Saturday, July 23, 2011

Chance Favors the Concentration of Wealth, -Estate Tax prevents, should be called Redistribution Taxes

Figure 1. Concentration of wealth over time. All simulations start with an even distribution of wealth. Unless otherwise noted, all simulations
were run with 100,000 individuals and a 5% yearly average return on investment. Red lines show the analytically expected trajectories (Eqn. 1); points
show the results from individual-based simulations. Three replicate simulations were run for each high variance simulation. (A) Higher variance
among individual rates of return increases the rate of wealth concentration. (B) Inequality as measured by the Gini coefficient also increases over
time. (C) Wealth concentrates even when the mean growth rate varies over time, such that in some years the total economy grows and in others the
economy shrinks. Average annual rates of return were randomly drawn from a normal distribution with m~ln 1:08&7:7% and s~0:19, with a new
value for the economy drawn each year. (D) Population growth and splitting estates among heirs does not significantly reduce rate of wealth
concentration. Dashed blue line shows the growing population. (E) A tax on inherited fortunes slows and arrests the concentration of wealth. (F)
Immigrants with mean wealth slow but do not arrest the concentration of wealth. Dashed blue line shows population increase from immigration.
doi:10.1371/journal.pone.0020728.g001
http://www.sciencedaily.com/releases/2011/07/110721172334.htm

Tuesday, July 19, 2011

Fewer Verbs and Nouns in Financial Reporting Could Predict Stock Market Bubble, Study Shows

 When the language used by financial analysts and reporters becomes increasingly similar the stock market may be overheated, say scientists.

After examining 18,000 online articles published by the Financial Times, The New York Times, and the BBC, computer scientists have discovered that the verbs and nouns used by financial commentators converge in a 'herd-like' fashion in the lead up to a stock market bubble. Immediately afterwards, the language disperses.

"Our analysis shows that trends in the use of words by financial journalists correlate closely with changes in the leading stock indices -- the DJI, the NIKKEI-225, and FTSE-100,"
"By plotting the distributions of words used in financial articles published online between 2006 and 2010 into a computer model, we were able to identify what we call 'verb convergence' and 'noun convergence -- where the language used by financial journalists shows converging agreement."
"Our study shows that reporters converge on the same language -- 'stocks rose again', 'scaled new heights', or 'soared' -- as their commentaries became more uniformly positive in the lead up to the 2007 crash."
"They also appear to refer to a smaller-than-usual set of market events -- presumably because of an increased fixation on a small number of rapidly rising stocks,"http://www.sciencedaily.com/releases/2011/07/110718101202.htm

Monday, July 18, 2011

Novel Compound Selectively Kills Cancer Cells by Blocking Their Response to Oxidative Stress

The plant-based compound piperlongumine (PL), derived from the fruit of a pepper plant found in southern India and southeast Asia, appears to kill cancer cells by jamming the machinery that dissipates high oxidative stress and the resulting ROS. Normal cells have low levels of ROS, in tune with their more modest metabolism, so they don't need high levels of the anti-oxidant enzymes that PL stymies once they pass a certain threshold.
"Piperlongumine targets something that's not thought to be essential in normal cells," said Stuart L. Schreiber, a senior co-author and director of the Broad's Chemical Biology Program. "Cancer cells have a greater dependence on ROS biology than normal cells."
Sam W. Lee and Anna Mandinova, senior co-authors from the Cutaneous Biology Research Center (CBRC) at MGH, weren't looking for a ROS inhibitor when they found PL. Their interest lay in the tumor suppressor gene p53, which is mutated in more than half of all cancer types. Teaming up with the Broad's Chemical Biology Program and Platform to screen libraries of chemical compounds, they were looking for something that might increase levels of the properly functioning p53 gene.
When they saw a promising signal for PL, they assumed it worked by enhancing the p53 gene. But to their surprise, PL induced cancer cell death independent of the tumor suppressor gene's activity. And when they tested PL in normal cells, the cells didn't die.
"The novelty of this compound was that it was able to recognize cancer cells from normal cells," said Mandinova, a Broad associate member and a faculty member at MGH and Harvard Medical School. "It has a mode of action that targets something especially important to the cancer cell."
Their second surprise came after the Proteomics Platform's quantitative analysis identified the target of PL. The researchers imagined that they might find a protein encoded by a cancer-causing gene was being inhibited in some way, but instead of an oncogene, they saw an indirect process on which cancer cells depend.
A small number of new cancer drugs target oncogenes directly, but this may not be the only promising new direction for treating cancers. Cancer genes do not act alone. PL exploits a dependency that develops after oncogenes transform normal cells into cancer cells.
"Our studies suggest that piperlongumine's ROS-associated mechanism is especially relevant to the transformed cancer cell," said co-author Andrew M. Stern, associate director of Novel Therapeutics at the Broad. "And this in part may underlie the observed selectivity of PL."
The scientists tested PL against cancer cells and normal cells engineered to develop cancer. In mice injected with human bladder, breast, lung, or melanoma cancer cells, PL inhibited tumor growth but showed no toxicity in normal mice. In a tougher test of mice that developed breast cancer spontaneously, PL blocked both tumor growth and metastasis. In contrast, the chemotherapy drug paclitaxel (Taxol) was less effective, even at high levels.
"This compound is selectively reducing the enzyme activity involved in oxidative stress balance in cancer cells, so the ROS level can go up above the threshold for cell death," said Lee, a Broad associate member and associate director of CBRC at MGH. "We hope we can use this compound as a starting point for the development of a drug so patients can benefit."
While hopeful, the authors remain cautious. Much more work needs to be done to better understand how the ROS process differs between normal and cancer cells before clinical studies can even be launched. Further studies will focus on different forms of cancer and their genotypes, or genetic information.
"Our next set of goals is to learn if there are specific cancer genotypes that will be more sensitive to this compound than others," said Alykhan F. Shamji, associate director of the Broad's Chemical Biology Program. "We hope our experiments will help be predictive of whether patients with the same genotypes in their tumors would respond the same way. It would help us to pick the right patients."
The research reported in Nature was funded by the National Cancer Institute and builds on work performed through the Initiative for Chemical Genetics and the Cancer Target Discovery and Development Network.http://www.sciencedaily.com/releases/2011/07/110713131421.htm

