Nomming on Nanotechnology: The Presence of Nanoparticles in Food and Food Packaging

Catalyst Volume 9

Nanotechnology is found in a variety of sectors—drug administration, water filtration, and solar technology, to name a few—but what you may not know is that nanotechnology could have been in your last meal.

Over the last ten years, the food industry has been utilizing nanotechnology in a multitude of ways.¹ Nanoparticles can increase opaqueness of food coloring, make white foods appear whiter, and even prevent ingredients from clumping together.¹ Packaging companies now utilize nano-sized clay pieces to make bottles that are less likely to break and better able to retain carbonation.² Though nanotechnology has proven to be useful to the food industry, some items that contain nanoparticles have not undergone any safety testing or labeling. As more consumers learn about nanotechnology’s presence in food, many are asking whether it is safe.

Since the use of nanotechnology is still relatively new to the food industry, many countries are still developing regulations and testing requirements. The FDA, for example, currently requires food companies that utilize nanotechnology to provide proof that their products won’t harm consumers, but does not require specific tests proving that the actual nanotechnology used in the products is safe.² This oversight is problematic because while previous studies have shown that direct contact with certain nanoparticles can be harmful for the lungs and brain, much is still unknown about the effects of most nanoparticles. Currently, it is also unclear if nanoparticles in packaging can be transferred to the food products themselves. With so many uncertainties, an activist group centered in Washington, D.C. called Friends of the Earth is advocating for a ban on all use of nanotechnology in the food industry.²

However, the situation may not require such drastic measures. The results of a study last year published in the Journal of Agricultural Economics show that the majority of consumers would not mind the presence of nanotechnology in food if it makes the food more nutritious or safe.³ For example, one of the applications of nanotechnology within the food sector focuses on nanosensors, which reveal the presence of trace contaminants or other unwanted microbes.⁵ Additionally, nanomaterials could be used to make more impermeable packaging that could protect food from UV radiation.⁵

Nanotechnology could also be applied to water purification, nutrient delivery, and fortification of vitamins and minerals.⁵ Water filters that utilize nanotechnology incorporate carbon nanotubes and alumina fibers into their structure, which allows microscopic pieces of sediment and contaminants to be removed from the water.⁶ Additionally, nanosensors made using titanium oxide nanowires, which can be functionalized to change color when they come into contact with certain contaminants, can help detect what kind of sediment is being removed.6 Encapsulating nutrients on the nanoscale-level, especially in lipid or polymer-based nanoparticles, increases their absorption and circulation within the body.⁷ Encapsulating vitamins and minerals within nanoparticles slows their release from food, causing absorption to occur at the most optimal part of digestion.⁴ Coatings containing nano-sized nutrients are also being applied to foods to increase their nutritional value.⁷ Therefore, there are many useful applications of nanoparticles that consumers have already shown to support.

While testing and research is an ongoing process, nanotechnology is already making food safer and healthier for consumers. The FDA is currently studying the efficacy of nanotechnology in food under the 2013 Nanotechnology Regulatory Science Research Plan. Though the study has not yet been completed, the FDA has stated that in the interim, it “supports innovation and the safe use of nanotechnology in FDA-regulated products under appropriate and balanced regulatory oversight.”^8,9 As nanotechnology becomes commonplace, consumers can also expect to see an increase in the application of nanotechnology in food and food packaging in the near future.

References

1. Ortiz, C. Wait, There's Nanotech in My Food? http://www.popularmechanics.com/science/health/a12790/wait-theres-nanotechnology-in-my-food-16510737/ (accessed November 9, 2015).
2. Biello, D. Do Nanoparticles in Food Pose a Health Risk? http://www.scientificamerican.com/article/do-nanoparticles-in-food-pose-health-risk/ (accessed October 1, 2015).
3. Yue, C., Zhao, S. and Kuzma, J. Journal of Agricultural Economics. 2014. 66: 308–328. doi: 10.1111/1477-9552.12090
4. Sozer, N., & Kokini, J. Trend Biotechnol. 2009. 27(2), 82-89.
5. Duncan, T. J. Colloid Interface Sci. 2011. 363(1), 1-24.
6. Inderscience Publishers. (2010, July 28). Nanotechnology for water purification. ScienceDaily. (accessed March 3, 2016)
7. Srinivas, P. R., Philbert, M., Vu, T. Q., Huang, Q., Kokini, J. L., Saos, E., … Ross, S. A. (2010). Nanotechnology Research: Applications in Nutritional Sciences. The Journal of Nutrition, 140(1), 119–124.
8. U.S. Food and Drug Administration. http://www.fda.gov/ScienceResearch/SpecialTopics/Nanotechnology/ucm273325.htm (accessed November 9, 2015).
9. U.S. Food and Drug Administration. (2015). http://www.fda.gov/ScienceResearch/SpecialTopics/Nanotechnology/ucm301114.htm (accessed November 9, 2015).

Megafires

Catalyst Volume 9

In 2015, American forests were ravaged by larger and more destructive fires than ever before. One of the most devastating wildfires occurred in Washington State and burned over 250,000 acres of forest at a rate of 3.8 acres per second.¹ These unprecedented grand burns of over 100,000 acres have been justifiably coined by researchers as “Megafires.”² Unfortunately, megafires are becoming an increasingly common feature of the American West.

