Category: essay

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The Intelligent Sea Lion

The Intelligent Sea Lion
By Shoshana Harlem, Terra Linda High School


The brain of a sea lion!

Can an animal still be a good scientist without thumbs? The answer is yes, because the sea lion is in this exact situation. Although sea lions have no thumbs, they have a big brain. Their brain is about the same size as a chimpanzee brain. They are one of the few mammals besides dolphins, humans, elephants, and whales that have brains that weigh more than 1.51Lbs. Scientists are not sure why the sea lion has such a big brain, but they think that it might be because they have a large body size and those two usually correspond. Other theories have to do with the weightlessness of the marine environment, coping with cold water temperature, or perhaps it is just a random outcome of evolution.

The sea lion’s brain consists of different regions for processing information from their whiskers. A specific, corresponding, area in the brainstem is devoted to each whisker on the sea lion’s nose. The areas in their brain that are responsible for processing touch information from the whiskers and the skin are the thalamus, cortex, and brainstem. Likewise, the human brain has specific areas which correspond to the individual fingers of a person. The whiskers on the sea lion assist with sea lion behavior and sensation. There are certain areas in the sea lion’s brain which are made for processing touch sensations from their flappers and tail. Scientists don’t know a lot about the sea lions cerebral skills. The sea lion has a particular part of their brain called the Bischoff’s Nucleus, which is very well-developed. It is surprising that sea lions have this part of their brain because it is usually found in animals with prominent tails such as kangaroos, raccoons, and whales. But the sea lion’s tail is tucked and small behind its hind flippers.
A sea lion’s very important whiskers!
On each side of a sea lion’s face, are 38 whiskers. The whiskers can grow to be eight inches in length and are really sensitive. The sea lion produces more nerve fibers than any other animal in the animal kingdom. Its whiskers can be helpful in many ways too. One way is that they use their whiskers is to spot a fish by looking for changes in the flow of the water. They can find fish that are swimming up to 590 feet away from them. The whiskers can also help a sea lion know the differences between shapes and sizes up to as far as a fraction of a centimeter.
Amazingly, the sea lion’s brain is capable of higher cognitive functioning. A sea lion can play a game of Concentration. Through trial and error, they can match unrelated symbol pairs. They can also recognize signals, which is really useful in the wild. In this way they can find food, and know if someone is their friend or their enemy. Sea lions also have the ability to think logically. The can know that if a=b and b=c, then a=c.

To learn more about why sea lions are such good scientists, come to the Marin Science Seminar at Terra Linda High School in room 207 on Wednesday, February 8, 2017. Claire Simeone DVM of the Marine Mammal Center in Sausalito will be speaking. Join us and learn!

Sources:


         

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Space Travel: How Does Outer Space Affect Your Body?

By Rachael Metzger, MSS Intern

          Have you ever wanted to become an astronaut? Travel to space? Have you dreamed about finding extraterrestrial life or communing with aliens? If your answer is yes, I can assure you that you’re not alone. Countless children dream of becoming astronauts, and many movies and TV shows have revolved around exploring space. The exploration of the unknown is a wonderful idea on paper, but it is a lot more complicated than jumping into a spaceship and traveling to Mars, even if we have the technology to do so. Space travel can take a huge toll on a human’s body if certain precautions are not taken; any error could result in death.
        The human body was not made to travel in space, nor has it had time to adapt to such an environment. When launched into space, some effects of that changed environment on the body take longer than others to be felt. Immediately one might experience nausea and/ or vomiting. This is caused by the sensitivity of the inner ear which affects balance and orientation. Thankfully, in a couple of days the inner ear will have adapted to the new environment and the nausea will dissipate (BBC “future”).
        In about two days, bodily fluids will rise to the upper body and face, causing a bloated appearance, and tissues will swell in the head, making a person feel like they are hanging upside down. This makes the body think that it is over–hydrated and it forces the liquid out through urine, causing astronauts to have 20% less fluids in their body while in space.  

