Xavier

Hello, 'Hormone' is one of those terms, like 'vitamin' that was brought into being before the science was mature in order to explain (or at least name) a series of groups of conditions or symptoms that shared traits in common (i.e. activity/trauma at one body site affecting another apparently unconnected site and the modes of failure of these traits by both 'disconnection' or uncontrolled activity). Clinicians were getting to grips with a bodies negative feedback and homeostasis systems long before there was any possibility of them directly detecting the hormone molecules themselves. The existence of the hormones was theorised from their effects and their sites of production and action discovered by piecing together clusters of symptoms seen in all the many rare tumours and congenital defects. It turned out that hormones are a disparate bunch of substances, chemically. Some are peptides, usually under a hundred base pairs long, such as parathyroid hormone [PTH] and Growth hormone [GH]. They typically have a half life up to a few days in the blood stream so cannot respond to rapid environmental changes, though as proteins go they do appear to be designed for quick deactivation (i.e. PTH has three regions of the peptide that may have some effect - its actions remain imperfectly known, as of the mid 1990's when I studied it - and they are strung out along a peptide chain such that almost any cleavage will seperate one from the other two.) The other big class is the steroid hormones, a large group of homeostasis and sex hormones, like testosterone, the oestrogens (there are three types), cortisol and aldosterone. They are all made in the adrenal gland from a cascade of enzyme mediated reactions that start with cholesterol as their raw material (though the total usage requirement of cholesterol by the adrenal glands is very small compared to even a dieters intake). The half life of steroid hormones in the blood is only enough for them to make a few circuits of the body and the levels of these chemicals in the blood is carefully maintained and tweaked from minute to minute. In the adrenal medulla, the catecholamines are made. They are broadly chemically similar to steroids but have a half life of minutes or seconds. These are adrenaline and epinepherine which can flood into the bloodstream and deliver their simple message - "Fight of Flee!" in seconds. They represent high technology of the chemical communications net. There are a bunch of other chemicals that have been used to signal remote areas. Thyroxine has a different approach to its production, activation and feedback. Several hormones trigger other (usually peptide) hormones in their target tissue whose only function, apparently, is to act as feedback for the remote secreting gland. And hormones are still being discovered: I was studying PTH-related peptide [PTHrp] 10 years ago. It had been found about a decade previously and, as you can tell by the name, no-one was even sure if it had a function (though it certainly acted a bit like a slow-moving, long lasting PTH - the best guess back then was that smoothed out the calcium metabolism due to its longevity thus counteracting other, overzealous hormones especially at puberty and old age). Atrial Natriuretic Factor [ANF] - or various other acronyms - was accepted as real more recently (or is it accepted still? I am 10 years out of date). It was like the 'fifth force' in physics, often suggested as an explanation of an oddity but without evidence. It turns out that it is very short lived and volatile and hard to capture in the laboratory. Its effect may be only to perform very short term tweaks of the bodys water balance to even out blood pressure - hard to spot clinically. Before I sign off I want to mention the complement system. Its arguable whether they should be called hormones as their site of production is not fixed and their range is tiny but on the scale of 1mm of blood vessel instead of the body entire the similarities are there. The complement system will cascade through 20 or so levels of one molecule type stimulating secretion of the next type in just a few seconds per level creating a fountain of chemical gradients that is information intensive, telling the distance from and time since the initiating insult occurred to every object in range(in the same way that an osteoarcheologist can learn the original homeland of a creature from the composition of isotopes in a sample compared with those known to exist at all locations). That is a fine-tuned, highly specialised system of chemical processes whose rates of production and decomposition is a vital part of its workings.

This is a far more insightful question than it first appeared to me. At first I thought, its enzyme mediated, of course; for example... ..hmmmm! But peptides are generally made in ganglia within cells and, whilst the formation is enzyme mediated, it is the translated DNA code that specifies the peptide sequence. Indeed an enzyme that non-specifically joined peptide strands together would be a liability anywhere in a body as proteins are so ubiquitous and so essential. In order to make a sufficiently specific enzyme, the nature of at least the last half dozen amino acids of each peptide being brought together would have to be examined by the enzyme, making it a complex beast (equivalent to an antibody, which uses a massively redundent system of trial and error to match up with its targets) I'm sure that somewhere out there such an enzyme exists, though. I can't think of an example. Am I missing something obvious?

Getting a chloroplast into a cell might be feasible - there is a lot of research into micelles and the like which can deliver payloads of drugs to specific sites within cells. (For example look over Advanced Drug Delivery Reviews 55(6) http://www.sciencedirect.com/science/journal/0169409X) These could probably be adapted to something as large as a chloroplast. It might even be possible to place the chloroplast in its own vesicle, away from the multitudinous enzymes and messengers, with ion transport channels to shuttle the oxygen, CO2, glucose etc. between the vesicle and the cytoplasm. It might even be possible to set this up in a way that it doesn't trigger immediate apoptosis ('cell suicide'), though this would have to be by trial and error as apoptosis is not really understood at all. But even then nothing would happen unless you altered the internal workings of the cell in very fundamental ways to make all the necessary carrier and messenger proteins travel to and from the chloroplast. This is the most complex part (no hope for trial and error) and the least understood. To genetically engineer this correctly would be more difficult that adapting an algal cell to work symbiotically within a human. There are examples of this sort of symbiosis, for example lichen and coral where plant and non-plant cells live so closely together that we think of them as essentially a single multicellular creature.

