Issuu

From left to right: Jacques Dubochet, Joachim Frank, and Richard Henderson.

JAN

and analyzed. Although cryo-EM has existed since the 1970s, more recent improvements allow direct reconstruction of the images in 3D. This new technique is rapidly replacing X-ray crystallography, a method that fires X-rays at crystallized proteins. In X-ray crystallography, some biomolecules interact with the high energy radiation, which in turn prevents the formation of large enough crystals needed to study their lattice structure. However, Cryo2018 EM allows for direct imaging of biomolecules without needing crystallization of the samples. The high-resolution pictures can illustrate a cell’s machinery in great detail or reveal where to best target a disease-carrying molecule with drugs. The work of Dubochet, Frank, and Henderson on cryo-electron microscopy will revolutionize structural biology and change the lives of future generations.

This experimental confirmation led the Nobel Academy to award Weiss, Barish, and Thorne the Nobel Prize in Physics two years after the LIGO data was interpreted and verified. LIGO (Laser Interferometer Gravitational-Wave Observatory) is not a typical observatory. Since gravitational waves are not part of the electromagnetic spectrum (such as visible light, x-rays, radio waves, etc.), LIGO does not use telescope mirrors or radio dishes that normally adorn traditional observatories. Instead, it has two, four-kilometer-long vacuum tubes placed in an L-shape that ‘feel’ and ‘hear’ the gravitational waves when they interact with a long metal bar. These long vacuum tubes are called interferometers--instruments that create an interference pattern from multiple light sources or lasers. The farther the lasers are projected, the more sensitive the interferometers become, allowing LIGO to detect the very faint gravitational waves. The work of Weiss, Barish, and Thorne on LIGO has opened up a new chapter in astrophysics by enabling scientists to ‘hear’ the universe through a whole new type of waves rather than simply ‘seeing’ it by capturing electromagnetic waves; it has opened a new window into the universe that can be used to explore spacetime.

Clockwise from top-left: Weiss, Barish, and Thorne.

Physics On October 3, 2017, the Nobel Prize in Physics was awarded to Rainer Weiss, Barry C. Barish, and Kip S. Thorne for their contributions to the LIGO detector, the largest gravitational wave observatory in the world, and for the first detection of gravitational waves ever. First of all, what is a gravitational wave? Gravitational waves are minute spacetime ripples, or distortions in space, caused by accelerating objects. These waves travel at the speed of light and are virtually undisturbed by low energy obstacles. Albert Einstein was the first to predict the existence of these phenomena: he calculated that when massive, accelerating objects such as neutron stars and black holes orbit each other, they could create disruptions in spacetime and send gravitational waves. These very faint signals give scientists crucial information about the origins of the collision and the nature of gravity. Because they are so feeble, gravitational waves are very hard to detect; the strongest waves come from the collision of black holes, the collapse of supernova stars, and the remnants from the birth of our universe. For this reason, gravitational waves were until recently considered only from the theoretical point of view. However, on September 14, 2015, the LIGO experiment detected gravitational waves emanating from two black holes that collided 1.3 billion light years ago. The magnitude of this accomplishment is monumental; for perspective, the gravitational wave signal from this collision was emitted when multi-celled organisms were just beginning to form on Earth. Furthermore, the confirmation of the existence of gravitational waves opens a whole new way to investigate highly energetic phenomena in the universe.

Image Credit: Flicker @ junaidrao; Flickr @ Bengt Nyman; Flickr @ Penn State; Flickr @ Konstantin Malanchev

Catalyst VOLUME 8

ISSUE 1

LETTER FROM THE PRESIDENT CCA— Welcome back to the first issue of the year! The entire Catalyst team has worked extremely hard to produce an engaging magazine for readers like you. In Catalyst’s seventh year running as CCA’s science magazine, we explore the newest and boldest of technologies, analyze the long-running pillars of STEM, and discover emerging fields of science and engineering. You will find many exciting topics in this issue. Ever wanted to understand the massive BOOM of the Manhattan Project? Explore the differences between the cute and cuddly llama and alpaca? Analyze the science behind that massive crush, or your little brother’s temper tantrum? Journey with our school’s iGEM team as they detoxify the world’s oil spills, and be one with the robot in our automation article. Read, learn, and explore, with the fields of STEM culminating into our first issue of the year! I’d like to thank the Catalyst team for all their efforts and hard work, as well as our advisor, Mr. Gaughen, and our generous sponsors. A huge thank you also goes to you, the reader. All the enthusiasm and support from you has made Catalyst thrive. If you have any questions or comments, please feel free to email us at ccacatalyst@gmail.com. Also, check us out on our website catalystmagweebly.com to see some past issues and our new blog, and like us on Facebook at facebook.com/catalystsciencemagazine to stay updated! Enjoy! Maggie Chen

President of Catalyst Science Magazine

STAFF Maggie Chen PRESIDENT

Aida Razavilar

Victoria Li

Ashley Zhang

Clara Guo

Anjali Gopinathan

Amanda Tanaka

Judy Qin

Aadil Rehan

VICE PRESIDENT

DIRECTOR OF FINANCE

EXECUTIVE LAYOUT DIRECTOR

EXECUTIVE EDITOR

VICE PRESIDENT

DIRECTOR OF FINANCE

SUPERVISING LAYOUT

SUPERVISING EDITOR

EDITING

Trevor Cai Samantha Chai Amy Cheng Kevin Cheng Alyssa Cho Sai Gantla Paymon Haddad Emily Kang Gabby Kang Paul Kreymborg Christina Lee

Jeanne Zheng

SUPERVISING EDITOR

LAYOUT

Mason Lee Susan Lee Jessica Li Andrea Liu Dhylan Patel Astha Patra Alex Shahla Kate Wang Ashley Zhang Michelle Zhang Natalia Zorrilla

Alisha Sandhu Jack Granholm Elizabeth Kwon Michelle Zhang Alyssa Cho Katie Sheng Dominique Dâ€™Lima Esther Jung Aarya Mishra Savannah Skrinak

01 03 04 05 TABLE OF CONTENTS

Nobel Prize Laureates 2017 Kaila Coimbra and Christina Lee

Laparoscopies: Staring Into Your Soul Alex Tran and Jason Ha

A Battery Thatâ€™s Goodenough Clara Guo

Immunosignatures Gabby Kang

Automation

Paul Kreymborg

The Science Behind Emotions

Jeanne Zheng

Manhattan Project: Comparing the Roles of Uranium and Plutonium in Nuclear Fission

Sai Gantla and Paymon Haddad

CLUB FEATURE

Making an imPAHct at CCA

Furry Friends: Alpacas and Llamas

Michelle Zhang and Maggie Chen

By Kaila Coimbra and Christina Lee

2017

Nobel Prize Laureates PHYSIOLOGY AND MEDICINE

From left to right: Young, Rosbash, and Hall.

