Sunday, April 11, 2010

What is Twitter (to me)?

I often come across people who say that they understand the point of Twitter. Given the fact that I am an active twitter user (according to, I am among the 500 most active and 500 most followed Danish twitter users), I thought I'd try to explain how I use twitter, and why it's not just the same as facebook statuses or instant messaging.

Before continuing, I should probably make clear that I am in no way any kind of communications expert, or even particular knowledgeable on the subjects of digital communication, social media, and social networks.

Having said all that, let's go into how I view Twitter.

For me, Twitter is a great media for social dialogue. It's not just someone telling me something, but rather a continuous conversation, with multiple entrance points and nearly unlimited participants. This can be a intimidating at first, but as soon as you realize that you can do it on your own premises, it works for you.

Let's try to see how a conversation usually get going.

1) Somebody posts something
2) Multiple people either re-tweets the post (sometimes adding their own comments)
3) People react to either the original tweet or a re-tweet.
4) People respond to the responders

The great thing about this is that you don't have to have been part of the conversation from the start - you can just jump in at any point, and add your view to the conversation (or reinforce somebody else view by re-tweeting).

Given the fact that you can only see tweets addressed at other people if you also follow that person, the conversation can also be a bit fractured, but at this point, twitter users have found out how to work around this (adding a dot in front of the tweet if it might be of general interest).

I hope you can see why this is different from both facebook statuses, where only a limited group of people can see it/participate in the conversation, and instant messaging, which are even more limited.

This is what makes Twitter more interesting for me.

Still, it wasn't always like that. I have been using twitter since the end of 2008, or thereabouts, but I didn't really start actively using it until summer last year. The reason I didn't use it so much before then, was that I had a hard time figuring out how to use the media so it worked for me.

So, what changed?

1) First and foremost, I got past a critical mass of people I follow. This means that there are always some kind of conversation going on, which I can dip into, if I feel like it.
2) Closely related, I learned that I don't have to read all tweets. My usage of twitter is to log in, and read the tweets on the screen. I generally don't scroll back, though if someone post a reply to someone else, which catches my interest, I will generally try to trace the conversation back.
3) I learned to ignore the fact that people don't react to my replies to their tweets. It's important to remember that at the time they read them, they have moved on in their conversation. Also, unlike , people get to pick and choose what conversations they want to participate in, without being considered rude.

I cannot stress the last point enough. It's not rude not to engage in a conversation on Twitter - instead it's rude to insist on a conversation. If people don't feel up to communicating with you, then look for a conversation somewhere else.

Hopefully, this post has made it a little clearer what Twitter can be used for. Keep in mind, however, that Twitter is different things for different people - some people use it to talk with their friends, other people use it as a sort of RSS feed, keeping an eye for interesting links being posted, and yet other people use the media entirely differently.

On an end note, just remember that because of Twitter's nature, you can't tell where your tweets will end up and who will read them. So, as in everything on the internet, think before you post.

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Sunday, April 04, 2010

Measles outbreak in German caused by anti-vaccinationists

In the first months of 2010 there has been a measles outbreak in Berlin, Germany.

According to this Eurosurveillance preliminary report there has been 62 cases as of the end of March. This is more than the entire number of cases in 2006 (57) which until now had been the year with the highest number of cases in recent years.

So, what caused this drastic increase? You guessed it - anti-vaxxers. Yes, the outbreak is among unvaccinated children.

The first case was diagnosed January 5th, and was in an unvaccinated child returning from a trip to India, where measles are endemic (what the hell were the parents thinking?). The first case is a pupil at a private school - a Waldorf-Schule, which is a Rudolf Steiner school, and thus unsurprisingly have many parents who are against sensible things such as vaccinations. According the preliminary report, the proportion of students vaccinated against measles is "significantly below 70%".

