How Octopuses Are Able to Taste by Touching

Giesen et al.Molecular Basis of Chemotactile Sensation in Octopus. Cell, October 2020.

Octopuses have often captured human interest with the ability to use their eight suction-cup covered tentacles for touch and taste. Scientists have wondered for decades how their appendages work but very few have studied what happens on a molecular level. In a new report, researchers got a glimpse into how the nervous system in an octopus’ tentacles manage these functions. They identified a novel family of sensors in the first layer of cells inside the suction cups that have adapted to react and detect molecules that do not dissolve well in water. The chemotactile receptors on these sensory cells use those molecules to help the animal figure out what it is touching and whether or not that object is prey. This allows an octopus to distinguish between a rock versus a tasty crab. The underlying mechanism is that there are two types of sensory cells in the suckers that line their tentacles: mechanosensory cells for touch and chemosensory cells for taste.  Both taste- and touch-oriented cells are critical for helping octopuses to decide when to hunt and when to retreat. It is well known that particles on land easily travel through the air before they might be sniffed by a bear or a wolf’s nostrils. However, the process of smelling or tasting is much less clear in cephalopods that live in the ocean. Some chemicals can travel far from their underwater source and thus make it possible for some creatures to catch a smell of their prey from afar. But for chemicals that don’t move through the ocean easily, a touch-taste strategy can be useful for marine animals, including octopuses. While people tend to perceive five basic tastes – sweet, bitter, sour, salty and umami (meaty) – octopuses experience the world of taste differently. Instead, scientists found the most success by stimulating octopuses to respond to what are called terpenoid molecules, a secretion that is often released by marine invertebrates that functions as a defense or warning signal. They smell these molecules and can, in a way, smell fear in their prey.

Natural Forest Regrowth May Be the Best Method to Combat Climate Change

Cook-Patton et al. Mapping carbon accumulation potential from global natural forest regrowth. Nature, September 2020.

Reforestation has been considered the leading strategy in the fight to mitigate the effects of climate change with previous studies highlighting the role it can play in capturing and storing atmospheric carbon. There are many ways to incorporate trees into our landscapes, however one of the cheapest and easiest options is to allow forests to regrow on their own if conditions can permit them to. Now, a new study has mapped the potential carbon accumulation in naturally regrown forests over the next 30 years. Researchers from 18 countries brought together more than 13,000 georeferenced measurements of carbon accumulation to generate a wall-to-wall, one-kilometer-resolution map spanning 43 countries that highlights areas with the greatest carbon returns if trees were allowed to reforest naturally. The team demonstrated that natural forest regrowth can capture up to 23 percent of global carbon dioxide (CO²) emissions from the atmosphere every year. This is on top of the carbon sequestration already provided by existing forests, which absorb around 30 percent of annual CO² emissions. The biggest advantage of natural restoration of forests is that it often requires nothing more than human inaction. Nature is constantly at work doing its duty to restore forests often unseen on the edges of fields, on abandoned pastures, and wherever forests lie degraded or former forest land is abandoned. Moreover, natural forest regrowth may promote the re-establishment of local tree species that are best equipped to survive in a given location and support the many organisms that eat them or dwell amongst their branches and roots.

However, natural regrowth may not always be the answer. For example, at sites that are highly degraded, or seed sources are far away, actively planting trees can help to start or speed recovery while helping to establish the right species mix for current and future conditions. While planting trees can sometimes be necessary it should usually be the last option since it is one of the most expensive and often least successful methods of combating climate change. It is estimated that humanity should collectively plant about a trillion trees over the next three decades to effectively fight climate change, which averages out to about a thousand new trees planted in the ground every second and assumes that every tree survives and grows in a healthy manner. Once the cost of nurseries, soil preparation, seeding, and thinning are accounted for, it would easily cost hundreds of billions of dollars. If natural forest growth is cheaper and better then why not work to protect the existing trees and let forests to grow on their own?

Li et al. Innate connectivity patterns drive the development of the visual word form area. Scientific Reports, October 2020

A new study suggests that humans are born with a part of the brain that is prewired to be receptive to seeing words and letters. Researchers analyzed brain fMRI scans of 40 newborns and found that the “visual word form area” (VWFA) was already connected to the language network of the brain, which is akin to the scans of 40 adults. These findings are quite surprising considering some researchers had hypothesized that the pre-reading VWFA starts out like any other part of the visual cortex that are sensitive to seeing faces, scenes, or other objects and only becomes selective to words and letters as children learn to read or at least as they learn language. However, a new study shows that even at birth, the VWFA is more functionally connected to the language network of the brain than it is to other areas. It is likely that experience with spoken and written language will strengthen connections with specific aspects of the language circuit and further differentiate this region’s function from its neighbors as a person gains literacy. The main goal of this study is to learn how the brain becomes a “reading brain” and to help understand the differences in reading behavior, which could become useful in the study of dyslexia and other developmental disorders.

“Free radicals” are a special type of atom that have been linked to many age-related diseases. They form as a result of a process called Oxidative Stress, which takes place when an oxygen molecule splits into single atoms with unpaired electrons. The nature of electrons is such that they like to be in pairs and as a result will “freely” and “radically” search throughout the body for another electron to pair with. They could almost be considered romantic if they were not so dangerous!

Their main danger comes from the damage that they cause to cells or cell membrane, proteins, and DNA. Cellular damage occurs when free radicals travel through cells and disrupt the structures of other molecules. The gradual accumulation of them, and the increased damage that builds as more and more of them collect, is what helps cause many of the aforementioned aging diseases. Our body is under constant assault from oxidative stress, and cells may function poorly or die if it occurs too frequently and without proper bodily maintenance.

Free radicals are a waste byproduct that form as a result of various chemical reactions that take place during our bodies’ normal metabolic processes. They are then “dumped,” and their eventual buildup will often harm our bodies much like how factory waste harms the environment However, they are not entirely useless; it is impossible for our bodies to turn air and food into chemical energy without a chain reaction of free radicals. Free radicals are also a critical part of the immune system, as they additionally move through our veins and can confront foreign invaders [1].

What are free radicals?

Understanding free radicals necessitates an elementary knowledge of chemistry.

Electrons orbit around atoms in levels called shells. Each shell is filled by a fixed number of electrons, and when the first shell is full then electrons will start to fill the next shell.

If there is an atom whose outer shell is not full then it may bond with another atom by using the electrons to fill its outer shell. These types of atoms are known as free radicals.

Atoms that have a full outer shell become stable, however free radicals are unstable. They are “desperate” to acquire the full number of electrons that are necessary to fill all of their shells and will therefore react quickly with other substances.

Take the example of oxygen molecules. If they split into single atoms that have unpaired electrons then they too will become unstable free radicals that seek other atoms or molecules to bond to. If this procedure continually occurs, then it will begin a process called oxidative stress.

Smoking, UV rays, air pollution, fast food, pesticides, ionizing radiation, drugs, and inflammation have all been linked to the formation of free radicals. We must be diligent when it comes to understanding how these influences can affect our bodily health, and then fight back with natural antioxidants.

Free radicals are heavily linked to aging

One of the effects of oxidative stress is that it can damage our body’s cells and thus promote many of the diseases and symptoms related to aging, such as wrinkles and gray hair. They will take electrons from other atoms in order to become more stable, a process that may cause diseases or signs of aging [2].              

In 1956, the “Free Radical Theory of Aging” was outlined as a way to understand how exactly our bodies age over time. Everybody ages, and as we age our body loses its ability to fight the effects of free radicals. Over time our bodies produce more free radicals and more oxidative stress, which increases the rate at which cells are damaged and thus can bring about degenerative processes.

Many age-related diseases such as muscular degeneration, certain cancers, atherosclerosis, cardiovascular disease, emphysema, Alzheimer’s disease, Parkinson’s disease, ulcers and all inflammatory diseases such as arthritis and lupus, and many others are linked to free radicals. Free radicals can be found in the food we eat such as fried foods, the medicines we take, the air we breathe, and the water we drink. Free radicals are also found in alcohol, tobacco smoke, pesticides, and air pollutants.

