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A journal of sorts to record Jonathan Sturm's (and others') thoughts and observations on things worth thinking about. Feedback welcome, but be aware that unless you prominently say you want your communication kept private, I may publish it. |
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| This week in: | 2001 | 2002 | 2003 |
Friday saw The Git's Sony monitor returned at last! After twenty four weeks without it, its restitution left him feeling more than somewhat relieved. It's certainly visually the best monitor The Git has ever owned even if the manufacturer is lax in the service department.
-oOo-
It has been a busy week, or so. The cottage renovation moves on apace. The Git's thinking cap has also been having a workout. Continuing the thread of thoughts on climate change required thinking deeply about Anthropogenic Global Warming Theory and that's firmly based on our understanding of atmospheric physics as distinct from solar physics, biological influences, deep ocean effects and the host of other factors that are cheerfully ignored by the climate modellers getting all the publicity. Atmospheric physics lacks the claimed "consensus" and the biogenic climate effects have The Git fascinated. Stay tuned as they say.
While the rest of the world is sweltering in Anthropogenic Global Warming, Tasmania is suffering yet another cool summer. The Git doesn't rely on anything particularly scientific in this assessment, he just looks at his crops. The French beans have dwarfed, curved pods, a sure sign that it's cooler than they prefer. Fortunately, the scarlet runner beans that drop their immature pods when it's hotter than they like are cropping prolifically. The earliest apple variety we grow, Early Blaze, won't be ready until fully two weeks after the usual harvest date.
-oOo-
The Git has decided to live dangerously and install Windows 2003 Server as a workstation OS. A full report will ensue, including how to achieve this, why and whether it's worth the effort. Hopefully, it will be a better experience than XP...
-oOo-
12 February 2004 17:00 GMT by Helen Dell
A complex network of 'nanotubular highways' can transport organelles between cells, report German neuroscientists. The results have uncovered a completely new mechanism by which cells communicate with each other, they say.
"Cell-to-cell communication is a crucial prerequisite for the development and maintenance of multicellular organisms," notes Hans-Hermann Gerdes, professor of biomedicine at the University of Bergen, Norway.
Several other communication systems have been described - the chemical synapses of neurons, for example, or the gap junction complexes formed between the membranes of adjacent cells - but this network of nanotubes is novel, says Gerdes, and might mean that previous interpretations of intercellular communication need to be reconsidered.
He and his student Amin Rustom observed fine filaments protruding from cultured rat kidney cells, and contacting other cells. The structures, which they dubbed 'tunnelling nanotubes' (TNTs), were just 50-200nm in diameter, but they could be up to several cell-widths long.
Looking closer, the researchers discovered that the membrane that forms the TNTs appears to be continuous between the two cells, because fluorescent-labeled plasma-membrane proteins flow between TNT-connected cells. Moreover, little vesicle-like organelles seemed to be moving along the tubes.
Fluorescent membrane-specific dyes could track the movement of the organelles along the TNTs, Rustom and Gerdes report in Science . "We could follow organelles entering a TNT on one side, organelles being transported along the TNT, and organelles exiting the TNT into the connected cell," says Gerdes.
What troubled him, however, was that fluorescently labeled cytoplasmic proteins and small dye molecules did not leak along the tubes into the adjoining cell, so passive transfer of small molecules seems to be impeded.
This presented a paradox. "On the one hand there is no cytoplasmic bridge because small molecules can't diffuse passively along the tubes," Gerdes told BioMedNet News, "but on the other hand the membrane was continuous between the TNTs and the cells, and the organelles are moving through them."
Thinking that the organelles might be transported actively from one cell to the next, the researchers looked for actin, and found that the tubes are packed with it. The motor protein myosin Va is also present - often located with the vesicles. This suggests an actin-dependent transport system, says Gerdes, but it also provides a possible solution to the paradox.
The actin could form a kind of "plug" for the TNT tube, he speculates, with the membrane tightly wrapped around the actin filaments, preventing passive diffusion. The speed at which the organelles move through the tube is a little slow for actin-dependent transport, he points out, but that might be due to the requirement for a "bulging" force to open up the narrow tube and allow the organelles through.
The results surprise Keith Mostov, professor of anatomy at the University of California, San Fransisco. "One would not have expected such large intracellular structures to be transported long distances and exchanged between cells through such slender connections," he said. "The findings open up new possibilities for how cell-to-cell communication might work."
The next step, according the Gerdes, is to confirm that the TNT system is present in tissue. Although he's not yet sure how to do that, he's confident that they will be there.
Jean Gruenberg, professor of biochemistry at the University of Geneva in Switzerland, agrees. "Cells do not invent things ex vivo," he said. "Cells in culture might do things in an unregulated fashion, but they still do things that they also do in tissue."
Gruenberg is intrigued to know what the TNTs are transporting, and how they are regulated. "We need to find the physiological relevance," he said. "It will not be very easy, but it will be very exciting."
From BioMedNet
Comment: prokaryotes exchange DNA through intercellular tubes.
In the case of the brain, I would be wondering about apoptosis and whether or not a cell gives up, say, it's mitochondria before dieing. I would also be looking at neural sculpting where too many active cells participating in a particular process actually slow down that process. As the brain matures and 'specialises (according, say, to the kind of activity to which it is most often employed) cells die or become atrophied or reduce intercellular connections (synapses) - does this new discovery play a role in this process?
Interesting research awaits...
Posted by Robert Karl Stonjek.
The Git has just been reading the Oxford biography of James Watson and Francis Crick, discoverers of the structure of DNA. Sadly, it's not all that well written -- very repetitive for such a short book. One interesting factoid from it though is Crick's belief in directed panspermia -- life on earth was seeded by an advanced civilisation living elsewhere in the universe.