Size Matters: Why Do People Eat Less When They Have Big Forks?

Learn to know what it takes to be full, instead of relying on external cues like forks:

"The fork size provided the diners with a means to observe their goal progress," the authors explain. "The physiological feedback of feeling full or the satiation signal comes with a time lag. In its absence diners focus on the visual cue of whether they are making any dent on the food on their plate to assess goal progress."

The authors tested this conclusion by varying the quantities of food. They found that when the initial quantity of food was more (a well-loaded plate) diners with small forks ate significantly more than those with large forks. When customers were served small servings, the fork size did not affect the amount of food. Interestingly, in a lab experiment the authors found that participants with small forks consumed less than those with large forks. The authors believe that the participants did not have the same goals of satiating hunger as the restaurant customers did.
To avoid overeating, the authors suggest consumers learn to better understand hunger cues. "People do not have clear internal cues about the appropriate quantity to consume," the authors write. "They allow external cues, such as fork size, to determine the amount they should consume."http://www.sciencedaily.com/releases/2011/07/110714150949.htm

Personality Plays Role in Body Weight: Impulsivity Strongest Predictor of Obesity

 Practice low neuroticsim and high concienceousness to be in the mental framework for maintaining a healthy weight.

The researchers, from the National Institute on Aging, looked at data from a longitudinal study of 1,988 people to determine how personality traits are associated with weight and body mass index. Their conclusions were published online in the APA's Journal of Personality and Social Psychology.
"To the best of our knowledge, we are the first to examine whether personality is associated with fluctuations in weight over time," they wrote. "Interestingly, our pattern of associations fits nicely with the characteristics of these traits."
Participants were drawn from the Baltimore Longitudinal Study of Aging, an ongoing multidisciplinary study of normal aging administered by the National Institute on Aging. Subjects were generally healthy and highly educated, with an average of 16.53 years of education. The sample was 71 percent white, 22 percent black, 7 percent other ethnicity; 50 percent were women. All were assessed on what's known as the "Big Five" personality traits -- openness, conscientiousness, extraversion, agreeableness and neuroticism -- as well as on 30 subcategories of these personality traits. Subjects were weighed and measured over time. This resulted in a total of 14,531 assessments across the 50 years of the study.
Although weight tends to increase gradually as people age, the researchers, led by Angelina R. Sutin, PhD, found greater weight gain among impulsive people; those who enjoy taking risks; and those who are antagonistic -- especially those who are cynical, competitive and aggressive.
"Previous research has found that impulsive individuals are prone to binge eating and alcohol consumption," Sutin said. "These behavioral patterns may contribute to weight gain over time."
Among their other findings: Conscientious participants tended to be leaner and weight did not contribute to changes in personality across adulthood.

Regulating P53 Is a Matter of Life or Death

p53 has much broader importance in the life and death of cells. "It's critical for determining whether a cell survives stress and continues to function in a variety of situations," says Wahl.
One problem with p53 is that it apparently evolved to protect the integrity of the genome for future generations, rather than to prolong the lives of individual cells or animals. From the point of view of an animal, p53 sometimes goes too far in killing cells or suppressing growth. Experiments in mice have suggested that even modest reductions in p53's activity greatly increases survival after exposure to radiation, without raising the long-term cancer risk to unacceptable levels.