One of the talking points among anti-vaxxers is that more children with vaccinations get sick from measles than children without vaccinations (which of course is pure nonsense, given the fact that a much larger proportion of non-vaccinated children get sick). Well, in this outbreak "[n]one of the reported cases had been vaccinated against measles before being exposed during this outbreak". In other words, every single case was an unvaccinated child.

In order to stop the spread of the disease, the District Health Offices took some drastic steps:

* Temporary exclusion of students and teachers without measles vaccination or naturally acquired immunity from schools with confirmed measles cases;
* Offering measles vaccination for unvaccinated students and teachers in affected schools (vaccinations in collaboration with private practitioners);
* Equivalent measures in kindergartens with measles cases;
* Active detection of contacts and exposed persons;
* Sampling of clinical material from measles patients to confirm diagnosis and perform genotyping at the National Reference Centre for Measles, Mumps and Rubella;
* Recommendation of temporary restrictions of private contacts with unprotected persons and of any public activities in groups for patients and their unvaccinated family members;
* Public health information to increase regional clinicians' alertness regarding measles in their area;
* Enhanced communication with educational institutions and parents with critical attitudes towards vaccination of the children.

This has helped stop the spread of the disease, but strikingly enough, few parents have taken the offer of getting their children vaccinated. What's more, some parents did something much more incredible - they filed an action against the District Health Offices at the Berlin Administration Court for not allowing their children to go to school so they could get infected.

In early February, parents whose children were affected by the temporary school exclusion filed an action against the respective District Health Office at the Berlin Administration Court. The claim argued that the health authority’s decision impeded the unvaccinated children’s rights to visit school and to acquire immunity against measles through natural infection. Measles was claimed to be a harmless infection in children without severe complications and possible long-term disabilities. The specific vaccination against measles was perceived to be inefficient and dangerous.

They wanted their children to get sick with a potentially deadly disease! What the hell is wrong with these people? How can anyone be so ignorant?

Luckily the claims were dismissed by the Berlin Administration Court, but cases are pending at the Berlin High Administrative Court. Hopefully they will be dismissed there as well.

Measles are a serious disease, which causes hundreds of deaths every day. For people to want to expose their children to it, shows how dangerous the anti-vaccination movement is.

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Lazy linking - science and skepticism edition

A few science and skepticism links that I thought I'd share.

* J. David Jentsch ask people in the LA area to Stand up for science on April 8. Jentsch is one of the scientists who has been targeted by animal rights terrorists because of his animal research.

* A new study shows that Spanking sparks aggression, does little to reduce behavior problems in children. One of the techniques studied (spanking) is illegal in Denmark, but the others are certainly still used.

* An interesting take on the use of statistics in science: Odds Are, It's Wrong. Personally, I don't find the article entirely convincing. Yes, it's true that there are possibilities of false positives and negatives, but it seem to me that enough studies should clean up these problems. I find the complains about meta-studies puzzling, and while I can see the author's point in a perfect world, we have to work with the material at hand. Still, it's a good article, and I think scientists conducting studies would do well to keep its points in mind.

* I can't remember where I found this link (almost certainly at a feminist blog), but I thought that it was well worth sharing. It's an article in Stanford Magazine about Stanford professor Clelia Mosher who probably was the first to do research into female sexuality: The Sex Scholar.

* Occasionally I come across people who seem to think that the cause of ice ages are unknown, which puzzles me, since I thought it was well-established that they were caused by shifts in the Earth's axis. Apparently this wasn't quite as well-established as I thought, or at least not for as long as I thought - I came across a ScienceDaily article from August 2009 which explains that this was now the established explanation: Long Debate Ended Over Cause, Demise Of Ice Ages? Research Into Earth's Wobble

* David Colquhoun tells us that the University of Buckingham does the right thing. The Faculty of Integrated Medicine has been fired. One less place educating people in woo.