The process of turning sugar to lactate is anaerobic. In order to get the slower acting anaerobic microbes to do this the aerobic microbes have to be finished off first by oxygen starvation. Filling the bottle to the brim will help but, as there will always be some oxygen dissolved in the liquid they will always manage to produce a little carbon dioxide before expiring. The carbon dioxide should dissolve happily in the space but chilling the bottle before opening the lid might reduce any residual overpressure. Otherwise an airlock of some sort will be needed to remove the excess CO2 without introducing more oxygen. (see winemaking paraphernalia) The bubbles given off by the freshly pressed cheese in brine are most likely CO2 as well as the high pressure in the bottle caused more of the gas to dissolve and it would take some time to coalesce into bubbles and escape the protein matrix. The bubbles are unlikely to be the result of an ongoing microbial process as aerobic bacteria that might be found in the cheese would not survive the acidity and the brine. HOWEVER in these days of intensive farming and universal pasteurisation a significant percentage of raw cows' milk are infected with listeria (and other pathogens). Unless you are sure of the sanctity of the cow that donated its milk, the product cannot be considered healthy. (The industry uses a variety of technological ways of sterilising the curd, I believe (i.e. pressure shock, irradiation)) Rennet is not absolutely necessary to make cheese - the first truly vegetarian cheese was made without it as the only source of rennet at the time was animal (c.1950?). Since then manufactured sources have become available and speedily adopted as the earlier vegetarian cheeses apparently had a texture more like grated nuts than cheese. (As an aside, the Vegan Society was formed in UK in 1949 after in was pointed out that with the post-war rationing still in place those who partook of a vegetarian diet actually ate more animal product that those with a standard diet. Rennet was one of the prime causes of this anomaly.) __________________________________________ "Blessed be the cheese-makers?" "It's allegorical. He's probably referring to any member of the dairy produce industry."

Vinegar comes from 'Vino Negro', or black wine. The fermenting process is quite similar but but if the wrong micro-organisms get into the mix ethanoic acid (acetic acid) is made from the ethanol and wine becomes vinegar. The oxidation of ethanol to acetate happens slowly anyways, so an opened bottle of wine turns sour.

Did you know...Caffeine is administered to premature babies to stimulate their immature lungs to breathe. The dosages are in micrograms and are monitored very closely as as little a double the recommended dose could kill. In a 100 gram body this is a very small margin of error.

I know of no reason to believe that musical sound waves have a direct effect on the brain, physically or chemically. However the effect of listening to, and interpreting music is considered a useful therapy. A few years ago the Chelsea and Westminister Hospital in London finished a long trial of non-clinical care for terminal cancer patients and of many alternates considered the most successful outcomes related to music and to art. The hospital employed various artists and performance artists to visit their chronic care wards to display, teach and involve patients. I haven't been associated with hospitals for a while but I understand that such therapy is becoming well integrated with 'establishment medicine' in the UK. The implication is that the patients state of mind is improved; simple pleasures and activity aid the 'will to live' but there may be a more influential unconscious effect on the emotions. A tonic pedal/ in a musical score (when the root note of the key is continuously played in the bass line) gives the music a stable, contented feel whilst a dominant pedal/ (when the note played is the fifth of the key) makes the music feel nervous,edgy. Studies into driving behaviour have indicated that listening to loud or fast beating music makes drivers accelerate harder than a gentle waltz, despite instruction to the contrary. Such effects are psychological, as opposed to neurochemical effects of or after the interpretation of the sounds has begun as they do not all transcend culture. Whilst cultures generally agree about cadences sounding 'good' and discords 'bad' and the same rhythmic devices are invented over and over by different cultures the emotional cues or dominant and tonic pedals were lost on asian music lovers (though they are fortunately saved from this state of insensibility by our western cultural imperialism) (As a neophyte music student I was warned to avoid the dreaded consecutive fifths/ in my compositions (when, in a chord the root and fifth notes of key are played and in the next chord the first and fifth of that key are played). It was said to make the music sound 'oriental' or -as risk of cultural slur(the english schooling system was still unenlightened back then) - 'ching-chong' music. Play it and you will hear that that phrase is basically onomatopaeic)

This is a restatement of the Einstein-Podolsky-Rosin Paradox (you are in eloquent company) Similar experiments have been done, notably by Alain Aspect in 1980, using electrons not cats, though. He had two electrons sent in opposite directions at close enough to the speed of light that their spins were measured at such a time and displacement that information travelling between them must travel faster than c. The spin on the second electron nevertheless matched up with the spin of the first electron. The most interesting implication is that, in a relativistic universe, if the first measurement affects the outcome of the second , the second would be seen to affect the first from another moving viewpoint. The information goes backwards in time! See http://www.kheper.net/cosmos/quantum_physics/quantum_physics.htm for a fuller explanation or http://www.mtnmath.com/whatrh/node75.html for lots of equations and detail

Hello all, I am a long time science junkie. I covered a fair selection of scientific disciplines academically and professionally over the years and have currently landed in nanotechnology (which is a lot less interesting than it sounds.) I'm much better at ideas than following-through with R&D so I look forward to sticking my oar into some of the more esoteric debates that crop up here. See you soon, Xavier