Thursday 31 December 2015

#73 Perfect Medicine for Alzheimer's Disease (English)

Alzheimer's disease
Alzheimer's disease is named after Dr. Alois Alzheimer, a German physician. After its first discovery in 1906, Alzheimer's disease has always been an issue that the world attention focused on. According to the Alzheimer's Society, Alzheimer's disease is a chronic neurodegenerative disease that gradually gets worse over time and is the most common cause of dementia. Currently, there are nearly 44 million people suffering from Alzheimer's disease. Although there has been vast amount of research on Alzheimer's disease, the perfect medicine for it is not yet developed.  However, KIST research team has delivered the news that it developed a new medicine that could completely cure the Alzheimer's disease. It is called EPPS.

The principle of EPPS
The medicine perfectly removes the β-Amyloid from the brain, so the dementia symptoms recovers to the normal level. β-Amyloid is the fundamental protein that causes Alzheimer's disease. β-Amyloid is commonly distributed in brains of normal people, but in case of Alzheimer, it is found in aggregate morphology in the brain. This medicine releases these clumps of β-Amyloid into nontoxic monomers. In fact, it also prevents acute secretion of GABA, which provokes the brain function to decline substantially. The dosing procedure is incredibly simple; the medicine is dosed with water like any ordinary medicine as it is easily integrated into the brain.

Morris water maze
EPPS was injected into a mouse suffering from the Alzheimer's disease and its brain was examined for over 3 months. All the clumps of β-Amyloid, which were present on Hippocampus and Celebral cortex before the injection were successively removed. (Hippocampus and Celebral cortex take in charge of the recognition ability in the brain.) Then, the mouse's memory was tested by several tests such as Y-maze, Fear conditioning, and Morris water maze. The results showed that the mouse's recognition ability recovered to the normal level. After its successive demonstration, KIST is currently waiting for EPPS's clinical demonstration before its appearance in the pharmacy. I hope that the EPPS substantially decreases the fatality rate of Alzheimer's disease.

KSJ

Wednesday 23 December 2015

#72 Tooth decay (English)

Tooth decay is decaying of the outer layer of the tooth due to bacteria. Tooth decay is caused by a higher intake of sugary snacks and drinks. Also if we do not brush our teeth these foods are left in the teeth. The bacterium that lives on our plaque reacts with the food and drinks in our teeth to form acids. This acid starts by attacking and eating away at the enamel of our teeth. The hole that is formed in the enamel is known as a cavity. Almost every single person in the world has experienced a hole in their tooth at least once in their life. On average it takes seven years for cavities to be formed so the majority of them go unnoticed. This is mainly due because tooth decay is a slow process that does not happen over night.

A less serious case of tooth decay is where there is not a deep enough hole so the dentist will fill in the hole to stop it from spreading any further.  A more serious case of tooth decay is where the tooth needs to be replaced to reduce further infection of the tooth. 

There are many ways to reduce the possibility of getting cavities/tooth decay. Firstly you can reduce the amount of sugary food and sugary drinks that you consume. Secondly you can brush your teeth thoroughly and floss in between your teeth minimum twice a day (in the morning and in the evening).  The last possibility that you could do to reduce getting tooth decay is by going to go get regular check ups with your dentist. If your teeth are aching go check up with your dentist.

There are not that many actual symptoms of tooth decay (that is why it is very difficult to find out unless going to a dentist). The main symptom you will find out (that you get when you have the infected tooth or dental cavity) is toothache. Toothache is a normal symptom for any damaged teeth. 

In conclusion our teeth are very necessary whether it’s for eating food or posing for that awkward family photo just look after your teeth.

SSP

#71 The effect of abortions on subsequent pregnancies (English)

Did you ever wonder whether abortions increase the risk of difficulties in subsequent pregnancies? Well, scientists claim abortion isn't thought to be directly linked to major fertility issues or complications in following pregnancies. Furthermore, it is argued that factors such as living conditions, poverty, economic state/development and level of hygiene largely impact birth rates thus modifying results.  However, researchers do suggest a certain tendency between abortion and an increased risk of:

Premature birth / Low birth weight:
Indeed, a study published in the medical journal Human Reproduction, found that women who had three or more abortions were up to three times more likely to have a future baby prematurely – even before 28 weeks in the womb – and of a poor weight. Such a phenomenon is extremely dangerous for the infant whom must be given much medical attention to ensure survival.