Several studies and theories have been linked to oxidative stress and the buildup of free radicals including: [3]

• Genetic degenerative diseases, such as Huntington’s disease or Parkinson’s
• Age-related changes in appearance, such as loss of skin elasticity, wrinkles, graying hair, hair loss, and changes in hair texture
• Cataracts and age-related vision decline
• Diabetes
• Cancer, which is associated with chromosomal effects and oncogene activation due to the reaction of free radicals [2]
• Central nervous system diseases, such as Alzheimer’s and various forms of dementia
• Cardiovascular diseases due to clogged arteries
• Autoimmune and inflammatory disorders, such as rheumatoid arthritis and cancer

The free radical theory of aging is comparatively new; however, several studies boost its credibility. Researchers focused on cell’s mitochondria, the “powerhouse” that process nutrients to power the entire cell. Experiments on rats, for example, showed a noteworthy increase in free radicals as the rats aged. These alterations coincided with age-related declines in their health. These experiments also showed that free radicals produced in the mitochondria harm the substances that the cells need in order to work properly. This damage causes mutations that produce more free radicals, thus accelerating the process of damage to the cell. This helps explain aging since aging quickens over time. The gradual, but increasingly rapid buildup of free radicals, offers one explanation for why even healthy bodies age and depreciate over time [2].

Antioxidants can stave off free radicals

Antioxidants, molecules that prevent other molecules from oxidizing and thus undergoing oxidative stress, can help to avert the harmful effects of free radicals. They can also decrease or even nullify the effects of free radicals, as they can provide an electron to free radicals and thereby reduce their reactivity. The uniqueness of antioxidants is that they can donate an electron without becoming reactive free radicals themselves.

There is no single antioxidant that can combat the effects of every free radical. Free radicals have different effects in different areas of the body, and every antioxidant performs differently due to its chemical properties. Antioxidants such as vitamins C and E, beta-carotene, glutathione, and plant estrogens called phytoestrogens all scavenge the body and help remove free radicals. Honey can also function similar to antioxidants by removing free radicals. Additionally, selenium, a trace metal that is required for proper function of one of the body’s antioxidant enzyme systems, is sometimes included in this category. The body cannot manufacture these micronutrients so they must be supplied in the diet.

Foods that are rich in antioxidants include citrus fruits such as oranges and limes, berries, and many other fruits that are rich in vitamin C. Carrots are known for their high beta-carotene content, while the soy in soybeans, and some meat substitutes, are high in phytoestrogens. Apricots, spinach, mangoes, pumpkins, broccoli, and eggplants are all also helpful, along with a plethora of other fruits and vegetables [4].

More research needed

A 2010 study on antioxidant supplementation for the prevention of prostate cancer found no benefits. Furthermore, a 2012 study found that antioxidants did not lower the risk of lung cancer. On the other hand, the study found that people who were already at a heightened risk of cancer, such as smokers, actually had a slightly elevated risk of cancer due to antioxidants.

Some investigators have found that supplementation with antioxidants is injurious when people take more than the recommended daily allowance (RDA). A recent analysis found that high doses of beta-carotene, or vitamin E, appreciably increased the risk of dying. One study found that long-term use of beta-carotene could reasonably reduce the risk of age-related mental problems [4]. But perhaps one of the most important discoveries is that antioxidants are unable to “cure” the effects of free radicals completely [5].  

Additionally, we do not yet fully understand why free radicals form in the first place. They may result as an early sign of cells fighting diseases, or that free radical formation is simply a natural expectation that comes with aging. It is not possible to understand them completely without more conclusive research, which should be encouraged considering the significant impacts that free radicals can have upon our bodies.

References

1. https://www.rice.edu/~jenky/sports/antiox.html
2. https://www.medicalnewstoday.com/articles/318652#How-do-free-radicals-damage-the-body
3. http://www.mytruehealth.info/mytruehealth_antioxidants_freeradicals.html
4. https://www.medicalnewstoday.com/articles/318652#Antioxidants-and-free-radicals
5. https://www.medicalnewstoday.com/articles/318652#What-we-do-not-know

“There was a footpath leading across the fields to New Southgate, and I used to go there alone to watch the sunset and contemplate suicide. I did not, however, commit suicide, because I wished to know more about mathematics.”
-Bertrand Russell, Nobel Laureate and Mathematician

It is mystical when you step outside on a snowy morning. Snowflakes are swirling around the vast sky and falling and blanketing the ground. If a snowflake lands on you, it is like a winter angel. There are no flowers around, for they cannot survive the cold; yet what lies before your eyes is an incredible beauty. And it’s remarkable, you come to realize, that no two snowflakes are alike. It is as if the uniqueness of a snowflake is controlled by a divine force. The individuality of a snowflake’s structure draws a parallel to human life. Like snowflakes, everyone has a unique story to tell.

I am not the only one who ponders about snowflakes; many mathematicians do the same. Actually, they think about the characteristics of snowflakes because they are particularly important for three basic mathematical principles: pattern, symmetry, and symmetry breaking.

A little-known scientist, Wilson Bentley, a.k.a. “the Snowflake Man” took pictures of snowflakes almost every day and observed them until he died. You can buy his book about his work on Amazon. If you wish to know why he did it, read about it at snowflakebentley.com.

“Under the microscope, I found that snowflakes were miracles of nature; and it seemed a shame that this beauty should not be seen and appreciated by others. Every crystal was a masterpiece of design and no one design was ever repeated. When a snowflake melted, that design was forever lost. That beauty was gone, without leaving any record behind.”
-Wilson Bentley

When I checked the Oxford dictionary, there were 3 definitions for the word “pattern.” Two of these definitions [listed below] are important for this article.

Pattern: 1. A repeated decorative design; 2. An example for others to follow.

When we check the pictures and delve deeper into each snowflake, we will see that the structures of the snowflakes are totally different. However, they have something in common: symmetry and a hexagonal structure.

These perfect ice crystals are genuine, even though it is hard to believe they are not fake.

When I take a close look at a snowflake, the beauty of the combination of ice molecules fascinates me every time; each flake is unique. However, uniqueness is not the point here. The things that make snowflakes important objects for mathematicians are their symmetry and their hexagonal structure. Math-loving people have a lot of interest in transformations. They love moving objects. And, surprisingly, if an object is symmetric, transformations are not even noticed by many.

To be more precise, when you have a hexagonal symmetric snowflake, or any other symmetrical object, when you rotate it in any direction, 60°, 120°, 180°, 240°, 300°, or 360°, people watching you wouldn’t realize it. If you check the images below, you will see rotated shapes but no difference. It appears to be the same shape in exactly the same place.

1- Counterclockwise rotation by 120°

2- Reflection through a vertical axis

3- Reflection axes of a snowflake[1]

Snowflakes also possess reflectional symmetry. If we stand in front of a mirror, our reflection looks exactly the same. Hence, if we put a mirror in the middle of a snowflake, there will be a reflection. For a snowflake, we can put a mirror 6 different ways. Thus, we can say that a snowflake has 12 symmetries: 6 from reflections, and 6 from rotations.[2]

Now we can define symmetry as a transformation that leaves things unchanged. We can also claim that a combination of any of the transformations will give us exactly the same shape. For instance, we can rotate our snowflake 60° two or three times in a row and flip it over, and it will remain unchanged.

At this point, you might ask the question: “You have all these fancy symmetries for this particular snowflake. But, does every snowflake possess the same symmetries?”

Snow is a molecular structure of an ice crystal. And ice is a structured substance. It is a different form of water. When the water cools down, the molecules move more slowly, and this begins to impact how the molecules line up. Hydrogen atoms of one water molecule bond with two oxygen atoms. As the water freezes, the molecules arrange into hexagonal patterns. They prefer to stay as far away from each other as possible, and that makes them take up more space. The large space affects density. The density of ice becomes less dense than water. This is why ice floats. Almost all other liquids have a higher density when they freeze.

When we examine an ice crystal carefully under normal conditions, we always see a combination of molecules with six-fold symmetry. Snowflake molecules make a honeycomb structure. This results in an inordinate amount of hexagonal symmetry in these molecular three-dimensional structures.

