Archive for the ‘Science’ Category

Bitcoin – not for me.

December 8, 2017

The recent enthusiasm for Bitcoin bothers me.

Not because it has got to the “taxi drivers are talking about it” indicator of bubble status.

Because it is being used widely enough to stay in use when the bubble bursts.

Many of the people using it are interested in the environment, and approve of replacing still-working globes with LED globes to reduce power consumption. They may have installed solar PV panels to contribute to low-emission power.

How will they feel when they understand the impact of the bitcoin computing approach?

The ConversationDigiconomist and IEEE   put it clearly.  A Bitcoin transaction uses 5,000 times as much energy as using a  credit card, and the energy cost will increase as the blockchain lengthens.  The multiple servers maintaining copies of the ledger, and comparing their versions, and doing the complex calculations to solve a puzzle  to be the lucky one to generate a Bitcoin (all the others’ discard the work they have done, wasted electricity) – all burn power and generate waste heat.

I believe  that cold climates are more ethical server locations, as the heat generated can at least be used for warming buildings or preheating for hot water systems, but even so the process leaves me uneasy.

I am glad that the alternative blockchain designers are testing less power-hungry approaches.  Until Bitcoin changes its approach, I think it should be avoided.

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What future for the average intelligence student? The problem with education “for employment”

July 10, 2016

Both our major political parties are talking about education to fit students for jobs in “the new economy.”  At the same time  Our Coalition Government wants to give Company Tax reductions to large businesses.  However, for large companies,  increased company profits invested in expansion tend to lead to job losses.

Not just from offshore subcontracting of labour to exploited workers with no leave entitlements, OH&S rights,  or superannuation. Consider  http://www.bbc.com/news/technology-36376966

It includes a quote from a former McDonald’s senior staffer : “It’s cheaper to buy a $35,000 robotic arm than it is to hire an employee who is inefficient, making $15 an hour bagging French fries.”

The main item in the article is that 60 000 (probably OH&S nightmare) jobs have gone because Chinese factories invested in technology not humans – even at their pay rates the robots are cheaper.

These job losses are not just the semi-literate jobs.  Consider the rise in expert systems, even self-reprogramming learning systems: the first white-collar job robots are already here, even doing work for lawyers: https://www.washingtonpost.com/news/innovations/wp/2016/05/16/meet-ross-the-newly-hired-legal-robot/

The students know about this.  They know that machine intelligence researchers are even starting to find ways to program the machines for creativity.
(see John Gero on Creativity emergence and evolution in design concepts and framework
and  https://www.jwtintelligence.com/2016/06/cannes-2016-creativity-and-machine-learning/  )

So why should the less bright and less creative struggle to learn the basics, if they are told education is “to get a job” and they know they are headed for love on the dole?   (Read Greenwood’s book, or at least a detailed review, if you haven’t come across a film or play adaptation yet )

It is time for the meme of “education to be fit for work” to die.  Move to “education to get tools to make more fun and happiness, or dodge trouble.”  Start classes in “Learning something new without a teacher’s help, and demonstrating it to others,” “Comparing and testing health benefit claims,”  “Bullshit detection,” “website reliability testing,” “effective complaints,” “Dealing with Bureaucracy 1:  Completing a basic tax return so you don’t pay your refund to an accountant,” and  “Dealing with Bureaucracy 2:  Complying with Dole paperwork requirements.”

Of course, you may end up with a lot of activists trying to improve the Nation because they realise that the  current socio-economic system is the source of much unhappiness.  They may even realise that money is just another social construct – and not a good one – and demand a world run on social obligation instead.
Would that be so bad?

Paracetamol, Aspirin, Fashion and Changing Disease Patterns.

March 25, 2014

I remember the last days of  “A cup of tea, a Bex, and a good lie down.”  I also remember the reports that kidney failure  was related to Bex’s phenacetin and digestive tract ulcers were  linked to its aspirin, and  the start of the emphasis on paracetamol (AKAacetaminophen  in the USA)  as a safe alternative.