Although forest fires are a natural and essential part of a forest’s life cycle, scientific records show a worrisome trend. Data from the National Climate Center in Asheville, North Carolina indicate that recent fires burn twice the forest acreage as wildfires 40 years ago.³ In contrast to replenishing wildfires that promote forest growth, megafires scorch the landscape, disabling forest regeneration and leaving wastelands in their wake.² In other words, they burn forests so completely that trees are unable to regrow.⁴ The increased incidence of megafires accordingly threatens to cause environmental change, particularly in the Western United States.⁵ Once-rich forests are now in danger of depletion and extinction as they give way to grasslands and shrubs. Even the hardy Ponderosa Pine, previously thought to be completely flameproof, is succumbing to megafires.⁵

What is the future of our forests, and what can we, as custodians of our natural lands, do to shape this future? Can we prevent megafires? Understanding the contributing causes of megafires is essential in devising a solution to prevent them. Current thinking by various ecologists identifies three primary causative factors, both behavioral and environmental: new firefighting strategies, the rise of invasive species, and climate change.¹

Government policies that promote aggressive control of forest fires are deceptive in their benefits. Fire-fighters have become incredibly efficient at locating and extinguishing wildfires before they become too destructive. However, certain tree species that have flame- and temperature-resistant properties, such as the Pine Barrens, Lodgepole Pine, and Eucalyptus, require periodic fires in order to reproduce.⁶ When facing wildfires these types of trees survive, whereas other plant species perish. Since flame-resistant tree species are often native flora to forest ecosystems, the selective survival of these trees maintains the forest’s composition over time and prevents shrubs and grasslands from overrunning the ecosystem. Flame-resistant trees accomplish their phoenix-like regeneration and self-sustainability by releasing their seedlings during a wildfire. In addition, forest fires destroy flora that would impede the growth of new seedlings through competition for space and light. This regenerative effect of forest fires has even resulted in the return of certain endangered tree species.⁴ One example, the Jack Pine, maintains its seedlings in cones that melt in the presence of fire. A policy to extinguish fires prematurely can inhibit seed release, threatening Jack Pine forests and others like it.⁶ To date, aggressive government policies toward forest fire-fighting have led to significant changes in forest composition accompanied by buildup of tinder and debris on the forest floor. This accumulated undergrowth now fuels megafires that burn with unparalleled intensity and speed. In contrast, forest management policies that revert to the practice of allowing small, controlled fires to clear away debris would maintain the forest’s long-term survival.

Invasive, flame-susceptible species provide the perfect fuel for megafires. During their westward expansion in the 1880s, settlers were not the only ones to achieve Manifest Destiny. Several species of grass also made the journey. The most common of these species was the Cheatgrass, a grass native to Europe, southwestern Asia, and northern Africa.⁷ Cheatgrass was inadvertently brought to the Americas on cargo ships in the 1800s and has been a significant environmental problem ever since. The short life cycle and prolific seed production of Cheatgrass causes it to dry out by mid-June, meaning that it serves as kindling for fires during the summer. Cheatgrass increases the size and severity of fires since it burns twice as much as the endogenous vegetation.⁷ Since the native vegetation is slowly being choked out by Cheatgrass, the landscape of the American West is transitioning into a lawn of this invasive species, poised to erupt into an inferno.

Global warming, one of the environmental causes of megafires, is perhaps an even more critical and challenging threat than invasive species. In 2015, forest fires ravaged more than 9 million acres of the Western mainland United States and Alaska.³ Studies of global warming demonstrate that every degree Celsius of atmospheric warming is accompanied by a four-fold increase in the area of forest destruction. Thus, the increase in global temperature is directly associated with the prevalence of megafires.⁸ Since the 1900s, the average temperature of the planet has increased by 0.6 degrees Celsius, primarily in the twenty-first century.⁹ Typically, severe fires burn less often at higher altitudes, due to cooler temperature and greater moisture levels, but as global temperatures increase, these areas become drier and more prone to forest fires. This warming of the climate contributes to massive burns that are fueled by centuries of forest debris and undergrowth.⁹ Climate change also contributes to a lack of precipitation, which further contributes to the expansion and intensity of forest fires. Wildfires themselves also contribute to climate change; as they continue to burn they emit greenhouse gases, which can contribute to accelerating global warming.⁹

Ultimately, due to poor policy practice, a destructive cycle is forming that serves as a catalyst to megafires. Finding long-term solutions that will prevent the occurrence of megafires will require policy adjustments at the regional, national, and international levels.⁶ Currently policies are changing, endorsing smaller burns to limit build up for megafire fuel. As more data is being introduced about global warming, efforts are being made to find more renewable forms of energy such as solar and wind.⁹ Ideally, this shift in resources will limit the increase in global temperatures and reduce the risk of megafires. Lastly research is being done to develop grasses that can out compete the problematic Cheatgrass.⁷ If we can meet these challenges, then megafires may finally be extinguished.

References

1.  Why we have such large wildfires this summer. http://www.seattletimes.com/seattle-news/northwest/why-we-have-such-damaging-wildfires-this-summer/ (accessed Oct. 9, 2015).
2.  National Geographic: How Megafires Are Remaking American Forests. http://news.nationalgeographic.com/2015/08/150809-wildfires-forest-fires-climate-change-science/ (accessed Oct. 11, 2015)
3. Climate Central: The Age of Western Wildfires. http://www.climatecentral.org/news/report-the-age-of-western-wildfires-14873 (accessed Oct. 9, 2015)
4. Deadly forest fire leads to resurrection of endangered tree. http://blogs.scientificamerican.com/extinction-countdown/deadly-forest-fire-leads-to-resurrection-of-endangered-tree/ (accessed Oct. 9, 2015)
5. Rasker, thesolutionsjournal 2015, 55-62.
6. NPR: Why Forest-Killing Megafires Are The New Normal. http://www.npr.org/2012/08/23/159373770/the-new-normal-for-wildfires-forest-killing-megablazes (accessed Oct. 11, 2015)
7. Keeley, International Journal of Wildland Fire, 2007, 16, 96–106
8. Stephens, Frontiers in Ecology and the Environment 2014, 12, 115-122.
9. Climate Central: Study Ties Warming Temps to Uptick in Huge Wildfires. http://www.climatecentral.org/news/warming-huge-wildfire-outbreaks-19521 (accessed Oct. 21, 2015)

Homo Naledi – A New Piece in the Evolutionary Puzzle

Catalyst Volume 9

Human beings share 96% of their genome with chimpanzees,¹ which is why modern science has accepted the concept that humans and apes share a recent common ancestor. However, our understanding of the transition from these ancient primates to the bipedal, tool-wielding species that conquered the globe is less clear than many realize. One crucial missing chapter in the evolutionary story is the origin of our very own genus, Homo. Scientists believe that somewhere between two and three million years ago, the hominid species Australopithecus afarensis evolved into the first recognizably human species, Homo erectus. However, the details of this genealogical shift have remained a mystery. In 2013, a discovery made in the Rising Star cave by two recreational cavers may have provided revolutionary insight into this intractable problem.

