Actualidade

2008-06-16T21:04:00.001+01:00

2008-02-17T17:27:00.000Z

The brain is the central information-processing organ of the body. It innervates the head through cranial nerves, and it communicates with the spinal cord, which innervates the body through spinal nerves. Nervous fibers transmitting signals from the brain are called efferent fibers. The fibers transmitting signals to the brain are called afferent fibers (or sensory fibers). Nerves can be afferent, efferent or mixed (i.e., containing both types of fibers).

The brain is the site of reason and intelligence, which include such components as cognition, perception, attention, memory and emotion. The brain is also responsible for control of posture and movements. It makes possible cognitive, motor and other forms of learning. The brain can perform a variety of functions automatically, without the need for conscious awareness, such as coordination of sensory systems (eg. sensory gating and multisensory integration), walking, and homeostatic body functions such as blood pressure, fluid balance, and body temperature.

The Cerebellum controls balance and movement. Without it, movements would not be coordinated.
Diagram showing the lobes of the human cerebral cortex and the cerebellum.
Diagram showing the lobes of the human cerebral cortex and the cerebellum.

Many functions are controlled by coordinated activity of the brain and spinal cord. Moreover, some behaviours such as simple reflexes and basic locomotion, can be executed under spinal cord control alone.

The brain undergoes transitions from wakefulness to sleep (and subtypes of these states). These state transitions are crucially important for proper brain functioning. (For example, it is believed that sleep is important for knowledge consolidation, as the neurons appear to organize the day's stimuli during deep sleep by randomly firing off the most recently used neuron pathways; additionally, without sleep, normal subjects are observed to develop symptoms resembling mental illness, even auditory hallucinations). Every brain state is associated with characteristic brain waves.

Neurons are electrically active brain cells that process information, whereas Glial cells perform supporting function. In addition to being electrically active, neurons constantly synthesize neurotransmitters. Neurons modify their properties (guided by gene expression) under the influence of their input signals. This plasticity underlies learning and adaptation. It is notable that some unused neuron pathways (constructions which have become physically isolated from other cells) may continue to exist long after the memory is absent from consciousness, possibly developing the subconscious.

The study of the brain is known as neuroscience, a field of biology aimed at understanding the functions of the brain at every level, from the molecular up to the psychological. There is also a branch of psychology that deals with the anatomy and physiology of the brain, known as biological psychology. This field of study focuses on each individual part of the brain and how it affects behavior.

Exercise benefits

2008-02-17T11:22:00.001Z

Exercise benefits

Physical exercise is important for maintaining physical fitness and can contribute positively to maintaining a healthy weight; building and maintaining healthy bone density, muscle strength, and joint mobility; promoting physiological well-being; reducing surgical risks; and strengthening the immune system.

Frequent and regular aerobic exercise has been shown to help prevent or treat serious and life-threatening chronic conditions such as high blood pressure, obesity, heart disease, Type 2 diabetes, insomnia, and depression. Strength training appears to have continuous energy-burning effects that persist for about 24 hours after the training, though they do not offer the same cardiovascular benefits of aerobic exercises. Exercise can also increase energy and raise one's threshold for pain.[citation needed]

There is conflicting evidence as to whether vigorous exercise (more than 70% of VO2 Max) is more or less beneficial than moderate exercise (40 to 70% of VO2 Max). Some studies have shown that vigorous exercise executed by healthy individuals can effectively increase opioid peptides (aka endorphins, a naturally occurring opiate that in conjunction with other neurotransmitters is responsible for exercise induced euphoria and has been shown to be addictive), positively influence hormone production (i.e., increase testosterone and growth hormone), benefits that are not as fully realized with moderate exercise.

Exercise has been shown to improve cognitive functioning via improvement of hippocampus-dependent spatial learning, and enhancement of synaptic plasticity and neurogenesis. In addition, physical activity has been shown to be neuroprotective in many neurodegenerative and neuromuscular diseases. For instance, it reduces the risk of developing dementia. Physical activity is thought to have other beneficial effects related to cognition as it increases levels of nerve growth factors, which support the survival and growth of a number of neuronal cells.

Both aerobic and anaerobic exercise also work to increase the mechanical efficiency of the heart by increasing cardiac volume (aerobic exercise), or myocardial thickness (strength training, see Organ hypertrophy).

Not everyone benefits equally from exercise. There is tremendous variation in individual response to training: where most people will see a moderate increase in endurance from aerobic exercise, some individuals will as much as double their oxygen uptake, while others will never get any benefit at all from the exercise. Similarly, only a minority of people will show significant muscle growth after prolonged weight training, while a larger fraction experience improvements in strength. This genetic variation in improvement from training is one of the key physiological differences between elite athletes and the larger population. Studies have shown that exercising in middle age leads to better physical ability later in life.

