Algebra Definition

Definition: A branch of mathematics that substitutes letters for numbers. An algebraic equation represents a scale, what is done on one side of the scale with a number is also done to the other side of the scale. The numbers are the constants. Algebra can include real numbers, complex numbers, matrices, vectors etc. Moving from Arithmetic to Algebra will look something like this: Arithmetic: 3 + 4 = 3 + 4 in Algebra it would look like: x + y = y + x 

Source: http://math.about.com/cs/algebra/g/algebradef.htm

Walking could be a useful tool in treating depression (BBC)

Something as simple as going for a brisk stroll could play an important role in fighting depression, according to researchers in Scotland.

Vigorous exercise has already been shown to alleviate symptoms of depression, but the effect of less strenuous activities was unclear.

A study in the journal Mental Health and Physical Activity showed walking had a "large effect" on depression.

One in 10 people may have depression at some point in their lives.

The condition can be treated with drugs, but exercise is commonly prescribed by doctors for mild symptoms.

Researchers at the University of Stirling scoured academic studies to find data on one of the mildest forms of exercise - walking.

They found eight studies, on a total of 341 patients, which fitted the bill.

Therapy

The report's authors showed "walking was an effective intervention for depression" and had an effect similar to other more vigorous forms of exercise.

"The beauty of walking is that everybody does it” - Prof Adrian Taylor University of Exeter

They said: "Walking has the advantages of being easily undertaken by most people, incurring little or no financial cost and being relatively easy to incorporate into daily living."

However, they cautioned that much more research needed to be done. There are still questions over how long, how fast and whether walking should take place indoors or outdoors.

Prof Adrian Taylor, who studies the effects of exercise on depression, addiction and stress at the University of Exeter, told the BBC: "The beauty of walking is that everybody does it."

He added: "There are benefits for a mental-health condition like depression."

How any form of exercise helps with depression is unclear. Prof Taylor said there were ideas about exercise being a distraction from worries, giving a sense of control and releasing "feel-good" hormones.

The mental-health charity Mind said its own research found that spending time outdoors helped people's mental health.

Its chief executive, Paul Farmer, said: "To get the most from outdoor activities it's important to find a type of exercise you love and can stick at. Try different things, be it walking, cycling, gardening or even open-water swimming.

"Exercising with others can have even greater impact, as it provides an opportunity to strengthen social networks, talk through problems with others or simply laugh and enjoy a break from family and work. So ask a friend to join you."

Source:  By James Gallagher Health and science reporter, BBC News

 http://www.bbc.co.uk/news/health-17701485

Comedy films 'good for the heart' (BBC)

Watching comedy films is good for the heart because it boosts the flow of blood, a study says.

 

A team from the University of Maryland in the US asked 20 healthy young adults to watch 15 to 30 minutes of sad and humorous films 48 hours apart.

While watching films such as There's Something About Mary, blood flow rose in all but one of participants.

Researchers said the effect was equivalent to starting a course of heart treatment drugs called statins.

But movies like Saving Private Ryan with its war scenes had the opposite effect, the Heart journal reported.

The team said it seemed likely that the act of laughing had the effect of widening the arteries - mental stress is known to narrow them.

Lead researcher Dr Michael Miller said that, even though more research was needed to confirm the findings, they would be of interest to cinema-goers.

"The overall difference in blood flow between the mental stress and laughter phases exceeded 50%."

And he added: "The extent of the impact of watching a sad film was of the same magnitude as remembering episodes of anger and doing mental arithmetic, while the impact of watching a funny film was equivalent to a bout of aerobic exercise or starting on statin treatment."

During the study, participants were asked to abstain from drinking alcohol, using vitamins or herbs, or taking aerobic exercise the evening before the experiment, as all these can affect blood flow.

                            

                                        Watching comedy increased the flow of blood to the heart
Artery

In all, 160 measurements of brachial artery blood flow were taken before and one minute after phases of laughter or sadness. The brachial artery runs from the shoulder to the elbow, and is a good indicator of blood flow around the body.

Brachial artery blood flow was reduced in 14 of the 20 participants after watching film clips that caused distress, but increased in 19 of the 20 participants after watching those that elicited laughter.

Dr Charmaine Griffiths, of the British Heart Foundation, said: "It is well known that changes in emotion can be reflected in changes in the heart and circulation.

"Scientists are becoming increasingly interested in the possibility that a good giggle has positive effects on heart health.

"Whether sharing a joke with friends or watching a comedy, a good laugh is likely to be good for your heart.

"However, we would like to reassure people that watching sad films won't have any long term detrimental effects on the heart or circulation." 

 

 "The impact of watching a funny film was equivalent to a bout of aerobic exercise or starting on statin treatment"

Dr Michael Miller, lead researcher

Source:  http://news.bbc.co.uk/2/hi/health/4616902.stm