Cervix damage hence vaginal bleeding during early pregnancy :
There are two types of abortions; a medical and a surgical one. A medical abortion requires the woman to take medication during the early stage of pregnancy in order to abort the fetus whilst a surgical abortion typically involves a vacuum device or a 'curet' (a spoon-shaped instrument with a sharp edge) used to extract the fetus from a woman's uterus. In some cases, surgical abortions are known to weaken and damage the cervix or uterus quite significantly, leading to the potential for the cervix to open prematurely and abnormal bleeding in a subsequent pregnancy. Although these consequences are rare, woman who have had multiple surgical abortions are most likely to endure such outcomes in which serious damage may even demand high level surgery to be corrected.

Researchers are currently turned towards Denmark (who maintains a national registry with information on abortion and subsequent pregnancies) and results have shown the rates of ectopic pregnancy in subsequent pregnancies were 2.4 percent for medical abortion and 2.3 percent for surgical abortion. The rate of miscarriage was 12.2 percent for the medical abortion group and 12.7 percent for the surgical group.

In conclusion, although these statistics reamain relatively low, and focused on short term side-effects of abortion, these negative outcomes do exist and women should know that there are ineed a positive correlation between the number of abortions and the risks of difficulties in subsequent pregnancies.
 
SAG

Tuesday 22 December 2015

#70 Deficiencia de la vitamina D y su relacion con la obesidad (Español)


 La obesidad es una enfermedad crónica que se caracteriza por la excesiva acumulación de grasa, la cual puede desencadenar procesos patológicos. Estudios recientes han demostrado que la obesidad es uno de principales factores de riesgo para presentar deficiencia de vitamina D. La vitamina D se clasifica como una vitamina liposoluble, cuya función principal es la regulación del metabolismo de calcio y fosfato.La vitamina D se acumula mayormente en tejido adiposo, es por esto que dicho almacenaje tiene como fin proteger al organismo contra toxicidad por sobredosis de vitamina D . Por lo tanto, se cree que la asociación invertida que existe entre obesidad y vitamina D se da como consecuencia del aumento de la depuración metabólica en el tejido adiposo . Sin embargo, también se ha postulado que los pacientes obesos realizan menos actividad física al aire libre y que además visten de manera más cubierta, lo cual interfiere con exposición al sol y por consiguiente con la síntesis de vitamina D.La síntesis insuficiente de vitamina D puede generar deformidades esqueléticas y discapacidades cognitivas en los niños. En los adultos se encuentra relacionada con osteomalacia y osteoporosis.

 Causas de la deficiencia de vitamina D:

   La edad es un factor determinante para la deficiencia de la vitamina D, debido a que en edades avanzadas se presenta una disminución en la cantidad de vitamina D que el intestino es capaz de absorber . Se ha probado que las personas mayores producen menos colecalciferol en la piel, por lo que para tener una adecuada producción de vitamina D deben exponerse más a la luz solar que la población más joven

   La deficiencia de la vitamina D es una condición común en países que presentan todas las estaciones del año. Se ha comprobado que personas con una situación nutricional normal sufren de deficiencia de vitamina D en otoño, invierno, y en primavera, esto debido a la falta de sol en tales estaciones.

    Se ha probado que la prevalencia de deficiencia de vitamina D es mayor en mujeres que en hombres, y es mayor en personas de piel oscura que en personas de piel clara, tanto en meses de sol como en meses con poca luz solar.

   Se han hecho estudios que prueban que la contaminación en el aire y la cantidad de nubes cubriendo el cielo pueden contribuir a que dentro de un mismo país hayan variaciones en la cantidad de vitamina D en la población

   Otro aspecto importante a considerar es la cantidad de tiempo que la población pasa adentro, ya que la luz UVB no atraviesa el vidrio y es por lo tanto incapaz que se logre la síntesis de colecalciferol en la piel. Por lo tanto, aquellos que pasan la mayor parte de su día bajo techo tienen una mayor tendencia a padecer de deficiencia de vitamina D.

AAM

Friday 11 December 2015

#69 Pimples (English)


Dear Pimples,

If you’re going to live on my face I need to see some rent.
Acne is something that men and women have to deal with the whole of their lives, particularly during adolescence. In order to treat it properly, or to try to avoid it, one must first understand how and why pimples are formed. 