Diet

2008-02-16T14:59:00.001Z

Traditional diets

The traditional diets of populations around the world vary greatly. The diet of Inuit hunters in the Arctic is composed almost entirely of meat and fish, but most hunter-gatherers in other parts of the world obtain more food from gathering plants than from hunting animals. Pastoralists keep different animals according to where they live, varying from reindeer in the north to camels in hot arid areas, but they always have a diet rich in animal foods such as milk, meat, and blood. Peasant agriculturalists grow different staple crops according to local conditions, but usually have diets composed largely of plant foods with only small amounts of animal foods.

The traditional diets of populations have been followed for hundreds or thousands of years and, except in times of severe food shortage, are certainly compatible with the maintenance of health sufficient for the survival and growth of infants and children, and for successful reproduction. However, traditional diets are sometimes far from optimal and may be accompanied by serious nutritional disorders, from which the people may have suffered for many generations. For example, approximately one-fifth of the population of the world is at significant risk for developing iodine deficiency disorders; pellagra was formerly common in populations subsisting largely on maize due to deficiency in the vitamin niacin and the amino acid tryptophan; and high blood pressure and stroke are common in populations with a diet high in salt.

Diets for health

2008-02-15T15:10:00.000Z

Diets for health

Within Western populations, the word ‘diet’ is commonly used to refer to patterns of food consumption which are followed for reasons of health or for ethical or religious reasons (vegetarian andvegan diets are discussed in separate entries). A good diet is of profound importance for the maintenance of good health; nutritional deficiencies severe enough to cause obvious diseases such as scurvy and pellagra are now very rare in Western societies, but diet is a major determinant of the risk for developing many of the commonest fatal diseases, including ischaemic heart disease, stroke, and cancers of the large bowel and stomach.

The commonest type of diet followed for health reasons is one intended to cause weight loss in the treatment of overweight, and the term dieting is often assumed to refer to a weight-reduction diet. Numerous types of weight-reducing diets have been marketed. Most will cause some initial weight loss, but this is difficult to maintain because obesity is associated with the typical Western lifestyle of low physical activity and constant availability of highly palatable, energy-dense foods.

After obesity, the most common reason for requiring dietary changes is a high blood cholesterol concentration and associated ischaemic heart disease. The blood cholesterol concentration is increased by diets high in saturated fat and cholesterol. Reducing the intake of these factors causes a reduction in blood cholesterol, but most individuals find it difficult to change their diet sufficiently to have more than a small effect. Other diets followed for health reasons include low salt diets for the reduction of raised blood pressure and gluten-free diets for individuals with coeliac disease.

Western diets

2008-02-15T15:06:00.000Z

The diets of affluent Western populations changed very rapidly during the twentieth century. In comparison with the diets of peasant agriculturalists, Western diets are usually much higher in animal protein and fat and much lower in starch and dietary fibre, and ample food is available throughout the year. It is well known that Westernization of the diet is usually associated with increases in the rates of some diseases, such as ischaemic heart disease, large bowel cancer, and obesity, but it should also be appreciated that Westernization is generally accompanied by an increase in overall life expectancy and by decreases in the rates of some diet-related diseases such as stomach cancer, as well as decreases in the incidence of most infectious diseases.

what is the Vegetarianism

2008-02-14T15:18:00.000Z

Vegetarianism is the practice of a diet that excludes all animal flesh, including poultry, game, fish, shellfish or crustacea, and slaughter by-products. The reasons for choosing vegetarianism may be related to morality, religion, culture, ethics, aesthetics, environment, society, economy, politics, taste, or health.

There are several variants of the diet, some of which also exclude eggs and or some products produced from animal labor such as dairy products and honey. Veganism, for example, excludes all animal products from diet. By some strict definitions, animal products are not used for attire either, whether or not the production of clothing or items has involved the actual death of an animal, dairy, eggs, honey, wool, silk, down feathers, etc. A generic term for both vegetarianism and veganism, as well as for similar diets, is Plant-based diets.

Vegetarian diets have been found to satisfy the nutritional needs for all stages of life, and large-scale studies have shown vegetarianism to increase longevity, improve health, and significantly lower risks of cancer and other diseases.

2008-01-21T22:43:00.000Z

Porto is a city in northern Portugal and is the second largest city in Portugal, with a 2006 estimated population of 238,465 in the 15 parishes of Porto municipality,1.6 million in the 14 Greater Metropolitan Area of Porto municipalities,which is an administrative and political entity, and 2.99 million people in the broader agglomeration of Northern Littoral Urban-Metropolitan Region.