* Over at Alice in Galaxyland there is a great report about a recent event at Skeptics in the Pub in Wincester: Skeptics in the Pub: Unnatural Predators by Jourdemayne at Winchester. Certainly makes me wish I had been there (though I am happy to have been spared the journey described).

* And finally, a shout-out to a fairly new blog. When I was in Perth in January, I met up with the Perth Skeptics on the last day I was there (which is when they participated in the 1023 mass suicide by homeopathy event). While I was there, I talked a bit about skepticism in Denmark (not much of it around) and blogging. One of the participants was thinking about starting his own blog, and after my talk he took the plunge - so I present to you Friend of Reason. There is some good stuff there.

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Friday, April 02, 2010

Not even bad science

Once in a while, one comes across a published study which is so bad that one cannot even consider it to be bad science, rather it's so completely wrong, that it has nothing to do with science at all.

I recently came across one such study.

For some strange reason, I had clicked on a homeopathy hashtag in Twitter, showing me the latest tweets about homeopathy. This is not something I recommend, as the stupidity is out in force there. Anyway, one of the most recent tweets at the time referred to a study demonstrating that homeopathy was as efficient as anti-depressants. Unsurprisingly, I took a closer look at the study.

The study is this one: Homeopathic Individualized Q-potencies versus Fluoxetine for Moderate to Severe Depression: Double-blind, Randomized Non-inferiority Trial by U. C. Adler et al. (read it at your own risk)

My last post was triggered by reading the study for reasons I will come into later, but let me just say for now that whoever was in charge of that study was obviously a true believer of homeopathy, and had very little grasps of science and evaluating results.

What makes me say that? Well, let's tackle the claim about the person in charge being a true believer and not understanding science. Passages like this one, should clearly demonstrates why I say that.

Hahnemann's dynamization gained support of physics: thermoluminescence emitted by ‘ultra-high dilutions’ (dynamizations) of lithium chloride and sodium chloride was specific of the salts initially dissolved, despite their dilution beyond the Avogadro number (11).

I think I can safely say that no physicist would agree that Hahnemann's idea of dynamization has gained the support of physics - as a matter of fact, physicists would call Hahnemann's claims pure nonsense.

Don't believe me? Well, this is what Hahnemann had to say on the subject of dynamization:

This remarkable transformation of the properties of natural bodies through the mechanical action of trituration and succussion on their particles (while these particles are diffused in an inert dry or liquid substance) develops the latent dynamic powers previously imperceptible and as it were lying hidden asleep in them. These powers electively affect the vital principle of animal life. This process is called dynamization or potentization (development of medicinal power), and it creates what we call dynamizations or potencies of different degrees.

In other words, this is the claim that diluting the substance makes it more potent.

The claim that physics supports this is based upon one article, Thermoluminescence ofultra-high dilutions of lithium chloride and sodium chloride (.pdf) by Louis Rey, which hasn't been replicated, and which certainly doesn't support Hahnemann's claims about the substance becoming more potent. There are also several people who points out problems with Rey's study.

So, all in all, a good scientist would most certainly not make claims like "Hahnemann's dynamization gained support of physics", since there is only one, non-replicated study which might support this claim - in terms of science, this amounts to an unsupported claim.

Still, even though the people in charge of the study are true believers, and don't really understand science, it doesn't mean that the study can't be useful - after all, if done properly, the results should speak for themselves. So, let's return to the study.

Basically, the study was conducted by assigning patients into two groups - one group which would receive Fluoxetine and a placebo, and one group which would receive the homeopathic remedy and a placebo.

I think you all can see the issue there. Since homeopathy is placebo, what this study is doing, is comparing Fluoxetine to placebo. Of course, the people conducting the study doesn't see it this way, but as I wrote in my last post: Until homeopaths can explain how homeopathy works in terms which doesn't mean that everything we know about chemistry, physics, and physiology is wrong, then we can safely reject their claims.

But let's for the sake of the argument accept that we are comparing two different types of remedies for depression, and look at what the study concludes.

