Tasting Room at Fairview, where Desiré was on hand to welcome us.
We spent a very relaxed 90 minutes or so working our way through the eight wines and eight cheeses under Desire’s expert and very well informed tutelage. The wines we tasted were:
As a bonus, because we were such well behaved tasters, Desire allowed us to taste the Fairview Durif/Petit Shirah as well. I can unreservedly recommend the very relaxed atmosphere and highly professional tasting Fairview presents in the Beryl Back Master Tasting Room.
At lunch, in the Goatshed Resaurant, our guest had a glass of Fairview Pinotage and I had a glass of Fairview Pinotage Viognier, both very enjoyable wines. Lynnette, being the driver, settled for Adam’s Ale with ice and commented that it was quite a good vintage. After lunch we headed east to Backsberg.
At Backsberg, Danwin James, the Tasting Room Manager, set up a tasting of eight wines for us. When I saw how many glasses he could handle in one go, I initially suspected he had been issued with more than the regulation number of fingers. Closer inspection showed this not to be the case and Danwin assured me it was just a matter of practice, lots of it. The wines we tasted were:
Sauvignon Blanc 2012
John Martin 2012
Backsberg Family Reserve Red 2005 (Cabernet Sauvignon and Merlot blend)
Cabernet Sauvignon 2009
Beyond Borders Pinot Noir 2010
For the grand finale, Danwin allowed us to taste a very interesting Backsberg Port. He only gave us, In the words of Poo Bear “a smidgen”, but a very memorable one.
We were both impressed with Danwin’s relaxed, quite personal, but very professional presentation. His personal charm, knowledge of the wines and obvious enthusiasm about Backsberg, are all impressive. Our guest was especially pleased to find that Backsberg could deliver to the doorstep of any address in Sweden, at rates that were extraordinarily competitive.
We then headed home for one of Lynnette’s excellent suppers before taking her back to her guest house, so that she could complete her packing, before departing Cape Town for Oslo the next day.
Researchers Peter Pessev & Benoit Neichel of the Gemini Observatory, La Serena, Chile claimed they had the best New Year’s Celebrations possible when they obtained this incredibly detailed data from the observatory’s adaptive optics (AO) system. The photo shown here features an area on the outskirts of the well known Orion Nebula and show cases the instrument’s very significant technological advances over the previous generation of AO instruments.
The system combines the use of five laser guide stars with multiple deformable mirrors enabling it to go far beyond what has previously been possible using adaptive optics in astronomy, Benoit Neichel, currently leading the AO program for Gemini, says that years of dedicated work have gone into the project culminating in this magnificent image. This image, he claims, is only a glimpse of the system’s enormous scientific potential. The Gemini Multi-Conjugate Adaptive Optics System (GeMS) is installed on the Gemini South telescope in Chile. This is the most advanced adaptive optics system available and will enable astronomers to study the universe with an unprecedented level of clarity and detail by removing distortions due to the Earth’s atmosphere.
This superb book by Dr. Dieter Willasch and Auke Slotegraaf is presently only available in German, but an English edition should be on the shelves toward the end of this year. This book is a very well produced and thoroughly researched collection of most of the astronomically significant objects in the southern skies. All the photographs were taken by Dieter from his observatory in Somerset West and other sites in South Africa and Namibia. The text was compiled by Auke in English and later translated into German.