The Rising Star cave lies 30 miles outside the city of Johannesburg in northern South Africa. A popular destination for spelunkers for the past 50 years, this cave is well-known and has been extensively mapped.² Two years ago, Steven Tucker and Rick Hunter dropped into the Rising Star cave in an effort to discover new extensions to the cave, with the hope of finding something more.² They found a tight crevice that was previously unexplored, which led to a challenging forty-foot drop through a chute. At the bottom, Hunter and Tucker came across scattered bones and fossils in what would later be named the Dinaledi chamber.² Hunter and Tucker consulted with Dr. Lee Berger, a paleoanthropologist at the University of Witwatersrand. It was clear to Dr. Berger that these fossils were not of modern humans -- an ancient hominid species had been discovered.²

Within weeks of this discovery, Dr. Berger assembled a qualified team and set up camp at the mouth of the Rising Star cave. In the largest hominid artifact discovery in Africa, over one thousand bones from multiple bodies were extracted and analyzed.²

As the fossils were being transferred out of the cave, paleoanthropologists at the surface worked to piece together a skeleton. Some aspects of this species’ bone structure were distinctly human, like the long thumbs, long legs, and arched feet.² Other features, including curved fingers and a flared pelvis, were indicative of a more primitive animal.² A large skull fragment from above the left eye of one of the skeletons allowed scientists to definitively determine this hominid’s genus.

The Australopithecus skull is characterized by a large orbital ridge above the eye, with a deep concavity behind it, leading to a flatter face with pronounced brows.³ The skull fragment collected by the team, however, had a shorter ridge and less of an indentation above the frontal lobe.³ This finding led the team to conclude that they had discovered a new member of the Homo genus, which Dr. Berger named Homo naledi. ‘Naledi’ in the Sotho language means ‘star,’ a reference to the vivid stalactites emanating from the ceiling of the Dinaledi chamber.³

Dr. Berger’s discovery in the Rising Star cave was an incredible breakthrough, but finding fossils is only half the battle. The next step is to find a place for this species in the million-year narrative of human evolution we have created.

In accomplishing this feat, a logical place to start is considering how the fossils of Homo naledi ended up in their final resting place. There were no signs of predation, as no other animal fossils were found at this location. In addition, these fossils accumulated gradually, meaning that the bodies did not all die from a single event. Dr. Berger postulated that these bodies were placed there with purpose, but intentional body disposal is an advanced social behavior which, up to this point, has only been exhibited by more evolved Homo species. The brain size of the discovered hominids is estimated to be between 450 and 550 cubic centimeters, about one third the size of Homo sapiens brain and only marginally larger than that of a chimpanzee.³ The possibility of such a small-brained animal engaging in intentional body disposal challenges ideas about the cognitive abilities necessary for such advanced social behavior. Dr. William Jungers, chair of anatomical sciences at Stony Brook University, argues that advanced social intelligence was not likely at play in this instance. He claims that “intentional corpse disposal is a nice sound bite, but more spin than substance […] dumping conspecifics down a hole may be better than letting them decay around you.”⁴

The idea of intentional body disposal is not the only one of Dr. Berger’s conclusions that has attracted criticism. Some in the scientific community argue that Homo naledi is a distant cousin, not a direct ancestor, of modern humans. Others, like UC Berkeley’s Dr. Tim White, argue that "new species should not be created willy-nilly,” and believe that these discoveries may just be fossils of Homo erectus.⁵ Biologist Dr. David Menton takes the small brain size of these hominids as well as well as their “sloped face” and “robust mandible” as indication that Homo naledi does not even belong in the Homo genus.⁶

It is clear that while the Homo naledi fossils are extremely significant in the scientific community, their placement within the story of human evolution is contentious. Our inability to definitively date the fossils makes the task even more challenging. However, Homo naledi’s unique mosaic of human and ape-like features provides support for a new model of human evolution that has recently gained traction in the scientific community. While scientists would prefer to draw a family tree of human ancestors with modern humans at the top, our evolution is not so simple. Dr. Berger likens the reality of evolution to a braided stream.² Like a collection of tributaries all contributing to a river basin, humans may have been the product of a collection of human ancestors, each contributing to our existence differently. We may never fully understand where we came from, but discoveries like Homo naledi bring us a little bit closer to completing the evolutionary puzzle.

References

1. Spencer, G. New Genome Comparison Finds Chimps, Humans Very Similar at the DNA Level. National Human Genome Research Institute [Online], August 31, 2005. https://www.genome.gov/15515096 (accessed March 1st, 2016)
2. Shreeve, J. This Face Changes the Human Story. But How? National Geographic [Online], September 10, 2015. http://news.nationalgeographic.com/2015/09/150910-human-evolution-change/ (accessed January 17, 2016)
3. Berger, L. R. et al. ELife [Online] 2015, 4. http://elifesciences.org/content/4/e09560 (accessed January 16, 2016)
4. Bascomb, B. Archaeology's Disputed Genius. PBS NOVA NEXT [Online], September 10, 2015. http://www.pbs.org/wgbh/nova/next/evolution/lee-berger/ (accessed January 19, 2016)
5. Stoddard, E. Critics question fossil find, but South Africa basks in scientific glory. UK Reuters [Online], September 16, 2015. http://uk.reuters.com/article/us-safrica-fossil-idUKKCN0RG0Z120150916 (accessed January 19, 2016)
6. Dr. Mitchell, E. Is Homo naledi a New Species of Human Ancestor? Answers in Genesis [Online], September 12, 2015. https://answersingenesis.org/human-evolution/homo-naledi-new-species-human-ancestor/ (accessed January 17, 2016)

Nano-Materials with Giga Impact

Catalyst Volume 9

What material is so diverse that it has applications in everything from improving human lives to protecting the earth? Few materials are capable of both treating prolific diseases like diabetes and creating batteries that last orders of magnitude longer than industry standards. None are as thin, lightweight, and inexpensive as carbon nanotubes.