On October 2, 2017, The Nobel Assembly at Karolinska Institutet awarded Jeffrey C. Hall, Michael Rosbash, and Michael W. Young the Nobel Prize in Physiology or Medicine. Hall, Rosbash, and Young displayed novel findings on the circadian rhythm, an evolutionary biological process that functions as a clock in the body and regulates physiological functions. The circadian rhythm explains the phenomenon of biological organisms adapting their own rhythm to match with that of the Earth’s, which is much like the heartbeat of the Earth. Although the existence of circadian rhythms had been established during the 1900s, the genes that controlled them were unknown In 1984, Hall and Rosbash isolated the gene, period, which is known to control the circadian rhythm by encoding proteins called PER, which accumulate during the night and degrade during the day in synchrony to the circadian rhythm of the organism. Using fruit flies, Drosophila melanogaster, they found that PER protein levels in the flies’ heads fluctuate during different times of the day, even in the constant darkness of nighttime. They also noted that the PER protein could rescue its mRNA expression after its peak which occurred early at nighttime, hours before the peak production of PER proteins. It was discovered that PER proteins are nuclear proteins that move in and out from the nucleus to the cytoplasm. Using this data, Hall and Rosbash hypothesized that by an inhibitory feedback loop, the PER protein is able to control and block its own synthesis by accumulating in the nucleus. However, a question remained: how did the PER protein enter the nucleus to control its production? 1

Michael Young identified the the partner gene of period: timeless. The timeless gene encodes for the TIM protein, which binds to the PER protein and transports it from the the cell’s cytoplasm to the nucleus. This allows the PER protein to bind to the period gene and stop the transcription of period, regulating the amount of PER produced by the cell. In his experiment, Young showed that when the PER and TIM proteins were expressed independently, they were allowed to accumulate in the cytoplasm; however, when they were jointly expressed in a single cell, the PER and TIM proteins both went into the nucleus of the cell. From the discovery of timeless, yet another question arose: how was the frequency of the oscillations of the 2 proteins controlled? Young went on to find another gene called doubletime. It codes for a DBT kinase which adds a phosphate group to the PER protein, regulating its degradation rate in the nucleus and accumulation in the cytoplasm. When PER and TIM proteins accumulate in the cytoplasm during the night, DBT binds to PER proteins and degrades them until TIM accumulates further and prevents the degradation of PER. As the PER and TIM complex makes its way into the nucleus, they are held together by the DBT kinase. Once the complex is inside of the nucleus, TIM unbinds from the complex and DBT continues to degrade PER, stimulating more clock genes. Through their novel discoveries, Hall, Rosbash, and Young have allowed us to learn more about the mammalian circadian rhythm, which will undoubtedly lead to further discoveries of our bodies and how they function.

CHEMISTRY The Nobel Prize in Chemistry was awarded to Jacques Dubochet, Joachim Frank, and Richard Henderson “for developing cryo-electron microscopy for the high-resolution structure determination of biomolecules in solution”. Although it sounds complex, the method is relatively easy to understand. Cryo-electron microscopy, or cryo-EM, is a procedure that shoots beams of electrons at frozen biomolecules, or proteins, to see and understand their structure. As the electron beam passes through the frozen protein sample, the electrons scatter around the protein. The electrons then pass through a lens that magnifies the image of the protein onto an electron detector. Once the electrons are detected, the images of the biomolecules can be distinguished

From left to right: Jacques Dubochet, Joachim Frank, and Richard Henderson.

and analyzed. Although cryo-EM has existed since the 1970s, more recent improvements allow direct reconstruction of the images in 3D. This new technique is rapidly replacing X-ray crystallography, a method that fires X-rays at crystallized proteins. In X-ray crystallography, some biomolecules interact with the high energy radiation, which in turn prevents the formation of large enough crystals needed to study their lattice structure. However, CryoEM allows for direct imaging of biomolecules without needing crystallization of the samples. The high-resolution pictures can illustrate a cell’s machinery in great detail or reveal where to best target a disease-carrying molecule with drugs. The work of Dubochet, Frank, and Henderson on cryo-electron microscopy will revolutionize structural biology and change the lives of future generations.

Clockwise from top-left: Weiss, Barish, and Thorne.

Image Credit: Flicker @ junaidrao; Flickr @ Bengt Nyman; Flickr @ Penn State; Flickr @ Konstantin Malanchev

Laparoscopies:

Staring Into Your Soul By Alex Tran and Jason Ha

Surgery is one of the most well-known contemporary forms of treatment. It is also one of the most difficult and taxing to perform— both for the surgeon and for the patient. Improvements in medical technology have allowed surgeons to employ modern techniques and tools. One of the most common forms of surgery is laparoscopy, in which a surgeon inserts a long, thin instrument with a camera attached to its end into the abdomen. From there, the surgeon can proceed with the surgery without having to drastically cut open and expose the abdominal area. This works as follows: first, the patient is put under general anesthesia to induce sleep and numb any pain. The surgeon can then make a small incision and insert a device known as a trocar that serves to keep the incision open for the laparoscope. Carbon dioxide is pumped in to inflate the abdominal areas so there is more room to work in. The laparoscope is put into the trocar and used to survey the insides of the patient. The images that the laparoscope captures are relayed to nearby computer screens so that the surgeon can see inside the patient. The surgeon may then create more incisions and insert more trocars to utilize other instruments as necessary. The adaptability of the trocars allows the the surgeon to stick laparoscopic graspers inside the abdomen, which are used to manipulate organs and complete the surgery. After the surgeon completes the surgery, a surgical assistant removes all instruments and stitches the incisions to aid in the healing process. Due to the small holes from the trocars, the patients’ scarring and discomfort from surgery is minimal. Sounds simple enough, right? Be sure to keep in mind, though, that it takes years of training to fully understand what’s going on inside and to know what you are doing. After personally watching a surgeon sift through a plethora of guts during a laparoscopic gastric bypass, I can guarantee that