1.    Puberty, stress, sexual stimulation and the consumption of dairy products lead to an increase in the presence of androgenic hormones in our bodies. These hormones are the first ingredients for a zit to form, as they are what make the sebaceous glands produce excessive sebum.

2.    Each of the hair follicles on our bodies is connected to glands, called sebaceous glands, which secrete an oily substance to lubricate our skin and hair. To do that, the substance, known as sebum, needs to move up the hair shaft and out the opening of the follicle.  

3.    However, sometimes the sebum is not able to exit the hair follicle very quickly. The skin cells continue to constantly shed dead cells and the glands continue to produce more sebum, creating the big problem. The sebum sticks to dead cells, and together they form a plug that blocks the follicle shaft.  

4.    Meanwhile, the glands continue to produce more sebum. The growing blockage stimulates bacteria like Propionibacterium Acnes (P. acnes), to reproduce. Under normal conditions, this bacteria wouldn’t cause any trouble, but in the presence of a clogged follicle that is warm, moist, dark, lacks oxygen and there is plenty of sebum to eat, the bacteria set up camp and have a feast with lots of eating and reproductive activities.

5.    The sebum, the dead cells and the bacteria together form the white pus at the top of the pimple.  

6.    Increasing bacteria leads to a response by the immune system. Chemicals are released into the body that the white cells pick up on. They try to kill the bacteria and heal the tissue thus leading to inflammation and redness. 

One of the major factors determining an individual’s likelihood of developing acne is the person’s genetic make up.  Genetics impact the structure of the hair follicle, sebaceous gland activity, hormone levels and the immune response to bacteria. Therefore, PIMPLES CAN NEVER BE FULLY AVOIDED. Nonetheless, several steps can be taken in order to reduce the likelihood of getting pimples:

v  Keep your face and hair clean!

v  Moisturize your skin!

v  Keep your hands off your face!

v  Stay out of direct sunlight!

v  Stay hydrated and eat healthily!

v  Don’t stress!

v  Consume less dairy products!

v  Exercise!

v  If things get serious, consult your doctor.

 One last word of advice, don’t worry, we all go through the same.
 
PSB

Thursday 10 December 2015

#68 Почему мы потеем? (Why do we sweat?) (Russian)

Почему мы потеем?


Потливость - проблема каждого человека, но далеко не каждый знает почему мы потеем. А вам никогда не хотелось узнать почему это происходит с нами каждый день и как это можно предотвратить различными способами?

Что такое при и как он образуется?
Пот – это жидкость сложного состава. На 98-99% он состоит из воды, но кроме того содержит азотистые вещества. Пот выделяют специальные железы, расположенные на коже. Их делят на эккриновые и апокриновые.

Работу потовых желез регулирует нервная система. Терморецепторы кожи, внутренних органов и мышц реагируют на жару, съеденный горячий суп, перегрев организма при тяжелой физической работе или при лихорадке. Сигнал, полученный от этих рецепторов, проходит непростыми нервными путями через мозг и достигает, наконец, нервных волокон, которые стимулируют секрецию пота в железах. Вся эта деятельность происходит без сознательного участия человека; он не может силой мысли заставить пот литься ручьем или высохнуть. 
 

Откуда берётся неприятный запах?
Сам по себе пот апокриновых желез не имеет запаха, но он содержит относительно много липидов. Жирная и вязкая жидкость служит питательной средой для бактерий, чаще всего стафилококков. Они разлагают органические вещества пота, а также отмирающие клетки на поверхности кожи вблизи потовых желез. В результате деятельности бактерий образуются ненасыщенные жирные кислоты и соединения аммиака, которые неприятно пахнут. А если человек налегает на специи, лук и чеснок, его пот будет пахнуть еще резче. Неприятный запах могут вызвать и некоторые лекарства, например, препараты, которые содержат серу.

Зачем же нам потеть?
 потения несколько функций, но самая главная – терморегуляция. Выделенный железами пот испаряется и охлаждает тело.
 потовых желез есть и другое назначение – они выводят из организма токсины и продукты обмена. С потом человек избавляется от ртути, мышьяка, железа, ядов и некоторых лекарств. На этом, в частности, основан лечебный эффект парной и бани. 