Carbon nanotubes are molecular cylinders made entirely of carbon atoms, which form a hollow tube just a few nanometers thick, as illustrated in Figure 1. For perspective, a nanometer is one ten-thousandth the width of a human hair.¹ The first multi-walled nanotubes (MWNTs) were discovered by L. V. Radushkevich and V. M. Lukyanovich of Russia in 1951.² Morinobu Endo first discovered single-walled nanotubes (SWNTs) in 1976, although the discovery is commonly attributed to Sumio Iijima at NEC of Japan in 1991.^3,4

Since their discovery, nanotubes have been the subject of extensive research by universities and national labs for the variety of applications in which they can be used. Carbon nanotubes have proven to be an amazing material, with properties that surpass those of existing alternatives such as platinum, stainless steel, and lithium-ion cathodes. Because of their unique structure, carbon nanotubes are revolutionizing the fields of energy, healthcare, and the environment.

Energy

One of the foremost applications of carbon nanotubes is in energy. Researchers at the Los Alamos National Laboratory have demonstrated that carbon nanotubes doped with nitrogen can be used to create a chemical catalyst. The process of doping involves substitution of one type of atom for another; in this case, carbon atoms were substituted with nitrogen. The synthesized catalyst can be used in lithium-air batteries which can hold a charge 10 times greater than that of a lithium-ion battery. A key parameter in the battery’s operation is the Oxygen Reduction Reaction (ORR) activity, which is a measure of a chemical species’ ability to gain electrons. The ORR activity of the nitrogen-doped material complex is not only the highest of any non-precious metal catalyst in alkaline media, but also higher than that of precious metals such as platinum.⁵

In another major development, Dr. James Tour of Rice University has created a graphene-carbon nanotube complex upon which a “forest” of vertical nanotubes can be grown. This base of graphene is a single, flat sheet of carbon atoms ‒ essentially a carbon nanotube “unrolled.” The ratio of height-to-base in this complex is equivalent to that of a house on a standard-sized plot of land extending into space.⁶ The graphene and nanotubes are joined at their interface by heptagonal carbon rings, allowing the structure to have an enormous surface area of 2000 m² per gram and serve as a high potential storage mechanism in fast supercapacitors.⁷

Healthcare

Carbon nanotubes also show immense promise in the field of healthcare. Take Michael Strano of MIT, who has developed a sensor composed of nanotubes embedded in an injectable gel that can detect several molecules. Notably, it can detect nitrous oxide, an indicator of inflammation, and blood glucose levels, which diabetics must continuously monitor. The sensors take advantage of carbon nanotubes’ natural fluorescent properties; when these tubes are complexed with a molecule that then binds to a specific target, their fluorescence will increase or decrease.⁸

Perhaps the most important potential application for carbon nanotubes in healthcare lies in their cancer-fighting applications. In the human cell, there is a family of genes called HER2 that is responsible for the regulation of growth and proliferation of cells. Normal cells have two copies of this family, but 20-25% of breast cancer cells have three or more copies, resulting in quickly-growing tumor cells. Approximately 40,000 U.S. women are diagnosed every year with this type of breast cancer. Fortunately, Huixin He of Rutgers University and Yan Xiao of the National Institute of Standards and Technology have found that they can attach an anti-HER2 antibody to carbon nanotubes to kill these cells, as shown in Figure 2. Once inserted into the body, a near-infrared light at a wavelength of 785 nm can be reflected off the antibody-nanotube complex, indicating where tumor cells are present. The wavelength then increases to 808 nm, at which point the nanotubes absorb the light and vibrate to release enough heat to kill any attached HER2 tumor cells. This process has shown a near 100% success rate and leaves normal cells unharmed.⁹

Environment

Carbon nanotube technology also has environmental applications. Hui Ying Yang from Singapore has developed a water-purification membrane made of plasma-treated carbon nanotubes which can be integrated into portable, rechargeable, and inexpensive purification devices the size of a teapot. These new purifications devices are ideal for developing countries and remote locations, where large industrial purification plants would be too energy- and labor-intensive. Unlike other portable devices, this rechargeable device utilizes a membrane system that does not require a continuous power source, does not rely on thermal processes or reverse osmosis, and can filter for organic contaminants found in brine water - the most common water supply in these developing and rural areas.¹⁰

Oil spills may no longer be such devastating natural disasters either. Bobby Sumpter of the Oak Ridge National Laboratory demonstrated that doping carbon nanotubes with boron atoms alters the curvature of the tubes. Forty-five degree angles form, leading to a sponge-like structure of nanotubes. As these tubes are made of carbon, they attract hydrocarbons and repel water due to their hydrophobic properties, allowing the tubes to absorb up to 100 times their weight in oil. Additionally, these tubes can be reused, as burning or squeezing them was shown to cause no damage. Sumpter and his team used an iron catalyst in the growth process of the carbon nanotubes, enabling a magnet to easily control or remove the tubes from an oil cleanup scenario.¹¹

Carbon nanotubes provide an incredible opportunity to impact areas of great importance to human life - energy, healthcare, and environmental protection. The results of carbon nanotube research in these areas demonstrate the remarkable properties of this versatile and effective material. Further studies may soon lead to their everyday appearance in our lives, whether in purifying water, fighting cancer, or even making the earth a better, cleaner place for everyone. Big impacts can certainly come in small packages.