Okay, we saw the structure of a snowflake under normal conditions. But, what if we changed those conditions? Johannes Kepler answered this question after his experiments and wrote a book about snowflakes, particularly The Six-Cornered Snowflake.

There are two key elements which affect the structure of a snowflake: temperature and moisture. Each time the temperature or the amount of moisture change, the structure of a snowflake changes. If you check the snow crystal morphology diagram below, you will see that when the temperature nears 0° and humidity is high, the structure of a snowflake will be flowery. Flowery structures are called dendrites. When you make it a little bit colder, the structure will be fancy hexagonal plates. We can apply many combinations and get varying structures.

The Snow Crystal Morphology Diagram. Source: Snow Crystals – http://www.snowcrystals.com/science/science.html

Professor of physics Kenneth G. Libbrecht is the owner of the diagram below. In a PBS interview, he said, “It’s a mystery as to why snowflake shapes go from plates to columns to plates to columns as the temperature lowers. That’s one of the things I’ve been trying to understand. It has been a mystery for about 75 years, and it’s still unsolved.”[3]

The Shapes of Snowflakes | Source

In the end, although the structure of (almost) all snowflakes are the same, some of them are not completely hexagonal. For instance, there are some snowflakes that have tree structures. Some snowflakes have branches, and each branch has tiny branches.

But, why is the structure of some snowflakes not hexagonal?

So far, we have talked about pictures which were taken at a particular instant. We have seen the pictures of the motion of the snowflakes for the smallest amount of time that can be measured. However, a snowflake never stops spinning in the air. They tend to oscillate. That means the shape of the snowflake is changing all the time. But how? When you see a snowflake in the air, it changes its place after a second because it would be whirled about, and it will be under different conditions at that time. This process will occur up until the snowflake lands on the ground. We know from the diagram that the temperature and amount of moisture always affect the shape of a snowflake. While small-scale conditions are almost the same, on a larger-time scale, conditions will differ. And these differences will change every corner of a hexagonal snowflake, resulting in a different structure. This is the main reason behind the variety of snowflake structures and uniqueness.

In conclusion, we can say that a snowflake can preserve its six-fold symmetry at all times. I think we have another reason to love mathematics! I want to finish my piece with Hermann Hankel’s words:

“In most sciences one generation tears down what another has built, and what one has established another undoes. In mathematics alone, each generation adds a new story to the old structure.”

Embryonic stem cells are cells in the early stages of embryonic development when a fertilized egg cell is divided first into two cells and then into four, eight, and sixteen. Each grows into a brand new cell type and multiplies as per the codes present in its DNA program as tissues form and organization starts. 

After twenty years of research and accompanying debates on the human embryo, we are finally on the threshold of both reshaping our present concepts in biology and moving on to clinical case studies. The first human embryonic stem cells were produced in 1998. Studies researching the question, “Can we treat diabetes by reprogramming the DNA in these cells at the beginning of life?” switched first to how human genes worked and which genes are responsible for the development of particular tissues and then to the embryonic stem cells for these areas and ultimately to replacing or reprogramming a “faulty or deficient” gene.

The most controversial topics in genetics and embryonic studies are related to bioethics. Many scientists are grappling with questions like whether is it ethically correct to intervene with the genetic programming of a fertilized human egg (zygote)? If so, what should be the limits? Are we trespassing a divine domain?

Embryonic stem cells have been an excellent source of information that we lacked throughout history about how living organisms started to develop. Like astronomers who trace their knowledge to the Big Bang in order to obtain fundamental information about the origin of the universe, biologists have been researching how the molecules in a single cell went through sequential and planned changes, how they transformed and acquired new functions that triggered the mind-blowing developments in diverse, miraculous living organisms. Scientists have found out how primordial embryonic cells transformed into more than 200 cell types that constitute various tissues and organs. The number of studies has skyrocketed about which molecule types can be used to regenerate the damaged tissue, say, after a traffic accident. Embryonic studies that focus on the regeneration or reparation of medulla cells (spinal cord) have been a source of hope for some patients with permanent paralysis because of a broken back injury or severed spine in a traffic accident or those who are still stranded in wheelchairs. Similarly, the preliminary findings of research into Parkinson’s and diabetes are extremely promising, and a new study reports of two blind people with macular degeneration (which causes blindness) who have been treated.

Initial studies

In 1981 researchers successfully obtained stem cells from a rat embryo culture. They soon realized that the cells held a secret potential: they could grow into 200 different types of cells. Later Wisconsin-Madison University biologist James Thomson derived stem cells from primates for the first time. Three years afterwards, Thomson derived the first human embryonic stem cells from donated but unused embryos.

The increasing number of research studies into embryonic stem cells sparked off intense debate both in religious circles and among the science community that care passionately about the sanctity of humans. Allegedly, lab studies were conducted on human embryos without restrictions, which were grown until tissues and organs formed but were then killed. In 2001, the US president George W. Bush slashed federal funds, stating that stem cell research was not strictly ethical. Deriving embryonic cells was banned in many countries including Germany and Italy. In other countries, however, studies went full speed ahead. Indeed, reports flooded in about stem cells grown by researchers in Australia, Singapore, Israel, Canada and the USA into nerve cells, immune system cells, and heart cells.

Before long, a new idea emerged about transferring new cells into the egg cell – like nuclei of body cells used in cloning Dolly the sheep – to produce various tailor-made, fully DNA-compatible tissues and organs, as they had the same genome as the donor’s. It became a topic of everyday conversations that spare organs could be cultivated for the human body just like spare parts of cars or other machinery were produced to replace a faulty or damaged part. In fact, if it were not for claims such as “creating a new human” there would be no objections against producing a kidney, lung, or heart from the DNA of a patient and thus overcome the major problem of tissue rejection in transplantation of organs.

If faulty or defective genes could be removed and replaced by healthy genes in the DNA of stem cells, many incurable genetic diseases could easily be fixed and many prospective parents who avoid having a child because of a defective gene they carry would welcome the development enthusiastically.

We are on the threshold of reshaping our present concepts in biology and moving on to clinical case studies. Embryonic studies have been a source of hope for even patients with diseases like paralysis and blindness.

Just in time and in the right amount

Embryonic stem cells are cells in the early stages of embryonic development when a fertilized egg cell is divided first into two cells and then into four, eight, and sixteen. Each grows into a brand new cell type and multiplies as per the codes present in its DNA program as tissues form and organization starts. It is most mysterious and miraculous that the molecules that lead a stem cell to transform into a new type of cell are synthesized at exactly the right moment and in the precise amount.  Scientists are currently trying to figure out which molecule leads a cell to become a nerve, muscle, or bone cell when attached to it. They are likely to decode the molecules by monitoring the tissues that remain undeveloped because of missing genes resulting from DNA mutations observed in certain genetic diseases.

The new field that has developed in the last two decades called regenerative medicine is predicated on tapping into the potential of stem cells by repairing missing or faulty tissues, or completing a link in the chain necessary for the functioning of a dysfunctional metabolic process. In 2006, stem cell biologist Shinya Yamanaka of Kyoto University in Japan successfully transformed adult rat cells into an embryonic state. The following year, human body cells were transformed into embryonic stem cells. The ensuing research has led to the acknowledgement that it was theoretically possible to transform stem cells into any cell type, a promising cure for diseased embryos that have genetically missing parts.

The major problem, however, is keeping these delicate cells alive in a culture medium. In 2007, Yoshiki Sasai discovered a molecule called rock inhibitor that nourished the cell colonies he grew. The success rate in generating new cell colonies rose to 27%. Parmar from Swedish Lund University heralded “a new golden era” by producing new neurons from embryonic stem cells for the treatment of Parkinson’s.

As new techniques were developed for producing cells fast and reliably, these cells turned out to involve a very low risk of developing cancer. “We don’t yet know how this hidden power and balance that can be transformed into any cell type is controlled,” states Hiromitsu Nakauchi, a stem cell biologist at Tokyo University who researches making blood platelets out of stem cells derived from the embryo or somatic cells.

Experiments are underway that aim to treat disorders by activating stem cells stored in the body that have not yet differentiated through the help of proper stimulating molecules. 