Due to its economic output and market size, Greater Porto area is one of the major financial and economic centers of the northwestern quarter of the Iberian Peninsula. Porto's municipality is the core of a large northern Atlantic conurbation, and Porto district is one of the most industrialized districts of Portugal.

One of Portugal's most internationally famous products, Port wine, was named after the city because it was originally shipped from the area or, more precisely, from Vila Nova de Gaia, a city just across the river which belongs to the same conurbation. The country was also named after the Latin name of this city, Portus Cale.

Porto is well known for its enterprising spirit, characteristic culture, people, and local cuisine. The city proper is sometimes referred to as capital do norte, or Capital of the North. In fact the city is today the capital of Norte, a region which covers entire northern Portugal.

Ribeira, the historic Centre of Porto, has been declared a World Heritage Site by UNESCO (1996).

NASA

2008-01-21T22:19:00.000Z

The National Aeronautics and Space Administration (NASA) is an agency of the United States government, responsible for the nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.

NASA's ongoing investigations include in-depth surveys of Mars and Saturn and studies of the Earth and Sun. Other NASA spacecraft are presently en route to Mercury and Pluto. With missions to Jupiter in planning stages, NASA's itinerary covers over half the solar system.

Managed by the NASA's Jet Propulsion Laboratory (JPL) in Pasadena, CA, the Phoenix mission was launched on August 4, 2007. It will search for possible underground water courses in the northern Martian pole. This lander revives much of its experiments and instrumentation from the failed 1999 Mars Polar Lander, hence its name. An improved and larger rover, Mars Science Laboratory, is under construction and slated to launch in 2009. On the horizon of NASA's plans are two possibilities under consideration for the Mars 2011 mission.

2008-01-21T22:13:00.000Z

A star is a massive, luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible in the night sky, when they are not outshone by the Sun. A star shines because nuclear fusion in its core releases energy that traverses the star's interior and then radiates into outer space. Almost all elements heavier than hydrogen and helium were created inside the cores of stars.

2008-01-21T22:00:00.000Z

Is it getting better, or do you feel the same?
Will it make it easier on you now
You got someone to blame

You say
One love
One life
When it's one need in the night
One love
We get to share it
Leaves you baby if you don't care for it

Did I disappoint you?
Or leave a bad taste in your mouth?
You act like you never had love
And you want me to go without

Well it's...
Too late
Tonight
To drag the past out into the light
We're one, but we're not the same
We get to carry each other
Carry each other
One

Have you come here for forgiveness?
Have you come tor raise the dead?
Have you come here to play Jesus
To the lepers in your head?

Did I ask too much?
More than a lot
You gave me nothing, now it's all I got
We're one, but we're not the same
Well we hurt each other
Then we do it again

You say
Love is a temple
Love a higher law
Love is a temple
Love the higher law
You ask me to enter but then you make me crawl
And I can't be holding on to what you got
When all you got is hurt

One love
One blood
One life
You got to do what you should
One life
With each other
Sisters
Brothers
One life
But we're not the same
We get to carry each other
Carry each other
One

Eu Sou

2008-01-21T21:57:00.000Z

I am love in the face of hate
I am kindness in the face of ridicule
I am strength in the face of diversity
I am patience in the face of the mule
I will not run away from fear, I will not run and hide
I am bravery, I am pride
I will make a difference in this world, big or small
That is my promise to me , my promise to all

Dedicated to: Margarida

Falling

2008-01-21T21:55:00.001Z

The desks line up
Perfectly.
I drift away
Move into a corner
Books fall onto my desk
10, 15 of them.

All I can see above the mountain
Of books is your head.
5 more books pile
onto my desk.

I can imagine myself
Running through the forest.
When I stop, I see the words
"You are bad."
"You will always be alone."
"No one will like you."

I believed you for years.
I thought I was worthless
Because my mother told me,
"The teacher's always right."

Nasa Picture

2008-01-01T22:27:00.000Z

some pictures of NASA space.

For a better christmas

2007-12-16T14:28:00.001Z

Mother Teresa, one of the most selfless people, once said that "if you can't feed a hundred people, then just feed one." You only have to help one person, according to her, to help the world. The woman built a life and a legacy on her ability to give to others. So, this year for the holidays, I'm taking her advice and helping someone out. I'm giving a hat, scarf and gloves to one of the mitten trees for underprivileged children at my city, but there are many other charities to choose from.

Here's another idea for you. Like many of you, I'm still working on my Christmas shopping. But I hate giving gifts that people will never use, so I like to give donations in a person's name. This is especially great for parents, who are traditionally difficult to shop for. You can make donations to almost any charity in this way. I would suggest finding your favorite charity online; most charities have a place to give on their websites, and you can usually donate in honor or in memory of someone.