References

1. Nanocyl. Carbon Nanotubes. http://www.nanocyl.com/CNT-Expertise-Centre/Carbon-Nanotubes (accessed Sep 12, 2015).
2. Monthioux, M.; Kuznetsov, V. Guest Editorial: Who should be given the credit for the discovery of carbon nanotubes? Carbon 44. [Online] 2006. 1621. http://nanotube.msu.edu/HSS/2006/1/2006-1.pdf (accessed Nov 15, 2015)
3. Ecklund, P.; et al. Ugliengo, P. In International Assessment of Carbon Nanotube Manufacturing and Applications, Proceedings of the World Technology Evaluation Center, Inc. Baltimore, MD, June, 2007.
4. Nanogloss. The History of Carbon Nanotubes – Who Invented the Nanotube? http://nanogloss.com/nanotubes/the-history-of-carbon-nanotubes-who-invented-the-nanotube/#axzz3mtharE9D (accessed Sep 14, 2015).
5. Understanding Nano. Economical non-precious-metal catalyst capitalizes on carbon nanotubes. http://www.understandingnano.com/catalyst-nitrogen-carbon-nanotubes.html (accessed Sep 17, 2015).
6. Understanding Nano. James’ bond: A graphene/nanotube hybrid. http://www.understandingnano.com/graphene-nanotube-electrode.html (accessed Sep 19, 2015).
7. Yan, Z. et al. ACS Nano. Toward the Synthesis of Wafer-Scale Single-Crystal Graphene on Copper Foils 2012, 6 (10), 9110–9117.
8. Understanding Nano. New implantable sensor paves way to long-term monitoring. http://www.understandingnano.com/carbon-nanotubes-implant-sensor.html (accessed Sep 20, 2015).
9. Understanding Nano. Combining Nanotubes and Antibodies for Breast Cancer 'Search and Destroy' Missions. http://www.understandingnano.com/nanomedicine-nanotubes-breast-cancer.html (accessed Sep 22, 2015).
10. Understanding Nano. Plasma-treated nano filters help purify world water supply. http://www.understandingnano.com/nanotube-membranes-water-purification.html (accessed Sep 24, 2015).
11. Sumpter, B. et al. Covalently bonded three-dimensional carbon nanotube solids via boron induced nanojunctions. Nature [Online] 2012, doi: 10.1038/srep00363. http://www.nature.com/articles/srep00363 (accessed Mar 06, 2016).
12.  Huixin, H. et al. Anti-HER2 IgY antibody-functionalized single-walled carbon nanotubes for detection and selective destruction of breast cancer cells. BMC Cancer 2009, 9, 351.   

Mars Fever

Catalyst Volume 9

The Greeks called it the star of Ares. For the Egyptians, it was the Horus of the Horizon. Across many Asian cultures, it was called the Fire Star. Mars has been surrounded by mystery from the time of ancient civilizations to the recent discovery of water on the planet’s surface.¹ But why have humans around the world and throughout history been so obsessed with the tiny red planet?

Human fascination with Mars began in the late 19th century, when Italian astronomer Giovanni Schiaparelli first observed canali, or lines, on the planet’s surface. Yet canali was mistakenly translated as “canals” instead of “lines.”² This led many to believe that some sort of intelligent life existed on Mars and these canals were engineered for their survival. While these lines were later found to be optical illusions, the canali revolutionized the way people viewed Mars. For perhaps the first time in history, it seemed that humans might not be alone in the universe. Schiaparelli had unintentionally sparked what became known as “Mars fever,” and indirectly influenced our desire to study, travel to, and even colonize Mars for more than 100 years. In Cosmos, Carl Sagan memorably described this odd fascination, “Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears.”

He was right.

After the canali misunderstanding, people began to believe that not only was there life on Mars, but intelligent life. The Mars craze escalated with the rise of science fiction, especially the publication of H.G. Wells’s classic Martian takeover novel War of the Worlds.^2,3 In 1938, the novel was adapted for a radio broadcast narrated by actor Orson Welles. The broadcast incited mass terror, as millions of listeners mistook the fictional broadcast for news of an impending alien Armageddon. Surprisingly, this is just one of the many instances where random events have been mistaken for extraterrestrial interaction. The public image of Mars quickly evolved to reflect a mystical red landscape inhabited by intelligent, antagonistic, green creatures. Mars fever was becoming contagious.

As decades passed, it became increasingly clear that Mars contained no tiny green men and that there were no flying saucers coming to colonize the Earth. The Mariner missions found no evidence of life on Mars, and as a result, Mars fever took on a new form: without the threat of intelligent, alien life forms, who was to stop us from colonizing the Red Planet? After all, perhaps the destruction of Earth wouldn’t be caused by invaders, but by earthlings themselves. Many contemporary science fiction writers focus on this idea of a second Earth in their stories. Award-winning novelist Michael Swanwick says, "We all are running out of a lot of different minerals, some of which our civilization depends on … There is a science-fiction idea for you."⁴ With natural resources dwindling and pollution on the rise, Earth might need a replacement.⁵ Mars’ relative similarity and proximity to Earth make it a strong candidate.

Rocket scientist Werner Von Braun even wrote The Mars Project, a book outlining a Martian colonization fleet that would be assembled in earth orbit.⁶ It was a proposition of massive proportions, calling for $500 million in rocket fuel alone and human explorers rather than rovers such as NASA’s Opportunity and Curiosity.⁶ However, these colonization efforts are not simply fictional. Elon Musk, CEO of Tesla and creator of the privately funded space agency SpaceX, has put intense effort into interplanetary travel, particularly in the case of Mars, but his methods remain abstract.⁷ Mars One has a similar goal: establishing a Martian colony. While not an aerospace company, Mars One is a logistical center for carrying out such a mission. They focus primarily on funding and organization, leaving systems construction up to more established aerospace companies.⁸ While both SpaceX and Mars One are dedicated to the cause of Martian colonization, it is evident that neither company will be able to accomplish such a mission any time soon.