Bodily Fluids in Space 
        Spaceflight can also quickly affect eyesight, creating anomalies such as optic nerve swelling, retinal changes in the shape of the eye, and other negative effects to the eye 
        In a week’s time muscle and bone loss can start to occur, and this sometimes includes heart muscle because not as much effort is needed to pump blood in anti-gravity. The lack of gravity can have such an extreme effect on bones that they can become very brittle; this is called “disuse osteoporosis” (The Dallas Morning News “Preparing Bodies for Liftoff”). Even astronauts’ skin will get thinner, making them more prone to cuts and infections which take longer to heal in space. Sleep deprivation is another problem among astronauts. Because of the change in the light-dark cycle, it can be a challenge for the body to adapt to the new sleeping schedule (NASA).  
The Effects of Space Travel on the Body

       After a while aboard a spacecraft, astronauts may find their immune system becoming less effective, making them more susceptible to diseases. Cosmic radiation is another huge issue facing astronauts. Astronauts seeing flashes of light in their brains is proof of the cosmic radiation. Astronauts’ brains could suffer brain damage from cosmic rays over long periods in deep space, affecting their mental performance (BBC “future”).
        All these dangers could be fatal and might make space travel seem impossible, but there are many precautions being taken to allow us to explore our universe in a safer way. Nausea and vomiting can not always be avoided, but anti-nausea pills and a strong stomach help towards inner ear balance in space. To battle losing 20% of bodily fluids, astronauts must stay well hydrated while their bodies adjust to the new climate. The rising of bodily fluids to the upper body may be uncomfortable but has not  been linked to long lasting negative effects on astronauts, and it subsides after a couple of days. Bone and muscle loss is one of the largest problems facing astronauts. On the International Space Station, astronauts stay fit with a machine for weight lifting, a treadmill adapted for microgravity, and a Cyclergometer, which is a modified cycler for microgravity (NASA). Astronauts have a very strict sleeping schedule to try and achieve the maximum hours of sleep possible. Astronauts have to be very careful of keeping waste and bacteria contained that could contaminate their lowered immune systems. For long expeditions such as to Mars, radiation  protection is being experimented with in the forms of water, waste, plastic, and many other substances.
         Being an astronaut involves more than just knowing about your area of study, it requires knowledge of how the human body operates. If your dream is to become an astronaut, consider the risks, know about your body, but don’t be scared off. Medical and technological advances continue to make space flight safer and easier on the human body, presenting an opportunity to explore space to a further extent.


Sources:
1. http://www.nasa.gov/missions/science/f_workout.html
2. http://www.space.com/29309-space-radiation-danger-mars-missions.html
3. http://nsbri.org/the-body-in-space/
4. http://interactives.dallasnews.com/2015/spacebody/
5. http://www.bbc.com/future/story/20140506-space-trips-bad-for-your-health
6. http://www.nasa.gov/content/study-compiles-data-on-problem-of-sleep-deprivation-in-astronauts/


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Ocean Acidification: How the Ocean is Acidifying and Affecting the Organisms That Call it Home