Image Credit: Unsplash @ GPiron

this is all you will pretty much be seeing for a couple hours. The versatility of laparoscopy allows it to be used for a multitude of procedures, such as removal of the gallbladder or parts of the intestine. It can be used to help make a diagnosis by observing abnormalities not shown in by an ultrasound, CT, or MRI scan. While laparoscopy is usually used for treating abdominal problems, smaller versions called arthroscopes can be used to treat joints in the knee or shoulder. The laparoscope has marked the emergence of modern technology in the medical field, and has brought along with it numerous benefits. For one, it allows doctors to perform surgeries with very few cuts in the abdomen. It also reduces pain and allows for a shorter recovery time, largely because the incisions are so small. However, it’s also important to remember that the laparoscope is not a perfect piece of technology. Its use can be problematic because doctors have limited movement inside the abdomen, preventing them from reaching areas that may need treatment. There are also a number of risks associated with laparoscopies, the major ones being the injection of excess carbon dioxide into the bottom and possible infections from trocar injection. Even though laparoscopes are fairly reflective of modern technological development, some are still looking for ways to expand on its capabilities. One proposed expansion is the use of robots in laparoscopic surgeries so that the burden on a doctor is heavily reduced. This, obviously enough, is still an idea in the works. The ideal situation would be to have the robot assist the doctor in areas like visual magnification and stabilization. However, this is not the case with the robots brought into the world so far. What’s clear though is that developers are not giving up and it may be possible that at this rate, the idea of a robot performing such a complex surgery may become reality soon enough.

a battery that's Goodenough

By Clara Guo

team of engineers in Austin, Texas led by John Goodenough and Maria Helena Braga created a new form of battery that has the potential to replace the commonly used lithium-ion battery. Lithium-ion batteries operate using liquid electrodes to transport lithium ions from the anode to the cathode. However, Goodenough’s team has made a huge breakthrough in electrochemical technology by creating the first solid-state battery that utilizes glass electrodes to transport ions. Glass electrodes improve upon the cost, safety, energy density, and rates of charge of the batteries’ production and operation. The solid state of the battery also remedies the main risk in using liquid based batteries: batteries catching on fire or combusting. A typical lithium-ion battery consists of a cathode core surrounded by the anode, with a separator soaked with liquid lithium-ion electrolyte acting as a divider. The battery consists of chemicals that will undergo a reduction-oxidation, or redox, reaction that will include the transfer of electrons from anode to cathode through the circuit you have attached to the battery while lithium ions will cross from anode to cathode through the separator. A solid glass electrolyte functions in relatively the same way. Rather than ions moving through liquid, ions can hop to unoccupied sites in the crystalline structure, which can only occur because the research team doped the glass with alkali metal ions, disordering the organized structure of a covalent network structure enough to leave molecular gaps. Doping, in this context, means adding ions into a structure to give it a charge. One of the most significant complications involved in the use of conventional lithium-ion batteries is the formation of dendrites—small growths or ‘whiskers’ of lithium metal—during the process of recharging. While the specific process of dendritic solidification is contested, Berkeley researchers hypothesize the root cause of such formations are the introduction of impurities into the liquid lithium anode, which serves as a catalyst for the liquid metal’s nucleation (crystallization). As the lithium-ion batteries degrade through multiple trials of charging and discharging, heating and cooling, the possibility of exposure to contaminants increases. This is because rapid charging requires a drastic change in temperature in very little time, weakening the battery’s structure. Once an impurity is introduced to the supercooled liquid lithium, a structure can form around the site of impurity, the nucleus, and form a dendrite, similar to how a crystal structure begins to form in a supersaturated solution once a seed crystal is introduced. These dendrites continuously form as the battery is cycled and lithium ions are unevenly deposited on the cathode, eventually spreading across the battery, through the separator, and to the cathode, short circuiting the battery and potentially causing fires as well as explo-

sions. The consequences of such electrochemical mishaps can be seen in the example of the Galaxy Note 7 combustions that were caused by dendritic formations short circuiting the phone. The use of a glass electrolyte largely prevents the problems mentioned earlier due to the covalent network structure of the solid glass, the most stable of the molecular arrangements. Furthermore, the solid structure of Goodenough and Braga’s battery facilitate the homogenous deposition of lithium ions compared to the loose, freely moving structure of liquid lithium. Goodenough and co-inventor Braga’s battery also has a greater the storage capacity and smaller charging time compared to the lithium-ion. They accomplished this by doping their glass electrolyte with alkali metals, particularly lithium and sodium, to create a highly conductive glass electrolyte that can increase the battery storage capacity threefold. This is due to the increased capacity for the battery to store energy in an electric field rather than solely in chemical potential energy; this behavior is similar to that of a supercapacitor and enables the battery to charge in a matter of minutes rather than hours. In this sense, the glass electrolyte serves as a dielectric-a polarizable insulator in which an electric field is passed through-that allows a negative charge to build up on the anode and a positive charge to build up on the cathode. The buildup of charges is caused by the glass electrolyte’s property of insulating towards electrons while having high ionic conductivity, reducing the resistance and thus enhancing its energy density. Basically, a glass electrolyte can store electrical energy in multiple ways, which decreases the overall charge time while increasing the storage capacity. The glass electrolyte presents new possibilities and capabilities for the renewable energy and technology industries. Notably, it will potentially revolutionize the electric car industry by increasing the number of miles per charge to make it more competitive with conventional gas-fueled cars. In addition, the battery has a much larger window of operational temperature. Glass electrolyte batteries are operable under a range from -20 degrees celsius to 60 degrees celsius, potentially allowing electric cars to operate in both sub-zero and scalding temperatures. In fact, this battery will be the first battery able to operate in such extreme temperatures. Goodenough and Braga’s battery also has implications in conservation. Sodium-doped batteries can be sourced directly from the sea rather than mined like lithium, and will make recycling much easier since sodium batteries can rather simply be placed in a recycling bin while lithium-ion batteries have to be recycled at a plant. While the glass electrolyte battery is still in it's developmental stages, the research team expects an updated version of the battery to reach the market in as little as three years. Image Credit: Flickr @ James Almond

