Artificial photosynthesis transforms CO₂ into liquefiable fuels

Yu and Jain. Plasmonic photosynthesis of C1–C3 hydrocarbons from carbon dioxide assisted by an ionic liquid. Nature Communications, May 2019.

Scientists have recently established a reliable “artificial photosynthesis” paradigm to produce fuels from water, carbon dioxide, and visible light. With the help of sunlight, chemical reactions between water and CO₂ are catalyzed in plants to generate and store solar energy in the form of glucose. This process is called photosynthesis. In the new study, the researchers developed an artificial process that uses the same mechanisms of natural photosynthesis to convert CO₂ and water into liquid fuel by using electron-rich gold nanoparticles as a catalyst. Gold nanoparticles function in the same role as chlorophyll in natural photosynthesis in the absorbing of light and transferring electrons and protons to catalyze the chemical reactions between CO₂ and water. They are known to be efficient at absorbing light and do not break down or degrade like other metals. The energy stored in the bonds of the hydrocarbon fuel can be freed by the conventional method of combustion or by new-generation, environmentally-friendly power fuel cells, thus producing electrical current. By converting CO₂ into more complex molecules like propane, green-energy technology is now one step closer to using excess CO₂ to store solar energy for use when the sun is not shining and in times of peak demand. While the development of this CO₂-to-liquid fuel may be exciting for proponents of green-energy technology, the artificial photosynthesis process is nowhere near as efficient as it is in plants. New methods should be developed to increase the efficiency of the catalysts and downstream chemical reactions at much higher scales.

Brain area that watches for walls identified

Henriksson et al. Rapid Invariant Encoding of Scene Layout in Human OPA. Neuron, May 2019.

Neuroscientists have identified the part of the human brain whose duty is to help us perceive the barriers which define the navigable space around us, such as walls or ceilings, so that so we can avoid bumping into things and navigate safely through our environment. By way of vision we have an almost instant sense of where we are in space. Although this process feels effortless, it requires the coordinated activity of multiple brain regions and neurons working together to give us this sense of our surroundings. This process has remained unknown. But thanks to a new study, we are a step closer to solving the puzzle. Using cutting-edge brain-imaging technologies, researchers examined the mental responses of volunteers as they were shown images of various three-dimensional scenes. The images depicted a typical room with three walls, a ceiling, and a floor, but then were abruptly changed by the removal of a wall or a ceiling. By doing this repeatedly, the team could pinpoint how the participant’s brain encoded every scene. In the brain scans of the volunteers, one brain area called the occipital place area (OPA) clearly stood out. OPA activity represented the geometry of the scenes and activity patterns, reflected the presence or absence of each component, such as a ceiling or a wall, and projected a detailed picture of the overall configuration. Interestingly, OPA seemed to ignore the surface appearance of the various components such as colors or textures in order to focus only on the geometric patterns. The OPA managed to perform all the necessary computations needed to get a sense of a room’s layout extremely fast – in just 100 milliseconds. In the future, the research team plans to incorporate virtual reality technology to create more realistic 3D environments for participants to experience, hopefully achieving much deeper insights into how our brains process and makes sense of the visual information.

Gut segments are organized by function

Esterházy D. et al. Compartmentalized gut lymph node drainage dictates adaptive immune responses. Nature, April 2019.

As food enters our intestine, it goes through a windy and lengthy journey. A new study provides new insights into how our intestines maximize nutrient uptake while protecting the body from potentially dangerous invading microbes. At first glance, the intestines appear to have a uniform tissue structure. But when scientists looked at them closer, they found that our food-processing canal seems to consist of multiple compartments that pace the immune system’s reactions to the food passing through. Scientists uncovered these functional intestine segments in mice when they examined the intestinal structures called gut draining lymph nodes, which orchestrate immune responses. The researchers found that nodes in different parts of the intestines had different cell composition, and they saw different immune responses between segments when they challenged the mice with a pathogen. They observed less aggressive defenses in the first segments where nutrients are absorbed, and more forceful responses at the end, where pathogens are eliminated. Researchers plan to exploit these immunological differences between the gut segments for treating gastrointestinal disorders. For example, by targeting immune-suppressing drugs to the specific gut segment where they’ll have the most effect, it might be possible to dampen their side-effects. The spectrum of immune responses along the intestines could also be used to make new and better oral vaccines. Thus far, scientists’ efforts to design oral vaccines have been hampered by the difficulty of generating a robust immune response; it is possible that the muted immune response at the beginning of the intestines might be part of the reason why oral vaccines tend to be less effective than injections. Thus, targeting the distant end of the intestine might be much more efficient way of inducing the immune response required.

Flies have two wings that are capable of moving independently from each other; these wings go back and forth on a single axis during flight. Technically, the unequal angles of the wings to the abdominal region could have prevented flight. Yet in the case of flies, this abnormal situation is not a hindrance and results in a harmonious wing stroke.

Let’s bring our palms together over our head and then lower them near our legs. How many times can we make this movement in a second? Let’s say two, three, or maybe four times if we are really quick. Flies have the ability to stroke their wings hundreds of times in just a second. There are benefits associated with this series of movements. The surface of the wings and the rear section of the head are equipped with sensitive hairs that are in charge of registering air currents and mechanical pressures and conducting relevant flight data to the brain. The unwanted effects of air currents towards the body surface and wings during the flight are detected via these hairs that house receptors. Thus, the wings are controlled according to the signals arriving from the brain. Therefore, a fly can feel an air curtain (like an insect screen) against it instantly and often times flies away. Sometimes, they also stroke their wings hundreds of times per second to avoid the negative effects of air resistance on the wings. Without these receptors and serial wing movements, the air current would stick to the wing’s surface and would not let the fly, well, fly.