By Zack Griggy, San Marin HS

             Pollution is a global problem. One way to find proof of this is to look to the seas. We all know that the oceans have suffered greatly from pollution, evidence of which can be seen almost anywhere, from areas suffering from oil spills to the huge cluster of garbage floating in the North Pacific Ocean. We also know that many aquatic species are dying and going extinct because of ocean pollution. However, oils spills and trash aren’t the only causes. Another cause is ocean acidification, which is caused by air pollution.
             Ocean acidification begins with carbon dioxide. Carbon dioxide is an essential part of photosynthesis in plants. However, it is also a greenhouse gas, and carbon dioxide emissions have become a global problem. Carbon Dioxide is one of the main contributors to both global climate change and ocean acidification. Carbon dioxide is emitted in huge quantities around the world. Part of these emissions are absorbed by the oceans. This leads to chemical reactions within the oceans to form Carbonic Acid from carbonate and hydrogen ions, which are formed using CO2 absorbed by the oceans. Carbonic Acid is the main cause of ocean acidification. For the past 300 million years, the oceans have had a pH of 8.2, but recently since the industrial revolution, that pH has dropped to 8.1. Estimates say that the ocean acidity may drop by another 0.5 pH
            The effects of ocean acidification can be very harmful to marine ecosystems. Many marine organisms such as arthropods, coral, and plankton will be impacted by ocean acidification. These organisms use the process of calcification to create shells, exoskeletons, etc. Calcification relied on using two ions, carbonate and calcium ions. However, Carbonic Acid also uses carbonate ions, which makes it more difficult for the aforementioned organisms to make their exoskeletons or shells. In addition, when more carbon is absorbed by the oceans, hydrogen ions become more abundant, which makes it increasingly more difficult for the organisms to make their exoskeletons.

Sources:
1. https://www3.epa.gov/climatechange/science/indicators/oceans/acidity.html
2. http://www.iiasa.ac.at/web/home/about/news/150203-Ocean-Acid.html
3. http://www.co2science.org/subject/c/summaries/calcification.php
4. http://www.pmel.noaa.gov/co2/story/Ocean+Acidification
5. http://hilo.hawaii.edu/academics/hohonu/documents/Vol09x06OceanAcidification.pdf

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Insidious Air: Defogging Air Pollution and its Pernicious Effects

By Zack Griggy, San Marin HS

           We all know that smoking is harmful to us, but what if the very air we breathe also contains toxic chemicals? The truth is the air we breathe contains numerous chemicals that have harmful effects on both humans and the environment. As a result, the issue of pollution has been a very important and significant problem. It has driven us to invest in green fuels, manufacture in more eco-friendly ways, and cut down on greenhouse gas emissions. However, the problem of air pollution still remains somewhat untouched. Although emissions have been significantly reduced from vehicles and manufacturing plants, the problem as a whole remains.  Air pollution is known to cause numerous issues for the environment and humans, but particulate matter and ozone pose more immediate threats to human health.
           Particulate matter consists of extremely small particles that are a result from burning and can have huge impacts on lung health. Particulate matter, if small enough, can breach through the body’s defenses (the nose, mucus in alveoli, etc.) and even enter the bloodstream. Clearly, this can cause catastrophic problems for human health, such as decreased lung function, irregular heart beat, heart attacks, or even premature death for people with lung or heart disease. In places like the Bay Area, where there is an abundance of hills, which can trap pollutants in small areas and with larger concentrations, pollution can easily accumulate. To make matters worse, particulate matter also has harmful effects to the environment, which include haze, acidification of water basins, depletion of nutrients in soil, etc. Clearly, particulate matter doesn’t just affect humans. Through depleting the nutrients in soil, particulate matter is capable of killing many sensitive plants and crops. In addition, freshwater acidification known to alter flora and fauna in affected ecosystems via increased acidity and toxicity.
             Ozone is an essential, but toxic, gas. In the stratosphere, ozone forms a protective layer that blocks UV radiation, and allows us to live on land. But the ozone layer and the stratosphere are both a considerable distance away from the Earth’s surface. When ozone is at or near Earth’s surface, it poses a threat to organisms that use that air. Ozone can affect entire ecosystems, beginning with plants. Ozone exposure may cause plants to have decreased photosynthesis, slowed growth, and increased risk of harm from disease, insects, storms, etc. But remember, in an ecosystem, damages at the bottom of the food chain can easily work its way up the food chain. Thus, damages from the plants can affect the entire ecosystem, causing a lack of biodiversity, reduced habitat quality, etc. However, in the case of humans, ozone can be much more pernicious. Humans exposed to smaller amounts of ozone or over a shorter period of time may have decreased lung function, airway inflammation, coughing, painful breathing, increased number of asthma attacks, increased risk of death from respiratory disease, shortness of breath, etc.
            These pollutants, and their effects, might seem unpreventable, but really it is the opposite. Both particulate matter and ozone are either emissions, or formed from other emissions. So, we return to the question: how do we prevent the effects of these pollutants? The answer: cut down on emissions. For example, particulate matter is often released during burning, especially burning wood or coal, so if we curtail our burning of wood and coal, we can reduce the effects and quantity of particulate matter. The choice of whether or not to poison our own air rests with everyone. Be sure to make the right choice

