OECD: PISA 2006 on Science

Programme for International Student Assessment (PISA) – Range of rank on the PISA 2006 science scale:
Rank/Country/Score
1 Finland 563
2 Hong Kong-China 542
3 Canada 534
4 Chinese Taipei 532
5 Estonia 531
6 Japan 531
7 New Zealand 530
8 Australia 527
9 Netherlands 525
10 Liechtenstein 522
11 Korea 522
12 Slovenia 519
13 Germany 516
14 United Kingdom 515
15 Czech Republic 513
16 Switzerland 512
17 Macao-China 511
18 Austria 511
19 Belgium 510
20 Ireland 508

Others…
22 Sweden 503
24 Denmark 496
25 France 495
27 Iceland 491
29 UnitedStates 489
31 Spain 488
33 Norway 487
34 Luxembourg 486
36 Italy 475
37 Portugal 474
38 Greece 473
39 Israel 454
46 Thailand 421
50 Indonesia 393

Psychology: Ten Politically Incorrect Truths about Human Nature

Listed in an article in Psychology Today, explained by evolutionary psychology:

#1: Men like blond bombshells (and women want to look like them)

#2: Humans are naturally polygamous

#3: Most women benefit from polygyny, while most men benefit from monogamy

#4: Most suicide bombers are Muslim

#5: Having sons reduces the likelihood of divorce

#6: Beautiful people have more daughters

#7: What Bill Gates and Paul McCartney have in common with criminals

#8: The midlife crisis is a myth—sort of

#9: It’s natural for politicians to risk everything for an affair (but only if they’re male)

#10: Men sexually harass women because they are not sexist

Gene: Monogamous?

Source: Gene treatment stops frisky voles being love rats, 17-06-2004

Not done on human yet.

When the brains of male meadow voles, usually the most promiscuous of lovers, are enhanced with a gene called the vasopressin receptor, they instantly reform their loose ways and form lasting pair bonds instead.

Because vasopressin is also active in the human brain, the remarkable experiment at Emory University in Atlanta, suggests that differing levels of the hormone could explain why some people find it harder to stay faithful than others.

“It is intriguing to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships,” Larry Young, who led the research, said.

Vasopressin and its receptors may also be implicated in drug addiction and social disorders such as autism, both of which affect the brain’s reward centre.

The Emory experiment, details of which are reported today in the journal Nature, has now proved this theory beyond reasonable doubt. In the study Dr Young’s team took the gene for the vasopressin receptor from the prairie vole and bound it to a harmless virus.

Dr Young said that while more than one gene and hormone is probably involved in regulating human monogamy and pair-bonding, the results have powerful implications for understanding the biological and chemical origins of relationships. “Our study provides evidence in a comparatively simple animal model that changes in the activity of a single gene can profoundly change the fundamental social behaviour of an entire species,” he said.

Experiment: Natural Born … Robin Hood?

Well, this is what some economic game theorist suggests:

Robin Hood took from the rich and gave to the poor. A recent study by a team of researchers headed up by University of California-San Diego political scientist James Fowler suggests that we may all have Robin Hood tendencies. Experimental economists and psychologists from around the world have been watching how people play various economic games as a way to probe the bases of human cooperation. One of the more interesting discoveries is that in economic games some people – altruistic punishers – will take fairly big hits to their winnings in order to reduce the ill-gotten gains of cheaters. Games with altruistic punishers elicit more cooperative behavior among players. In addition, other researchers have found that players will happily spend some of their own winnings in gambling games in order to reduce the “undeserved” winnings of other players.

In re-analyzing some earlier studies, Fowler and his colleagues suggested “that egalitarian motives are more important than motives for punishing non-cooperative behaviour.” In other words, people are really more interested in enforcing income equality than they are in punishing cheaters. To tease out motives, Fowler and his colleagues devised a game in which there was no possibility of reciprocity or cooperation. Their hypothesis was that people would spend some of their incomes to equalize the incomes of other players.

Read more on the experiment details, outcome and discussion here.

Gene: Pain

Source: Gene secrets of the boys who couldn’t feel any pain, 14-12-2006

The discovery of a single gene that can switch painful stimuli on and off without affecting other body systems raises the prospect of a new class of analgesics with none of the side-effects of conventional painkilling drugs. Neuroscientists said that the findings could ultimately prove as important as the discovery of the receptor for morphine.