Miraculous differentiation

As the techniques for producing and feeding stem cells got easier, researchers aimed at growing and forming tissues and organs. A connective tissue or an outer covering like the skin that lacks a shape but takes the shape of the underlying muscles and bones can be produced even in a Petri dish and then transplanted to a burned or missing area of the skin. The present aim is the production of organs such as the kidney or the heart that has a particular shape and is made up of a number of different tissues. If the correct signal molecules responsible for cell division and differentiation can be identified and readily used where necessary and at the right amount, then organs including any type of tissue can be produced. Researchers like James Wells at Cincinnati Children’s Hospital in Ohio have tested the damage of drugs on intestines by using the partial intestines they developed from stem cells rather than administer them to normal humans, thereby hailing the imminent age of intestine transplants.

In 2004, the doctors who did tube baby experiments for a patient in Chicago known to have a genetic disorder started to produce a series of stem cells from generated embryos. They made models at the cellular level of the emergence of such genetic disorders as thalassemia, Huntington’s disease, Marfan syndrome, and muscle dystrophy. In 2007, they used embryonic stem cells to suppress molecular changes that trigger mental disorders caused by a genetic disorder called fragile X syndrome.

Research shows that multipotent (mesenchymal) cells stimulated at the outset of tissues are even more promising than embryonic cells with respect to diseases because it is easier to repair damaged or missing tissue by guiding them. However, it is essential in a genetic disorder that cells derived at the beginning of the embryonic stage should be used in order to replace faulty genes with healthy ones and address the disorder at its outset.

Experiments are underway that aim to treat disorders by activating stem cells stored in the body that have not yet differentiated through the help of proper stimulating molecules. In this way, as many as ten illnesses are likely to be treated, some of which include diabetes, macular degeneration in the eye, and neurodegenerative diseases such as Parkinson’s.

Douglas Melton from Harvard Stem Cell Institute in Cambridge has worked for fifteen years to transform embryonic stem cells into insulin-producing β-cells. He has produced pancreatic cells that sense glucose and produce insulin and he hopes to transplant them to end the dependence of patients of diabetes type-1 on insulin shots. The last obstacle remains to be the introduction of these cells to the system so that they are not destroyed by the patient’s immune system.

Clinically, it is believed that stimulated multipotent cells have a greater advantage than embryonic cells because the produced cells and tissues have the same DNA as the patient and thus do not cause any immune reaction when they are transplanted. The problem for many genetic disorders including type-1 diabetes is that the patient has the same mutation in his or her genes, and a method should be devised for cleaning and replacing these cells.

Another problem is the cost. It is reported that preparation of a series of multipotent cells will cost about one million dollars. However, the cost is expected to decrease and cells will be developed for the treatment of Parkinson’s disease, which is caused by a loss of neurotransmitter substance, which enable communication between nerves, and dopamine.

Treatment of macular degeneration is a popular target in this field. Patients gained the ability to read, though slowly, one year after the transplantation of part of stimulated multipotent cells to a damaged retina.

Such research studies normally cause some opposition. Playing with genes and embryos involve certain ethical and health risks. Yet, as reported in a Prophetic tradition, with all our God-given abilities like intelligence, curiosity, and willpower, humans can, and hopefully will, find cures for all diseases. Research into stem cells has the potential to provide many breakthroughs in these efforts to find healing for every human. Scientists and ethicists have to work together to determine our direction not to cause any unintended harm to any single soul while moving forward with this research.

One of the processes that occurs in the body is called “inflammation.” Inflammation occurs when a cut into the skin also punctures a blood vessel. This situation directly exposes the blood to the air. Inflammation occurs in a few steps. First, the blood vessels near the wound are expanded (which causes the swelling that we see near the cut) and special proteins called “fibrins” are brought in. These fibrins bind to each other to form a net-like structure. We are all quite familiar with this net, which we call a blood clot. This net stops the bleeding and cuts the interaction between the air and the blood within a few minutes.

Next, it is time to quickly eliminate any foreign objects that got into the tissue. Special immune cells called “macrophages” are sent to the crime scene to clean up. Macrophages are large white blood cells that “eat” microbes and other foreign objects using a process called “phagocytosis.” After the scene is all cleaned up, these macrophages excrete special molecules that induce tissue repair and return the blood flow to normal. An important note here is the specific order of these events. Like every single process in the body, they occur in the most purposeful way possible. What do I mean? I mean that, first the wound is closed urgently; second, macrophages are sent in; third comes the tissue repair. Any other order would have greatly lowered the effectiveness of inflammation. Imagine that the wound is closed after the macrophages are sent in. Then, by the time the macrophages killed all the microbes, twice as many would have entered the scene. The body seems to know every single event beforehand and plans its defense accordingly.

Our body is perfectly calibrated to keep our blood, the milk of our organ systems, absolutely pristine.

Let’s say a microbe managed to sneak into the blood before inflammation occurred, and is long gone to another region of the body. Does the microbe win? Unfortunately for the microbe, it has to pass another test. This time the tester is the lymphatic system. The lymphatic system is the sewage system of the body. When the blood transfers its nutrients to the tissue, the fluid goes through the “interstitial area” (the empty space between organs). During this process, some of the fluid stays in this area and starts to accumulate. This is where the lymphatic system kicks in. The lymphatic system consists of many tubes running parallel to the blood vessels and recollects any excess fluid and transports them to the subclavian vein near the neck. This way, excess fluids of the body and all of the molecules in them, are reintroduced into the circulation. If there is a problem with this process, an abnormality called “edema” occurs. Of course, the blood is a very sensitive fluid because it travels through the whole body and seeps into almost every single cell. If a microbe were to get into it, it would easily spread and cause disease. So, the lympatics first does a checkup on the body fluid. This checkup occurs at special nodes in the system called lymph nodes found all over the body. Two of the most famous lymph nodes are the spleen and the tonsils. Within these nodes are lymphocytes, special immune cells that “tag” bacteria and other microbes to be later destroyed by macrophages. Thus, the blood is continuously cleaned and kept safe from harmful microbes.

Last but certainly not the least, the final inspection the blood goes through takes place in the kidneys. The aforementioned two checkpoints prevent the entrance of any foreign materials into the blood, and the elimination of any microbes lucky enough to somehow make it through. So, the only task to be completed is the elimination of excess molecules formed in the metabolism. For example, the blood in the veins (the vessels that carry carbon dioxide formed by the respiration of cells) is carried to the lungs where the carbon dioxide is exhaled. But, a much more precise mechanism comes into play in the kidneys. Blood vessels that come from all around the body form a knot-like structure in the kidney called the “glomerulus.” This knot-like shape increases the surface area of filtration. The blood running from the glomerulus is then filtered into the “Bowman capsule,” which surrounds the glomerulus.

But wait! The sanitation system is not satisfied with this first filtration and “thinks” that the filtrate is not ready to be excreted by the urine. So, a more delicate filtration occurs right after the filtrate enters the “proximal tubule.” While passing through this tubule, essential molecules are immediately reabsorbed into the body. The most valuable of all these molecules is glucose, since it is the main source of energy in the body. The proximal tubule reabsorbs around 98 % of all the glucose, while the distal tubule scouts out the rest. After the tubules are done with the filtration, not a single glucose molecule is left in the urine. As a matter of fact, the presence of even a few glucose molecules in the urine leads to a diagnosis of “renal glycosuria.”

After the proximal tubule, the filtrate goes into the “loop of Henle,” where it is dipped into a high-concentration environment. Water travels passively (without the need for energy) from low-concentration to high-concentration areas. In the loop of Henle, the urine is low-concentration, so water runs back into the body. Thus, any excess water in the urine is effectively and economically reabsorbed. The big machine that consists of the glomerulus, the Bowman capsule, the tubules, and the loop of Henle is called a “nephron.” Everything described above occurs in a single nephron. The average number of nephrons in one kidney is around 1,000,000. The human bladder holds around 150 ml of urine on average. So, each nephron is actually responsible for 0.00015 ml of urine production. The kidneys filter over 1,000 liters of blood each day, so our blood is kept just as we want it. Millions of tiny nephrons work in unison to take in huge amounts of blood and they know exactly what to leave and what to keep, 24 hours a day, 7 days a week.