Sources:
1. Sitting by a Cozy Fire – Wood Burning, Air Quality, and Your Health (from notes taken during seminar)
2. What’s Getting into Your Lungs? The Effects of Smoke, Ozone, Allergens, and More (from notes taken during seminar)
3. http://www3.epa.gov/pm/health.html
4. http://www.air-quality.org.uk/13.php
5. https://www3.epa.gov/apti/ozonehealth/population.html
6. https://www3.epa.gov/pm/
7. https://www.epa.gov/ozone-pollution/ecosystem-effects-ozone-pollution

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A Tale of Two Tremors: The Nepal Quake and the San Ramon Swarm

by Zack Griggy, San Marin HS

            The earthquake is an awe-inspiring disaster that can occur anywhere at anytime where two tectonic plates contact. Tectonic plates make up most of the Earth’s crust and move freely, so they can rub up against, move away from, or compress against other tectonic plates, which results in huge amounts of energy. The place where said actions occur are called faults. Earthquakes are the result of rocks along the fault breaking as the faults move. This releases all the pent-up energy from the tectonic plate movement, and results in a tremor. There have been countless earthquakes recorded, but recently, there have been many events in particular that have attracted a large amount of attention in the seismological community, among which include the San Ramon Swarm and last April’s Nepal Quake.

Destruction from April’s Nepal Earthquake

             Since October 15, the town of San Ramon in Contra Costa County, California has been rattled by more than 200 small earthquakes. Thirty of which occurred over two days. The tremors have been small, the largest to date barely reaching 3.2 on the Richter Scale. According to the US Geological Survey, there have been numerous instances of earthquake “swarms,” where numerous earthquakes occur in a close vicinity and in a short period of time. However, the past swarms have occurred over a long period of time, which raised the question of how long this swarm will last. The longest swarm was in the nearby town of Alamo that lasted 42 days with over 350 earthquakes. Residents are concerned about the earthquake swarm but seismologists say that the swarm may be beneficial, because the fault is releasing pent up energy and abating the risk of a large magnitude tremor for years to come.
            However, earthquakes are very capable of wreaking havoc into both the developed and undeveloped world. The recent Nepal Quake of last April is an example of the destructive power earthquakes possess. This quake, centered about 85 miles from Nepal’s capital of Kathmandu, was responsible for the death of over 8000 people and the destruction of over half a

A diagram that shows the risk for earthquakes worldwide

million homes. Millions are still in need of humanitarian aid because of this quake and its aftershocks. The quake reached 7.8 on the Richter Scale, which made this tremor more than 800 thousand times stronger than the strongest tremor in the San Ramon Earthquake Swarm. What really raises concerns however, is the realization that a quake like this could happen almost anywhere. According to TIME, the three cities most at risk for a large magnitude earthquake are Tehran, Istanbul, and Los Angeles. These are densely populated cities, and the fallouts of a large earthquake there could be devastating.

Sources:
1. http://www.ktvu.com/news/east-bay-news/32982571-story
2. http://www.sfgate.com/bayarea/article/Small-earthquake-strikes-in-area-of-recent-swarms-6590014.php#photo-8857844
3. http://www.ga.gov.au/scientific-topics/hazards/earthquake/basics/causes
4. http://time.com/3882272/nepal-earthquake-death-toll-2/
5. http://time.com/3838716/earthquake-risk-nepal/

To learn more about earthquakes and the science behind them, attend Dr. Diego Melgar’s presentation on Wednesday, November 15, 2015 from 7:30 – 8:30 at Terra Linda High School, Room 207, 320 Nova Albion Way. 