Thought for the day:
The really idle man gets nowhere. The perpetually busy man does not get much further.
Sir Heneage Ogilvie
Current Listening:
Spectrum/Indelible Murtceps -- Terminal Buzz
From the Inbox:
Science Magazine
1/30/04 p.601:
"To deduce past climate, researchers pore over everything from tree rings to ice cores to historical tallies of grape harvests. This new database opens up another source: records kept by sailors, whose lives depended on carefully noting the weather. Sponsored by six institutions in Europe and South America, the Climatological Database for the World's Oceans, or CLIWOC, amasses weather data from ships plying the seas between 1750 and 1850, the time period when industrial emissions began to transform the atmosphere. Such observations can allow climate scientists to analyze monthly or even daily changes.
To compile the collection, researchers trawled the logbooks of British, Spanish, French, and Dutch ships, translating the crews' meteorological descriptions into numerical values for wind speed and direction, air temperature, and other variables. The site's first cargo of data--derived from more than 1300 logs--came aboard last November; a new load should arrive this spring. Check out the logbook of the Noord Beveland, a Dutch ship traveling the English Channel in 1761."
Cheers,
Peter
Many thanks for that, Peter. That should put the cat among the climatological pigeons :-) Dr John Hunter made some scathing remarks about the usefulness of historical accounts for scientific research. Presumably because they run counter to what Currently Accepted Theory says they should have written at the time. Presumably those ships' captains were all lying to confuse the Great Anthropogenic Global Warming Debate.
-oOo-
And while we are on that topic... not that it's ever very far from The Git's thoughts, consider the following train of thought:
The chart below shows the IR radiation absorbed by the atmosphere:
CO2 absorbs IR at 2.8 microns and at 4.3 microns. You will note from the chart that the atmosphere as it is presently constituted absorbs close to 100% of the IR at those frequencies. [Theory does not allow it to be 100%, so it's 99 point several nines.]
Two questions arise in my mind from this. First, how can increasing the CO2 level result in the absorption of more than 100% of the IR at those frequencies, an apparent requirement if an increase in CO2 actually causes an increase in temperature through IR absorption? Second, at what height above the surface of the earth has this effectively 100% absorption taken place? A friend's back-of-envelope calculation says: probably no more than 100 metres!
It seems to me that albedo and cloud effects are more likely sources of atmospheric temperature change.
-oOo-
Some idiot set fire to the forest several kilometres to the west today and the prevailing westerly wind is blowing like a bastard. Fortunately, due to the cool summer and the record rainfall in January means that the grass is green and the cinders falling from the sky pose no threat of spot fires. The event is too unimportant for mention on the TV news, though The Git hears the weather woman utter the words "up to seven degrees below average" while he busies himself in the kitchen cooking up the evening's feast.
-oOo-
'Persecuted' Aussies flee to US
By Mark Dunn February 19, 2004
MORE than 30 Australians have sought asylum in the US.
At least two Australians have been granted asylum in America after complaining they faced religious, racial or political persecution in Australia.
Four other Australians await the outcome of US asylum applications.
Privacy reasons prevent authorities detailing specific arguments used by Australians for asylum, but it is known Aborigines have made official complaints to US diplomatic staff claiming racial persecution in Australia and allegations of genocide.
Human rights lawyer Julian Burnside, QC, said the Australian applications came as a shock, but Aboriginal claims of persecution could well be entertained by US immigration courts considering asylum.
"I can understand how some Aborigines might complain of a fear of persecution," he said.
Between 1997 and 2002, 31 Australian nationals applied for asylum, US Department of Justice figures show. And UK Home Office documents also show Australians have sought asylum, but the Asian region statistics are not broken down to show precisely how many Australians have applied for refuge.
While several Australians apply for asylum in the US every year, it is extremely rare for them to succeed. Two Australians were granted asylum in 1999 and 1997.
Mr Burnside said Aboriginal issues including land rights and the so-called Stolen Generation might be considered as background in support of a persecution case.
"If you see that, the history, it helps explain more recent treatment," Mr Burnside said.
"What they have to show is that they genuinely fear persecution."
The persecution did not have to be actual, but had to be shown to be genuinely perceived.
"These cases come as a bit of a shock to us, because we are inclined to believe we are a very tolerant society," he said.
The Aboriginal and Torres Strait Islander Commission said it was unaware of indigenous claims for asylum.
High-profile refugee lawyer Eric Vadarlis was also surprised Australians had sought asylum overseas, and said he was "gob-smacked" at least two were successful in the US.
"I am extremely surprised. Whatever we say about this country, there is a lot of tolerance generally," Mr Vadarlis said.
Most applicants make their claim for asylum once they reach the US or after they have been in the country some time.
Under the US system, applicants must persuade immigration officials they are unable to return to Australia "because of persecution or a well-founded fear of persecution on account of race, religion, nationality, membership in a particular social group, or political opinion".
Australian Civil Liberties Union president John Bennett said real or perceived persecution by police may also lead to asylum applications.
"Although Australia is a reasonably fair society, I could see why some people don't feel treated fairly."
Falun Gong spokesman Katerina Vereshaka said she was not aware of Australian asylum seekers from her group, but she said some members had been harassed by Chinese officials in Australia.
The Foreign Affairs and Immigration departments and the Attorney-General's office said they had no knowledge of the asylum cases.
Presumably these people weren't getting enough oppression in Australia, so they went to a country where there's an apparent oversupply ;-)
Thought for the day:
There are two days in the week on which I never worry; One is yesterday and the other is tomorrow.
Robert Burdette
Current Listening:
Velvet Underground -- White Light, White Heat
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