Our blood is our life source. It is the milk of the organs, and our organs would dry up without it. Believe it or not, our organs are quite picky. If they are to receive anything they don’t like, they will start acting up. In order to keep the organs happy, the three mechanisms mentioned above have to work hard and not make a single mistake. These mechanisms are, of course, also made up of cells. These miniscule cells “know” exactly what their clients on the ends of the body like and don’t like, and prepare the blood composition accordingly. Only one word can describe these wondrous mechanisms: Impeccable.

Brian Turk is a medical student from New Jersey. He writes on medicine, health, and biology on a freelance basis.

As science develops further, the “veils” of the universe are lifted and humanity can explore realms beyond which our senses would normally allow.

We are conscious beings and we seek answers to our existence. People search for answers to questions like, “Who am I and why do we exist?” The sciences reveal that existence is full of meaning and purpose. However, judgmental values and beliefs enter the process; restrictive and ideological approaches lead to confusion during man’s voyage to truth.

Take the question of how we exist. Different perceptions have their own point of view and reach different conclusions. While a materialist person accepts the matter to be eternal, for some the theory of evolution has all the answers; yet on the other hand, a person of faith explains existence with creation. Therefore a materialist, an evolutionist, and a believer struggle to reach a common conclusion.

Human vision is somewhat veiled; the things that are not witnessed are considered unknown. The events of both the micro and macro cosmos are veiled to us. Yet the more our science advances, the more of these worlds we begin to see. We understand how complex existence is, while also appreciating how majestically it has come into being.

Can senses and observations guide humanity to the truth? Our strongest senses are seeing and hearing; however, these senses can only perceive a narrow band of the electromagnetic spectrum. The human eye can see the wavelengths in between 4,000-7,000 angstroms; the ear can hear frequencies in between 16-20,000 Hz. When we rely only on our senses to understand and comprehend existence, the things that are outside our ability to see or hear become absent.

Dimension and distance are very important for vision. The dimension that humans can see with the naked eye starts at the millimeter scale; in perfect conditions, we can barely see beyond 18-25 miles. Things at dimensions much smaller than a millimeter and at considerably longer distances remain out of our visual range. A microscope brings the small dimensions into our visual spectrum and the telescope does the same for long distances. Before the invention of these devices, humankind was not aware of things such as the atom, molecule, galaxy, nebula, or black hole. Today, because of scientific advances, as we get closer to seeing things on the nanometer dimension, we are newly discovering structures at this scale and the laws that are effective here. The inner makeup of the atom has not yet been elucidated; our knowledge is based on certain theories and experiences. Our information regarding the universe is also limited. It is considered that in an expanding universe, according to the expansion velocity of galaxies and gravitational force calculations, the amount of visible matter only corresponds to 4% of the total mass of the universe, the rest estimated to consist of 26% dark matter and 70% dark energy.

When the true nature of things (objects, existence) that are unknown or seem to be simple are explained through science, the truth is found to be very different. From space, the earth looks like a small and pale blue dot. After getting closer, at first the oceans, continents, and major mountain ranges start to appear. There is not any indication of people or other organisms on earth yet. However, after looking closely enough, it is observed that earth is filled with numerous life forms.

We witness the twinkle of countless stars when we gaze at the sky on a dark night. These stars, each shining as a small spot, may seem insignificant. When we turn our telescope towards one of these spots, we face a giant star or a galaxy that houses billions of stars; we become astonished. And when we take a better look at these stars, some of which are colossal, we witness interesting events. In these thermonuclear cauldrons that are utilized like millions of atomic reactors, enormous amounts of energy are released into space after being produced each second under immense pressure at temperatures reaching millions of degrees. Humans should think for a while and be amazed by these things. The power required is immense and they last millions of years.

People can also observe the wonder of the universe by delving into much smaller dimensions (the micro world). Here, we witness the creation of wonderful beings and the employment of tiny creatures in vital tasks, even though this micro world is hidden secret from the naked eye. For instance, in the thousands of small chemical factories fitted in a seemingly plain leaf, sugars are produced from carbon dioxide and water via sunlight; nutrients are synthesized from various minerals in the soil and stored in the fruits, seeds, and roots of plants to serve as nourishment for the living.

The biological structure of a human body is built by the proliferation of a fertilized single cell, called a zygote, through division. More than 200 different cells executing very unique functions in tissues such as the brain, liver, kidneys, muscles, and bones are created from a single cell. Cells have specific structures and tasks according to their types, each housing various work benches and laboratories. For example, the make-up and function of a brain, liver, or muscle cell is very diverse, each shaped for their assigned task. The organelles inside the cells are also specialized; the job of one cell type cannot be completed by another. The molecules, secreted enzymes, and hormones synthesized in cells are different. While a pancreatic cell secretes insulin and glucagon, a thyroid cell releases thyroxine. Various dimensions and models of protein, hormone, enzyme, and antibody molecules are formed with structures called ribosome to be employed in unique processes. The energy that cells need is generated in organelles of mitochondria. In addition, various transmission lines, communication networks, and defense mechanisms are established inside cells.

Organs are not just packs of meat. Billions of cells in each organ are completing their works around a common goal. In each organ and cell, micro factories and laboratories of microscopic dimensions are set up, micro-machines and robots are being utilized, and atoms and molecules are employed like conscious workers.

The entire body is formed by the specialization of this zygote into very diverse cell types during the formation of these organs. The set of tasks in different organs is programmed to sustain the life of a single organism and to serve a common goal. How could one not be amazed by the combination of trillions of cells in a way to serve one purpose, form a body, and distribute tasks to different organs?

It is also important to analyze the composition of atoms and their relations with each other for a better understanding of the facts of creation. Different atoms form with varying numbers of protons, neutrons, and electrons in their atomic structures. A different element is generated when the proton number is changed; an isotope of the same element is generated with the replacement of the neutron number. Millions of types of molecules with unique features can be made via different combinations of atoms. Molecules are the smallest units that determine the chemical properties of matter. While the simplest compound is the hydrogen molecule, formed by two atoms, there are also molecules composed of millions of atoms.

There are molecules of diverse types and sizes present in the universe. Each molecule type is constructed in a three dimensional and unique way. The number, order, and shape of the bonds present among atoms in a molecule, even the angle between atoms, is very important. Because of these differences, despite the fact that they both contain a carbon atom, a diamond and graphite (coal) are distinct substances. The carbon atom can miraculously form 1,700,000 types of compounds on its own. Just as in hydrogen peroxide (H₂O₂,) and water (H₂O) molecules, a change of an atom in a molecule can alter the entire property of that particular molecule. A small change taking place on a single base sequence of the DNA chain may disrupt its condition leading it to be ineffective or cause a disease.

As humans, we only observe the tangible side of such materials. Yet the universe contains multitudes that we cannot detect or know. Just like a software composed of commands is required for computers and electronic devices made up of physical elements, the presence of an intangible world that is dominated by souls and commands undetectable by senses is necessary within the matter where the program of fate is operated.

As mankind accumulates knowledge about the universe and existence, we notice that not only do we have a greater understanding of the nature of things, but also that each dimension in existence is a veil and this veil is lifted with science.

Despite that, there are more than 100 types of amino acids found in nature; only 20 of them are employed for protein synthesis. Among these 20 amino acids, excepting glycine, which does not display chirality, only the L-form of the 19 is used for protein synthesis. This is because ribosomes, where protein synthesis occurs, do not feature the utilization of D-form amino acids. As nothing in the universe exists in vain but with multiple tasks, D-amino acids have a job in the maintenance of life after protein synthesis in very different fashions. The way D-amino acids are employed in the execution and control of physiological preferences amazes scientists.

Up until recent times, D-amino acids were believed to be synthesized mostly by bacteria and plants, unlike mammals, and were considered dysfunctional as they passed, via consumption of nutrients, from bacteria and plants. However when D-amino acids were noticed for having roles as important as L-amino acids during the 1990s, the field gained significance. It was demonstrated that D-amino acids were found widely in invertebrates, vertebrates, and humans as free forms or inside proteins, undertaking critical functions in the nervous and endocrine systems. The most interesting point is the conversion of amino acids from the L-form into the D-form after the protein synthesis occurs in the peptides that are present in the venomous secretions of various animals. This conversion leads to the alteration of the peptide identity and function. Racemase and isomerase (epimerase) enzymes are utilized as they are created for this task. Usually, one or two amino acids of the D-form peptides are in D-form.