The possible mechanisms for colonizing Mars are endless, ranging from pioneering the landscape with 3D printable habitats to harvesting remnants of water from the Martian soil. But the challenges arguably outweigh current technologies. In order to survive, humans would need space suits that could protect against extreme temperature differentials.⁵ Once on the surface, astronauts would need to establish food sources that were both sustainable and suitable for long term missions.⁹ Scientists would need to consider accommodations for the mental health of astronauts spending more time in space than any other human in history. Beyond these basic necessities, factors like harmful cosmic rays and the sheer cost of such a mission must also be considered.¹⁰

The highly improbable nature of Mars exploration and colonization only seems to add fuel to the fire of humanity’s obsession. In spite of the challenges associated with colonization, Mars fever persists. Though Mars is 225 million kilometers away from Earth, it has piqued human curiosity throughout civilizations. Schiaparelli and his contemporaries could only dream of the possibilities that dwelled in Mars’s “canali.” However, exploration of Mars is no longer the stuff of science-fiction. This is a new era of making the impossible possible, from Neil Armstrong’s “giant leap for mankind” to the establishment of the International Space Station. We are closer to Mars than ever before, and in the coming years we might just unveil the mystery behind the Red Planet.

References

1. Mars Shows Signs of Having Flowing Water, Possible Niches for Life, NASA Says, http://www.nytimes.com/2015/09/29/science/space/mars-life-liquid-water.html?_r=1, (accessed September 28, 2015)
2. A Short History of Martian Canals and Mars Fever, http://www.popularmechanics.com/space/moon-mars/a17529/a-short-history-of-martian-canals-and-mars-fever/, (accessed September 28, 2015)
3. The Myth of the War of the Worlds Panic, http://www.slate.com/articles/arts/history/2013/10/orson_welles_war_of_the_worlds_panic_myth_the_infamous_radio_broadcast_did.html, (accessed October 10, 2015)
4. Why Colonize Mars? Sci-Fi Authors Weigh In., http://www.space.com/29414-mars-colony-science-fiction-authors.html (accessed Jan 30, 2016)
5. Here’s why humans are so obsessed with colonizing Mars, http://qz.com/379666/heres-why-humans-are-so-obsessed-with-colonizing-mars/, (accessed Oct 10, 2015)
6. Humans to Mars, http://history.nasa.gov/monograph21.pdf, (accessed Oct 10, 2015)
7. SpaceX's Elon Musk to Reveal Mars Colonization Ideas This Year, http://www.space.com/28215-elon-musk-spacex-mars-colony-idea.html, (accessed October 10, 2015)
8. About Mars One, http://www.mars-one.com/about-mars-one (accessed Jan 30, 2016)
9. Talking to the Martians, http://www.popsci.com/martians, (accessed September 28, 2015)
10. Will We Ever Colonize Mars?, http://www.space.com/30679-will-humans-ever-colonize-mars.html (accessed Jan 30, 2016)

Delving into a New Kind of Science

Catalyst Volume 9

Since ancient times, humans have attempted to create models to explain the world. These explanations were stories, mythologies, religions, philosophies, metaphysics, and various scientific theories. Then, about three centuries ago, scientists revolutionized our understanding with a simple but powerful idea: applying mathematical models to make sense of our world. Ever since, mathematical models have come to dominate our approach to knowledge, and scientists have utilized complex equations as viable explanations of reality.

Stephen Wolfram’s A New Kind of Science (NKS) suggests a new way of modelling worldly phenomena. Wolfram postulates that elaborate mathematical models aren’t the only representations of the mechanisms governing the universe; simple patterns may be behind some of the most complex phenomena. In order to illustrate this, he began with cellular automata.

A cellular automaton is a set of colored blocks in a grid that is created stage by stage. The color of each block is determined by a set of simple rules that considers the colors of blocks in a preceding stage.¹ Based on just this, cellular automata seem to be fairly simple, but Wolfram illustrated their complexity in rule 30. This cellular automaton, although it follows the simple rule illustrated in Figure 1, produces a pattern that too irregular and complex for even the most sophisticated mathematical and statistical analysis. However, by applying NKS fundamentals, simple rules and permutations of the building blocks pictured can be developed to produce these extremely complex structures or models.²

By studying several cellular automata systems, Wolfram presents two important ideas: complexity can result from simple rules and complex rules do not always produce complex patterns.²

The first point is illustrated by a computer; relying on Boolean logic, the manipulation of combinations of “truths” (1’s) and “falses” (0’s), computers can perform complex computations. And with proper extensions, they can display images, play music, or even simulate entire worlds in video games. The resulting intuition, that complexity results from complexity, is not necessarily true. Wolfram shows again and again that simple rules produce immense randomness and complexity.

There are other natural phenomena that support this theory. The patterns on mollusk shells reflect the patterns generated by cellular automata, suggesting that the shells follow similar simple rules during pattern creation.² Perhaps other biological complexities are also results of simple rules. Efforts are being made to understand the fundamental theory of physics based on ideas presented in the NKS and Wolfram’s idea might even apply to philosophy. If simple rules can create seemingly irregular complexity, the simple neuronal impulses in the brain might also cause irregular complexities, and this is what we perceive as free will.²

The most brilliant aspect of NKS lies in its underlying premises: a model for reality is not reality itself but only a model, so there can be several different, accurate representations. Our current approach to reality -- using mathematical models to explain the world -- does not have to be the only one. Math can explain the world, but NKS shows that simple rules can also do so. There may be methods and theories that have been overlooked or remain undiscovered that can model our world in better ways.

References

1. Weisstein, E. W. Cellular Automaton. Wolfram MathWorld, http://mathworld.wolfram.com/cellularautomaton.html (accessed Mar 26, 2016).
2. Wolfram, S. A New Kind of Science; Wolfram Media: Champaign, IL, 2002

Dangers of DNA Profiling

Catalyst Volume 9

DNA profiling has radically changed forensics by providing an objectively verifiable method for linking suspects to crimes. Currently, many states collect the DNA of felons in order to ensure that repeat offenders are caught and convicted efficiently.¹ Over the past few years, situations in which law enforcement officials can collect DNA from suspects have increased drastically. In 2013, President Obama strongly supported the creation of a national DNA database that included samples from not only people who are convicted, but also those arrested.¹ In Maryland v. King (2013), the Supreme Court declared that law enforcement officials are justified in collecting DNA prior to conviction if it aids in solving a criminal case.² In the years since this decision, the creation of a national DNA database has become a particularly polarizing and contentious issue. Proponents argue that a database would dramatically improve the ability of law enforcement to solve crimes. However, detractors argue that the potential for misuse of genetic information is too great to warrant the creation of such a system.