Now there is research suggesting that aspirin use has many useful side effects.  This has hit the popular press – compare http://www.womenshealthmag.com/health/aspirin and  http://www.medicalnewstoday.com/articles/243265.php

There are also problems with overuse of paracetamol having its own risks, and (unlike aspirin) it does not much reduce inflammation, so will not provide the same range of beneficial side effects as aspirin.  (As an aside,  it has great value for those who cannot risk aspirin’s blood-thinning properties, and for those young enough to be at risk of Reye’s syndrome.)  Other new painkillers (e.g. ibuprofen, naproxen) are selling well, and will no doubt be found to have a range of unexpected good and bad side effects.  There is a lot unknown about analgesics – for example, they don’t yet know why some people don’t respond to some analgesics, but some genes (e.g. melanocortin 1 receptor (MC1R)) seem to play a role.

The statistics on western women’s life expectancies in the seventies were based on generations of women who used aspirin-based medicines to keep going when family needs meant they had to keep going – no sick leave for Mothers.   (Well, not until they got bleeding bowels or failed kidneys from other things in the painkillers.)  They also had generations of  men who soldiered on bravely – painkillers were for softies.  And generations where women got heart problems and the diseases of aging later than the men.

Now we have a generation who changed from aspirin to paracetamol and other analgesics, and  under 40s who grew up with paracetamol for both genders.  Here is one more  public health change among the thousands of deliberate improvements in our lives.

And look, the gap between the genders’ life expectancies has shrunk while both genders have greater life expectancies.

Ten years ago I said that there would be a decline in the gap between the genders’ life expectancies.  I would now bet that there will be a continued decline in the gap between male and female  life expectancies, possibly a reversal of the gap, and that the change will have many causes.  I expect that most of the talk will be about the social changes such as mothers working outside the home – but I hope someone does some research on the outcomes by preferred general painkiller.

Why I am optimistic

March 4, 2014

Many people I know are less prone to depression than I am, yet seem overall more down when they talk about the world and the people in it.

Why?  Partly  because I grew up in a politically aware household, and understood the huge changes in and from the years of my childhood.  So many people don’t seem to have paid attention, and don’t realise how much things can change in our country.  Partly because I know some deep history of places-other-than-this, so I know how much human lives have changed globally, how they can react to a changing environment, and just how amazingly NICE many people can be.

But, day to day, I find the thing that keeps me up-beat is … reading New Scientist and listening to ABC Radio National science/health programs.

Here’s an example.   New Scientist, page 18, 22 Feb 2014, “Tiny rod reels cancer cells to their death.”

So you have glioblastoma,  brain cancer cells, sitting beside some vital part of the brain that you really don’t want to lose, building up numbers and crushing something like your ability to make new memories, or to distinguish between your wife and a hat until one of them speaks.   If you cut out the cancer you may lose the ability anyway, and drugs to kill the cancer may kill you before they kill all the cancer.

So the doctors get a thin tube lined with a sneaky material, and at the top have a chemotherapy gel.  They poke the tube down into the cancer, and the cancer cells crawl up the tube and are killed with minimal disruption to your biochemistry.  Imagine saying to your cancer “Crawl off and die!”

Imagine if they put a collection chamber on the end and an access-flap in your skull, and took out live cells to analyse their weaknesses, or to prime your immune system against them.

How cool is that?  It brightened my whole day.

Fight “Lying for the cause”: time for the pillory.

August 7, 2012

Too many people speaking with authority on serious public controversies are “either lying or incompetent”; too few interviewers / debate participants call them on it.

I don’t mean just that they are pushing the predictions of a model which has not yet made reliably accurate predictions – a model may only fit known results, but it is arguable that it should  be considered in decision making if no other model has yet succeeded.