IMMUNOSIG Last year,

I was blessed with the joy of blood testing—and lots of it. Vial after vial, test after test, I watched as each sample was carted off to the lab and awaited the results. Most of the time, the blood samples took days (literal ages, I tell you) to return. Though these occasions were far and few, I even had to give up more blood to repeat tests that came back with questionable results. And that got me thinking, is this really the best way to test for diseases? (And what the heck are they doing with my blood?) Answers to the second question aren’t too hard to find, given the extent of modern-day Internet. Hematology, the study of blood, kicked off around 1642 with the creation of a microscope that could identify individual blood cells. Fast forward to 1770, when William Hewson, “Father of Hematology”, introduced the clotting properties of blood as well as the characteristics of leukocytes (white blood cells). In the following years, the world came to learn more and more about blood: how it’s organized into types, how to transfuse blood depending on these types, and how to understand what these cells, vital to all life and function, actually do. However, hematology doesn’t find a truly practical and accessible use until much later on. In 1985, researcher George P. Smith revolutionized the entire world of hematology with one of the oddest, tiniest solutions. During this year, Smith performed the phage display experiment, also known as the Totally Scientific Genetic Guess and Check (TSGGC). In this experiment, researchers use bacteriophages, tiny viruses that specifically target bacterium, to isolate and identify specific proteins in the blood. First, a specific protein or slice of DNA in the blood is isolated. Then, the genetic game begins. Researchers are given a large, almost immeasurable selection of genetically modified bacteriophages, each one of which is specialized to target a unique protein. These phages are then introduced to the blood sample to do what they do best: infect and attach to proteins. The bacteriophages that manage to successfully attach themselves to the protein are removed and amplified. The pool of phages is then altered to only include the amplified phages. And so the cycle repeats. Bacteriophage to blood, attached phages back through the cycle. At the end of the test, these attached phages are numerous enough to be specifically identified, allowing their targeted protein to be identified as well. For a time, phage display was great, but scientists soon realized the inefficiency of the TSGGC. After all, the experiment really was nothing more than a guessing game through more complicated and

BY GABBY KANG

extensive means. The protein was a lock and each bacteriophage was a key, but there were a lot of keys. Furthermore, researchers could only look for the key to one lock at a time, requiring a larger amount of blood and time for each test. Deciding which key to look for could take valuable time, as the pathogens would often have to spread far enough to cause symptoms before potential keys could be identified. So scientists asked the same question as before: is this really the best way to test for diseases? The scientific world had one answer to that question: immunosignatures. I’m sure the common reaction towards this would be “Immuno-what now?” and I can’t say I blame you. At this very moment, my oh-so-helpful computer is screaming at me with a bright red, squiggly underline to correct my words, but I’ll stand by them. The term immunosignature can basically be related to a much more familiar term: the biomarker. Biomarkers are organic substances that indicate the presence of disease, infection, or other environmental exposure; in other words, the exact things blood tests are looking for. Immunosignaturing works by specifically observing the naturally produced antibodies in the immune system. The immune system is always active, even when symptoms aren’t identifiable. It’s why we can go days without having a runny nose or a cough only to come down with a cold the next morning. By specifically targeting the immune system’s antibodies, immunosignaturing is able to identify illnesses earlier, faster, and easier. In contrast to the phage display method, immunosignaturing takes one sample and tests everything at the same time. Peptides, tiny chains of amino acids used to make proteins, are applied to a sample. Each of these peptides are designed to bind to a specific antibody, just as the bacteriophage binds to a specific bacterium. The bound peptides end up forming extremely tiny strips with their corresponding antibodies and rearrange themselves into a specific order onto a microarray, which is a laboratory tool used to determine the gene expressions of thousands of genes at the same time. The strips themselves are practically impossible to identify with the human eye because of their small size, so scientists use extremely powerful cameras to identify which strips are present and which are not. By determining which antibodies are present, lab workers can discern their corresponding pathogens, even if the pathogens themselves are small in number. With immunosignaturing, the single lock was easily undone. The door was opened to reveal an entire wall of locks, and scientists rejoiced. While the

GNATURES locks had grown, so had the keys. With a single drop of blood, researchers were able to test for multiple illnesses without waiting for visible or identifiable symptoms. Furthermore, the size of the strips provided quantitative data on the presence of illnesses, assigning numerical values to the presence of pathogens based on the size of the strips: a revolutionary feature that phage display previously couldn’t hope to define.

(a)

(b)

Phage display

Selection, sequencing

pVIII

pVII

I had the opportunity to interview Alexander Sun, one of the graduate students at UCSD working on this project, for more details. In most cases, electrochemical sensors work by applying a continuous electric current to a solution and then measuring the returning ionic charge through a process called amperometry. The problem with this, he says, is that the returned charges were too small, requiring larger and more complicated readout circuitries to detect

pIX

Creation of phage libraries

Peptide microarray

Scan, align, interpret

Syntheisze peptides print microarrays

pIII Panning of serum against phage-displayed random antigens

Incubation of serum on microarray. Detect with antispe

Figure 1. A diagrammatic representation of phage display (a) versus immunosignaturing (b). Phage display used a large combinatorial library of peptides that are displayed on the surface of a phage against which serum is panned. Multiple rounds of selection produce candidates that are then sequenced. Immunosignaturing also uses random sequence peptides but they are longer (20 amino acids including linker) and are physically attached to the surface of a glass microscope slide. Serum is exposed to the array and detected with fluorescent and electrochemical probes.