DNA is popularly referred to as the “blueprint of life” and contains extremely sensitive information such as an individual’s susceptibility to genetic disorders. One of the major arguments against the creation of a national DNA database is that such information could be hacked. Yaniv Erlich, a geneticist at MIT, illustrated this when he used “genome mining” to find the true identities of individuals in a national genome registry. In his study, Erlich obtained genomes from the 1000 Genomes Project, a large database used for scientific research. He then used a computer algorithm to search for specific DNA sequences known as short tandem repeats (STRs) on the Y chromosome of males. These STRs are remarkably invariable from generation to generation. Erlich was able to use the Y chromosome’s STR marker to identify the last names of the individuals to whom the DNA belonged by using easily accessible genealogy sites.³ With just a computer and access to genome data, Erlich could identify personal information in DNA registries. Clearly, the creation of a national DNA database could give rise to widespread privacy concerns. Though there are large fines associated with unauthorized disclosure or acquisition of DNA data, current federal regulations do not technically limit health insurance companies from using genome mining in order to determine life insurance or disability care.⁴

Hacking of federal databases is not an unreasonable scenario—just this past July, sensitive information including the addresses, health history, and financial history of over 20 million individuals was stolen in a massive cyber-attack.⁴ That attack uncovered information about every single individual who has attempted to work or has worked in the United States government. A similar abuse of genetic information by third parties is undoubtedly a danger associated with a national DNA database. Despite advances in federal protections such as the Genetic Information Nondiscrimination Act, there are still numerous instances where genetic information regarding disease is used in employment decisions.⁵

Another potential issue associated with the creation of a DNA database is the notion of genetic essentialism. Genetic essentialism argues that the genes of an individual can predict behavioral outcomes.⁶ Critics of a national DNA database argue that certain factors—such as the extra Y chromosome—may lead law enforcement officials to suspect certain individuals more than others, which sets up a dangerous precedent.

The notion that chromosomal abnormalities can alter behavioral outcomes has generated numerous studies examining the link between criminality and changes in sex chromosomes—the genes that determine whether an individual is male or female. Normally, females will have two X chromosomes, whereas males have one X chromosome and one Y chromosome. However, in rare cases, males can either have an extra X chromosome (XXY) or an extra Y chromosome (XYY). General literature review suggests that XXY men have feminine characteristics and are substantially less aggressive than XYY or XY men.⁷ Conversely, studies like Jacobs et al. have suggested that the XYY condition can lead to increased aggression in individuals.⁸ However, Alice Theilgaard, one of the most prominent researchers on this topic, found that most behavioral characteristics associated with the XYY chromosomal abnormality are controversial.⁷ Even tests based on objective measures, like testosterone levels, have been inconclusive. Theilgaard argues that the XYY chromosomal abnormality does not cause increased aggression or propensity to commit crimes. Rather, she states that the criminality of XYY individuals might be a socially constructed phenomenon. XYY individuals often have severe acne, lowered intellect, and unusual height. This makes it difficult for people with this condition to “fit in.” As a result of their physical characteristics, XYY individuals might feel ostracized and become antisocial.⁸ Thus, it is reasonable to conclude that merely having an extra Y chromosome does not predispose someone to be violent; rather a wide variety of social factors play a role.

It is entirely plausible that law enforcement individuals could misinterpret genetic information. For example, they could mistakenly believe that an individual with the XYY condition is more likely to be a suspect for a violent crime. Such an assumption would hinder law enforcement officials from objectively evaluating the evidence involved in a crime and shift the focus to individual characteristics of particular suspects. People in favor of a national DNA database often argue that it would be a great method of solving crimes. Specifically, some officials argue that a database would prevent recidivism (a relapse in criminal behavior) and deter people from committing crimes. However, research done by Dr. Avinash Bhati suggests that the inclusion of DNA in a national registry only seems to reduce recidivism for burglaries and robberies; in other crime categories, recidivism is generally unaffected.⁹ This suggests that a convict’s knowledge that he/she is in a DNA database is not a true deterrent. The concerns raised by this study should show that databases might not be as effective a crime-fighting tools as proponents suggest.

Both genome mining and genetic essentialism present very real harms associated with the creation of a national DNA database. Having sensitive genetic information in one centralized registry could potentially lead to abuse and discriminatory behaviors by parties that have access to that information. Even if genome databases are strictly regulated, the possibility of that information being hacked still exists. Furthermore, assuming that genetics are the only determinants of behavior could lead to people with genetic abnormalities being suspected of crimes at a higher rate than “normal” individuals. Social factors often shape the way an individual acts; the possibility of law enforcement officials embracing the genetic essentialism approach is another associated harm. In the end, it seems that the negative consequences associated with the creation of a national DNA database outweigh the benefits.

