My most recent visits were to Pakistan and Finland, two countries that on the surface have very few in common, if any, in terms of continent, climate, people, culture, population, economy, politics, stability… you name it. And my conviction was once again confirmed that it is absolutely a necessity to see a country with your own eyes and get firsthand knowledge to be able to see beyond what you have through other means.

The Fountain presentation on media and values was conducted in four universities with great interest and participation. Students and faculties actively joined the discussion with invigorating questions on the universal themes and values The Fountain cherishes. Despite what the Western mind would expect of Pakistan, interestingly, the female ratio in the academia is visibly very high and their voice is no less strong than their counterparts in the West.

Finland has its own texture and character by all means. Although it was mid-April, there were still pockets of muddy snow especially in the northern-facing shades of the landscape and buildings. Hardly anyone in the streets was around, even at the airport terminal, with the exception of those enjoying the spring sun during their lunch break.

However different any given country might be from another, culture of coexistence is inevitably a common theme in both regardless of continent or culture. The Minister of Culture and Sports, Paavo Arhinmäki, who opened the conference organized by Finland Dialog Association and The Fountain in Helsinki on April 24, said “Encountering ethnic and cultural diversity is no longer the experience of just a few. It has become an everyday reality for many more people worldwide. Interactive skills and conflict resolution must become part of everyone’s civil preparedness. The desire to participate and act only becomes greater through personal involvement.”

This quote summarizes the universality of our need for greater awareness of peaceful coexistence and proves that our differences are a richness of diversity. Hence, this is one of the many reasons why The Fountain is actively engaged in different continents and societies and what we try to reflect in the contents. In the same vein, this issue covers themes that are universally relevant, like What It Means to Be Human, food safety, environment, bad memory, and senior citizens. This issue also offers thought-provoking articles on natural sciences, appreciating the compatibility of the type of food animals consume with their digestion system, the perfect physical make-up of birds, and the very interesting balance in the world that is bound with its rotation. Challenges in the gifted education are also separately discussed.

For those of you in the northern hemisphere, we wish you a good summer, and a reasonable winter for those of you in the south.

In the early 1970s, a young graduate student, Richard Blakemore, observed an interesting group of bacteria in a mud sample collected from Eel Pond in Massachusetts. These bacteria were migrating through a certain edge of the microscope slide. Rotating the slide did not affect their motion; they were still moving through north. Repeating the experiment in the dark also showed that it was not light that affected the bacteria’s swimming direction. The experiments left one possible explanation to the directed motion of the bacteria and that was a crazy one-that they were sensing the magnetic field of the earth! It wasn’t hard for Blakemore to place a magnet next to the microscope slide and to prove that the crazy idea was indeed true. The bacteria were attracted by the south pole of the magnet and repelled by the north pole of it. This was the beginning of a new field of an interdisciplinary research, which attracted many scientists from very different fields such as, microbiology, physics, geophysics and paleogeology.

To understand how magnetotactic bacteria feel the magnetic field, it would be useful to check one’s transmission electron micrograph (Figure 1). The chain of magnetite (iron oxide) crystals forming a specialized organelle, called magnetesome, can be seen easily. The length of the whole chain is around one micron and each small crystal is around 50-60 nanometers. Each small crystal can be considered as a small magnet. These small magnets are aligned in a way that they support each other and the chain becomes a strong magnet. A lipid bilayer membrane surrounds this chain and holds them together. Forming chains on a straight line is not an expected behavior for small magnetite crystals. If they are produced synthetically, they accumulate together to form an aggregate. The pathways of chain formation in magnetesome are still an open question.