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Angiosperms: How the Disappearance of Bees Put Flowers At Risk


By Zack Griggy, San Marin HS

          Plants are unique organisms. They have unique cell structures, ways of making energy, and reproduction. There are many different kinds of plants, but a category of plants called angiosperms makes up 80% of plants. But some of these angiosperms are at risk, as bees and other pollinators, which are vital to angiosperm reproduction, are disappearing.
         Plant reproduction varies among different kinds of plants in two significant ways. The two distinguishing factors that divide the kingdom Plantae are seeding and flowering. Angiosperms are the only group of plants that makes both flowers and seeds.

The various parts of a flower.

         Flowers are the reproductive system of an angiosperm. In a flower, two structures in particular play a vital role in plant reproduction. These parts are the pistil and stamen of a flower. The pistil consists of the ovary, the style and the stigma. The ovary is a small are in the bulb of the flower where eggs are stored. Atop the ovary is the style, a narrow region of the pistil that elevates the stigma. The stigma is the tip of the pistil that catches pollen and directs it down a tube so it can fertilize an ovule. The stamen consists of anthers and filaments. The anther rests atop a filament, which is a long narrow structure that supports the anther, and produces pollen, which can fertilize ovules in the ovary. The plant uses pollination to move pollen from the stamen to the pistil. However, the anther is not capable of pollinating on its own, as the pistil and anther are separated by a small distance. Something needs to pollenate the flower, whether it be wind or a pollinating insect, for the plant to be able to reproduce.
          Bees are unbelievably important pollinators. According to the Michigan State University, bees play a huge role in the environment by maintaining many plant communities. Many of these pant communities are farmed for food. Most fruits and nuts, along with cotton and alfalfa are maintained by bee populations. We need bees for our food and as our population grows, so will our need for bees. 
          Unfortunately, the bee population has been declining over the past 50 years. The decline of the bee population is due to many causes, including pesticides, colony collapse disorder (in which worker bees leave their queen and a few young and nursing bees), predators, and carnivorous plants. These causes are serious threats to the bee population and therefore a serious threat to us.
          Angiosperms are flowering plants that make up 80% of the plant population. They are at risk because bees, their primary source for pollination are disappearing. This can lead to agricultural problems for humans when bees cannot pollinate all of our crops.

Sources:
http://nativeplants.msu.edu/about/pollination
http://www2.epa.gov/pollinator-protection/colony-collapse-disorder
http://time.com/3821467/bees-honeybees-environment/

To learn more about the disappearance of bees, attend Dr. Amber Sciligo’s research presentation on Wednesday, October 21st at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30. 

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Carnivorous Plants

by Jane Casto, Terra Linda High School Freshman

Carnivorous plants is a term often associated with flies and Venus fly traps. There is much more however, to learn about these organisms, and about their complex functions that allow optimal survival and ideal food supply. Scientists have been unraveling the true genius of these plants for years, and even now, breakthroughs are being made in research. To begin, we answer the question: what is a carnivorous plant? 
Carnivorous plants, or insectivorous plants, are plants that have adapted to consuming and digesting insects and other animals. These plants work in a variety of ways based on their species, of which there are 600 known to man. The basic understanding of the makeup of carnivorous plants is uniform throughout the different species. Carnivorous plants have adapted to a low-nutrient environment, making digestion of invertebrates optimal, as it is a low-nutrient energy method of consumption.
the Venus fly trap’s deadly leaves, the vibrant trap ready for action

