Author Archives: Kamyar Kazemiashtiani

How does our immune system work ?

We are constantly encountering pathogens (anything that can cause disease), so why don’t we become sick more often?
The answer to this question is our immunes system, which is responsible for protecting us from diseases.

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                                     The immune system
                      Credit: In a nutshell – Kurzgesagt

From a scientific point of view, the immune system includes many biological structures and processes that an organism has in order to response to diseases that come from bacterial or viral infections.
The immune system reacts to diseases with layered defenses of increasing specificity. There are two lines of defenses in our body: 1- innate defenses, 2- adaptive defenses

Cells of Immune system      Credit: Wikimedia

The innate defenses include two major parts. In the first part, there are physical barriers such as a tough outer skin, mucous membranes and secretions that are all impenetrable to viruses and bacteria. In the second part, which is more detailed, body protects itself by phagocyctic cells and natural killer cells, which are white blood cells. In addition to these white blood cells, complement proteins and the inflammatory response (swelling, fever and redness) also play important roles in this kind of defense.
After innate defenses, there is a more specific line of defense, which is called adaptive immune response. This kind of defense provides immunity against particular pathogens that the innate immune response is not able to kill and remove them. T cells and B cells are lymphocytes that play the most important role in the adaptive immune response.
B cells respond to presence of pathogens by recognizing them, secreting antibodies which are types of proteins that bind to pathogens and inactivate them and create the memory of them.
The last part of the adaptive immune response is T cells. These cells have receptors on their surface and use them in order to recognize infected cells, kill invaders and stimulate more B cells.

Adaptive immune response        Credit: Wikimedia

Kamyar Kazemiashtiani

Possibility of Life in Mars

Mumma, Michael J. in the article “The Search for Life on Mars” states that because of considerable similarities of earth and mars, it may be possible that life exists in some forms in Mars. Although, up to now, there has been no evidence to prove the idea of existence of life in Mars, recent discoveries propose that Mars was once habitable.

Credit: Wikimedia

Scientists have conducted several investigations and researches in order to prove the possibility of life in Mars. Finding factors that are vital for the possibility of life, has been the most important goal for NASA. For example, NASA has done many studies by “Mars curiosity rover” and “Mars opportunity rover”.
For this purpose, scientists use an approach that includes 19 or 20 abiotic factors, with an emphasis of availability of liquid water, presence of nutrients, temperature, sources of energy and protection from cosmic radiation.'s_Concept,_Wide.jpg’s_Concept,_Wide.jpg

                      Curiosity Rover
                    Credit: Wikimedia

Some liquid water may flow on Mars surface, this can happen only under very specific conditions. Due to the atmospheric pressure of Mars water evaporates or freezes quickly. Therefore, it is very hard to find liquid water on Mars.

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                          Water Flowing on Present-day Mars
                                                 Credit: NASA

As we know existence of elements including: carbon, nitrogen, oxygen, hydrogen, phosphorus and sulfur are necessary for life. Many. Studies have shown that these elements are present in surface of Mars in some rocks. In turn , this can lead to an increase in possibility of life.

Another parameter that contributes to the possibility of life Mars is energy needed for metabolism. This can either be met by solar energy or geochemical energy.

Temperature also plays an important role in possibility of life. Because of loss of atmosphere in Mars, temperature has decreased significantly during the time.

Finally, because there is no global magnetic field in Mars to protect the planet from the life-threatening cosmic radiation, existence of life may not be probable.

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                                      Wind and radiation on Mars
                                                     Credit: NASA

To sum up, because there is lack of factors that are essential for existence of life in Mars, the idea of existence of life in Mars has a long way to go. However, with advancements in technology, we can hope to discover more evidence needed for life in Mars.

Kamyar Kazemiashtiani

How to Stop Global Warming

Global warming is one of the biggest problems that human beings have ever experienced. This problem has numerous negative impacts on our health and economy . Therefore, it seems necessary for us to find ways to tackle this problem.

First of all, we should know the clear definition of global warming.

According to “Annex II Glossary” Intergovernmental Panel on Climate Change (IPCC), Global warming is a phenomenon that is caused by increas in Earth’s average surface temperature because of the effect of greenhouse gases such as CO2, which prevents heat to escape from the Earth.

Because global warming has so many catastrophic results on environment, it is important to identify the reasons for it and realize how to combat this phenomenon . The first reason is because of the greenhouse gases effect ; absorbing heat by these gases from the surface and the emitting it back to the surface lead to warming the the surface and lower atmosphere . Furthermore, scientists believe changes in solar radiation and variations in Earth’s orbit are other reasons.
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       Global Warming
       Credit : National Geographic

Scientists have realized some practical ways to combat this unsolved issue.

Reducing tropical deforestation can have a significant effect in lowering emissions that are the causes of global warming. Because CO2 is the most important greenhouse gas, stopping deforestation and planting trees can have a major effect on reducing the global warming. This is due to the fact that plants take carbon dioxide in and then release oxygen to their environment. Therefore, planting new trees could be a positive approach.

                                Credit : Wikipedia

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          Deforestation and Global Warming
           Credit : VOA News

Another solution to global warming is reducing the waste that we produce. Disposal of waste can produce combination of several greenhouse gases that are the main reasons for climate change. For example, methane that is one of the most important greenhouse gases which is produced when organic matters decompose in landfills. Recycling items such as plastic, paper and glass can significantly reduces the amount of emissions .

                     Wastes and Dirty River
                     Credit : Wikipedia

Our personal cars are considered to be the most significant source of the greenhouse gases that are in troposphere. For example, emissions from cars and trucks in The United States of America account for 20% of all emissions. So, we can contribute to reduce greenhouse gases in some ways including: travelling by public transportation and driving smart .

                 Credit : Wikipedia

Since consumption of fossil fuels is the reason for releasing carbon dioxide and other greenhouse gases to atmosphere, it seems necessary to find other ways to generate energy. Renewable energies such as solar power, wind and geothermal heat are the most striking examples of clean and sustainable alternative energies. With using these energies, we can combat global warming by the reduction of carbon dioxide emissions.

                               Wind Power
                              Credit : Pixaby

By using mentioned solutions and the modern technologies that we have, we can reduce the amount of heat-trapping gases in the atmosphere.

Kamyar Kazemiashtiani