Category Archives: Biology

Is olfactory sense crucial to bird’s navigation?

Researchers from universities of Oxford, Barcelona, and Pisa have done an experiment about bird’s navigation; they embark an experiment to find out whether the sense of smell is important to the birds for navigating.  They progressed an experiment with the bird named “Scopoli”, separated by three parts:

  1. Temporarily anosmic group
  2. Group carrying small magnets
  3. Control group

The researchers made these three groups of birds to have a trip across the ocean. As a result of the experiment, all of these three groups of birds came back to their home, where they are sent. Therefore, we can conclude that olfactory sense is not a necessary sense for navigation of birds. However, the researchers analyzed the route that the three groups of birds flew and found out that the idea “Olfactory sense is not necessary for birds to navigate” was a misconception. The orientation that the birds of the first group made over the ocean was significantly different with that of the control group. The orientations of the first group’s birds were curiously straight but poor, although the third group’s birds’ orientations were well oriented.

Through this experiment, the researchers were able to find out the significant fact that the olfactory sense is crucial for the birds to find the way back to their home.

 

 

 

 

 inferences:  

06 September 2017 – Episode 635 – This Week in Science Podcast (TWIS) / The bird nose knows, ya know??

Advertisements

Psychology Disorders

Mental health workers view psychological disorders as persistently harmful thoughts, feelings, and actions. People are fascinated by the exceptional, the unusual, and the abnormal. This fascination may be caused by two reasons: first, during various moments we feel, think, and act like an abnormal individual. Second, psychological disorders may bring unexplained physical symptoms, irrational fears, and suicidal thoughts. Humanity tried to fix this problem with different approaches for every era. Ancient Treatments of psychological disorders include trephination, exorcism, being caged like animals, being beaten, burned, castrated, mutilated, or transfused with animal’s blood. The first scientific research was done by Philippe Pinel (1745-1826) from France, who insisted that madness was not due to demonic possession, but an ailment of the mind. When physicians discovered that syphilis led to mental disorders, they started using medical models to review the physical causes of these disorders.

 

  1. “Insanity” labels raise moral and ethical questions about how society should treat people who have disorders and have committed crimes.

  2. “Dissociative Disorder” is when conscious awareness becomes separated (dissociated) from previous memories, thoughts, and feelings.

  3. “Dissociative Identity Disorder” (DID) is a disorder in which a person exhibits two or more distinct and alternating personalities, formerly called multiple personality disorder.

Finding Possible Treatment for the Breast Cancer

According to a research, about one in eight women suffer from the breast cancer in their lifetime.  Furthermore, the death rate of the breast cancer is higher than any other types of cancer. The breast cancer is regarded as a conundrum. However, a team of researchers from the University of Zurich in Switzerland has found a way to invent a treatment for the breast cancer. They developed the new way to destroy cancer cell that they were not able to kill before.

Currently, antibodies such as pertuzumab and trastuzumab are used for the treatment of breast cancer. They detect and target HER2 which plays a vital role in the breast cancer. However, the antibodies only deactivate cancer cells, so cancer cells can be reactivated at any time.

The researchers wanted to find the reason why the antibodies cannot totally destroy the breast cancer cells. They figured out that HER2 uses multiple signaling pathways to develop and reproduce cancer cells, but commonly used antibodies are formed to only block one signaling pathway, which enables cancer cells to recrudesce.

The researchers also found out a solution to overcome the lack of antibodies. They made a protein compound which is able to combine itself with two HER2 receptors and change the structure of receptors. It prevents the growth signals from the RAS, a central hub in the cell, and reactivates the signals released by the HER2 receptor. Furthermore, the antibodies might have negative effects, attacking the healthy body cells, but this protein compound only targets the cancer cells.

It is expected that the way treating breast cancer will be more opened in the future through this research

 

 

<references>

http://www.medicaldaily.com/good-breast-cancer-genes-2-genes-linked-better-survival-rate-395235

http://www.medicaldaily.com/invasive-breast-cancer-new-treatment-388652

http://www.roche.com/research_and_development/what_we_are_working_on/oncology/about-her2-positive-breast-cancer.htm

What is a vaccine?

The immune system of our body works as a bastion from innumerable kinds of germs. Briefly summarizing, when a germ invades into the body, the immune system sends special cells to fight it off. However, it is apocryphal to say that it works for every single germ. There might be some germs that cannot be prevented by our natural immune system. Thus, scientists came up with unprecedented, laudable idea, and that idea was a vaccine.

Vaccines are substances that prepare the immune system to fight a disease-causing germ or other pathogens by imitating an infection. Vaccines deter the diseases by tricking the immune system to make a “memory” of that germ without ever having to fight the real germ in the first place. Thus, conspicuously, if the virus comes, the immune system is ready to attack it. Therefore, rather than being languished, people can overcome the diseases such as smallpox and diphtheria easily through a vaccine.