Magnetotactic properties are not limited to a certain species. There are many different bacteria that have magnetotactic properties. Therefore the magnetesomes may differ in size, length and even in chemistry. Some magnetotactic bacteria have greigite (iron sulfide) minerals instead of magnetite. Alsothere are magnetotactic bacteria that have more than one magnetesomes. (Figure –2)

Magnetesomes passively align bacteria parallel to the geomagnetic field but do not exert a force on bacteria to change their speed. Aligned with the magnetic field, the bacteria decide to either move towards south or north. Interestingly, almost all magnetotactic bacteria in northern hemisphere are north seeking, almost all magnetotactic bacteria in southern hemisphere are south seeking, and magnetotactic bacteria living around the geomagnetic equator consist of almost equal number of bacteria of each magnetic polarity. The bacteria in northern and southern hemispheres may have different polarities but they have one thing in common; they both move downwards. The geomagnetic field is not exactly parallel to the earth’s surface except around the geomagnetic equator. As it may seem in figure-3, the magnetic field lines are tilted up and down respectively in southern and northern hemispheres. Therefore the north seeking bacteria in northern hemisphere end up at the bottom of the water and so do the south seeking bacteria in southern hemisphere. Most of the magnetotactic bacteria cannot survive in atmospheric oxygen levels, so sensing vertical position and moving downwards, where oxygen concentration is low, is crucial for them.

Being north seeking or down seeking, i.e. polarity, is a genetic property for magnetotactic bacteria. Almost all progenies (descendants) of a north-seeking cell are also north-seeking cells. However this requires partition of magnetesomes to each daughter cell during the division. Occasionally, daughter cells may have no magnetesomes or they maybe too small to have a magnetic moment, so they develop their own magnetesomes. When these progenies develop their own magnetesomes they may have either polarity. Therefore any natural population of magnetotactic bacteria has less than 0.5% “wrong” polarity members. Wrong is written in quotation marks because without that “mistake” magnetotactic bacteria would live only in one hemisphere of the earth.

Magnetotactic bacteria are not the only creatures that can sense geomagnetic field. For example birds, also, can sense geomagnetic field and find their direction while they are migrating. However, birds use other factors such as sun and the horizon to find their direction and their body is much more complex. Also they do not sense magnetic field in a mechanical way like magnetotactic bacteria do, but probably they have some complex chemical ways of magnetic reception. That is another research field by itself and this article’s volume is not enough to go into it.

Everything, every entity that we see around us calls us to reflect upon their Creator. The ones that we see with electron microscopes or high-tech tools are not exceptions. Magnetotactic bacteria synthesizes magnetite crystals from scratch and then puts them in an order like beads hitched on a string. Could it be possible for them to manage this incredible task on their own accord and without acting in the name of God? To this day we cannot even understand the basic principles of that process to its complete degree in order to mimic it. In fact, the more we understand the more we esteem and at awe we become from the great craft of Supreme Artist.

Auroras (northern lights), with their beautiful colors, make long winter nights more bearable in Arctic Circle. They are emitted by charged particles, something very harmful for living creatures if ever reached to earth’s surface and trapped in earth’s geomagnetic field. (Figure-4) While thinking about magnetotactic bacteria I remember those beautiful scenes I had seen in pictures that had caught my awe and wonder and can’t help but express deep gratitude once more to the Creator and Sustainer of it all, of us all, who guides the tiny little cells to more livable environments with the very same geomagnetic field that He protects us from harmful solar winds. Extraordinary is the ordinaries we are surrounded by!

Ahmet Uysal is a PhD candidate in Physics at Northwestern University, Evanston, IL.

References

1. Richard P. Blakemore, 1982, “Magnetotactic bacteria”. Ann. Rev. Micrbiol. 36:217-238
2. Dirk Schüler, 2008, “Genetics and cell biology of magnetesome formation in magnetotactic bacteria”. FEMS Microbiol. Rev., 32:654-672
3. Arash Komeili, 2007, “Molecular mechanisms of magnetesome formation”. Annu. Rev. Biochem. 76:351-366
4. Thorsten Ritz, Salih Adem, and Klaus Schulten, 2000, “A model for photoreceptor-based magnetoreception in birds”. Biophysical Journal. 78:707-718
5. http://www.birdgeo.com/images/CTE1810.jpg
6. http://solar-center.stanford.edu/images/solar-wind-magfield_b.gif