Как уменьшить потливость и избавится от столь неприятного запаха?
1.    Самый очевидный и распространённый способ это использование дезодорантов. Однако это может быть не всегда настолько эффективно на сколько бы нам хотелось. В этом случае стоит соблюдать некоторые правила которые непременно помогут вам:

   Диета - не стоит употреблять продукты содержащие кофеин и теобромин, так как эти вещества стимулируют потоотделения.

   Соблюдение гигиенических правил - желательно принимать душ два раза в день и избегать синтетической одежды.

2.    Электрофорез - сеансы должны проводиться раз в неделю и хороший эффект будет заметен чек 8-9 сеансов.

3.    Использование инъекций ботулотоксина А - даёт отличный эффект, но необходимо делать повторные инъекции раз в 6-8 месяцев.

4.    Если у вас чересчур обильная потливость, то вы можете рассмотреть вариант операции что бы решить вашу проблему. Например, различные виды кюретажа подмышечной впадины. Это выскабливание кожи изнутри через небольшой разрез. Показан кюретаж при изолированном подмышечном гипергидрозе. У большинства пациентов происходит прекращение или значительное снижение потоотделения. Со временем (после 6 месяцев) потливость может восстановиться.
 
KAA

#67 Болезнь Альцгеймера (Alzheimer's disease) (Russian)

Болезнь Альцгеймера
Что это такое?
Болезнь Альцгеймера — нередко в разговоре ее не совсем верно называют старческим маразмом, — это болезнь, при которой определенные системы клеток мозга (нейронов) как бы отмирают, что приводит к развитию старческого, или сенильного слабоумия (деменции). 

Болезнь Альцгеймера является наиболее частой причиной слабоумия, развивающегося в пожилом и старческом возрасте. Первые симптомы могут появиться уже после 40 лет, а после 70-летнего возраста частота заболевания доходит до 30%. 

Это заболевание чаще наблюдается у людей малообразованных, с неквалифицированными профессиями. У человека с высоким интеллектом меньше шансов столкнуться с проявлениями болезни Альцгеймера по той причине, что у него существует большее количество связей между нервными клетками. А значит при гибели одних клеток утраченные функции могут передаваться другим, которые ранее не были задействованы. Чаще возрастное слабоумие поражает женщин — возможно, причина этого кроется в большей продолжительности жизни женщин: многие мужчины просто не доживают до болезни Альцгеймера. 

От чего это бывает?
При болезни Альцгеймера в головном мозге происходит отложение белка в виде «сенильных бляшек» и образование так называемых нейрофибриллярных клубочков, состоящих из поврежденных нейронов, — оба этих процесса ведут к разрушению нервных путей мозга.
 
Пока до сих пор не выяснено, что же конкретно вызывает эти изменения, однако в последние годы ученым удалось выделить специальные гены, ответственные за предрасположенность человека к болезни Альцгеймера. 

Что происходит?
Болезнь начинается с нарастающих нарушений памяти. Ранняя стадия может остаться незамеченной для окружающих, поскольку человек, отметив у себя первые симптомы заболевания, всячески пытается скрыть их. С нарастающей потерей воспоминаний появляется чувство растерянности, непонимания, недоумения. Постепенно человек перестает ориентироваться в месте и времени, из его памяти выпадают накопленные знания, опыт, навыки, причем забываются сначала ближайшие по времени события, а потом более отдаленные. Нарушается узнавание формы, цвета, лиц, чувство ориентации в пространстве. Это может сказываться, например, в беспорядочности и асимметрии почерка: буквы скапливаются в центре или в углах страницы, по вертикали. Речь становится все более непонятной. 

Когда заболевание начинает прогрессировать, нужно использовать любую возможность, чтобы поддержать способность больного к самообслуживанию, уменьшить его изоляцию от окружающих, постараться предупредить развитие депрессии. Например, могут помочь новые, лучше подобранные очки, более совершенный слуховой аппарат, простой в обращении радиоприемник, книги с картинками и крупными буквами. 

Лечение
Специальных препаратов, излечивающих болезнь Альцгеймера, пока не существует. Однако есть лекарства, которые облегчают проявления болезни и существенно сдерживают ее развитие.
 
