Posts Tagged ‘science’

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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An International Unit of human stress

June 3, 2014

Stress is a measure of continued irritation (irritation over time).  It is commonly described as the sensation of the brain overruling one’s natural desire to get antisocial, and has measurable physical results such as increased cortisol levels and  reduced immune function.

Unit of irritation : 1  RED  = 1 Red-light Expedition Deferral –
The irritation of the moment when one is in a hurry and – just at the safe stopping point – the light goes red, so one knows one should stop.

Unit of Irritation over Time :  1 RED-hour = 1 Western Industrialised Student (WIS, pronounced “Whizz”) interacting with a neutral teacher for one hour on a sunny afternoon.

A level of average daily  stress associated with lapses of self-control, such as puns or comfort eating, is 9.8 WIS (1 g-WIS)

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.

I Mix Fish and Cannabis to suggest a research proposal.

February 27, 2014

While listening to the Australian Broadcasting Corporation’s “Science Show on Saturday last, I was interested by the interview at the AAAS with the editor-in-chief of Science, Dr Marcia McNutt, and researcher Barbara Block on the effects of crude oil on fish heart rhythms  as found in research published in Science this week (1), which suggested that polycyclic aromatic hydrocarbons were the problem.    They said

“The authors found that the crude oil altered the normal function of cardiac muscles through two clear mechanisms. First, it binds at potassium channel sites that play a critical role in resetting electrochemical potential to properly pace cardiac action. And second, it interferes with calcium release transients that are vital for heart muscle contraction. Together these cardiac toxic mechanisms impact regulation of cellular excitability, potentially leading to life-threatening arrhythmias.Science was interested in pursuing this study because it shows in an ecologically relevant species not only that oil is cardiotoxic to fishes but the mechanism by which this toxicity acts reveals the susceptibility of the vertebrate heart to the highly toxic compounds present within the oil that we continue to distribute widely around the globe….the potassium channels being impacted by oil in this vertebrate are similar to the human potassium channel of the same type which is already known to be very sensitive to drugs…”

and went on to suggest that  a range of polycyclic aromatic hydrocarbons PAHs)  is found in common atmospheric pollution in big cities , and that our  inhalation of them is an effective way of getting them to our blood stream and thus our hearts.

Reading New Scientist, 22 February 2014, I came across an article “Cannabis kills without other drugs – or guns”  (p.14.)  It reports that researchers found that 2 of 15 people whose deaths were linked to cannabis use died of cardiac arrhythmias with no predisposing factors, and states that

“It is not clear how cannabis could trigger arrhythmias.”

Well, burning plant matter is a rich source of aromatics.   I bet someone is already trying to fund the research:  do dung-fired cooking in the Third World, pollution in big cities, and inhaling plant smoke all increase risk of arrhythmias by the pathway Brett et al 2014 suggest ?

(1) Crude Oil Impairs Cardiac Excitation-Contraction Coupling in Fish     Fabien Brette,    Ben Machado,    Caroline Cros,    John P. Incardona,    Nathaniel L. Scholz,    Barbara A. Block   Science 14 February 2014: Vol. 343 no. 6172 pp. 772-776  DOI: 10.1126/science.1242747

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.

Psychology: Why I class it as a science.

November 21, 2011

It is sometimes said that Psychology shouldn’t be classed as a science, because psychologists can’t accurately predict what individual people will do:  in a real science, we expect testable predictions.

To be generous, I will allow all  brain-scan linked psychology to be put under neuroscience, and all chemical-linked psychology to be under psychopharmacology.  I will consider only social psychology and the study of individual behaviours.

It is clear that any situation brings out different responses from different human individuals, and that the range of these responses is predictable.

Some situational responses are very common.  In a previous post  I gave some examples of famous response patterns,  but there is a huge range of psychological research into common effects.  (For a quick start, there are many videos and books from Richard Wiseman .)  However, for every standard response there is a sizeable minority who are non-standard.  Does this invalidate the claim to scientific status for psychology?  Consider the reasons for the range of responses:

To begin with, testing of famous effects has made it clear that different cultures prime us to different response sets.  (Laura Spinney’s article on being WEIRD gives a few examples. )

On the individual level, personality and past experience also prime individuals to particular responses.   Research on resilience gives many examples of this.

Finally, for each of us, there is a probability of a particular behaviour in a given situation – even in rats with strongly conditioned responses there is a degree of variability in response.

So, psychologist have found many aspects of variability in response, and are trying to identify causes and measure their effects – alone and in combination – and are testing their predictions.   That sounds like science to me.  However, they still can’t usually predict what an individual will do. So, is that a fatal flaw?

Let us consider Chemistry – that is a science.  Given a set of chemicals, in a given environment, the outputs are predictable – right?  Well, take burning an archetypical carbohydrate:  CH2O (s) + O2 (g)  – >  CO2 (g) + H2O (g).   Can the chemist predict which of the Oxygen gas’s atoms will end in the carbon dioxide?  Consider the history of producing  isocyanides  :  the proportions of different products from a given starting mix was initially hard to predict, and much research was needed before the exact conditions for high yield were found.   With the invention of microwave ovens, chemists found  a new range of conditions for chemical reactions – and again started by finding out the changes in  mixture of products from changes in process.  ( One example is the processing of methane, of interest to the natural gas / syngas industry.)

So, I argue that Psychology can be classed as a science precisely because  (like research Chemists) the researchers accept that there are limits to their knowledge,  that they must measure reality to form ideas of what might be happening (hypotheses),  and that their predictions (from hypotheses) of the results of given processes must be tested against reality before a strong theory can be developed.