they found that p53 lacking its "dimmer switch" turned on too much of a gene called p21, which acts as a brake to halt cells from dividing. "To confirm the significance of that finding, we created mice that expressed the mutant p53, but had only one instead of the normal two copies of p21," Wahl says. "This reduced p21 levels after irradiation. Remarkably, this was enough to significantly reduce the mortality of the 'dimmerless' p53 mice. They were much less sensitive to radiation when they just had one less copy of p21." The study underscores the importance of an evolutionarily conserved regulatory segment of p53 and the importance of p53 activity in the response to conditions that produce DNA damage. "Our study indicates that the amount of damaged DNA caused by radiation or toxins, isn't the sole determinant of life or death," says Wahl. "The extent to which p53 is also very important."
One implication of this research is that drugs to lower p53 levels, or to reduce its transcription of other growth-stopping genes such as p21, might be used temporarily to reduce unwanted tissue damage from DNA-altering drugs or radiation. Another implication is that p53-boosting drugs, which are currently being tested in cancer patients, could have dangerous side effects if used in combination with other drugs that cause DNA damage. "Our mouse model suggests that if you use a p53-activating agent, the last thing you should do is combine it with a general DNA-damaging chemotherapy or radiotherapy," Wahl says.http://www.sciencedaily.com/releases/2011/06/110630171717.htm

Thursday, July 14, 2011

Is Meditation the Push-Up for the Brain? Study Shows Practice May Have Potential to Change Brain's Physical Structure


"It is possible that actively meditating, especially over a long period of time, can induce changes on a micro-anatomical level," said Luders, herself a meditator.
As a consequence, she said, the robustness of fiber connections in meditators may increase and possibly lead to the macroscopic effects seen by DTI.
"Meditation, however, might not only cause changes in brain anatomy by inducing growth but also by preventing reduction," Luders said. "That is, if practiced regularly and over years, meditation may slow down aging-related brain atrophy, perhaps by positively affecting the immune system."
But there is a "but." While it is tempting to assume that the differences between the two groups constitute actual meditation-induced effects, there is still the unanswered question of nature versus nurture.
"It's possible that meditators might have brains that are fundamentally different to begin with," Luders said. "For example, a particular brain anatomy may have drawn an individual to meditation or helped maintain an ongoing practice -- meaning that the enhanced fiber connectivity in meditators constitutes a predisposition towards meditation, rather than being the consequence of the practice."
Still, she said, "Meditation appears to be a powerful mental exercise with the potential to change the physical structure of the brain at largehttp://www.sciencedaily.com/releases/2011/07/110714091940.htm

Researchers Demystify a Fountain of Youth in the Adult Brain

The scientists found that neighboring "epithelial-like" ependymal cells -- not stem cells themselves -- maintain a special structure that keeps neural stem cells "neurogenic," able to make new neuronshttp://www.sciencedaily.com/releases/2011/07/110713131413.htm

Prediction Markets on the Debt Ceiling, U.S. Credit Downgrade

via Freakonomics » Blog by Freakonomics on 7/14/11

Over at Intrade, there are two “hot” markets involving the odds that Congress will raise the U.S. debt ceiling.
- Congress to approve increase in U.S. debt ceiling before midnight on July 31, 2011: 40% (It was 65% a month ago)
- Congress to approve increase in U.S. debt ceiling before midnight Aug. 31, 2011: 75% (It was 85% a month ago)
And at Irish bookmaker PaddyPower.com, here is the line on a Moody’s downgrade:
Will Moody’s downgrade the U.S.?
-Yes: 9/2
-No: 1/8

Tuesday, July 5, 2011

Changes in Specific Dietary Factors May Have Big Impact On Long-Term Weight Gain

In a series of three separate studies looking at how changes in multiple dietary and other lifestyle factors relate to long-term weight gain, Harvard School of Public Health (HSPH) researchers found that modest changes in specific foods and beverages, physical activity, TV-watching, and sleep duration were strongly linked with long-term weight gain. Changes in diet, in particular, had the strongest associations with differences in weight gain.
When relations of lifestyle changes with weight gain were evaluated, the findings were strikingly similar in all 3 studies.
For example, the foods associated with the greatest weight gain over the 20-year study period included potato chips (for each one increased daily serving, +1.69 lb more weight gain every 4 years), other potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed meats (0.95 lb), and processed meats (0.93 lb). Of note, several foods associated with less weight gain when their consumption was actually increased, including vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb) and yogurt (−0.82 lb). Evaluating all changes in diet together, participants in the lower 20% of dietary changes gained nearly 4 lbs more each 4 years than those in the top 20% -- an amount equivalent to the average weight gain in the population overall.
For diet, focusing only on total calories may not be the most useful way to consume fewer calories than one expends, say the researchers. Other yardsticks, such as content of total fat, energy density, or sugars, could also be misleading. Rather, they found that eating more healthful foods and beverages -- focusing on overall dietary quality -- was most important.
The most useful dietary metrics for preventing long-term weight gain appeared to be:
  • Focus on improving carbohydrate quality by eating less liquid sugars (e.g. soda) and other sweets, as well as fewer starches (e.g. potatoes) and refined grains (e.g. white bread, white rice, breakfast cereals low in fiber, other refined carbohydrates).
  • Focus on eating more minimally processed foods (e.g. fruits, vegetables, whole grains, nuts, yogurt) and fewer highly processed foods (e.g. white breads, processed meats, sugary beverages).
  • http://www.sciencedaily.com/releases/2011/06/110622224457.htm