Before the vaccine was invented, it was incoherent and futile to overcome several illnesses such as measles, polio, smallpox, and diphtheria. However, due to extreme scrutiny regarding the bacteria and fervor to invent the medicine, scientists developed a vaccine that protected the people who didn’t suffer from the disease yet. Infamous diseases that killed millions of people were relegated due to the inventions of vaccines, and scientists figured out that vaccinations also can help protect people who are not vaccinated.

It is an objective fact that vaccine is good. However, the way it works is esoteric. It is important to know how it works in order to understand it thoroughly.

image (6)

It is a hackneyed fact that the body is designed to fight off foreign invaders, such as germs. Nonetheless, in order to do this, it needs to be able to distinguish elements of itself from that of outside agents. So, the immune system is always on the lookout for evidence of foreign stuff or antigens. Pathogens are covered with small particles, and they look unfamiliar to the human body, so immune system calls out its antigen attack squads. But antigens are specific and only stick to a particular germ.

When a pathogen enters the body, the immune system immediately dispatches antibodies. When the antibodies find the particular antigens, they either disarm the threat by locking onto the antigens or send the signals to adjacent immune cells to come to the site of the infection. After an infection goes away, the immune system memorizes the features of the pathogen’s antigens in B cells. So if the same germ enters the body again, existing antibodies can recognize it immediately and annihilate those germs before it multiplies. This process in our body is called immunity.

One way to amass immunity is through infection. However, it is too risky to have an infection to have immunity since severe infections can kill the person. Therefore, people use injections that contain a weakened form of a disease-causing germ. The vaccine won’t cause severe disease because the weakened germ is ephemeral and can no longer copy itself to release new germs inside the body. But they provide the opportunity for antibodies to get used to the specific types of pathogens.

Even though some dangers still exist with hedonistic diseases such as influenza viruses, scientists are working to enhance new effective vaccines. It is uncertain to say that vaccine can prevent all the diseases, but it can surely save lives from series infections.

Reference

https://www.sciencenewsforstudents.org/article/explainer-what-vaccine

https://en.wikipedia.org/wiki/Vaccine

https://www.news-medical.net/health/What-are-Vaccines.aspx

 

 

 

Tongues ‘taste’ water by sensing sour

All we know about water is that water is an odorless, tasteless, slightly compressible liquid when it’s pure. However, when we drink water, we can know that it’s water. It might be unsurprising to notice that we’re drinking something liquid. But how do we know that it’s water, not syrup? Then, does it mean that water has a taste? – actually not. According to the new study, we can recognize the water not by tasting the water itself, but by sensing acid which is produced when we drink water.

All mammals need water to sustain their life. When we drink water, we have to drink the water through our mouth.According to Yuki Oka who studies the brain at the California Institute of Technology in Pasadena, our tongue has evolved to detect some necessary materials for survival like salt and sugar. This, in other words, means that the sense of detecting water would have evolved.

It is already found that a brain area called the hypothalamus controls thirstiness of mammals. But a brain cannot decide the taste of something alone because, in order to taste something, the brain should cooperate with a mouth and receive a signal from it to know what the person’s eating or drinking. Oka says, “There has to be a sensor that senses water, so we choose the right fluid.” If we cannot distinguish the water from others, we might make a fatal decision, such as drinking poison instead of water.

To prove the water sensor, Oka and his group used mice. They dripped different flavors of liquid onto mice’s tongues. They observed a signal from the nerve cells attached to the taste buds when they were drinking, and mice showed a great nerve response to all tastes. However, the main point is that they reacted to water similarly. Somehow, the scientists discovered that taste buds are able to detect water.

Our mouth is filled with a lot of saliva— a mixture of enzymes and other molecules. Also, the mouth includes bicarbonate ions (HCO3-), which make saliva more basic. The pure water has lower pH than basic saliva. When we pour the water into the mouth, it washes out the basic saliva and enzymes in our mouth instantly starts to replace the ions. It combines carbon dioxide and water to produce bicarbonate. As a side effect, it also produces protons. The bicarbonate is basic, but the protons are acid. Then, the receptors on our tongue detect acid that we usually call ‘sour flavor’ and sends a signal to the brain.

To confirm this, Oka and his group used a technique called optogenetics. In this method, scientists insert light-sensitive molecules, which trigger an electrical impulse when shone with light, inside cells. With this principle, Oka’s team added a light-sensitive molecule to the sour-sensing taste bud cells of mice. As they shone the light to their tongues, they started to lick the light as if they lick the water. By stimulating acid sensor, they misunderstood it as water.

To the other group of mice, Oka’s team removed the sour-sensing molecule by blocking the genetic instructions that make this molecule. As a result, they weren’t able to know whether what they’re drinking is water or not. They even drank thin oil instead. Oka and his group published their results on May 29 in the journal Nature Neuroscience.

Scott Sternson, who studies brain’s mechanism for controlling animal behavior at a Howard Hughes Medical Institute research center in Ashburn, VA, says it’s crucial to learn how we sense simple but vital things, such as water. “It’s important for the basic understanding of how our bodies work,” he says.