In the example of a Venus fly trap, this ability to digest small insects and organisms is remarkably dependent on the transfer of electrical signaling. According to ScienceLine, “Each trap is actually a modified leaf: a hinged midriB . . which joins two lobes and secretes a sweet sap to attract insects.” This modified leaf is constant throughout all carnivorous plants, while the sap it produces varies in color, sweetness, and other qualities. Following the example of a Venus fly trap, the sap can attract virtually any small creature, and thus, the Venus fly trap often digests small frogs along with the usual fly. When the actual trap of the Venus fly trap is open, the red belly is exposed for all invertebrates to see. Once the prey has been attracted to the trap, the lips of the trap, or the lobes, close within one tenth of a second! So how does a plant move so quickly?
The answer is within the lobes of the Venus fly trap, where three or more small hairs lie. These hairs act as sensors, and if something brushes against two of these hairs, or brushes against one hair twice, the lobes of the plant will snap shut within 30 seconds of initial contact.
small hairs on specialized leaf, or lobe, of the Venus fly trap.
The science behind the closing of the trap is in the pressure caused by something brushing against the hair. This mechanical energy is translated into electrical energy, causing a small electrical signal. This electrical signal is enough to open pores within the center of the lobe, which allow water flow between the cells on the surface of the lobe. Thus water is transferred from the inner layers of the cells to the outer layer of the cells. During the transfer of water, the pressure within the lobes is drastically changed, causing the lobes to invert. This is how the effect of the Venus fly trap is achieved. 
These beautiful and deadly plants have a unique way of maintaining survival, and in turn are incredibly interesting to learn about and study. 
More on carnivorous plants and when
insects fall victim to them
during the October 21st seminar,
7:30 – 8:30 P.M.
Terra Linda High School, Room 207
320 Albion Way, San Rafael, CA 94903
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E-Cigarettes: A Subtle Danger?


By Zack Griggy, San Marin HS

          E-cigarettes, or electronic cigarettes, are marketed as a healthier and safer cigarette. But is it really? Multiple organizations, such as the Centers for Disease Control and Prevention and the World Health Organization have found that they are not at all safer that traditional cigarettes.

Newer e-cigarettes sometimes don’t resemble
traditional cigarettes at all.

          A traditional cigarette burns the leaves from the tobacco plant. Tobacco is a plant that naturally contains nicotine, the main addictive agent in cigarettes. Nicotine is also used as a strong insecticide and is so strong that a drop of pure nicotine can kill a person. When tobacco is burned, nicotine is released in the smoke. The smoker can then inhale the smoke and experience a high feeling, which is caused by excess levels of dopamine from the nicotine. In addition to

tobacco,cigarettes can also contain thousands of toxic chemicals, the purpose of which could be anything from making cigarettes combustible to enhancing the addictive effects of the nicotine.

          An e-cigarette, on the other hand, vaporizes liquid nicotine, and releases vapor. The process of smoking e-cigarettes was dubbed “vaping” because of this process. The e-cigarette is composed of a cartridge that contains e-liquid, an atomizer that heats the e-liquid, a battery, a sensor that determines when someone is taking a drag and activates the atomizer, and, sometimes, a light that simulates smoking. When a person decides to take a puff of the vapor, the sensor detects this and activates the light and atomizer. The atomizer, once activated, vaporizes the e-liquid and then releases the vapor so it can be inhaled.

E-cigarettes are composed of five parts. The orange section is
composed of the sensor and cartridge. The metallic silver section is the
atomizer. The white section is the battery and light.