Some charities you can contact: IASD; Banco Alimentar; AMI and LBV.

know better give than to receive. For a better christmas.

The realy celebrashion of christmas.

2007-12-16T14:05:00.000Z

Jesus was born during the reign of Herod the Great, that the Romans had appointed to govern the Judea. The calendars are starting from the year in which it is supposed to have Jesus born, but the people who made this counting wrong with the dates: Herod died in the year 4 BC, so that Jesus was born 3 years before, when the census the Jewish people, which was, exactly, 1 year after the census of other people also subjugated to the power Romano. These censuses were to the Romans to facilitate the counting of the people and the collection of taxes. The Jews always been opposed to any attempt to count, for that reason, this was a year after it occurred in neighboring nations. Since the fourth century, Christians celebrate the Christmas, or birth of Christ on Dec. 25. This was an adaptation of the parties to god Sol pagans of peoples, acquired by the Romans. But the most important of this season festive is your birth and the purpose of his birth.

Radio control Car

2007-12-16T12:22:00.000Z

VIDEO

Hello, today im going to talk about the R\C, or radio control, it´s a hooby to me.

All hobby-grade radio-controlled cars require regular maintenance to ensure smooth and trouble-free operation. In comparison, cheaper "toy-grade" cars, found in discount and consumer electronics stores, are generally unserviceable. For those interested in mechanics, this maintenance provides an interesting adjunct to the hobby. Due to their modular construction, in the event that parts of a hobby-grade radio-control car breaks or wears out, they can be replaced individually. The availability of many replacement and high-performance parts for hobby-grade model vehicles allows them to be extensively upgraded (sometimes, to the extent of having no original parts remaining of the vehicle); in comparison, parts are generally impossible to find for toy-grade model cars. In recognition of this distinction, Radio Shack released the popular XMODS and ZipZaps toy cars; these are mid-grade cars which can be tuned, modified, and repaired, although still to a lesser degree than hobby-grade vehicles. Their recently released "Pro-Pulse" cars, lower quality clones of the hobby class Associated RC18MT and RC18B, have many upgrade parts available such as aluminum alloy parts and upgrade motors, but little original parts support.

In recent years, hobby-grade "ready-to-run" (or "RTR") models have become available from every major manufacturer of radio-controlled cars, attracting many hobbyists who would otherwise have purchased a pre-assembled car. Vehicles of this type need little or no final assembly and in many cases, the bodies are shipped painted and trimmed, requiring little work from the owner before they can be used (other than purchasing and installing batteries). A number of cars and trucks are presently available only in ready-to-run form, such as the Traxxas Revo, a nitro powered model truck. The growing popularity of the RTR vehicle has prompted manufacturers to introduce kit versions of their RTR cars that include factory upgrades but have no radio gear installed and often no motor or speed controller.

Symptoms

2007-11-07T21:27:00.000Z

Symptoms of influenza can start quite suddenly one to two days after infection. Usually the first symptoms are chills or a chilly sensation but fever is also common early in the infection, with body temperatures as high as 39 °C. Many people are so ill that they are confined to bed for several days, with aches and pains throughout their bodies, which are worst in their backs and legs. Take care of you. Stay alert, run away from the chickens.

Types of influenza virus

2007-11-07T21:17:00.000Z

Structure of the influenza virion. The hemagglutinin (HA) and neuraminidase (NA) proteins are shown on the surface of the particle. The viral RNAs that make up the genome are shown as red coils inside the particle and bound to Ribonuclear Proteins (RNPs). Diagram of influenza virus nomenclature The influenza virus is an RNA virus of the family Orthomyxoviridae, which comprises the influenzaviruses, and Thogotovirus. There are three types of influenza virus: Influenzavirus A, Influenzavirus B, and Influenzavirus C. Influenza A and C infect multiple species, while influenza B almost exclusively infects humans. Wild aquatic birds are the natural hosts for a large variety of influenza A viruses. Occasionally viruses are transmitted to other species and may then cause devastating outbreaks in domestic poultry or give rise to human influenza pandemics. The type A viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease. The Influenza A virus can be subdivided into different serotypes based on the antibody response to these viruses. The serotypes that have been confirmed in humans, ordered by the number of known human pandemic deaths.

Saude (HIV)

2007-10-11T19:12:00.000+01:00

Human immunodeficiency virus (HIV) is a retrovirus that can lead to acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Previous names for the virus include human T-lymphotropic virus-III, lymphadenopathy-associated virus, or AIDS-associated retrovirus.
Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells. So, be very careful.