And yet, the scientists still weren’t satisfied. The high resolution imaging used in optical immunosignaturing was too bulky for widespread use, not to mention point-of-care (POC) devices. Despite its accuracy, it didn’t seem like optical immunosignaturing could be used outside of centralized labs. And so the search for a solution began. In the Department of Electrical and Computer Engineering at UCSD, a group of graduate students is currently working on an alternative to optical immunosignaturing. The key, as many engineers are prone to say, lies within chips. More specifically, the answers lie in something called electrochemical biosensors. As the name suggests, these “life” sensors use a combination of electric charges and chemical properties to detect specific organic substances. Perhaps the most common example of these sensors would be glucose sensors—small POC devices that most diabetics use to track their sugar levels—but the field of immunosignaturing could see use from biosensors as well. The end goal of a transference from optical to electrochemical detection would be the creation of a single sensor about the size of your fingernail that could deliver the same results of immunosignaturing, only with greater accessibility and greater efficiency.

the results. The remedy: find a way to get larger responses from the solution. These new sensors use an alternative method of sensing based on coulostatic discharge theory; instead of applying a continuous charge to the solution, the sensors use short bursts of high voltage. The higher potential applied to the solution, the higher the rebounding results. And the larger that the results end up returning, the easier it is to detect them, even if the readout circuitry is reduced. With this technology, the world of hematology might be revolutionized once again. Because of this, traditional blood tests would no longer be needed. Why waste vials upon vials of blood when a small chip could do even better with just a single drop? Why spend days waiting for tests to be completed when the results could return within a few minutes? Personally, I’d be grateful for these new biosensors. After all, my experience with blood testing last year made it the bane of my existence, and who doesn’t want results with minimal effort? Unfortunately, we’ll have to wait a bit longer to see how this new technology pans out. But who knows? Unlike those grandiose flying cars or gigantic robots, our next technological revolution might be able to fit in the palms of our hands.

AUTOMATION By Paul Kreymborg

Only a fraction of an American’s life is spent doing work, or, effectively, things useful to other people that the American is paid for. What would a breakdown of a hypothetical machine’s time look like? To some, this prediction may seem unrealistic, or at least unlikely to occur to the degree described here. This skepticism is understandable—the last case of an industry being so much and comprehensively reduced in the number of people required in it was the agriculture industry, a change people generally are unlikely to remember. Most people who witnessed the heavy decline of agriculture employment, that is, actively seeing and experiencing the effects of it, especially when that decline was changing the largest fraction of all jobs, are dead. High schoolers like my-

75 70

Share of the labor force working in Agriculture (in %)

s current robots become better and better at what they do, several processes, or jobs, in factory production lines are becoming automated. Things that were once accomplished by having people come into a factory and do work in exchange for wages now can be done (and are done) by robots. However, robots (at least currently practical ones) have remained large, expensive, and bulky - looking more like the Hulk rather than Captain America. Advancements in the robots that are being used today are only refinements on older designs. But if robots are made, eventually, that (1) have or come close to having the physical abilities of a human being, and (2) are cost efficient enough to replace manual labor, the resources required to create the majority of manufactured items will drop substantially. For example, consumer luxury goods and basic commodities will become cheaper. Also, very importantly, unless restrictions are placed on the uses of robots, the amount of jobs requiring mainly physical labor (repetitive work like construction) will most likely drop precipitously, eventually approaching a maybe negligible quantity.

65 60

57%

55 50 45 40 35 30 25 20 15

12.6%

10 5 1300

1400

1500

1600

1700

1800

1900

1.2%

2012

Data source: Pre 1800 is from Allen (2000), “Economic Structure and Agricultural Productivity in Europe, 1300-1800.” Newer data from the World Bank. Adapted from Max Roser’s “Share of the labor force working in Agriculture, since 1300.”

self (and the main audience of Catalyst) have only seen a world with few developments or radical changes outside of computer technology. So, skeptics of the widespread automation of several jobs that are today performed by we humans should look to the example of agriculture as an example of why they’re probably wrong. If (and when) this automation happens, and it will, most likely soon, unless something stops it, things formerly relatively expensive will become lower in cost, due to the drop in human labor required for manufacture. The price of living, for those with jobs, should decrease substantially. But, like other major changes to the world, automation will create new problems that will be difficult and time-consuming to work out, unless we’re ready. On the bright side, opportunities will be plenty from cheap, newly available work. Labor-intensive industries such as min-

ing, recycling, refinement, electronics manufacturing and many low-volume production industries will require much lower amounts of human—and in some cases physical—resources to get given output from. A person at home with enough materials could probably manufacture many things for themselves, allowing for far more practical and efficient self-sufficiency than possible now. Eventually there may be a point where all of a person’s physical needs will be fulfilled by automation, leaving the person able to pursue their own goals without requiring anything from others. It’s difficult to project from predicted advancements what will certainly happen, but in the near future, if those with relative power handle the transition to robot labor smoothly, we can expect more personal time, more personal freedom, lower taxes, and more. Image Credit: National Institutes of Health