          E-cigarettes are widely marketed as a safer way to get high off of nicotine, but the FDA has found that contrary to the marketing, e-cigarettes are not safe. E-cigarettes are not yet regulated by the FDA. This means that e-cigarette manufacturers do not have to list any or all of the nefarious substances found in the e-liquid. So, when someone “vapes,” they inhale all sorts of unknown chemicals. With
e-cigarettes, one might be inhaling a few toxic chemicals or a few thousand. However, e-cigarettes are slightly healthier than traditional cigarettes, mainly because e-cigarettes do not result in as much smoke as traditional cigarettes.
          To make matters worse, e-cigarette use is on the rise. E-cigarettes were invented in 2003, but has only recently gained popularity. Now, it is the most commonly used tobacco product in US high schools, and from 2013 to 2014, e-cigarette use among high school students tripled from 660,000 students to over 2 million students. E-cigarette use is clearly a growing problem. Marketing, mostly the TV marketing, was attributed to this recent spike in e-cigarette usage.
          E-cigarettes in spite of their marketing, are not safe products. E-cigarettes contain nicotine, a poisonous chemical, and all sorts of other unknown toxins. Because of marketing, e-cigarette use is increasing. E-cigarettes are slightly healthier than traditional cigarette because there is not nearly as much smoke produced.
       
Sources
1.http://healthliteracy.worlded.org/docs/tobacco/Unit4/1whats_in.html
2.http://www.drugabuse.gov/publications/research-reports/tobacco/what-are-medical-consequences-tobacco-use
3.http://www.nbcnews.com/tech/tech-news/vaping-101-how-do-e-cigarettes-work-n88786
4.http://www.nbcnews.com/health/health-news/5-facts-about-e-cigarettes-fda-no-its-not-ban-n88746
5.http://www.cdc.gov/media/releases/2015/p0416-e-cigarette-use.html

To learn more about e-cigarettes and the risks attributed to them and other important health issues, be sure to join us Wednesday, October 7th, to hear Julie Pettijohn MPH of the California Department of Public Health discuss these important topics at Terra Linda High School, 320 Nova Albion Way, in Room 207 


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Bacteria, Botulism, and Beauty

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By Talya Klinger, MSS Intern

The molecular structure of botulinum toxin
What do foodborne illnesses, neck dystonia treatments, and celebrities’ beauty regimens have in common? Clostridium botulinum, baratii, and other species of Clostridium bacteria produce all of the above and more. These seemingly innocuous, rod-shaped bacteria, commonly found in soil and in the intestinal tracts of fish and mammals, produce one of the most deadly biological substances: botulinum toxin, a neurotoxin that intercepts neurotransmitters and paralyzes muscles in the disease known as botulism. Nonetheless, botulinum toxin isn’t all bad: this chemical not only protects the bacteria from intense heat and high acidity, but it makes for an effective treatment for medical conditions as wide-ranging as muscle spasms, chronic migraines, and, yes, wrinkles. 


C. botulinum
Clostridium botulinum and similar bacteria can make their way into the human body in a number of ways. Wounds infected with Clostridium botulinum or spores ingested by infants can lead to the rare but serious disease of botulism, as can accidental overdoses of medicinal or cosmetic botulinum toxin. Botulism is often foodborne, usually contracted by infants from honey or by adults from improperly home-canned foods and unrefrigerated herb-infused oils. Regardless of where any case of botulism comes from, it causes muscle paralysis, which can manifest as blurred vision, dry mouth, and muscle weakness in adults or lethargy and constipation in infants. These are only early warning signs for an illness that, if left untreated, can paralyze a patient’s respiratory muscles to the point of asphyxiation. Although 95-97% of botulism patients receive treatment and survive, they often require months of intensive care and suffer years of muscle weakness, fatigue, and shortness of breath.

So how does the neurotoxin that makes botulism so deadly work? Clostridium bacteria produce several protein compounds with similar structures and molecular weights, consisting of two chains of amino acids—one small and one large. These two amino acid chains are linked together by a covalent bond between two sulfur atoms, one in each chain. The botulinum toxin proteins bind to nerve endings where they join muscles, blocking the neurotransmitter acetylcholine, which ordinarily causes muscle contractions. This blockage is permanent, paralyzing the muscle until a new nerve ending forms a synaptic connection with it. Because the process of forming new neuromuscular junctions takes at least 2 or 3 months, the affected muscle will often atrophy in the meantime, causing the long-term side effects that plague botulism survivors.