Is it a fly or a plane?

We sometimes witness comparisons between the flight specifications of planes and flies. However, it is a great injustice to the fly to be put in the same basket as a plane. The products of modern technology, such as a plane, are invented after drawing inspiration from the meaningful skills of animals like a fly. It is not possible to build planes with a wing width smaller than 15 centimeters; there are disadvantages to wings smaller than that in terms of generating lift. On the other hand, flies have much smaller and more fragile wing structures (relative to their bodies) and can maintain their flight in a perfect fashion. When a fly extends its rear legs, covered with hairs designed especially for cleaning the wings, and sweeps them over its wings, doesn’t this suggest a fly is more impressive than a plane?

It challenges mountaineers!

A fly challenges mountain climbers by easily moving on the four walls and ceiling of a room – and even on slippery surfaces like glass. What is its secret?

Its ability to stand or walk on the ceiling without being defeated by gravity is possible via some of its organs. The final sections of fly’s legs are like hooks and the tip of this hook is equipped with suction pads. When flies touch a surface, a sticky fluid is secreted from the suction pads. Flies can remain suspended on the ceiling with the help of this fluid. When it approaches the ceiling, extends its legs to the front and flips towards the opposite direction of its approach, it sticks to the ceiling on its abdomen.

The grand architecture in the eye of the fly

Can you complete a jigsaw puzzle of 8000 pieces in a second without any missing pieces? It seems impossible, but let’s accept that you have. Can you fit this puzzle into an area that’s just a couple of square millimeters? It’s not possible for a man of intelligence to pass this test. However, the fly completes this miraculous task every time it uses its eyes in our rooms. We are unaware of the fact that the fly, which draws patterns of colors under the sun light, has such amazing eyes. Its eye is created to contain nearly 8000 ommatidium, which function almost as small eyes. Different areas can be seen via each ommatidium and once images are put together in the brain, the whole picture forms. Through these tiny eyes, shaped as hexagons that resemble honey combs, a fly can see as close as 2 mm – and can even see behind its body! Because of the wise hexagonal design, the ommatidia are placed in the most economical way possible; there are no missing spaces which could cause a lack of clarity. The optical speed of a fly’s eye is nearly 4-10 times faster than the human eye. Flies can see the ultraviolet section of the light spectrum and this allows them to evade predators easily in dim environments. Every time a fly uses its eyes, it’s as if it gives the message, “Look at how miraculously I’ve been created. Do you think that my creation could have been in vain?” Such complexity is an inspiration to scientists as they try to develop new technologies.

One of the features of flies that surprises scientists most is the way they use a neural network of a very limited number of neurons to perform so many complex movements. Biologist Michael Dickinson expresses his astonishment as to how a neural system of such small scale can accomplish all of these features.

Do not ever kill a fly!

Flies consume plenty of energy during flight. A regular supply of oxygen is needed to compensate for the energy they use. Air is inhaled via a constriction of the abdominal muscles when the fly lands on a surface. However, during the flight, air enters via the serial movements of the wings. Air that enters through the openings of the chitin layer surrounding the fly is transported to cells via small channels.

Flies locate their food via their smell receptors. Thus, a fly in the air easily lands on the food source that it detects. The taste organ detects whether the food is an ideal source or not. Usually, their choices of food are human foods, waste remains, and dirt. There are two tubes located in the mouth of the house fly. It sucks liquid food with one of the tubes; saliva containing enzymes is secreted on the food source with the other hose so that digestion is facilitated. A fly secretes plenty of saliva in order to liquefy the solid foods it prefers.

Flies that use dirt and waste as a nutritional source are considered as disease contracting pests. However, this is a major fallacy. Flies are actually the health officers of the ecosystem. They turn microorganisms ineffective as they take in their food; the digestive enzymes that they carry play role in completing this important task. Due to this important task, it should be remembered that killing a fly is very unfortunate. Great scholar, Bediuzzaman Said Nursi, notes that flies are assigned to terminate unhealthy microorganisms and materials.

Scientists led by Prof. Andy Beattie have noticed that flies are resistant to all kinds of dirt, including from meat and manure. He said that these organisms should be super resistant to infections, otherwise they could not survive and that our work to gain antibiotics from them has been partially successful. In fact, studies focused on obtaining antibiotics from flies started in the past century. English and Swedish scientists isolated certain antibiotics from flies in 1930 and 1947. Efforts to isolate antibiotics from flies continue today.

Reproduction in black flies!

Black flies reproduce quickly. In suitable humidity and temperature, eggs start to hatch in just 10 hours. Larvae feed on liquid materials, though they need bacteria living on solid food to convert it into liquid form. Therefore, an acid is secreted inside the digestive track of the fly that can terminate most of the bacteria. Thus, the insect becomes free of bacteria, ready to fly. One fly can lay more than 100 eggs at one time and between 600 and 1000 in their lifetime. They can lay eggs again after just three days.

When looking at the information we have, it’s clear that flies are acrobatic flight masters with mind blowing features. We should abandon the negativity towards flies and contemplate the perfection of creation by considering their many remarkable skills – and working to discover even more secrets about them.