#30 Could we cure HIV with lasers? (English)

Could we cure HIV with lasers?
[TED Talks Science and Medicine: 'Could we cure HIV with lasers?' by Patience Mthunzi]

HIV patients take in staggering numbers of pills to withstand the intense pain. However, compared to the number of pills swallowed, they are not effective. As the pills travel through many organs to reach the nerve system, the lungs and the lympth notes (where the virus is sleeping), they dilute. At the time, the pills dilute and lose its efficacy, the virus starts to spread more and to infect other cells (especially, the CD4 T-cell) in the blood.

The three headed device by Patience Mthunzi

The question is raised: could we treat HIV directly without the risk of the anti HIV drugs' dilution? Patience Mthunzi, laser scientist in South Africa, finds the answer with the the use of lasers. She strongly believes that lasers could be the most efficient type of treatment to cure the HIV. As of now, lasers are only used to poke or drill extremely tiny holes in HIV infected cells. In fact, Dr. Mthunzi is inventing a three heades device: the laser (first head) making an incision, the camera (second head) leading, and the drug sprinkler (third head) delievering the drug directly to the site of infection. When this technique is actualized, the complete eradication of HIV in the body will be realized.

People living with HIV

Several facts about HIV:

• HIV (the human immunodeficiency virus) is found in blood and sexual fluids and spreads mainly through unprotected sexual contact and the sharing of hypodermic needles and equipment.
• When a person becomes infected with HIV, it damages his or her immune system, leading to immunodeficiency; the immune system can no longer fight off common germs and pathogens, so a person infected with HIV becomes ill from diseases that don't usually affect someone without HIV.
• HIV is one of the world's most significant public health challenges, particularly in low and middle income countries.
• An HIV-infected person may not have any symptoms of diease during the asymptomatic period.

[Reference]
TED Talks science and medicine, WHO, WebMD, CBC

KSJ

#29 Why do leaves change color in the fall? (English)

Why do leaves change color in the fall?

In the spring and the summer is when the leaves create food needed for the trees growth, this process is known as photosynthesis. This process requires cells containing chlorophyll, which gives the leaf its green color, to convert the light energy into food. Chlorophyll is only found in plant cells, which is why humans aren't green. In the fall, the amount of light and changes in temperature stop the leaves from making food. The cholorophyll breaks down and the other pigments like xanthophyll (yellow) and carotenes (orange) that were masked by the green are visible. While this is happening a special layer of cells develop at the stem of the leaf which gradually severs the supporting tissues, making the leafs fall. Weather also has an impace on what color the leaves turn. Above freezing temperatures will make bright red maples, while early frost will dull this bright red. Rainy/Overcast days also increase the intensity of fall colors.

Evergreen trees do not lose their needles in the winter. This is due to the difference in the kind of leaves that Evergreens have compared to other trees. Evergreens have needles, needles have less surface area than larger, flatter leaves, and can resist changes in temperature and humidity easier. This allows the chloroplasts to survive and continue to produce food for the tree all year round.

 PoS

#28 Sleeping and the Biology of Dreams (English)

Sleeping and the Biology of Dreams 

Dreams, we all have them. They can be good, bad or just plain weird. The question is, what exactly are they? The word dream can be defined as series of thoughts, images and sensations occurring in a person’s mind during sleep. Only around 95% of our dreams are remembered by the time we get out of bed which is crazy seeing as the average person dreams four to six times every night. Now, these dreams can last a few seconds but usually they range from five to twenty minutes.  People are more likely to remember their dream if they are awakened during the REM phase. REM stands for rapid eye movement and is a phase of sleep distinguished by random movement of the eyes, low muscle tone throughout the body, and the tendency of the sleeper to dream vividly. It is said that dreaming can indeed help you learn, as well as develop your long term memories.

There are four stages of sleep. The first stage is where you drift in and out of sleep and can be awakened easily. Muscle activity and eye movement both get slower. It is in this phase where individuals can often feel the sensation of falling as they experience sudden and random muscle contractions. In stage two eye movement stops and brain waves become slower with the infrequent burst of fast brain waves. As a person enters stage three, extremely slow brain waves, known as delta waves, are distributed with faster and smaller waves. Finally, in stage four, the brain pretty much only secretes delta waves. The last two stages are referred to as deep (delta) sleep. However, in 2008 the use of stage four was removed by the sleep profession in the US and is now considered stage three. These four stages can be seen on the graph above.

We dream for several reasons such as to represent unconscious wants, to explain random signals from the brain and body, to strengthen and process information gathered during the day or perhaps to work as a form of psychotherapy. Not only this but there has also been several surveys conducted which show that men and women often dream about different things. For example most women’s dreams feature family members, babies and children. Men’s dreams are also found to be more aggressive.

To conclude, despite lots of research and experiments, our knowledge of dreams remains very limited.

 

McA