When chemist Gunther Kreil of the Austrian Academy of Sciences learned about the use of South American poisonous tree frogs (Phyllomedusa sauvagei ) during Shamanic hunting ceremonies by local Peruvian tribe (Matses), he studied this poison in detail. Participants of the ceremony first caused a burn on their chest region, then applied the poison they obtained from the frog skin over it. Diarrhea and tachycardia started within a minute, followed by a brief faintness. Once they recovered after a few minutes, they were to find themselves in a much more vigorous and exhilarated state of mind. The poison they were applying to their chest contained the dermorphin peptide, which has psychoactive, hallucinogenic effects and a D-amino acid. This peptide is a pain killer 30-40 times more effective than morphine. Among the 7 amino acids found in this peptide (heptapeptide), all are in L-form, except for one. Only the alanine, as the second in the peptide sequence, is in D-form and is produced via the isomerase enzyme from the L-alanine after the protein synthesis. G. Kreil discovered this D-form synthesizing enzyme in 2005. When this peptide was synthesized artificially in the laboratory, it did not display any biological activity or hallucinogenic effect. After a careful investigation of the case, it was found that frog skin based peptide had a D-form alanine second in its sequence; however, the one produced in laboratory had an L-form alanine. It was the presence of only one D-amino acid that made the difference in discovering the identity and function to the natural peptide in the poison.

In recent years dermorphin has started to be used as an illegal performance enhancer during horse races because of its pain killer feature. Horses on dermorphin can run longer and faster since they cannot feel the pain related to foot fatigue.

P. Kuchel of Sydney University also showed a D-amino acid presence in the peptide structured of the poison in the Platypus, a semiaquatic egg-laying mammal. Males use this poison as a weapon to fend off competitors. In 2009, Matthew Waldor and his friends at Harvard University discovered that the sugar-protein mix (matrix) called peptidoglycan found in the composition of bacterial cell walls is structured in a way to contain primarily D-alanine, D-methionine, and D-leucine. More interestingly, D-amino acids of the peptidoglycan structure were able to play a stimulatory role in coordinating the activities of other bacteria in the colony. For example, they acted as light houses in the use of florescence and helped in the formation of thin layers (bio-films) on various surfaces in bacteria. Once we understand the way D-amino acids help in communication between bacteria, it will be possible to use them as a drug. It’s possible they can be used to disintegrate bacteria that forms on teeth, in the lungs of cystic fibrosis patients, on clogs in fuel lines and water tanks, and in medical devices such as catheters.

D-amino acid containing peptides found in lobsters help maintain salinity levels and facilitate courtship in mating seasons. In recent years, D-amino acid containing antimicrobial peptides were discovered (bombinines) in the secretion glands of fire-bellied toad skins (Bombina sp). In this peptide, the second amino acid was in the D-form (D-allo-isoleucine). Two different peptides were found containing D-amino acids in the second position of the amino acid sequence of the poison secreted by Platypus males.

One of the reasons for D-amino acids to exist in animal poisons is that peptides containing D-Amino acids can not be easily degraded by the proteases (peptide bond breaking enzyme) of the host or opponents. Even though proteases can quickly and easily digest proteins composed of L-form amino acids, they struggle to do so with peptide bonds between D and L form amino acids. Pharmaceutical companies are trying to add D-amino acids to the peptide-structured drugs to prevent the quick degradation of peptides and proteins used for treatments when ingested. However, the addition of a D-form amino acid brings the high possibility of a situation that changes the function of a peptide or protein, or causes the loss of a protein. Nonetheless, specialists in this field point out that at least some amount of the D-amino acids that are produced by trillions of bacteria found on the skin, in the digestive track, and among other parts of the body can still be utilized for human health and convenience.

The D-serine of the mammalian nerve systems (glial cells and neurons), the D-aspartate of the neuro-endcorine, endocrine tissues, and testicles, and the D-alanine and D-aspartate amino acids of aquatic animals are abundant. D-Serine in the brain is synthesized by the conversion of L-serine into D-serine by the serine racemase enzyme. D-aspartate is in charge of hormone synthesis and secretion, and the regulation of spermatogenesis, and is produced by aspartate racemase and degraded by D-aspartate oxidase. It is also predicted to play role in the synthesis of hormones such as melatonin and testosterone.

As of now, four enzymes have been detected to be in charge of D-amino acid metabolism in mammals. How these are controlled is still unknown.

Publications pertaining to the association of epilepsy, schizophrenia, and bipolar disorders with enzymes in charge of D-amino acid synthesis and break down have increased in recent years. From this point of view, serine racemase and D-amino oxidase can be used to develop new potential drugs regarding the treatment of similar NMDA receptor associated diseases.

The first data demonstrating the use of D-amino acids in saliva in organs outside of the human brain was obtained by Y. Nagata and his team at the University of Nihon, Tokyo. A team led by Kenji Hamase of the Kyushu University discovered high levels of D-alanine storage in the beta cells of the rat pancreas. Kuchel, who discovered the enzymes converting the L-amino acids in to D forms in duck-billed Platypus poison, also found similar enzymes in the hearts of mice and humans. According to Kuchel, the physiological roles of those in humans remain to be unknown.

As a result, the common feature of toxins and antimicrobial peptides that are produced and secreted by animals is to contain D-amino acid. These peptides can be the source of a potential drug in the treatment of diseases such as cystic fibrosis, schizophrenia, and macular degeneration of the eye.

These prove that, especially in biology, exceptions are common; life is enriched via examples of extraordinary lives, processes, and mechanisms in unexpected places by unpredictable molecules or interesting reactions that can’t be predicted. Such discoveries help deepen our wonder at the intricacy and wisdom of creation.

While wandering near a creek, have you ever seen bugs walking on the surface of the water? Have you felt any resistance when you hit the surface of the sea with your palm? Have you ever thought about what causes these to happen?

The two examples of events given above happen to be related to “surface tension.” This situation is described as the force per distance unit that is generated in the opposite direction of the direction of expansion between two different surfaces. It can take place in between two different liquid layers, as well as among liquid-gas and liquid-solid layers. For example, the surface tension of a liquid forms in the transitional region where liquid and gas molecules make contact. The source of this force generated on the liquid’s surface is the intermolecular attractions that hold the liquid molecules together. Each molecule in the liquid is pulled via opposite but equal forces by neighboring molecules, thus no single force is acting on the molecules. However, the molecules on the surface are only surrounded by one side, therefore they are pulled inwards with a net force (Figure 1), causing a tension similar to an inflated balloon on the surface of the liquid.

When we look carefully to a stagnant pool of water in a container, the surface of the water seems to be covered with a thin layer of film, resembling a stretched membrane. In order for a substance to enter or leave the body of water successfully, it must puncture this membrane. In other words it has to overcome this intermolecular force. If a steel blade is laid horizontally on the surface of the water slowly, it floats despite that it is made of denser steel because it cannot overcome this surface tension. Surface tension is the principle responsible for the trampoline-like behavior of liquid surfaces. Many insect species created for aqueous habitats can maintain their lives on the water via their adapted leg parts. The best example of this is the water strider. This insect lives on water by taking advantage of water surface tension. Though the surface tension principle is a requirement to be on the water, it is also necessary that the strider not to stick to the surface. Therefore, this insect is also equipped with a paddle made of waxy hairs at the end of their legs (Figure 2).

Forces of cohesion and adhesion

The intermolecular force of a liquid among the same kind of molecules is called the “cohesion force,” and intermolecular attraction between different types of liquid molecules is called the “adhesion force.” These forces of adhesion and cohesion determine the behavior of a liquid in a container. If some mercury is put in a glass tube, because the cohesive forces among the mercury atoms is greater than the adhesive forces in between the glass container and the mercury, the mercury assumes a convex shape. Here, mercury has a tendency to reduce its contact with the glass and does not wet it. In contrast to mercury, when water is put inside the tube, the surface layer between the water and air takes an inward concave shape. This is caused by the greater adhesion force between the water and glass compared to the intermolecular cohesion forces of water. Water wets the glass since it has a tendency to spread towards the greatest surface possible (Figure 3).