This sample consisted of patients with moderate to severe depression, because their mean MADRS depression scores were close to the 31 score cut-off for moderate and severe depression (28). Initially, 284 subjects were screened, 105 of them met the inclusion criteria, 14 out of them did not attend the first appointment, 91 were randomized and 55 completed the 8-week trial. A detailed flow chart of subject progress through the study is shown in Fig. 1.

So, out of 91 people, only 55 completed the 8-week trial. That's a drop-out rate of ~40%. That's a quite significant number, and would impact the reliability of the study. Let's see how they go into this later.

There were no significant differences between the proportions of excluded and lost for follow-up patients in the two groups (P = 0.99), though there was a trend toward greater treatment interruption for adverse effects in the fluoxetine group, as can be seen in Table 1.

Well, true, there was no significant difference between the proportions, but there were quite different reasons why people were excluded.

As they state, there was "a trend toward greater treatment interruption for adverse effects in the fluoxetine group", hardly surprising since they were given actual medicine, rather than placebo, which has side-effects. What's more surprising is that there were actually 3 people excluded from the placebo homeopathy group for adverse effects. Since there are no active ingredients in the homeopathic remedies, this must either be due to an negative placebo effect (called the nocebo effect), or due to a misdiagnosis of e.g. clinical worsening.

What they did leave out was the fact that there is a significant difference in the clinical worsening in the two groups. Among people receiving the medicine, there was one person excluded because of worsening (approximately 2.3% of the cohort), while among the receivers of homeopathic remedies, there were five who were excluded for this reason (more than 10% of the cohort, 10.4% to be more precise). Again, this is entirely in line with our knowledge of which group is receiving actual medicine, and it certainly is a significant enough difference for it to be taken into consideration when writing about the results, yet this was not done.

The rest of the result section goes on to analyzing the results of the people who made it through the 8 week period, yet doesn't address neither the high drop-out rate nor the differences in the reasons for exclusions.

Going to the discussion section, there are a couple of things which jumps out, particularly this paragraph:

A placebo-arm was not included in the present study because it was not authorized by the National Ethic Council. Although placebo interventions are associated with mean response or remission rates of ~35% (37,38), a placebo effect cannot be ruled out, since the homeopathic Q-potencies were compared with an antidepressant and ‘it is becoming more and more difficult to prove that antidepressants—even well-established antidepressants—actually work better than placebo in clinical trials’ (39). Nevertheless, it also has to be taken into consideration that the antidepressant-placebo difference seems to be smaller in the trials aiming at mild to moderate depression (40,41) and the present sample consisted of patients suffering from moderate to severe depression. Placebo-controlled studies would be recommendable to clarify these findings.

The first part of the paragraph is what caused the ranting in my last post. I presume that the National Ethic Council didn't allow a placebo-arm in the study, because it considered it unethical to submit people suffering from depression to placebo, yet by allowing this homeopathy study to go ahead, it submitted the very same type of people to something which we know is placebo. What the hell is wrong with these people? Are they really so gullible that they don't realize this?

And when reading the rest of the paragraph, it becomes clear that the people who conducted the study is aware that they were comparing homeopathic remedies to something which hasn't been shown to be any better than placebo. In other words, they are comparing one type of placebo, homeopathy, to something which might very well be another type of placebo, or which at the very least seems to have a very limited effect on top of the placebo effect. And we are supposed to be impressed that homeopathy is as effective?

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Nothing in Medicine Makes Sense in the Light of Homeopathy

I am not the first person to state this, but I think that it's important that we all keep up saying this: Testing of homeopathic medicine should end.

Why do I say this? Well, for a very simple reason: There is no evidence that homeopathy works. And what's more, the whole concept of homeopathy flies against everything we know about chemistry, physics, and physiology.

This blog post is triggered by a truly abysmal study where homeopathic medicine was compared to proper medicine used for treating moderate to severe depressions - there were numerous flaws in the study (which I plan to address in a later post), but the fundamental problem was that it was comparing medicine with remedies based on nonsense.