The gene, SCN9A, is responsible for making a protein called a voltage-gated sodium channel, which seems essential to pain perception.

The discovery, by a team led by Geoffrey Woods, of the University of Cambridge, is particularly exciting because the abnormality appears to have no adverse effects in the children with the mutation, apart from the dangers that come with pain insensitivity.

The article in Journal Nature.

Gene: Fighting, Bullying and Violent

Source: Want a fight? Scientists say it’s all in your genes, 04-02-2007

SCIENTISTS have found an answer to one of the most intractable squabbles in family life – argumentative and disruptive children are born, not made.

A study by American scientists has found that antisocial traits such as being argumentative, bullying and lying, are often inherited. The new research challenges the scientific consensus that difficult children are the product of disruptive homes and are copying parents’ behaviour.

The implication of the research, conducted by the University of Virginia, is that children with “antisocial” genes would behave badly even if they had been adopted and brought up in a happy family.

The effect appears to pass down the generations. It means that couples who fight a lot may be driven by their genes and pass them on to their children, who tend to behave in the same way.

More from other source:

In a study of adult twins and their children, researchers found that genes, rather than parents’ own argumentative behavior, seemed key in the children’s odds of serious conduct problems — like bullying, skipping school and shoplifting.

The findings, published in the Journal Child Development, touch on the classic nature-versus-nurture question.

In the case of child behavior, research has linked parents’ marital conflicts to long-term, serious conduct problems in their children. However, it has been unclear whether that means that marital woes themselves cause the behavioral problems.

The new findings suggest it’s more a matter of genes. That is, parents who are naturally argumentative pass on these traits to their kids.

“Marital conflict doesn’t appear, in this study, to cause stable patterns of conduct disorder,” explained lead study author K. Paige Harden of the University of Virginia in Charlottesville.

“Rather, marital conflict is influenced by parents’ own characteristics — including their genes — and these genes are passed on to children,” she told Reuters Health.

Harden and her colleagues arrived at their conclusions by studying 1,045 adult twins and their children. Some of the twin pairs were identical, which means they shared all of their genes; the rest were fraternal, meaning they shared only some of their genes.

On similar note,

In 2002, Avshalom Caspi, Ph.D., of the Institute of Psychiatry in London and colleagues reported in the journal Science that a particular version of a gene plays a role in anti-social behavior. The gene in question was the monoamine oxidase A gene (MAO-A gene), located on the X chromosome. This gene helps people digest food containing amine groups such as serotonin and inactivates neurotransmitters such as dopamine.

Specifically, Caspi and his coworkers found that maltreated boys who had a particular variant of the MAO-A gene that produces low MAO-A activity were more likely to develop antisocial problems than were maltreated boys who had a version of the MAO-A gene that produces high MAO-A activity. In other words, it looked as though possessing the MAO-A gene version that leads to low MAO-A activity might interact with an adverse childhood to produce antisocial behavior.

The above finding has now been replicated by a group of researchers at Virginia Commonwealth University. The lead investigator was Debra Foley, Ph.D., an assistant professor of human genetics at Virginia Commonwealth University. Results appeared in the July Archives of General Psychiatry.

The MAO-A gene, in fact, appears to be the first gene strongly linked with either conduct disorder or antisocial behavior, Foley indicated to Psychiatric News. Or at least, she said, there are “none with major effects that has been independently replicated that I know of.”

The study included 514 white male twins from the community-based, longitudinal Virginia Twin Study for Adolescent Behavioral Development. The twins were 8 to 17 years old. Twins and their parents were interviewed at home by trained field workers at several different time points to learn whether the twins were exhibiting signs of conduct disorder and/or were being brought up in an adverse environment—that is, one of inconsistent discipline, parental neglect, or interparental violence. DNA samples were also taken from the twins at two different time points for analysis to see whether the twins contained a version of the MAO-A gene that produces low MAO-A activity in the body.

The researchers found that among the twins participating in the study, the prevalence of conduct disorder was 11 percent, the prevalence of a low-activity MAO-A gene was 29 percent, the prevalence of exposure to inconsistent parental discipline was 17 percent, the prevalence of exposure to parental neglect was 13 percent, and the prevalence of exposure to interparental violence was 3 percent.