I mean claiming that which has been tested and found not so, or denying the existence of things which are.  For example, in the former case, claiming that the MMR vaccine puts children at greater risk of brain damage or death than not vaccinating despite the statistics.  For an example of the latter,  claiming that there are no GM [genetically modified (other than by selection of natural mutations)] crops in existence which are not designed to need increased use of Big Chemical Companies’ products – despite the news, months before, that activists had whippersnipped a test-field of three types of wheat GMd (a new abbreviation as far as I’ve read) for better nutrition and for better growth with less fertilizer ; depite Golden Rice; and despite statistics showing that GM cotton resulted in lower use of industrial chemicals.

Also, there are those who make claims that a high-school student who has followed the news can see are laughable.  For instance, one said (of the Queensland premier blaming previous governments for budget problems) “What’s he grumbling about?  So he has a budget shortfall – his state is barely a year past two major natural disasters, and his budget is only 10% in deficit! That’s pretty good.  Catastrophes will happen, and cut our income – isn’t that why we save in good years?””

This “lying for the cause” attacks the foundation of Western democracy – serious decisions the electorate makes on on the basis of best available information cannot be good if the information is corrupted.  Most citizens have not the scientific and mathematics training to see flaws in research, and do not follow scientific news enough to know of the background to claims, so they rely on those “who ought to know”.  Appeal to Authority may be a logical fallacy, but it is the basis of daily decision making.

It is time for a public pillory: a program which is watched in full school assemblies, where top experts in the field which was misrepresented stand together to say that the person (picture and name of organization in backdrop) was “either lying or incompetent”, and making clear the facts.  The person concerned is invited to  provide expert support foot their claims – but the expert support is tested and the case decided by qualified people before the program is run, as many “expert” claims are not based on scientific and mathematically sound approaches.  The expert support – if found to be unconscionably flawed – is also criticised in the program.  And the experts’ faces are shown, with name and organization,  as their claims are demolished.

Watching what you eat: foods having delayed effect on appetite

November 28, 2011

On a very low energy diet(often called VLCD), the dieter starts considering each additional item of  food or drink on the basis of the energy it will add.   Science has provided another basis for considering foods:  the subsequent effect on appetite.  I want to list a few where it will be interesting to watch for future research:

1. Milk products:  In those with a low calcium intake, reduce feelings of hunger more than an energy-matched drink. The calcium and protein in milk may be the triggers for this effect.(1, 2)

2. fats and oils

The short-term effect of fats is to reduce the sensation of hunger shortly after the fatty acids from digestion of fats reach the duodenum.   Surprisingly small amounts of oil can have this effect, but in those who eat much fat it is suppressed –  the whole matter of fat digestion is horribly complex (3)   However, improved sensitivity was measured in obese men after 4 days on a VLCD . (4)

Unfortunately, it has been found that eating fats/oils  does not always reduce appetite later, and may increase appetite the next day (5).   This fits with anecdotal evidence – for example, following a cheesecake relapse, a dieter experienced more hunger than usual the next two days, where the same effect was not felt after a protein-binge.

More confusingly, the type of oil is important – for example, fish oil seems to add less energy (that is, result in less fat) than do maize oil or beef fat. (6)

3. Citrates

Lemon juice, and various similar chemicals often added to cordials.   In some people, citrates seem to make it more difficult to adhere to a VLCD.  This may be linked to  the role of citric acid in favouring gluconeogenesis over ketogenesis (7).  (VLCDs emphasise ketogenesis for weight loss.  Making glucose inside the body does burn energy, but seems linked to increased appetite

Research needed:

Most studies emphasise same-day or long-term effects of particular food types.   More reliable studies on two- or three-day effects on appetite and perceived tiredness/energy levels, with titles showing on net searches, would be welcome.