Ironically, the very mechanisms that make botulinum toxin so dangerous give it a wide range of beneficial medical applications. When botulinum toxin is administered in small, controlled doses, its muscle-contraction preventing effects make it a viable treatment for neck dystonia, sustained involuntary eyelid closure, chronic migraines, neurogenic bladder dysfunction, and other conditions caused by involuntary muscle movements. In popular culture and tabloid media, Botox’s serious medical applications are often overshadowed by its cosmetic notoriety: smoothing out wrinkles. Cosmetic Botox inhibits the neuromuscular activity that leads to wrinkles, relaxing the surrounding skin. Seeming to reverse one of the telltale signs of aging may have given botulinum toxin its Hollywood appeal, but its wide ranging pharmaceutical uses are what continue to fascinate research scientists.

In a nutshell, the molecule botulinum toxin is a toxic protein made by clostridium botulinum bacteria. In measured amounts, the toxic protein is marketed as Botox for pharmaceutical uses. When uncontrolled doses of the bacteria are ingested, however, Clostridium botulinum can result in deadly cases of muscle paralysis called botulism. 

 If you are intrigued by the terrible beauty of such a versatile molecule as botulinum toxin, come to Marin Science Seminar on September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm, when bioanalysis and pharmacology expert Dr. Erik Foehr will discuss his research on botulinum toxin.


Images:
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Chemosynthesis in the Deep Sea

Chemosynthesis In the Deep Sea
by Jane Casto, MSS Intern, Terra Linda High School
     
          The deep sea- where cold, stable pressures and darkness rule. Within that darkness lies life; a broad spectrum of biodiversity. The most fascinating thing about the deep sea, however, lays within what goes against lifeforms on land. 
          On land, plants and animals alike require some form of energy. The same is true in the deep sea, but one thing, particularly about plants, is quite different. Photosynthesis, the process plants use to turn sunlight into usable energy through chlorophyll, is almost always the method that plants use to get said energy. However, in the deep sea, quite a difference can be seen with that process.
          One of the reasons as to why deep sea ecosystems, such as hydrothermal vents, do not use the process of photosynthesis is obvious. Little sunlight reaches that far down into the ocean. With that in mind, however, the question presents itself: how do these ecosystems get their energy?
          Jenna Judge has studied just that. Her research has been following Marine Biology, specifically the deep sea and, our answer, chemosynthesis. Chemosynthesis is the process in which energy is obtained by reactions of inorganic chemicals, occurring within bacteria and other living organisms. 
          “Chemosynthesis also seems to be fueling ecosystems at organic substrates, such as whale falls and wood falls.” Jenna said during her presentation, Patterns of Specialization in the Deep Sea, “We found that rather than sunlight fueling this reaction, it’s reduced molecules such as sulfide, and in other cases, methane, than can fuel these microbial metabolisms.” 
          According to wiseGEEK.org, the process relies on oxidation, or redox reactions. Organisms, namely bacteria and those that belong to the kingdom archea, use chemosynthesis to manufacture food. This food is used as a carbohydrate, made of carbon dioxide and water, rendering it usable for the bacteria just as a carbohydrate would be usable to us. 
          While the deep sea is one of the most extreme examples of chemosynthesis, believe it or not, chemosynthesis is also found on land. The key is that chemosynthesis occurs where sunlight is not present. Therefore it can occur in a variety of places above land, i.e. in soil, in the intestines of mammals, and in petroleum deposits. In fact, some scientists believe that due to the tendency of chemosynthesis to take place in extreme environments, it may feature prominently on other planets depending on weather patterns. 
          The deep sea has many unexplored aspects. It is nice to know that some things are no longer a mystery, and it is also exciting to think about the fact that it is not yet fully explored, leaving room for ventures for years to come.
Wednesday, September 9th, 2015
7:30 – 8:30 pm
Terra Linda High School, San Rafael
Room 207
        
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