KAA

Tuesday 24 November 2015

#66 Albinism (English)

Albinism


Otherwise known as achromia, achromasia, or achromatosis, albinism is a genetic condition characterized by a deficit in the production in melanin resulting in the partial or complete absence of pigment in the skin, hair and eyes. This hereditary disease can be found in humans, mammals, birds, fish, reptiles and amphibians. Despite the fact that albinism is a hereditary condition, in most cases, there's no family history of it. People with albinism often have vision problems and are vulnerable to sunburns and skin cancers if they do not protect themselves well enough. According to The National Organization for Albinism and Hypopigmentation, one in every 17,000 people in the United States has some type of albinism.

Oculocutaneous albinism is used to refer to people with little or no pigmentation in their eyes, skin and hair. Little or no pigmentation in the eyes alone is known as ocular albinism. An individual with complete absence of melanin is called an albino. One with only a small amount of melanin is described as albinoid. People with albinism are very pale with fair hair and very light eyes. In some cases, the eyes appear red or purple as the iris actually has so little color that  blood vessels inside of the eye show through. Hence why the main test for albinism is an eye test.

A person with albinism is generally as healthy as the rest of the population. However, problems with vision and skin are particularly common. Vision problems result from abnormal development of the retina and patterns of nerve connections between the eye and the brain. The lack of pigment in the eyes results in problems with eyesight leading to discomfort in bright light. Concerning the skin, the lack of melanin, which helps protect the skin from UV radiation, means that their skin can burn more easily. Precautions, such as applying lots pf suncream and staying covered, need to be take to avoid damage to the skin caused by the sun.

Albinism is caused when a person inherits one or more defective genes that cause them to be unable to produce the normal amounts of a melanin. Melanin is a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for the tanning of skin when exposed to sunlight.

Researchers have identified several genes that result in albinism. The genes are located on "autosomal" chromosomes - chromosomes that contain genes for general body characteristics. Genes carry the information that makes you an individual. Albinism is a "recessive trait" - a person without albinism can carry the albinism trait. Both parents must carry a defective gene to have a child with albinism. When neither parent has albinism but both carry the defective gene, there is a 25% chance that the baby will be born with albinism.

Individuals with this condition are often outcasted and misunderstood by society. They can be the center of ridicule, fear and even violence.
 
McA

Sunday 22 November 2015

#65 Cloning (English)

Cloning

To clone is to make an identical copy of. Now, cloning isn't as futuristic as people often believe it to be. When people think of cloning they often picture someone entering a machine and exiting with a twin by their side. This however is not the case.
 
In biology, a clone is a group of genetically identical organisms or a group of genetically identical cells derived from a single parent cell. The first mammal to be cloned from an adult somatic cell using the process of nuclear transfer was Dolly the sheep. Nuclear transfer is a two-part process where scientists first remove the nucleus from an egg which they then replace with the nucleus of an older donor cell. A new clone is formed when the egg starts to divide. Dolly was cloned by taking udder cells from a donor sheep. These cells were cultured in a low nutrient medium to make the genes switch off and become dormant. An unfertilized egg was taken from another sheep and its nucleus was removed by using a micropipette. The egg cells were fused with the udder cells using a pulse of electricity. The fused cells developed like normal zygotes and became embryos. These embryos were then implanted into another sheep who’s role was to be the surrogate mother. One lamb was born successfully and called Dolly. Dolly was genetically identical to the sheep from which the udder cells were taken.
 
Human cells can also be cloned however several ethical issues are raised when it comes to it. For example, embryonic stem cells can be used for therapies that save lives and reduce pain for patients. Cells can also be taken from embryos that have stopped developing meaning they would have died anyway and they are taken at a stage when the embryos have no nerve cells and therefore can not feel pain. Nonetheless, every human embryo is a potential human being and should be given the chance of developing. Not to mention there is an abundance of embryos produced and so many are killed. Finally there is a risk of embryonic stem cells developing into tumor cells.
 
In my opinion cloning is useful to a certain extent. However when it reaches a point where scientists get to decide the outcome of a certain organism then something needs to be done. Otherwise all sense of individuality will be gone and nothing will be down to chance. We will live in a society where everything is planned and imperfection ceases to exist. Not only this but cloning can still go wrong and lead to further complications. For example, cloned animals that survive tend to be much larger at birth resulting in breathing problems. On the other hand some argue that scientists and doctors should not "play God," however aren't we technically already playing God by curing disease and implanting embryos? In saying this, how is cloning any different?