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Footnotes
1. Gilbert JA, Joanisse DR, Chaput JP, Miegueu P, Cianflone K, Alméras N, Tremblay A.   (2011)  “Milk supplementation facilitates appetite control in obese women during weight loss: a randomised, single-blind, placebo-controlled trial.”     Br J Nutr. 105(1):133-43.   http://www.ncbi.nlm.nih.gov/pubmed/21205360

2. Major GC, Alarie FP, Doré J, Tremblay A. (2009) “Calcium plus vitamin D supplementation and fat mass loss in female very low-calcium consumers: potential link with a calcium-specific appetite control.” Br J Nutr. 101(5):659-63. http://www.ncbi.nlm.nih.gov/pubmed/21205360

3. Little, Tanya J. and Feinle-Bisset, C  (2010)  “Oral and Gastrointestinal Sensing of Dietary Fat and Appetite Regulation in Humans: Modification by Diet and Obesity” Front Neurosci. 2010; 4: 178. Published online 2010 October 19. Prepublished online 2010 May 20. doi:  10.3389/fnins.2010.00178   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2981385/

4.

Brennan, I M,  Seimon, R V, Luscombe-Marsh, N D, Otto, B, Horowitz, M and Feinle-Bisset C (2011). “Effects of acute dietary restriction on gut motor, hormone and energy intake responses to duodenal fat in obese men” International Journal of Obesity 35, 448–456; doi:10.1038/ijo.2010.153; published online 3 August 2010  http://www.nature.com/ijo/journal/v35/n3/abs/ijo2010153a.html

5.http://www.reebokcrossfitone.com/Nutrition/Effect-of-dietary-fat-on-satiation-within-and-between-meals.html?print=1&tmpl=component (does not display well in my browser, but deserves credit for links to the fulltext article

Blundell, JE, Burley, VJ,  Cotton, JR, and Lawton CL  (1993) “Dietary fat and the control of energy intake: evaluating the effects of fat on meal size and postmeal satiety.”  American Journal of Clinical Nutrition, Vol 57, 772S-778S  http://www.ajcn.org/content/57/5/772S.abstract?sid=d31ef1ca-bb08-4d39-9f0b-ec12322c5e74)

6.Jang IS, Hwang DY, Chae KR, Lee JE, Kim YK, Kang TS, Hwang JH, Lim CH, Huh YB, Cho JS. (2003) “Role of dietary fat type in the development of adiposity from dietary obesity-susceptible Sprague-Dawley rats.”  Br J Nutr. 2003 Mar;89(3):429-38. http://www.ncbi.nlm.nih.gov/pubmed/12628037

7. Kreitzman, S.N. (1992)  Factors influencing body composition during very-low-calorie diets   Am J Clin Nutr 56:217S-23S.

“It’s Just Water” … well, no. Early weight loss in dieting.

November 7, 2011

One of the common statements in low-energy dieting is that “The first couple of kilos is just water.”   (That is, once you allow for the change in bowel contents.) If it is just water, how can one lose two litres of water and not feel the effects of dehydration?

To understand this, we have to understand a little human  biochemistry.

Glucose,  glycogen stores, and water

Our brains and muscles “burn” glucose – a simple sugar, found in many carbohydrate rich foods (for example, cane sugar is one fructose molecule bound to one glucose molecule).   It  is disassembled to release chemical energy, carried in the form of a small molecule called ATP (Adenosine triphosphate).   Glucose is so important that our bodies can use other molecules and energy from other foods to make glucose (gluconeogenesis).

As with other important materials, our bodies store glucose for later use.  The stores are not glucose itself – they are molecules which the body can take apart for glucose.  The first storage is as a molecule called glycogen, stored in the liver and muscles;  secondary storage is as fat.  When there is plenty of glucose and ATP,  insulin promotes the conversion of glucose into glycogen.

When there is little ATP and little glucose, our cells’ first response is to disassemble glycogen to keep the blood sugar level up.   So, in dieting, our cells first use the glycogen stores. A common estimate of adult glycogen stores is 400 to 500 g.   However, glycogen is not stored alone – like glucose, its pure form is not a soft or liquid substance.  It is stored with three to four times its weight in water (1).   So, in the initial stages of dieting, the glycogen stores are used up and the associated water is released.