Don’t Be Afraid to Catch Feels: By Jeanne Zheng

Vibrant joy. Tingling nervousness. White-

hot anger. Icy fear. These emotions are perhaps some of the only constants among all people, crossing geographical boundaries and cultural divides. However, despite the omnipresence of emotions, they have remained mysteries for millennia. Psychologists finally began taking an interest in them, or rather their scientific basis, in the mid-20th century. Since then, researchers have illuminated the neurological pathways behind some of humanity’s most fundamental emotions, most prominently that of love. More than a decade ago, anthropologist Helen Fisher and her team researched college students to find a scientific explanation for romantic love. They achieved this by showing subjects images of their significant other and then measuring their brain activity. Fisher found that, when subjects were shown pictures of someone they love, the levels of dopamine—a neurotransmitter associated with positive feelings such as pleasure—increased dramatically. Increased brain activity was also detected in the caudate nucleus and ventral tegmental areas, which have functions such as response to visual beauty, motivation, and sustaining reward circuitry. Further investigation indicated that a variety of different chemicals also play a part in causing the euphorically nerve-wracking, heart-pounding effects of love. For instance, levels of cortisol, a hormone that causes stress, are especially heightened during the early stages of romantic love. On the other hand, levels of serotonin, a neurotransmitter, drops at the beginning of love—this decrease is what causes infatuation. However, with time, a hormone called oxytocin increases; this change diminishes the excitement and nervousness that characterize the initial phases of romantic love, but in return increases attachment and comfort between a couple. Although the biological causes of emotions have now been more or less well defined, another question still intrigues scientists and cultural researchers. Do people of different societies and locations express their feelings in the same way? If so, does that mean that these facial expressions and gestures are basic instincts of humanity? According to Paul Ekman, they are. A student in the 1950s, Ekman was one of the first psychologists to take an interest in studying emotions--more specifically, their role in global cultures. In one study, he traveled all over the Americas, showing different people photographs of facial expressions; Ekman

The Science Behind Emotions then asked the people he encountered to match the expressions to their respective emotions. This and similar studies yielded very similar results: most people were able to accurately match the emotion to its facial expression--on average, about 58% of the time. Overall, people struggled to tell the difference between fear, surprise, and sadness, achieving an accuracy rate of just 28%. On the flip side, people did exceedingly well identifying happiness, disgust, and anger, with an accuracy rate of 100%. This indicated to Ekman that a range of basic facial expression is common to people all over the world. However, Ekman’s findings have garnered some criticism from the scientific community. One of the first and most prominent dissenters was anthropologist Margaret Mead—she believed that rather than coexisting with culture, expressions of emotion are more resultant of those societal factors. Years later, some psychologists are beginning to agree. They now believe that the experience of emotions is a multifactorial process, one that should be considered with regard to elements such as “language use, context, culture, or individual differences in prior experience” (“The Experience of Emotion”). If Ekman’s findings hold true, though, they could have some significant repercussions. If psychologists figure out how to “hack” human expressions, how to find correct interpretations of facial expressions both obvious and subtle that could apply universally, the possibilities are endless. It would be much more difficult for people to hide their true intentions if everyone else is able to notice their microexpressions—those small twitches and quirks that are normally too minimal for others to notice. One major field that could benefit from this is that of criminal justice. It would be so much easier to catch a witness or a suspect that was lying, to infer the truth of the situation from someone’s face. But before scientists get there, there are still a variety of factors to consider and multiple obstacles to overcome. The greatest of those is—as Mead, Barrett, and Mesquita point out— the issue of neglecting the effect of cultural experiences on human expressions of emotion. Perhaps when psychologists learn how to reconcile those factors, they will be able to establish a firmer connection between innate instincts and how humans over the world physically express their emotions. For now, though, this is an area of study that requires more extensive research.

Manhattan Project: Comparing the Roles of Uranium and Plutonium in Nuclear Fission

By Sai Gantla and Paymon Haddad 9

The birth of nuclear weaponry, in many

ways, can be viewed as a byproduct of paranoia, one that eventually led to the direct loss of over 200,000 Japanese lives. This topic is not one to consider apathetically, but understanding the developmental process that ensued is almost synonymous with an understanding of nuclear enrichment and its potential. By 1939, the Second World War was well underway, but the United States’ direct involvement in the conflict was still, for the most part, absent. However, August of that year marked a change, a change that was fueled out of warnings by European-born American physicists Eugene Wigner and Leo Szilard regarding Nazi Germany’s alleged attempts to develop a new type of weapon altogether: the nuclear bomb. The physicists proposed the initiation of a nuclear program as a direct response to possible Nazi developments. Although the Nazis never followed through in their efforts at nuclear proliferation, the United States-led Manhattan Project was born in 1942—and with it, the nuclear bomb. The primary raw material used in the Manhattan Project was uranium, used to fuel the reactors used in the project. It was also utilized in some of the bombs in a completely enriched form. Due to increasing demand of the material, the United States turned to multiple uranium mines to produce enough uranium for the project. The raw ore was refined into uranium metal through a complex process (performed by Mallinckrodt Incorporated). First, it was dissolved in nitric acid. Then, ether was added to remove impurities from the uranium. This was heated to form uranium trioxide, which was then reduced to uranium dioxide. The issue was turning this into uranium metal. The processes occurring at the time took too long and produced low quality metal. As a result, the Ames project was started in 1942. This led to the development of the Ames method, which consisted of combining uranium tetrafluoride and powdered magnesium and placing the combination into a furnace. The combination exploded in the furnace, producing metal ingot. The process of retrieving uranium usable in experimentation was further inhibited by the fact that natural uranium contains 99.3% uranium-238 and 0.7% uranium-235. The issue was that only uranium-235 is fissile, meaning it was the only kind of Uranium that could be used in a nuclear reaction. Researchers needed to extract the uranium-235 isotope from the natural uranium. They accomplished this through another set of processes. The first idea included using a centrifuge, which spins a substance around to separate different substances within it. This didn’t end up working, as it was determined that many thousands of centrifuges would have to be used, all spinning at an incredibly high speed that threatened to rip the machinery apart. The logistics of this were impossible to overcome, and as a result, this idea was scrapped. Electromagnetic separation, gaseous diffusion, and thermal diffusion technologies were all successful, though. Electromagnetic separation works by deflecting particles according to their mass by using a magnetic field. This helped separate the lower density uranium-235. Gaseous diffusion used a semi-permeable membrane in order to separate lighter gas molecules from heavier ones. This worked because the lighter gas molecules would leave the container much more quickly than the heavier ones. This process was repeated multiple times, eventually resulting in a gas that was almost purely uranium-235. Thermal diffusion acted by using a temperature gradient on uranium gas. The lighter molecules tended to concentrate around the warmer end, while the heavier molecules would concentrate around the colder end. This helped separate different isotopes (as their densities vary).