Some people might think it’s a weird concept that the water has a sour ‘taste’. Flavor is a complex interaction between taste and smell. So, detecting water is quite different with tasting. Water may still taste like nothing, but to our tongues, it’s definitely something.

Reference: https://www.sciencenewsforstudents.org/article/tongues-taste-water-sensing-sour

 

What is “Phantom Pain?”

Phantom pain sensation refers to a person’s feeling related to limbs or organs that are physically not a part of their body. For example, let’s say that a part of a person’s body, such as an arm, was amputated because of an accident. If the person has a phantom pain sensation, then he would feel pain in the position where his arm supposed to exist, even though he doesn’t have an arm (this particular phantom pain related to the limbs are called phantom limb pain).

Then why do these kinds of phenomenon occur? According to the scientists, when a part of a body is amputated, then the region of the brain that was needed for the control of that part of the body is no longer needed, and the neuronal system in the part of the brain falls into disarray. To fill the empty spots in the brain, those parts of the brain take over the tasks of the neighboring neurons and become rearranged to do different things. However, when the brain tries to adapt to the new situation, in some cases this process goes wrong, which eventually causes the phantom pain.

As you can see, there are no apparent causes of the phantom pain discovered by scientists because there might be other reasons other than the cerebral shifts such as inherited nerve damages. However, using fMRI, a method to distinguish the active parts of the brain while it’s working, scientists have discovered that degree of the shifts related to the functions in our brain caused by amputation (and many other factors) is directly proportional to the intensity of pain the patient receives through the phantom pain. Also, researchers found out that a person with a functional artificial limb has felt less phantom limb pain than the patients that do not have it.

Even though it might take some time, a cure for phantom pain keeps on developing as the researches related to phantom pain proceed. I hope that later, the patients would not suffer from their phantom pain, or, in my own words, “false pain.”

 

References

12 July, 2017 – Episode 627 – This Week in Science Podcast (TWIS)

http://www.twis.org/broadcasts/

https://en.wikipedia.org/wiki/Phantom_pain

What is CRISPR Cas9?

Have you ever heard about hemophilia? It is a rare genetic disease that disables people from clotting blood. There is not yet therapy for hemophilia. However, a new technology to change the genes related to hemophilia was developed recently. The key point in this new technology is CRISPR-Cas9. It is genetic engineering tool which enables people to cut specific region of DNA and to insert another homologous DNA. Cas9 and guide RNA (gRNA) are important molecules in CRISPR-Cas9.

Cas9, a restriction enzyme, was first discovered in the 1980s. When a virus infects a bacteria, the bacteria cut the intruder’s DNA by using Cas9.

gRNA is made from a small piece of pre-designed RNA sequence. gRNA helps the Cas9 enzyme to cut particular regions of DNA.

CRISPR stands for Clustered Regularly Interspersed Short Palindromic Repeats. Also, Cas means “CRISPR associated.” Even though this method does not destroy surrounding genes, it is possible to change a particular DNA sequence. Treatments for hemophilia using CRISPR-Cas9 are being studied now in the USA. Researchers say, “If a ‘normal blood clotting factor’ gene is inserted into a hemophilia patient, his or her blood will be clotted.”

In addition to hemophilia, CRISPR therapy related to HIV is also being studied. HIV, or Human Immunodeficiency Virus, is a virus that infects the body immune cells and corrupts the immune system.  One typical thing of HIV is that it can go into the immune cell using the specific receptor proteins that are on the surface of the immune cells. Using CRISPR method, scientists found out that getting rid of these proteins makes HIV unable to infect another cell. Then, without the proteins that enables them to infect other cells, HIVs cannot replicate themselves and therefore collapse.

Also, CRISPR is applied to not only curing genetic diseases but also developing plants and animals. By using CRISPR, researchers made MSTN, which limits the growth of pigs, not perform its role. As a result, researchers were able to get a “super pig,” that has more muscles than normal pigs.

The usage of CRISPR can make valuable crops. In 2016, Dr. Yang and his companions made new mushrooms that doesn’t turn into brown by eliminating the enzymes that cause browning in mushrooms. Korean researchers also developed various crops, such as lettuce that has resistance in harmful insects and bean that decreases the level of cholesterol.

Although CRISPR Cas9 is touted through many positive results, it is a controversial topic. For example, CRISPR Cas9 can be used in manipulating embryonic genes, which causes the whole fetus to change. Some countries prohibit this for ethical reasons. In contrast, the Human Fertilisation and Embryology Authority authorized to alter human embryos in the UK in 2016. Even though there are lots of positive effect modifying genes, we must know that there are some ethical issues that we must concern.

References

http://www.alphr.com/bioscience/1001654/darpa-offers-50-million-to-make-crispr-gene-editing-safer
http://news.mk.co.kr/newsRead.php?year=2017&no=461478

http://science.ytn.co.kr/program/program_view.php?s_mcd=0082&s_hcd=0010&key=201706011107334239

https://www.youtube.com/watch?v=2pp17E4E-O8

http://www.yourgenome.org/facts/what-is-crispr-cas9