It takes energy to make and store glycogen, and to transport its related water.  So, in using up glycogen, dieters  reduce the stored energy within their bodies.   Therefore, the weight loss is not just water, and does reflect a real improvement in body mass – just not as much in terms of fat-equivalents.

After the diet

When the dieter returns to a weight-maintenance eating pattern, it is reasonable for ver to rebuild ves glycogen stores.  So, ve must plan for that: ve must be aware that the first couple of kilos (after accounting for bowel contents) will not be fat, will be valuable for maintaining blood sugar levels, and are to be expected to be back very soon after leaving off the strict regimen (in days, not weeks.)  An immediate effect is that the target weight should reflect this expectation: if ve wishes to weigh 65 kilos, ver goal in dieting would be 63 kilos (minus an amount  for bowel contents depending on diet) .

Upsides and downsides of continuing low-energy dieting for more than the water-loss period

Upside

The body does not burn its fat stores significantly until the glycogen is low.   This is one reason to value the rapid initial glycogen and water weight loss stage, and to continue beyond it.

A second reason is not commonly known:  the brain relies on glucose for energy until blood sugar levels have been low for some time, but after about three days it starts using smaller molecules called ketone bodies (the things which give dieters ketosis, resulting in  “nail polish breath (2) “).  From about 40% after three days of starvation (3), after about a month it can get up to 7o% of its energy from ketone bodies.  In human evolution periods of  low-carbohydrate diets  – and real hunger – were common, so is reasonable that our bodies are adapted to use other energy sources.  It is now suggested that there may be benefits to deliberately triggering this shift in brain metabolism. (4)  As with decreased exposure to diseases with modern lifestyles (5,6), decreased exposure to hunger may not be entirely to our benefit.

Downside

There is one main downside:   Low blood sugar is linked to various problems, including difficulty  controlling impulses.  In dieting these are not as severe as those diabetics may experience , but a degree of crankiness is to be expected – especially in the days before the brain shifts to using ketone bodies.

A second downside is the risk that low energy intake may be associated with a poorly balanced diet with poor essential nutrient levels.  One may get away with this in the short term, but over longer periods one must plan very carefully.   I feel that this is minor, as there are several well balanced VLCD (very low calorie diet) systems available.  However, unless the dieter is competent in dietary analysis, it would be best to have nutritional advice from a University-trained source.

A third downside is that the process is a physical strain – which is why the packaged approaches recommend medical supervision: there is a risk that unrecognised problems (such as liver failure) may flare up under the stress.

Conclusion

It isn’t just water, and it is a sign that you are, at least, not getting fatter.  The hard work is worth it – but watch your temper and watch your nutrition.

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1.  Kreitzman, S N  (1992)  Factors influencing body composition  during very-low-calorie diets Am J Clin Nutr 56:217S-23S.   http://www.ajcn.org/content/56/1/217S.long

2. Note that this mild ketosis is different from the severe and life-threatening ketoacidosis (commonly from diabetes or alcoholism), where the smell is stronger and medical attention is required.

3.Hasselbalch, SG; Knudsen, GM; Jakobsen, J; Hageman, LP; Holm, S; Paulson, OB (1994). “Brain metabolism during short-term starvation in humans.”. Journal of cerebral blood flow and metabolism 14 (1): 125–31. doi:10.1038/jcbfm.1994.17. PMID 8263048.

4. http://www.ncbi.nlm.nih.gov/pubmed/20188215   , http://www.ncbi.nlm.nih.gov/pubmed/20009300

5. Committee on The International Study of Asthma, Allergies in Childhood (ISAAC), Steering Committee. Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema. ISAAC Lancet. 1998. pp. 1225–32.

6. Nowak D, Wichmann H-E, Magnusson H. Asthma and atopy in Western and Eastern communities- current status and open questions. Clin Exp Allergy. 1998;28:1043–6. [PubMed]