The Little Boy bomb, the first atomic bomb ever used in warfare, used fission of uranium-235 to cause a nuclear explosion. The bomb was made with two parts, a projectile and a target. The projectile was a hollow container that housed multiple uranium rings, while target was a cylinder. The bomb operated by driving the projectile down the barrel of the bomb into the cylinder, causing an explosion. Little Boy was dropped on Hiroshima on August 6th, 1945, killing 66,000 people and injuring 69,000 more. Nuclear fission using uranium-235 turned out to be very powerful. However, the bomb dropped on Nagasaki, code named “The Fat Man”, utilized a different element to undergo nuclear fission: plutonium. Plutonium was discovered in 1940 by a group of physicists working on the Manhattan Project. Its discovery led many of the physicists working on the project to speculate how it could potentially be applied to create a different kind of bomb altogether. The creation of plutonium, in the theoretical level, is neither complex nor particularly problematic. To do so, the physicists would bombard uranium-238 with neutrons to create a minute quantity of uranium-239. The newly formed uranium-239 isotopes would then spontaneously and rapidly decay into plutonium-239. Therefore, the problem did not rest so much in the creation of plutonium as in how to separate it from the uranium it was contained in. These problems were what much of the physicists’ research was mounted on. To combat this problem, Charles M. Cooper proposed the lanthanum fluoride process for separating the two substances. This method involved the addition of lanthanum fluoride to the mixed solution, which was then precipitated to extract the plutonium within it. However, this idea was quickly dismissed due to the corrosive nature of lanthanum fluoride and the development of a safer, more efficient process involving bismuth phosphate. The bismuth phosphate process of separation, proposed by Stanley G. Thompson, used the same theoretical idea of adding a carrier to the mixed solution, but was generally a safer and more efficient method of extracting plutonium. Once the bismuth phosphate had been precipitated with the plutonium, it would be dissolved in a high concentration solution of nitric acid. Then, the plutonium would be oxidized, usually with potassium permanganate, in order to convert it into a form that would no longer be carried by the bismuth phosphate. Once converted into this form, the bismuth phosphate would be precipitated, leaving refined plutonium. Over the course of many months, the process enumerated above would be perfected to yield 90% efficiency for plutonium aggregation. With the method of separation determined, the question now turned to how the plutonium would be utilized in a nuclear weapon. Initial proposals involving gun-type nuclear weaponry proved infeasible based off of the instability and impurity involved with the plutonium isotopes being used. Eventually, Seth Neddermeyer’s proposal for an implosion-type nuclear bomb was taken into action. The basic idea behind this implosion-type nuclear bomb was to uniformly detonate a combination of slow and fast explosives towards the center of bomb, where the plutonium rested. The plutonium that rested in the center of the bomb, by default, would preside below a measurement known as critical mass. If a fissile material achieves critical mass, a nuclear chain reaction can then ensue. Keeping the plutonium at sub-critical mass prior to detonation greatly decreased the likelihood of a premature detonation from occurring, an event that would mark literal catastrophe. Therefore, the implosion model, along with various additional safeguards, was manifested into “The Fat Man”; this bomb led to the loss of thousands of lives in Nagasaki on August 9th, 1945. Photo Credit: Flickr @ SADSM, 1946

ager to foster a continuing culture of science here at Canyon Crest Academy, students in the synthetic biology club have participated annually in the International Genetically Engineered Machine competition—dubbed iGEM—since 2012, when the club was founded. iGEM offers unprecedented opportunities for high school students to independently create, develop, and publicize novel research projects in conjunc-

iGEM team CCA_San_Diego presenting their work to the judges. From left to right: Victoria Li, Martin Holmes, Philippe Hansen-Estruch, Anjali Gopinathan, Michelle Zhang, Aida Razavilar, Jasmine King.

tion with other universities and high schools from around the globe or under the mentorship of professional companies. The annual competition is hosted by the Massachusetts Institute of Technology in Boston. CCA’s iGEM team is broken up into four main sections: lab, outreach, organization, and finance. The team facilitates the broad range of interests that students at CCA have from molecular biology to art and design. CCA’s iGEM team encourages teamwork and student diversity in order to undertake a large research project incorporating biology, mathematics, biochemistry, student education, and coding. This year, CCA’s iGEM team’s project aims to harness crude oil spills and industrial byproducts as a biological energy sources in order to render them easier to degrade and non-toxic. Crude oil is composed of polycyclic aromatic hydrocarbons (PAHs), compounds that are difficult to degrade and environmentally harmful. It is crucial to find a time and cost effective procedure that will metabolize some of the most prevalent, toxic PAHs—fluorene and phenanthrene—to innocuous compounds, such as salicylate and phthalate. Certain bacteria, such as terrabacter and the toxic pseudomonas aeruginosa, contain PAH targeting degradation pathways in their 11

genome. CCA’s iGEM team selected genes and constructed two sophisticated degradation pathways (one for fluorene and one for phenanthrene) using multiple bacterial strains after extensive genome mining. The team proposed a novel meth-

Some of the iGEM team members describing their outreach events and projects to an iGEM coordinator.

odology for the degradation of multiple PAHs through the design of catabolic pathways under multiple strength promoters and their successful expression in E. coli. The transformed bacteria has been shown to harness PAHs as a carbon source and efficiently render them less toxic. The synthetic bacteria containing these synthetic pathways were even shown to be able to degrade PAHs in oil from sites in Pennsylvania, Ecuador, and Saudi Arabia. An RK2 vector was also created to add

Three iGEM students at an local elementary school teaching the students some of the basics of bioengineering.

Making an ImPAHct at CCA to the international iGEM parts registry as a broad host range vector due to its incorporation into the project design. These synthetic bacteria can be incorporated in oil spill remediations and pump and treat systems to achieve proper detoxification through combinatorial genetic bioremediation. Not only has CCA’s iGEM team been hard at work in the lab, but it has also exposed the community to the field of synthetic biology. The team’s outreach events included a summer camp, a library STEM event, a bioethics seminar featuring guest speakers, and more! Last summer, the team simultaneously ran two one-week long summer camps targeted at students in 5th through 8th grades. One of the camps was focused on genetics and environmental science, while the other was centered around physics. As another way of reaching out to children involved in science, the team also hosted a STEM event in the Cardiff by the Sea public library. Here, the team conducted beginner level biology experiments and explained certain aspects of synthetic biology to those who were interested. In addition, CCA’s iGEM team along with Envision Conservatory for the Humanities and Speech & Debate hosted a bioethics seminar, in which various topics such as stem cell testing, cloning, and drug discovery were discussed in depth. The student-run bioethics seminar featured 4 guest speakers,

A student of the CCA iGEM Summer Camp partaking in one of the many science based activities for the week long camp.