There is a famous essay by Theodosius Dobzhansky called "Nothing in Biology Makes Sense Except in the Light of Evolution", which goes on to explain how our knowledge of biology wouldn't make sense except if evolution is true. One could write a similar essay, called say "Nothing in Medicine Makes Sense in the Light of Homeopathy", in which one explains how all our knowledge of medicine and physiology doesn't make sense if homeopathy is true.

I don't think this can be stressed enough.

It's not just a matter of science not understanding homeopathy. If homeopathy was true, it would mean that the basic building blocks upon which our knowledge is built would be wrong.

Given we know that this is not the case, homeopathy must be wrong. No, that's too mild; homeopathy must be absolute nonsense.

The basic concepts of homeopathy are things like "like cures like", miasms, and and the concept of "memory" in water, all of which is nonsense.

"Like cures like" (or law of similars) is the idea that medicine should be based upon things which gives the same symptoms as the original disease. This was perhaps plausible back when Hahnemann first proposed it two hundred years ago, but we now know that there is no truth to this idea. Sometimes the medicine will be based upon substances which gives similar symptoms, but mostly it won't.

Miasms are an old concept, in which diseases are caused by pollution or bad air. This idea was replaced by the germ theory of diseases, and is not taken serious by anyone except for certain branches of alternative "medicine" such as homeopathy, where they have added their own twists to the concept, but still stay largely true to the old Medieval concept.

The "memory" of water (or sugar for that matter) is the explanation used to explain how homeopathic medicine can have any effect. Homeopathic remedies are based upon the concept of diluting, in which the remedies are diluted to a degree where none of the original molecules are left (see this rather poor Wikipedia article for the numbers).

Oh, and the homeopaths also claim that the more diluted a remedy is, the more potent it is. Yes, this is really what they claim. No, it doesn't make any sense.

So, all in all, we know that homeopathy doesn't work. So, why the hell are we continuing to test it against proper medicine?

There are a lot of alternative "medicines" which might work, even if the concepts they are based upon are nonsense (e.g. acupuncture), and it makes sense to test these (so far, the effect of acupuncture seems to be placebo), but this is most certainly not the case with homeopathy. There is no way in which that can work.

Homeopaths might claim otherwise, but then it's up to them to explain how our basic understanding of chemistry, physics, physiology, and medicine is wrong in this matter, and yet works in every other case. In other words, it's up to the homeopaths to propose new theories in which homeopathy works, and which still supports our current state of knowledge, and until then, they should be ignored.

Not shunned, but ignored. Like we ignore perpetual motion machine builders, flat-earthers, and other weirdos.

Conventional medicine is not perfect, and our knowledge is expanding all the time, but theories like the germ theory of diseases are well established through science. We understand the mechanisms at play, and this knowledge enables us to fight diseases more efficiently. Much like our understanding of vira has helped us fighting other diseases more efficiently.

Why does claims of memory in water and strength through dilution bring to the table? In what ways are they expanding our knowledge? What diseases are we able to cure because of them? Nothing, none, and none are the answers. So stop bringing them to the table. Instead focus on the many valid ideas, which don't fly in the face of all the collective knowledge of the sciences.

Woos like to bring up Nobel Laureates Barry Marshall and Robin Warren, and their discovery that ulcers were caused by the bacterium Helicobacter pylori as an example of how outsiders can turn conventional knowledge on its head.

This is of course pure wishful thinking from their side. Marshall and Warren were very much part of the established scientific community, and while their proposal was received skeptically at first, it was not dismissed out of hand for some very simple reasons:

  • It was built upon evidence.

  • The mechanisms etc. all worked within conventional science and the mechanisms known at the time.

  • There seemed to be some problems with the prevalent hypothesis at the time.

