The brain is a complex system made of billions of neurons (nerve cells) and thousands of connections that relate to every human feeling, including one of the strongest emotions, fear. Researchers have started using computer models of the brain to study the connections.
Most neurological fear studies have been rooted in fear-conditioning experiments. Now, University of Missouri (U-M) researchers are using computational models to study the brain's connections.
Guoshi Li, U-M electrical and computer engineering doctoral student, has discovered new evidence on how the brain reacts to fear, including important findings that could help victims of post-traumatic stress disorder (PTSD, an anxiety disorder associated with serious traumatic events).
'Computational models make it much easier to study the brain because they can effectively integrate different types of information related to a problem into a computational framework and analyse possible neural (bearing on nerve cells) mechanisms from a systems perspective,' Li said.
From previous experiments, scientists have found that fear can subside when overcome with fear extinction memory, but it is not permanently lost.
Fear extinction is a process in which a conditioned response to a stimulant that produces fear gradually diminishes over time as subjects, such as rats in auditory fear experiments, learn to disassociate a response from a stimulus.
One theory has concluded that fear extinction memory deletes fear memory, and another concluded that fear memory is not lost, but is inhibited by extinction memory as fear can recover with the passage of time after extinction, says an U-M release.
For PTSD victims, the fear circuit is disrupted and they cannot retrieve the fear extinction memory. However, the fear extinction memory exists, so the fear memory dominates every time victims get a fear cue.
Sunday, October 4, 2009
Scientists detect chink in virulent stomach bug's armour
Scientists have detected a crack in the armour of the Helicobacter pylori, a common microbe that infects the stomachs of one-sixth of the world's population, causing gastritis and ulcers.
They identified a group of substances that block a key chemical pathway that the bacteria need for survival. Their study could lead to new, more effective antibiotics to fight these hard-to-treat microbes.
Javier Sancho, biologist at the University of Zaragoza, Spain, and colleagues note in the new study that Helicobacter pylori (H. pylori) bacteria infect the stomach lining.
Treatment with broad-spectrum antibiotics can cure H. pylori infections. However, an estimated one billion people remain infected worldwide because of the cost of existing antibiotics and the emergence of antibiotic resistant strains of the bacteria, the researchers say.
The scientists know from past research that blocking flavodoxin, a key protein that H. pylori needs for survival, could be the key to developing narrow-spectrum antibiotics that specifically target H. pylori.
Sancho's team screened 10,000 chemicals for their ability to block flavodoxin and identified four that showed promise. They then showed that three of the four substances killed H. pylori in cell cultures and did not have any apparent toxic effects in lab animals.
'These new inhibitors constitute promising candidates to develop new specific antibiotics against H. pylori,' the study states, according to a Zaragoza release.
These findings are slated for publication in the Oct 16 issue of American Chemical Society's (ACS) Biology.
They identified a group of substances that block a key chemical pathway that the bacteria need for survival. Their study could lead to new, more effective antibiotics to fight these hard-to-treat microbes.
Javier Sancho, biologist at the University of Zaragoza, Spain, and colleagues note in the new study that Helicobacter pylori (H. pylori) bacteria infect the stomach lining.
Treatment with broad-spectrum antibiotics can cure H. pylori infections. However, an estimated one billion people remain infected worldwide because of the cost of existing antibiotics and the emergence of antibiotic resistant strains of the bacteria, the researchers say.
The scientists know from past research that blocking flavodoxin, a key protein that H. pylori needs for survival, could be the key to developing narrow-spectrum antibiotics that specifically target H. pylori.
Sancho's team screened 10,000 chemicals for their ability to block flavodoxin and identified four that showed promise. They then showed that three of the four substances killed H. pylori in cell cultures and did not have any apparent toxic effects in lab animals.
'These new inhibitors constitute promising candidates to develop new specific antibiotics against H. pylori,' the study states, according to a Zaragoza release.
These findings are slated for publication in the Oct 16 issue of American Chemical Society's (ACS) Biology.
Software for better data on immunisation
Health Minister Ghulam Nabi Azad is not happy with data on the outcome of immunisation drives and his ministry is developing a software which will keep a thorough record of all such health campaigns.
'The outcome of immunisation drives is not satisfactory. I asked my officers how they arrive at these figures and the reply was not very convincing. I have told them to have a new software which will help us in getting the authentic figures,' Azad said.
'These software will be provided to all blocks under the National Rural Health Mission as they already have computers and a person to man it. The data will be collected at that level.
'All the kids will have their name, father's name and telephone number (in the database). If someone does not have a telephone number then his neighbour's telephone number will be there. This will help monitoring the immunisation drive better,' he said at a diabetes conference organised by the Sir Ganga Ram Hospital.
'By the end of this year, you may see this happening.'
He said his ministry spends a lot on surveys and he would like to 'do away with them'. 'I have respect for NGOs. But what the so many people in government cannot do, how can three-four people (of a NGO) do?'
India has been carrying out several immunisation drives - some universal and others targeted. However, at least half of the children do not get vaccinated for various diseases.