The investigators found that inconsistent parental discipline, parental neglect, and exposure to interparental violence were independent risk factors for conduct disorder, but a low-activity MAO-A gene was not. However, a low-activity MAO-A gene was determined to be a risk factor for conduct disorder when combined with an adverse childhood environment.

The findings suggest “a relatively robust effect of MAO-A in combination with exposure to environmental adversity on risk for conduct disorder,” Foley and her team concluded in their study report. The results, they pointed out, “are also consistent with reports from adoption studies describing an increased risk for antisocial behavior in boys in association with an interaction between aggregate genetic effects and exposure to adversities within the adoptive family.”

Gene: Obesity

Source: ‘Fat’ gene found by scientists, 13-04-2007

A gene that contributes to obesity has been identified for the first time, promising to explain why some people easily put on weight while others with similar lifestyles stay slim.

People who inherit one version of the gene rather than another are 70 per cent more likely to be obese, British scientists have discovered. One in six people has the most vulnerable genetic make-up and weighs an average 3kg more than those with the lowest risk. They also have 15 per cent more body fat.

If the biological function of the gene, known as FTO, can now be understood, it could become possible to design drugs that manipulate it to help people to control their weight. “Even though we have yet to fully understand the role played by the FTO gene in obesity, our findings are a source of great excitement,” Mark McCarthy, of the University of Oxford, who led the research, said.

Update: in 2006, older article on gene and obesity – Common Genetic Link to Obesity Is Discovered is reported.

A genetic variation predisposing people to obesity has been detected by a team of researchers at Boston University and elsewhere. Though the gene is expected to be just one of the many that contribute to the disease, its detection raises hopes that the others may be discovered within the next five years or so, said Michael F. Christman, a leader of the team.

The finding is reported in the current issue of the journal Science.

The team scanned genetic variations in people participating in the Framingham Heart Study, a long-running survey of heart disease. They found a link between obesity and a short section of the genome that lies between two genes. One gene is of unknown function, but the other, known as Insig2, is well known as a regulator of fatty acid and cholesterol synthesis.

Math! How much CH4 is released by Cattle/Beef Cow?

Math time again! 🙂

This time, I am set out to find how much CH4 is released by cow, or cattle around the world. Total cows/cattle in the world, according to FAO, in year 2003 is around 1 331 526 305. Note that this number does not include the dairy cow, or the cow for milking purpose.

Next, the quantity of CH4 gas emitted by a cow/cattle is searched. So far there are 2 claims, and may be more will be found in the future.

Claim#1:  according to wikipedia,

An average cow is thought to emit between 542 litres (if located in a barn) and 600 litres (if in a field) of methane per day through burping and flatulence, making commercially farmed cattle a major contributor to the greenhouse effect.

Let’s say the adult cow emits 550L of CH4 per day. Divide by standard volume molar (22.414 L/mol), the number of mole of CH4 is 24.538 mol.

Thus, the weight of CH4 = 24.538 x 0.016 kg = 0.3926 kg per day.

Or, 143.3 kg CH4 per year.

Claim#2: according to US Enviromental Protection Agency,

An adult cow … emitting only 80-110 kg of methane (annually).

It is noted that claim#1 is almost 43% higher than claim#2, if the value of 100kg per year is assumed.

Therefore, total CH4 released by cattle/cow annually in weight for year 2003 is:

Claim#1: Total CH4 = 143.3 x 1 331 526 305 = 190.81 x 10^9 kg = 190.81 million tonnes.

Claim#2: Total CH4 = 100 x 1 331 526 305 = 133.15 x 10^9 kg = 133.15 million tonnes.

More livestock’s impact on environment can be read from UN’s news release and the report.

source: FAO, Global Livestock Production and Health Atlas.

How do you know mice is not stressed?

Simple. Just do this:

The consequence of that release is stress-free mice. Dr Lowry was able to measure their stress by dropping them into a tiny swimming pool. Previous research has shown that unstressed mice enjoy swimming, while stressed ones do not. His mice swam around enthusiastically.

There is something new to learn everyday 😛

source: Economist, Bacteria and Depression.