When there is a thin layer of water or tea left in between a tea glass and its plate, the adhesion force glues the glass and plate together. Since the adhesion force is greater than the weight of the plate, the glass cup can be lifted together with the plate. Contact lenses also stay in position on the eyes without falling through the help of adhesion forces. Tears strongly pull both cornea and the contact lens together, holding it in place.

The capillary effect

A liquid inside a thin vertical tube is pulled upwards by the inner surface of the tube until the adhesion force becomes balanced with the liquid weight. This event is called the capillary effect or capillarity. Liquids naturally rise in narrow channels if there is sufficient adhesion force. This effect is enhanced in narrow tubes due to the smaller volume of the liquid, but reduced in wider tubes because of gravity. Therefore, there is an inverse ratio between the channel diameter and liquid height in capillarity.

The reason a sponge absorbs water effectively is the easy rise of water in the capillary openings of the sponge. In a similar fashion, there are small openings found in paper napkins and towels. When a napkin makes contact with a wet surface, water is pulled inside the small openings with capillary action, thus removing the water from the surface. This is because the adhesion force in between the napkin tissue and water is greater than the cohesion force of the water molecules. This principle is also utilized while getting blood samples with capillary tubes. In addition, the removal of continuously excreted tears by the capillary ocular ducts that extend into the nasal cavity is another example of this wise law.

Capillary action is also important for the transportation of water molecules from humid parts towards drier areas in soil, providing for the spread of water. The same principle is also vital to nourishment of trees. Every part of a tree encompasses capillary channels, all the way from the tips of the roots to very ends of the branches. Water molecules are transported to the leaves against gravity when they enter the tips of these capillary channels at the roots. Even though the adhesion forces between the water molecules and the root’s tissues win the war against gravity, at a certain height, this force becomes equal to the gravitational pull, thus not allowing water molecules to climb higher. This is the ultimate height a tree reaches. Capillarity also affects internal water pressure of a tree, leaf size, photosynthesis, and other factors. This is why the leaves of a tree are usually bigger on lower branches compared to higher ones (Figure 4).

The surface tension of water is the highest among the known values of other liquids and this has very significant biological effects. If the surface tension of water was to be lower, like other liquids, it would not be able reach the higher parts of plants through capillary action, thus preventing the survival of taller plants. The vegetation waits patiently as nourishment is delivered to its roots. Water has been assigned a vital role in this service.

The water-dependent survival of plants is made possible through the capillarity and surface tension. Could this amazing phenomenon, in which the capillarity is on duty to water the leaves on the highest branches of the tallest trees to ensure the maintenance of life, take place via blind atomic interactions or accidental occurrences?

How do liquid droplets get their shape?

Objects with a wider surface will have a greater surface tension. Since the force of surface tension, acting on per unit distance, is equal to the surface energy per surface area, a wider surface requires greater accumulation of energy on the surface. All the matter in the universe tends to stay at a lowered energy level. Therefore, it is ideal for objects to reduce their surface area. When the surface area to volume ratio of the known geometric shapes is investigated, the smallest ratio is found to belong to a sphere. A small value of this ratio means the most reduced surface area per volume. Among enclosed containers of equal volume, a sphere is also the one with the smallest surface area. When two equal volume watermelons of spherical and cubical shape are peeled, the spherical one will produce the least amount of rinds.

Because of the reasons mentioned above, liquids take a droplet shape immediately when they fall, reducing their surface area. That is why a water droplet dripping from a faucet, a falling rain drop, and a droplet on a leaf are all in the shape of a sphere (Figure 5). It is the same principle that makes planets and other heavenly bodies resemble a globular form. This indeed points to an Almighty Power who plans the motions, positions, and assignments of all the objects, from particles to giants, managing and dispatching them as The Self-Existent One holding everything together.

Factors affecting surface tension

Temperature increase is directly proportional to a decrease in the surface tension in most liquids. When the temperature of a liquid rises, so does the kinetic energy of the particles in it, making these particles move faster. This leads to a weakened intermolecular attraction that binds molecules together. Since this change affects the particles at the surface, it decreases the tension. Improved soaking of hands and laundry can be achieved with warm water during cleaning because heat reduces the surface tension. This helps with better cleaning results in a shorter amount of time.

In a similar fashion, soap and detergents also reduce the surface tension of water. If a small soap bubble is placed on a water droplet, the droplet spreads away instantly. This indeed tells us that the soap bubble reduces surface tension.

If a substance dissolves in a pure material, surface tension is found to change depending on the solute and the solvent structure. For example, salt decreases the surface tension of water. Salt weakens the intermolecular bonds of the water molecules, and therefore reduces the cohesion and surface tension. That’s why sea waves foam when they hit shore.

Can surface tension be associated with the ability of unconscious and primitive atoms as the principle behind many functions and tasks in the lives of plants and animals? Do such wondrous events happen by chance? Isn’t this principle such a blessing of the One who easily provides what is necessary to all living things, nourishing them in time according to their needs?

Some medications are effective directly over the area they are applied to. Some however are transported to distant regions via blood flow and that is where they are most effective. Medication is either taken orally or through injection. When medicine passes into the blood stream from the place of administration, it is considered to be absorbed. A good example is the transportation of medicine into the blood stream of capillary vessels between the muscle cells when injected into muscle tissue. A drug taken orally however is absorbed through the blood vessels in the gastro-intestinal system.

For orally-taken medication to be absorbed, it should be able to dissolve in gastro-intestinal fluids. First, it is broken into smaller units due to the corroding effects of stomach acid and various enzymes are secreted, then chemicals in the drug composition pass into the gastro-intestinal fluid in a molecular form. This event resembles the dissolving of a sugar cube inside a glass of hot tea. First, the sugar cube gets broken into pieces and then dissolves. A mix with a tea spoon makes this event happen a little faster. In a similar fashion gastro-intestinal movements help with the absorption of medicine. Liquid drugs like syrups dissolve in the gastro-intestinal fluid faster since they are already in smaller units; therefore they get absorbed faster.

Drugs mostly get absorbed through the small intestine. The most important task of this organ is to enable the absorption of nutrients. It is approximately 10 meters long and 4 centimeters wide. The inner lining of the small intestine has finger-like projections called villus and even smaller projections that are located on these villi are called microvillus. One of the reasons, maybe the most important reason, why the our intestines are created in this way is that as a result, the inner surface area of intestines increases multifold. Such that the inner surface area of a human beings small intestine can increase up to 200 m2 and this greatly facilitates the absorption. These projections are made of intestinal cells.

The molecules carrying the medication reach the capillary vessels by passing through these cells and then join the blood stream by crossing through capillary vessel cells. Furthermore, intestinal cell membranes host a special protein that filters unwanted substances for the cell and returns them back to intestinal lumen. Thus these unwanted substances are excreted out of the body along with other unabsorbed matter. In the same way, some drugs are held by this protein and released back into the lumen thus decreasing absorption rate for drugs experiencing this reaction.

Liver: The organ responsible for eliminating the harmful effects of medication

As soon as medication joins the bloodstream after absorption, it is first transported to the liver. This is because pulmonary veins that collect blood from the intestines are connected primarily to the liver. One of the many functions of the liver is the elimination of harmful substances entering the body. For this reason, absorbed substances are directly sent to the liver. The liver is employed with the task of chemical conversion with these substances that are transported to it. One of the wisdoms behind liver metabolism is to reduce the effects of these harmful substances via these events and to convert them into an excretal material. In the same way, drugs are metabolized in the liver, lose their efficacy and prepare for excretion.

Many drugs interfere with each other’s metabolism. If one drug’s metabolism is inhibited, blood concentration of such chemicals increase and adverse effects of drugs become more frequent. Irresponsible drug use must be avoided for this reason. Drug interactions may lead to major damage in addition to the drug’s individual adverse effects. Moreover different nutrients also affect drug metabolism. For instance, grapefruit inhibits metabolism of certain medicines, as a result blood concentration of these medicines increase and adverse effects can be observed. On the other hand, some nutrients like broccoli, cabbage, and charcoal roasted meat speed up the metabolism of certain medicines. In this case, the blood concentration of the affected drug drops and may lead to reduced benefits from intended use. Because of this reason, patients on long-term medicine treatment should not consume these types of food.