Team co-presidents Aida Razavilar (left) and Martin Holmes (right) holding the awards won at the 2017 Giant Jamboree.

all of whom are bioengineering professors at UCSD. Professors Bruce Wheeler, Peter Yingxiao Wang, Daniela Valdez-Jasso, and Gert Cauwenberghs spoke about careers and youth in bioengineering, molecular engineering, soft-tissue biomechanics, and neural computations, respectively. Also, CCA’s iGEM team has collaborated with teams from various places around the world - ranging from Germany to Kazakhstan. The team worked with NU Kazakhstan’s iGEM team, University of Nebraska-Lincoln’s iGEM team, Bristol University’s iGEM team, and Technische Universität Dresden’s iGEM team in order to improve CCA’s iGEM team’s project and participate in the international iGEM community. With the help of these teams, CCA’s iGEM team championed the team’s wiki page coding, project mishaps, lab safety, and community outreach. Along with the help of CCA’s amazing EcoClub, CCA’s iGEM team was able to successfully participate in the iGEM GOES GREEN initiative including planting a tree on CCA’s campus. As a culmination of 8 months of hard work, CCA sent 7 members of the team to Boston in November 2017 to participate in the official iGEM “Giant Jamboree”. They received an unique opportunity to meet fellow researchers and scientists from across the world that they have previously only video chatted with, created memories over the long weekend for Veteran’s Day, and enjoyed a great learning experience! CCA’s iGEM team was nominated for four special awards and received awards for Best Part Collection as well as Best Poster. Check out ccaigem.weebly.com to read about the details of the team’s project from the 2017 Giant Jamboree. Image Credit: Flickr @ igemhq

Furry Friends: Alpacas and Llamas By Michelle Zhang and Maggie Chen

Alpa

o you’ve seen them everywhere. At the zoo. In National Geographic magazines. On those quirky Facebook posts. But you’ve never been able to truly identify what they are. Your friend excitedly shouts, “It’s an alpaca!”, but you, being the animal expert, indignantly reply, “No, I’m pretty sure that’s a llama.” A dispute quickly ensues and both of you rush online to settle the conflict and finally answer the question: what are the differences and similarities between alpacas and llamas? At first, distinguishing an alpaca from a llama may be confusing. Both are charming and endearing, rendering it impossible for them to not receive a myriad of sighs of adoration and constantly eliciting squeaky outbursts of “It’s so cute!” or “I want one!” from people who spend way too much time on animal blogs. Both the alpaca and llama are the two species of Camelids from South America that were domesticated about 6000 years ago in the Central Andes. People in Andean societies would make clothing from the llama’s fiber (which was collected from their dung), obtain food from the meat, and create leather clothing. Alpaca fleece was acknowledged to be the most prized form of currency and was gifted to loyal nobles as a reward. Its fiber is rather unique, considering that its strength is comparable to that of silk. Furthermore, it is lightweight, thermally efficient, and soft to the touch. It is clear these animals held religious significance in Andean society, as they, especially alpacas, were not only worshiped and presumed to be a gift from the Earth Mother Pachmana, but were also a central figure in many amulets and religious objects; for instance, conopas—traditional stone carved figurines—followed after the forms of these animals. Even though you may not have been able to confidently differentiate between these two furry friends, it is likely that you have noticed subtle discrepancies in physical appearance. So, maybe you were right about the alpaca versus llama debate. Here’s a quick Britannica-esque rundown and a final conclusion to help settle the weeklong argument you and your friend have perpetuated. For starters, llamas have rather elongated faces, whereas alpacas possess a characteristic “smushed” appearance, making them absolutely irresistible to us. Another defining quality of these animals is, not surprisingly, the

ears. Llamas are described as having “long banana-shaped ears” as opposed to the alpaca’s “shorter spear-shaped ears.” Moreover, while alpacas range in weight from 100 to 175 pounds, llamas are almost double this weight, ranging from 200 to 350 pounds. Because of their large size, llamas are used as pack animals, cart-pullers, and guard animals for alpacas. While llamas have two coats of hair, a thick and coarse outer coat coupled with a soft inner coat, alpacas only bear one coat of fine hair. Interestingly enough, even though alpacas and llamas were both domesticated around the same time, they were bred for different purposes. The alpaca was bred as a “luxury fiber-producing animal”; thus, alpacas produce a substantially greater amount of fiber than llamas do since the llama was originally bred as a pack-carrying animal. Llamas tend to roam alone, as they are more independent creatures, whereas alpacas, although shy and quiet, seek the presence of their herd mates. However, despite these differences in appearance, the llama and alpaca are quite similar in their distinctive behaviors. The defining motion of “spitting” is something unique to both animals. Used as a warning sign to competitors, sign of lack of mating interest, and expression of crabbiness, spitting is the weapon of choice to ward away offending persons (or animals). Generally, the spitting begins with a gentle warning—a small puff of air and saliva, coupled with a “pft” sound. If the offending party does not retreat, the grenade of choice is unleashed. The llama or alpaca will regurgitate the contents of its stomach, spitting everything up to 10 feet away. Like the bee sting, however, this regurgitation is just as unpleasant for the animal as it is for the receiving party. With mouths hanging open from the acidity of gastric goo, the llama or alpaca will seek the much more pleasant taste of a leaf to shake the oppressive taste away. However, do not let this seemingly frightening action scare you away. As gentle giants, llamas and alpacas are kind, loving, loyal—and, of course, come completed with layers of warm woolen fur. So, the next time you visit the zoo, don’t let the schism between these two animals turn into a cause for worry. Just enjoy their softness.

Lla

Image Credit: Flickr @ sk8geek; Flickr @ vastateparksstaff