'The outcome of immunisation drives is not satisfactory. I asked my officers how they arrive at these figures and the reply was not very convincing. I have told them to have a new software which will help us in getting the authentic figures,' Azad said.
'These software will be provided to all blocks under the National Rural Health Mission as they already have computers and a person to man it. The data will be collected at that level.
'All the kids will have their name, father's name and telephone number (in the database). If someone does not have a telephone number then his neighbour's telephone number will be there. This will help monitoring the immunisation drive better,' he said at a diabetes conference organised by the Sir Ganga Ram Hospital.
'By the end of this year, you may see this happening.'
He said his ministry spends a lot on surveys and he would like to 'do away with them'. 'I have respect for NGOs. But what the so many people in government cannot do, how can three-four people (of a NGO) do?'
India has been carrying out several immunisation drives - some universal and others targeted. However, at least half of the children do not get vaccinated for various diseases.
Wednesday, September 30, 2009
Correlation In Forex Trading and Profiting
Looking on the internet at comments about forex trading, one wonders how people expect to make money without having a basic grasp of the principles involved in trading. People tend to rush in, with promises of easy money, but they then discover that it is a lot harder than it looks. This article seeks to identify a fundamental principle that leads to creating a successful trading model, it is founded on the idea of correlation.Correlation exists where there is a mutual relationship of interdependence between two entities. Why is it that people feel so sure that they can earn money in forex? Surely the reason is that they immediately see that there are patterns, that is, correlation in the graph that can be exploited to make money. For example, consider AUDUSD (15 mins, 19th March) in the graph below:We can see that there is correlation between the graph and the yellow line and is is tempting to think that, as a consequence this can be easily traded. The problem is that there are too many unknowns. How could anyone foresee that the price would bounce off of this line? How can we know how high the price will bounce off the line? How can we tell when the price will stop bouncing?I would suggest that the reason that the majority lose money in currency trading is that although there is correlation in the graphs, yet people fail to realize that the nature of the correlation is very complicated. There is not only a relationship of interdependence between the price and the line on the graph above. Below is the graph with the inclusion of the stochastic (5, 3, 3) oscillator:We can see that there is correlation between these two graphs. Although the price doesn't move directly proportional to the stochastic graph, yet the former generally turns at similar times to the latter. The result is that we have another tool to contribute to our understanding of how the price moves.I would suggest that this is the nature of currency trading; it involves the accumulation of indicators that correlate with the price and as a consequence contribute to creating a successful trading method.
Forex scalping Success - 5 Key Facts You Need to Know
Forex scalping and day trading is more popular than ever and is the choice of most new forex traders but is it the right one and how do you enjoy forex scalping success - lets find out.1. Short Term Volatility is RandomMillions of forex traders trade trillions of dollars in currency each day and to say that you can measure what this diverse number of traders will do in a few hours, or a day is laughable you cant.2. Support and Resistance Levels are MeaninglessTo trade any market you need to have valid levels of support or resistance to key off however with all volatility being random in short term trading, prices can and do go anywhere and support and resistance cannot be used - as the data simply isn't valid.3. No Trading system Will WorkIt doesn't matter how good or well thought out the trading system is - if volatility is random and support and resistance not valid it wont work!In any financial market to win you need to trade the odds and if you cant, you are going to lose longer term. It's a bit like being in a casino - if you can count the cards in a game such as blackjack you win but in a game of pure chance like roulette, play long enough with the odds against you and your going to lose and it's the same in forex scalping.You cant get the odds on your side and you cant win - PERIOD4. Forex Scalping Systems Don't have Track RecordsYes they do many traders will say - I have seen them. Sure they have and written all over the track record will be "hypothetical" or "simulated" This means it wasn't traded in the market but done on paper knowing the closing prices!How hard is that?You could do it and so can I and even my 10 year old daughter could - but the markets don't work backwards its harder - You have to trade going forwards!5. Why is it So Popular?Because it makes a good story and vendors know this.Most of them have never traded in their lives - but the story of small regular profits and low risk is an easy one to sell, to naive or greedy investors who are looking for an easy way to get rich in forex.Of course there is no easy way to get rich in forex and you wouldn't expect there to be, with the rewards on offer.THE GOOD NEWS!The good news is you can make money in forex trading if you avoid forex scalping and concentrate on trading the odds. This means valid data where you can get the odds in your favour with your forex trading system and trade them for profit.You can swing trade, looking for trends of a few days to a few weeks, or trend follow looking for trends that last weeks, months or even years. In both forex methods you can trade the odds - the key to a successful forex trading strategy.Forex scalping is not the only myth in currency trading - but it's a popular one and you need to ignore it and concentrate on getting the right forex education to win.So leave forex scalping and day trading to the dreamers and greedy traders, who think forex trading is simply a walk in the park and concentrate on building your own forex trading strategy based around trading the odds.Learn the odds, learn how to trade them and there is nothing to stop you enjoying currency trading success.