The rest of the drug molecules that escape these metabolisms is directed towards blood vessels feeding other organs. Some drug metabolisms in the liver present individual differences as metabolic levels change from person to person. Thus, a drug with the same dosage develops desired blood concentrations for some people, fails to meet this level for others or can even cause high blood concentrations enough to generate adverse effects in other individuals. That is why a medicine that has benefited a patient should never be used by somebody else without consulting a doctor.

The function of bile

Bile secretion originating from the liver and gall bladder has critical importance in the digestion and absorption of fats. Bile breaks apart fats into small pieces so that digestive enzymes can affect them. As a result of this, absorption is provided for fats and vitamins like A, D, E, K that are soluble in fats. In a similar fashion bile improves solubility and absorption of some drugs that does not dissolve in gastro-intestinal fluid. Another task of bile secretion is the removal of certain substances from the body. Waste materials in the bile that is dumped into duodenum are excreted through the digestive track. Some drugs are excreted in this way.

Drug intake before or after meals

It is a well known practice that medications are advised either to be taken after or before meals. When medications are taken after a meal, they cause less of the possible unwanted disturbances such as stomach sickness, aches or indigestion.

On the other hand, nutrients may reduce intake of certain drugs, therefore they need to be taken before meals. However medications taken right before a meal does not apply in this case since the food will still mix with the medication in the stomach. When taking these medicines, it should at least be an hour before meals. Generally consumption of a medicine before or after a meal does not really change its absorption level. But medications taken before meals pass the stomach into the intestines without delay and therefore get absorbed faster. This practice is important in cases where an immediate effect is desired such as pain relief. Plentiful water intake also helps with faster and improved absorption of drugs.

Some medications are packed into capsules made of gelatin-like substances. Medicines with undesirable taste and smell can be offered in this form for consumption. Moreover, if a drug is harmful to the stomach or gets degraded in stomach acid, then this drug can be prepared in capsules that are durable to stomach acid but soluble in the intestines. That is why consumption of medication without its intended capsule should be avoided. In a similar fashion, some medicinal tablets are designed to deliver its molecular contents particularly to the intestines. These types of medication must be taken as a whole unit. Otherwise it can be ineffective or may lead to harmful reactions.

Delivery of drugs to targeted regions

The molecules carrying medication that join the blood via absorption get dispersed by blood circulation throughout the body. These molecules reach various parts of the system via blood vessels, and then diffuse into organs via capillary vessels. However, their entry to the brain is difficult because this vital organ of the body has a special protection to guard itself from possible harmful effects of various substances that enter the body from the outside. Capillary vessels in the brain are different from other capillary structures in the rest of the body as they are created without an intercellular space in between vessel cells. Furthermore, these cells are bound to each other with their tight connective regions.

These capillaries are surrounded by a thicker membrane compared to other capillary vessels. This membrane is also host to various cells that wrap around the vessel. Therefore, because of these factors and other similar ones, some medications can enter the brain in very limited amounts. Drug molecules can display their targeted effects when they bind to target proteins, called receptors, in the organs. These proteins, which are very unique to each drug, exist on the cell membrane or in the cell. In addition, drug molecules also bind to other receptors that are not specific for them, and this causes adverse effects as a result.

Excretion of drugs from the body

Drugs are excreted from the body via the liver and kidneys. One function of these organs is to filter the blood from foreign substances. It was previously mentioned that absorbed substances from intestines are transported to the liver first where some amount gets metabolized and the remaining amount rejoins blood circulation that feeds other organs. Drug molecules that pass through the liver return back to it repeatedly many times because of continual blood circulation. In each of these arrivals, some amount is again metabolized. Molecules of metabolized drugs are excreted out of the body via the kidneys and through the bile at a limited level.

Only some portion of drug molecules get excreted via the kidneys without being metabolized. This ratio is higher with some medications. These types of medications are considered to be removed only by the kidneys, whereas some other drug types cannot be excreted without getting metabolized through the liver. As previously mentioned, the purpose of drug metabolism is to convert drugs into easily removable forms. If these types of drugs are not metabolized, they are rejoined to the blood circulation after filtration by the kidneys without joining the urine. It is impossible for the liver to sense these happening within the kidneys if it was not that the liver and every cell in it were employed by one authority who created them in the first place. Drug molecules concentrate in the liver and kidneys since these organs are employed with drug removal. As a result harmful effects of drugs are often experienced in these organs. Therefore unnecessary drug use should be avoided, otherwise the health of these organs deteriorate and eventually fail to carry out their basic functions.

As noted above, events that are taking place within many of our organs, stomach and elsewhere like kidneys impact on the journey of drugs in our body, therefore changing its effect. The harmonious creation of our organs that are home to many miraculous events is the major component of the entire process in which causations have their due role only as much as they are allowed by their Creator. As a test for humankind, both illness and the cure is provided by God, the All-Healer. Therefore it is the duty of a patient to see a doctor, take the medication properly and never forget that cure is only provided by the Almighty, without obsessing over causational chains.

References

• Guyton, Arthur C., John E. Hall. 1991. Textbook of Medical Physiology, Saunders.
• Patton, Kevin T., Gary A. Thibodeau. 1993. Anatomy & Physiology, Mosby.
• Rang, Humphrey P., Maureen B. Dale, James M. Ritter. 1999. Pharmacology, Churchill Livingstone.
• Brunton, Laurence, John Lazo, Keith Parker. 2006. The Pharmacological Basis of Therapeutics. McGraw-Hill Professional

Why is this surface area so large? What could the wisdom behind it be? Tiny endoplasmic canals play a role in inner cell transportation and distribution of matter. ER is the organized industry district in the cell. Most of the factories of molecules produced by chemical reactions are found here. ER is the production spot in the cells of proteins and hormones. Consequently, a broad surface area is very necessary and important.

Different degrees (pH) of acid are necessary for each reaction. However, because the acid necessary for one reaction can negatively affect the other reactions, thousands of opposite, intricate and different reactions take place. For this reason, membrane surface areas need to be wide. Sometimes hundreds of protein molecules are produced in just a second in a cell. The rapid and flawless lining up side-by-side of tens, hundreds or thousands of amino acids can only be achieved with a knowledge and power that surpasses these very small structures.

Wrapping the inside of the cell like a web and forming a buffer against mechanical effects, ER is responsible for establishing the flexibility and soundness of the cell. In muscle cells, ER takes the name Sarcoplasmic Reticulum (SR), which has a very important duty in the contraction of muscles. The size of the surface area of SR in the muscles of the structural frame is proportionate to the speed of muscle contraction. Consequently, there is more SR in muscle cells where there is rapid contraction. SR also serves as a calcium depot in muscle cells. Normally calcium is a deadly poison for the cell, and for this reason it is kept out of the cell. The concentration of calcium outside the cell is 10,000 times more than it is inside the cell. However, SR stores calcium in the cell in its own body. Thus, it both prevents the cell from being harmed and it provides the necessary calcium for contraction.

ER has the duty of eliminating the poison in the liver cells from the body by means of gall. For example, jaundice-causing bilirubin is a deadly poison for the brain especially in newborn babies. If jaundice is not treated, motor loss (paralysis) and intelligence loss can result from brain damage. Bilirubin and glucuronic acid combine by means of some enzymes on the surface of ER in the liver and are thrown into the gall bladder. In this way ER plays an important role in making foreign matter harmless and in reducing the side affects of medications to a minimum. Babies’ sensitivity to some medications during the first three months of life is due to ER’s not yet being developed enough to eliminate their harmful effects.

If it is taken into consideration that all of these mechanisms exist in human, animal and plant cells, it can be clearly seen that a broad and complex structure in such a small volume and its many functions can only have been placed there by the All-Powerful whose knowledge, wisdom, artistry, will and power permeate every moment and every spot.

Celaloglu is a freelance writer from Turkey with a degree in biology.