In other words, not only did they work within the established science, they actually addressed some known issues and presented evidence for their claims.

Yes, it took some time (and a very drastic demonstration) to convince people, but the scientific and medical community was very willing to be convinced, and as soon as there were sufficient evidence, the new explanation was universally accepted in quite a short time.

This is how it is done.

So, in what way has proponents of homeopathy done any of this?

The truth is that most people with a basic understanding of science understands that homeopathy is nonsense of the worst order, yet money is still spent on testing this nonsense, demonstrating again and again that it doesn't work. Why? We know that it doesn't work, since we understand the fundamental flaws in the premises behind homeopathy, and we know that homeopathic remedies are nothing but water, alcohol, or sugar (depending on whether they are liquid or in pill form), so they cannot work any better than placebo - they ARE placebo.

Let's put an end to this.

All it does is to lend credibility to homeopathy in the eyes of observers who don't know any better. They think that since homeopathic remedies are continuously being tested, there must be something to them. Why do we let this misconception continue? Science wins nothing from these sham studies, and it only lends cranks an aura of respectability. Stop it.

Yes, I am very passionate about this - we are allowing a lie to continue perpetually. That's wrong. Homeopathy has been around for 200 years, providing no value to society as a whole, and generally decreasing the general level of health, and it's time to stand up and say so.

It goes without saying that I have only contempt for hospitals and doctors who provide homeopathic remedies to their patients. Homeopathic practitioners are usually acting in good faith, believing in their nonsense, but doctors and nurses should know better - they have an education behind them, which provides them with the knowledge necessary to understand what nonsense homeopathy is.

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Thursday, April 01, 2010

Why ancient earth wasn't an iceball

One of the great science mysteries might finally have been solved - why wasn't ancient Earth covered in ice?

Back in the early days of our planet, it was mostly covered in seas. Since the Sun was warming much less back then, it has puzzled scientists why these seas were not frozen. Now Danish and US scientists offer an explanation.

Why Earth Wasn't One Big Ball of Ice 4 Billion Years Ago When Sun's Radiation Was Weaker

Scientists have solved one of the great mysteries of our geological past: Why Earth's surface was not one big lump of ice four billion years ago when Sun radiation was much weaker than today. Scientists have presumed that Earth's atmosphere back then consisted of 30 percent CO2 trapping heat like a greenhouse. However, new research shows that the reason for Earth not going into a deep freeze at the time was quite different.


Now, however, Professor Minik Rosing, from the Natural History Museum of Denmark, and Christian Bjerrum, from the Department of Geography and Geology at University of Copenhagen, together with American colleagues from Stanford University in California have discovered the reason for "the missing ice age" back then, thereby solving the Sun paradox, which has haunted scientific circles for more than 40 years.

Professor Minik Rosing explains: "What prevented an ice age back then was not high CO2 concentration in the atmosphere, but the fact that the cloud layer was much thinner than it is today. In addition to this, Earth's surface was covered by water. This meant that the Sun's rays could warm the oceans unobstructed, which in turn could layer the heat, thereby preventing Earth's watery surface from freezing into ice. The reason for the lack of clouds back in Earth's childhood can be explained by the process by which clouds form. This process requires chemical substances that are produced by algae and plants, which did not exist at the time. These chemical processes would have been able to form a dense layer of clouds, which in turn would have reflected the Sun's rays, throwing them back into the cosmos and thereby preventing the warming of Earth's oceans.

So, the lack of life, which in turns leads to less clouds, and the liquid surfaces, are the reasons why the water didn't freeze, even when the heat from the Sun were lower.

This is a much better explanation than the earlier proposed explanation (also mentioned in the ScienceDaily article) that the CO2 levels were much higher back then. The new investigation which led to the new explanation demonstrates that the CO2 levels back then were higher, but nowhere nearly as much higher as the old explanation would have required.

The actual study is behind a paywall at Nature, but if you have access, you can find it here.

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