References

1. Barnes, R. Supreme Court upholds Maryland law, says police may take DNA samples from arrestees. Washington Post, https://www.washingtonpost.com/politics/supreme-court-upholds-maryland-law-says-police-may-take-dna-samples-from-arrestees/2013/06/03/0b619ade-cc5a-11e2-8845-d970ccb04497_story.html (accessed 2015).  
2. Wolf, R. Supreme Court OKs DNA swab of people under arrest. USA Today, http://www.usatoday.com/story/news/politics/2013/06/03/supreme-court-dna-cheek-swab-rape-unsolved-crimes/2116453/ (accessed 2015).
3. Ferguson, W. A Hacked Database Prompts Debate about Genetic Privacy. Scientific American, http://www.scientificamerican.com/article/a-hacked-database-prompts/ (accessed 2015).
4. Davis, J. Hacking of Government Computers Exposed 21.5 Million People. The New York Times, http://www.nytimes.com/2015/07/10/us/office-of-personnel-management-hackers-got-data-of-millions.html?_r=0 (accessed 2015).
5. Berson, S. Debating DNA Collection. National Institute of Justice, http://www.nij.gov/journals/264/pages/debating-dna.aspx (accessed 2015).
6. Coming to Terms with Genetic Information. Australian Law Reform Commission , http://www.alrc.gov.au/publications/3-coming-terms-genetic-information/dangers-‘genetic-essentialism’ (accessed 2015).
7. Are XYY males more prone to aggressive behavior than XY males? Science Clarified, http://www.scienceclarified.com/dispute/vol-1/are-xyy-males-more-prone-to-aggressive-behavior-than-xy-males.html (accessed 2015).
8. Dar-Nimrod, I.; Heine, S. Genetic Essentialism: On the Deceptive Determinism of DNA. Psychological Bulletin, http://www.ncbi.nlm.nih.gov/pmc/articles/pmc3394457/ (accessed 2015).Are XYY males more prone to aggressive behavior than XY males? Science Clarified.
9. Bhati, A. Quantifying The Specific Deterrent Effects of DNA Databases. PsycEXTRADataset. 2011. https://www.ncjrs.gov/app/publications/abstract.aspx?id=258313 (accessed May 2015).

3D Organ Printing: A Way to Liver a Little Longer

Catalyst Volume 9

On average, 22 people in America die each day because a vital organ is unavailable to them.¹ However, recent advances in 3D printing have made manufacturing organs feasible for combating the growing problem of organ donor shortages.

3D printing utilizes additive manufacturing, a process in which successive layers of material are laid down in order to make objects of various shapes and geometries.² It was first described in 1986, when Charles W. Hull introduced his method of ‘stereolithography,’ in which thin layers of materials were added by curing ultraviolet light lasers. In the past few decades, 3D printing has driven innovations in many areas, including engineering and art by allowing rapid prototyping of various structures.² Over time, scientists have further developed 3D printing to employ biological materials as a modeling medium. Early iterations of this process utilized a spotting system to deposit cells into organized 3D matrices, allowing the engineering of human tissues and organs. This method, known as 3D bioprinting, required layer-by-layer precision and the exact placement of 3D components. The ultimate goal of 3D biological modeling is to assemble human tissue and organs that have the correct biological and mechanical properties for proper functioning to be used for clinical transplantation. In order to achieve this goal, modern 3D organ printing is usually accomplished using either biomimicry, autonomous self-assembly, and mini-tissues. Typically, a combination of all three techniques is utilized to achieve bioprinting with multiple structural and functional properties.

The first approach, biomimicry, involves the manufacture of identical components of cells and tissues. The goal of this process is to use the cells and tissues of the organ recipient to duplicate the structure of organs and the environment in which they reside. Ongoing research in engineering, biophysics, cell biology, imaging, biomaterials, and medicine is very important for this approach to prosper, as a thorough understanding of the microenvironment of functional and supporting cell types is needed to assemble organs that can survive.³

3D bioprinting can also be accomplished through autonomous self-assembly, a technique that uses the same mechanisms as embryonic organ development. Developing tissues have cellular components that produce their own extracellular matrix in order to create the structures of the cell. Through this approach, researchers hope to utilize cells themselves to create fully functional organs. Cells are the driving force of this process, as they ultimately determine the functional and structural properties of the tissues.³

The final approach used in 3D bioprinting involves mini-tissues and combines the processes of both biomimicry and self-assembly. Mini-tissues are the smallest structural units of organs and tissues. They are replicated and assembled into macro-tissue through self-assembly. Using these smaller, potentially undamaged portions of the organs, fully functional organs can be made. This approach is similar to autonomous self-assembly in that the organs are created by the cells and tissues themselves.

As modern technology makes it possible, techniques for organ printing continue to advance. Although successful clinical implementation of printed organs is currently limited to flat organs such as skin and blood vessels and hollow organs such as the bladder,³ current research is ongoing for more complex organs such as the heart, pancreas, or kidneys.

Despite the recent advances in bioprinting, issues still remain. Since cell growth occurs in an artificial environment, it is hard to supply the oxygen and nutrients needed to keep larger organs alive. Additionally, moral and ethical debates surround the science of cloning and printing organs.³ Some camps assert that organ printing manipulates and interferes with nature. Others feel that, when done morally, 3D bioprinting of organs will benefit mankind and improve the lives of millions. In addition to these debates, there is also concern about who will control the production and quality of bioprinted organs. There must be some regulation of the production of organs, and it may be difficult to decide how to distribute this power. Finally, the potential expense of 3D printed organs may limit access to lower socioeconomic classes. 3D printed organs, at least in their early years, will more likely than be expensive to produce and to buy.

Nevertheless, there is widespread excitement surrounding the current uses of 3D bioprinting. While clinical trials may be in the distant future, organ printing can currently act as an in vitro model for drug toxicity, drug discovery, and human disease modeling.⁴ Additionally, organ printing has applications in surgery, as doctors may plan surgical procedures with a replica of a patient’s organ made with information from MRI and CT images. Future implementation of 3D printed organs can help train medical students and explain complicated procedures to patients. Additionally, 3D printed tissue of organs can be utilized to repair livers and other damaged organs. Bioprinting is still young, but its widespread application is quickly becoming a possibility. With further research, 3D printing has the potential to save the lives of millions in need of organ transplants.

References

1. U.S. Department of Health and Human Services. Health Resources and Services Information. http://www.organdonor.gov/about/data.html (accessed Sept. 15, 2015)
2. Hull, C.W. et al. Method of and apparatus for forming a solid three-dimensional article from a liquid medium. WO 1991012120 A1 (Google Patents, 1991).
3. Atala, A. and Murphy, S. 3D Bioprinting of Tissues and Organs. Nat. Biotechnol. [Online] 2013, 32, 773-785. http://nature.com/nbt/journal/v32/n8/full/nbt.2958.html (accessed Sept. 15, 2015)
4. Drake, C. Kasyanov, V., et al. Organ printing: Promises and Challenges. Regen. Med. 2008, 3, 1-11.