To conclude the concept of cloning is still relatively new and futuristic as well as controversial. Several ethical issues come in to play when the subject is brought up, however it definitely has its strengths and weaknesses.
 
McA
 


Saturday 21 November 2015

#64 Sharks can't get cancer? (English)


Sharks can't get cancer?

Although it is not true that sharks do not develop cancer, they do have a remarkable cancer shield. Tumors are uncontrolled cellular growth and to support their very high metabolism, they secrete a hormone called 'angiogenin.' This causes nearby blood vessels to grow new branches that surround the tumor, bringing in nutrients and carrying away waste products. A part of the tumor then breaks away and establishes another cancerous colony elsewhere in the body. Research has revealed a promising anti-tumor agent obtainable from shark cartilage. Shark cartilage contains a compound opposed to the effects of angiogenin, called 'angiogenin inhibitor.' This prevents the formation of new blood vessels so that the proto-tumor 'chokes' in its own waste products.

Sharks seem to possess only one class of broad-spectrum serum antibody - similar to that found in human infants. An antibody is a blood protein produced in response to a specific antigen. In humans, this broad-spectrum class of antibody is replaced by more specific antibodies as the child matures and is exposed to a greater variety of pathogens. Sharks however keep their non-specific immune response throughout their lives. This generalized immune system is one of the reasons sharks are able to detoxify many potentially harmful compounds quickly without need of previous exposure. It has even been suggested that sharks may be helpful in our fight against HIV and AIDS. This was originally disregarded as no one could see why a shark would develop a response to something it is very unlikely to encounter. 

Finally, Sharks have all the internal organs one would expect of a gill-breathing vertebrate as well as something 'extra' called an 'epigonal organ'. This lies underneath each of the kidneys and is quite unique to elasmobranchs (cartilaginous fish.) The epigonal organ seems to be composed of lymphoidal tissue and seems to be concerned with hemopoetic functions. Recent data also indicates that the organ is the site of T-cell differentiation in elasmobranchs, playing an important role in the immune system of these fishes. Without long bones to serve as a site for leucocyte development, sharks have jury-rigged a scrap of available tissue to bear that function.

McA

Thursday 19 November 2015

#63 Sexually transmitted diseases (English)

Sexually transmitted diseases

Sexually transmitted diseases (STDs) are diseases transmitted through sexual activities. They are transferred through the exchange of bodily fluids or by direct contact with the infected area. They can however be prevented from the use of protection during intercourse. Condoms, for example, are highly effective when it comes to preventing disease. Herpes, gonorrhea and chlamydia are all types of STDs.  

Herpes is identified by painful blisters of the mouth or genitals. It is caused by two types of herpes simplex virus (HSV.) HSV enters the body through a mucous membrane or a small opening in the skin. Although the virus is most contagious through direct contact with herpes sores, it can also be transmitted through saliva. After the primary infection, the herpes virus travels along the nerves and becomes dormant within nerve cells. It is reactivated during times of stress where it travels back out through the same pathway, causing recurring blisters. Antiviral drugs can help people with herpes to stay outbreak-free for longer.

Gonorrhea is caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in mucus membranes of the body in the warm, moist areas of the reproductive tract. In women symptoms include whitish discharge from the vagina, pelvic pain, burning when urinating, bleeding between periods and several others. Men also experience a whitish discharge from the penis, a burning sensation when urinating and painful or swollen testicles. Symptoms for men usually appear two weeks after infection. However with women some symptoms are so mild that they go unnoticed. Gonorrhea can be treated with antibiotics and other medication. 

Chlamydia is easily spread and often goes unnoticed. Abnormal vaginal discharge that may have an odor, bleeding between periods and pain when having sex are all symptoms of chlamydia in women. In men painful urination, burning and itching around the opening of the penis and swelling around the testicles are all common signs. Once again this disease can be treated through the use of oral antibiotics.

Sexually transmitted diseases however can be prevented through the practice of safe sex or just refraining from any sort of sexual intercourse. Another way to keep safe is not sharing towels or underclothing as well as getting a vaccination for hepatitis B.
 
McA

Thursday 12 November 2015

#62 Why do we shiver? (English)

Why do we shiver?

Its well-known that we shiver when we are cold but why do we shiver? Is there a specific and biological reason why we shiver?