Forex Fundamentals: Knowledge You Can Profit From
An in-depth knowledge of macroeconomics or international trade isn't necessary to trade the Forex. But knowing how these forces affect currency pairs can only make you a more savvy trader. Here are a few highlights.When a country raises its interest rates, often their stock market will go down as investors move their funds to greener financial pastures. This tends to weaken the internal economy of the country, but strengthens it in relation to other countries. Which effect will have the most impact on that nation's currency pairs is often discussed well in advance by the "talking heads," and each Forex trader has to decide for herself who to believe!Crude oilCanada is an oil-producing nation. Exporting crude oil raises their GNP and improves the balance of trade, strengthening their economy.As the price of crude oil goes up, the USD/CAD goes down. (That's because the Canadian dollar, the cross currency, has appreciated against the base currency, the U.S. dollar.) At this point, the Canadian dollar is almost at parity with the U.S. dollar, a situation not seen since the 1950s.As an interesting exercise, try laying the chart of the USD/CAD over the chart of crude oil prices for the same time period. The two charts are almost a flipped image of each other.Japan, on the other hand, is an oil-consuming nation, strongly industrial but with no real energy reserves of their own. Importing crude oil at increasingly higher rates to power their economy raises the cost of production and slows or reverses their economic growth.The change in the USD/JPY has not been as dramatic as that in the USD/CAD, and the correlation between the charts not as impressive, but that's because the cost of crude oil has affected the USD half of the equation as well as the JPY side.Precious metalsDuring troubled political or economic times, investors tend to move their capital from speculative investments to something more conservative and solid. Precious metals, particularly gold, tend to go up in value at these times. When the situation returns to normal, gold tends to decline as investors seek higher returns from their money.The Swiss franc, like gold, is considered a safe harbor for capital. As the U.S. dollar has depreciated (mainly due to the government deficit, a large trade deficit, and low interest rates when much of the rest of the world is raising theirs), investors have moved much of their capital to these harbors. Therefore, as the price of gold rises, so does the franc in relation to the dollar.Like the Canadian dollar discussed above, the USD/CHF (Swissie) has declined because of the pressure of the cross currency against the base. Again, lay a chart of the USD/CHF over one for gold with the same time interval, and see how one reflects the other like trees in a lake.Australia is a major gold and copper producer. Copper is not only a precious metal, it's also a substantial element in the housing market (copper plumbing, wiring, etc.). As demand for copper rises on both fronts, the Australian dollar climbs against the U.S. dollar. This is also a reflection of high Australian interest rates versus the low ones in the United States.
Forex Fundamentals: Knowledge You Can Profit From
An in-depth knowledge of macroeconomics or international trade isn't necessary to trade the Forex. But knowing how these forces affect currency pairs can only make you a more savvy trader. Here are a few highlights.When a country raises its interest rates, often their stock market will go down as investors move their funds to greener financial pastures. This tends to weaken the internal economy of the country, but strengthens it in relation to other countries. Which effect will have the most impact on that nation's currency pairs is often discussed well in advance by the "talking heads," and each Forex trader has to decide for herself who to believe!Crude oilCanada is an oil-producing nation. Exporting crude oil raises their GNP and improves the balance of trade, strengthening their economy.As the price of crude oil goes up, the USD/CAD goes down. (That's because the Canadian dollar, the cross currency, has appreciated against the base currency, the U.S. dollar.) At this point, the Canadian dollar is almost at parity with the U.S. dollar, a situation not seen since the 1950s.As an interesting exercise, try laying the chart of the USD/CAD over the chart of crude oil prices for the same time period. The two charts are almost a flipped image of each other.Japan, on the other hand, is an oil-consuming nation, strongly industrial but with no real energy reserves of their own. Importing crude oil at increasingly higher rates to power their economy raises the cost of production and slows or reverses their economic growth.The change in the USD/JPY has not been as dramatic as that in the USD/CAD, and the correlation between the charts not as impressive, but that's because the cost of crude oil has affected the USD half of the equation as well as the JPY side.Precious metalsDuring troubled political or economic times, investors tend to move their capital from speculative investments to something more conservative and solid. Precious metals, particularly gold, tend to go up in value at these times. When the situation returns to normal, gold tends to decline as investors seek higher returns from their money.The Swiss franc, like gold, is considered a safe harbor for capital. As the U.S. dollar has depreciated (mainly due to the government deficit, a large trade deficit, and low interest rates when much of the rest of the world is raising theirs), investors have moved much of their capital to these harbors. Therefore, as the price of gold rises, so does the franc in relation to the dollar.Like the Canadian dollar discussed above, the USD/CHF (Swissie) has declined because of the pressure of the cross currency against the base. Again, lay a chart of the USD/CHF over one for gold with the same time interval, and see how one reflects the other like trees in a lake.Australia is a major gold and copper producer. Copper is not only a precious metal, it's also a substantial element in the housing market (copper plumbing, wiring, etc.). As demand for copper rises on both fronts, the Australian dollar climbs against the U.S. dollar. This is also a reflection of high Australian interest rates versus the low ones in the United States.
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