The answer is yes! The human body needs to be at a constant temperature of 37 degrees Celsius in order for us to work properly. Your brain has a gland called the hypothalamus gland which helps control your body temperature. In order to prevent things such as hypothermia and other diseases, your brain must be very careful with your body temperature. Your skin contains receptor cells which send messages to your brain telling your brain if your body temperature to go up or down and uses different tacts to do this.

Shivering is a tactic your brain uses in order to keep your body temperature at 37 degrees Celsius. In order to shiver, your muscles contract and relax very quickly repeated times. Twitching enables your muscles to produce heat which will in turn make your body temperature warmer. Your brain sends signals and some of these signals may also go to your jaw which is why, sometimes, your teeth start to chatter as your whole body are getting signals and some may get sent to your jaw. When your muscles produce heat, your muscles release the hormone Irisn which helps to heat your core temperature back to 37 degrees Celsius.

Some may argue that shivering is the opposite as sweating, which in fact, it is! Instead of helping you cool down like sweating does, shivering helps you warm up meaning that it helps your core temperature heat up.

This is why, next time you feel shivers down your spine, it may mean that you should grab another sweater and sit by a fire!

Resources:
http://www.livescience.com/32475-why-do-we-shiver-when-cold.html
http://blog.zocdoc.com/shiver-cold-weird-science-daily-life/

PRM

Tuesday 10 November 2015

#61 Why does food taste different on airplanes? (English)

Why does food taste different on airplanes?

We have all at in point in time complained about the bland, sometimes disgusting food on an airplane. Many people think that it’s due to the low cost food that the airline provides, but recent studies suggest that might not be the case at all. Ever noticed how your ears pop when you reach a high altitude? Well, that’s not the only thing that changes in your body. Your taste buds change when you take off too! This is due to low air pressure so it can affect the way things taste? Also sense of smell and background noise can effect flavor perception.

Your sense of smell is directly related to the humidity in the cabin. This means that when you take off and air pressure decreases, so does humidity. At worst the air can be drier than the desert, causing your taste buds to be less sensitive to sweet and salty foods, whereas bitter, spicy and sour  foods are not changed that much. Also, smell can affect how a food tastes. Smell relies on nasal mucus, but in a dry plane there is less, which affects the smell of the food. Ultimately what you smell is what you taste, so the taste of the food can be perceived differently. Airlines try to combat this problem by using more salt, sugar and spices to food (this is often why airline food is not the healthiest) so foods such as curry can be more flavorful in the air. Just remember this the next time  you fly: having slightly less salty, sweet or flavorsome food is a very small price to pay for being able fly across the globe so quickly and if you really can stand airplane food, wait until the flight has ended and your taste buds have gone back to normal before enjoying a meal!

SJS

Monday 9 November 2015

#60 Why does plastic degrade slower than other substances (English)

Why does plastic degrade slower than other substances

                  An important definition to know when talking about degrading is the term, biodegradable. Biodegradable means materials that can be broken down by microorganisms into organic matter. For example, vegetables may degrade in a month or so, while metals might take longer than a month. This shows that one of the factors affecting biodegradability is the type of material that makes up the object. Another factor affecting biodegradability is the environment. Air, water, and light all affect the biodegradability. In the case of plastics, they are not affected by air, water, or light, and therefore do not biodegrade to any significant degree. One of the reasons that plastics degrade slowly, is because the links joining the atoms are linked more intricately. In things like wood or cotton, the atoms are linked to each other naturally, therefore allowing bacteria to easily break down the links. The conditions for plastic to decompose is limited to ultraviolet light or heat, neither of which are found naturally in landfills where plastic is discarded after its use.
             When we normally consider biodegradables, we think of the materials degrading in landfills. However, it has recently been found that certain plastics degrade in water. Not only that, but they also break down within a year of contact with water. Although this may seem positive for people finding ways to speed up the degradation of plastic, it poses a threat to the underwater ecosystems. The plastics that break down in the water are made up of a molecule called polystyrene, a chemical pollutant. The plastic not only releases this dangerous molecule into the water, it also introduces chemicals not found near the water, to the water. These chemicals have the power to create cancer in humans, and simpler creatures in the water may be more susceptible to these harsh chemicals. In the food chain, the animals at the top would be consuming the highest amount of these dangerous chemicals, potentially threatening the entire ecosystem as we know it.
PoS