The Catalyst September 2016 Issue

1C a t a l y s tSeptember 2016

September 2016 l septembre 2016Volume 7: Issue 1

Student Science Journal - Journal étudiant scientif ique

Humans Evolved From Walking Fish? Yes, You Read That Right! PAGE 10

101 WEEK SPECIALS INSIDE!

Food Science:

Ice CreamPAGE 8

C a t a l y s tSeptember 20162

THE TEAM | L’ÉQUIPEEditor-in-Chief Tanya Yeuchyk

Production Manager Christine Wang

Rédacteur-en-chef Setti Belhouari

Website ManagerMichael Leung

Authors | AuteursSetti Belhouari

Winston CheungZerin KhanAlek Tirpan

Yen TranÉmilie Vaillancourt

Tanya Yeuchyk

Editors | RédacteursShobhitha Balasubramaniam

Sanmeet ChahalAlex Chen

Alya HammamiConnie You

Illustrations and PhotographsItzel Lopez-Carreon

Sasha NewarKatherine Power

Ashley Tenn

Translators | TraducteursSanmeet ChahalSetti Belhouari

Narimane Ait HamouShamei Benoit Leblanc

Mihaela Tudorache

September Contents | Contenu de septembre

Articles6 Ethical Considerations with the CRISPR/Cas9 system

8 Food Science: Ice Cream

10 Humans Evolved From Walking Fish? Yes, You Read That Right!

12 Novel Aptamer-based Therapeutic System against Cancer

14 Zika: le nouveau fléau

16 Science de la bouffe : la crème glacée

18Les humains ont-ils évolué de poissons qui marchent ? Oui, vous avez bien lu !

Entertainment3 Comic Corner

11 The Accident

15 Funky Fungi

101 Week Specials4 10 Tips for Freshman Students

5 Tips for Incoming Science Students

13 Enriching Your Undergrad Experience


By: Itzel Lopez-Carreon, 2nd year CHM

By: Sasha Newar, 4th year BIO

Nous cherchons des traducteurs et des auteurs francophones. Ça

vous intéresse? Contactez le rédacteur-en-chef:

[email protected]


10 Tips for Freshmen StudentsThe life of a science student is definitely a challenging one. However, there is one thing that can be more challenging: be-ing in your first year as a science student. You will be in a larger establishment among thousands of students who, just like you, are lonesome, homesick, and stressed about their future. Do not panic! I have been there and survived. In addition to being a second-year biochemistry student (with a minor in math), I am also your Rédacteur-en-chef. I am always asked how I juggle so much work. In this excerpt, I hope to share with you the secrets of being a well-rounded and productive

student, especially during your first year of studies.

Though this list may seem general, it has helped me succeed my first year at University. I am sure it will help you too. May you have a healthy, successful first year.

By Rédacteur-en-chef: Setti Belhouari, 2nd year BCH

1 Sleep well: Ensure that you have sufficient sleep. Sleeping-in during the weekend does not

make up for your all-nighters during the week. For more on the importance of sleep, be sure to read our November 2015 issue.

2 Prioritize: Put your health at the top of your priorities list. Realize that your assignments, laborato-

ry reports, midterms, and exams are weighted differently. Put more time doing practice questions to prepare for your exams and midterms. Laboratory reports may seem like huge tasks, but they are not worth much of your final mark.

3 Contact your professor: At the beginning of the semester, ask your professor whether you

should put a greater focus on your textbook or your lecture notes. Office hours are your opportunity to clarify concepts with your professor. Get to know your professor better; he/she may become your research supervisor!

4 Wash your hands: Wash your hands to prevent yourself from catching the common cold during

midterm season. Take care of yourself. If you are feeling sick, visit a health

care professional who will treat you and write you a note justifying your absence.

5 Extracurricular: Join an extra-curricular activity. Being in at least one extracurricular activity

will teach you how to accomplish more with your limited time. This will also help you learn important life skills that are not covered during your lectures. Many extracurricular activi-ties organized in the University, offer wonderful rewards such as scholar-ships, trips abroad, gift cards, etc… Still, be careful not to overburden yourself with extracurricular activi-ties. Good grades are also important because they, too, can be equivalent to an Admission Scholarship.

6 Procrastination: To avoid pro-crastination, prepare daily goals. Tell yourself, that you will finish

your organic chemistry lab report within 3 hours. If you do, reward yourself with an outing with friends, a delicious restaurant dinner, or, simply, an extra hour of sleep.

7 Confidence: Do not shake while studying for your midterm. Believe that everything you are

being taught is within your reach.

Never demean yourself. Never com-pare yourself to the so-called geniuses in your math class. Believe in hard work.

8 Study groups: Study groups may be important for students to learn from one another. Nonetheless,

give yourself time to study by your-self. Study groups have a tendency of becoming grueling stress groups, especially when they are held the night before a midterm.

9 Last-minute: Before a midterm or an exam, do not stand amongst the mass of students who are

frantically going through their study notes. Try to find a quiet place to relax and stretch.

10 Enjoy: Do not attend your lectures and your extracur-ricular activities like they are

some sort of drudgery or punishment. Think this way: if you pay for you education, you’d better enjoy it.


Welcome to uOttawa Science! Take a moment to pat yourself on the back - you’ve made it to the next big chapter of your life. Not only that, but you have picked the most awesome facul-ty in all of uOttawa! To help you start your journey, I offer you an assembled collection of wisdom for surviving first year. . .

Once you get your syllabi, take a calendar and write down the dates of all your midterms. Trust me, they come quicker than you think, and this method will help you be better prepared. It also helps to know in advance if you have more than one in the same day (so that you can start cry-ing early).There are many groups on Facebook where you can buy used textbooks from other students. This is a great alternative to getting them brand new, and can save you lots of money!Go to your professor’s office hours when you have a question. You’ll get the most qualified explanation, and some profs will even give extra hints when they see a student putting in the effort. It also doesn’t hurt to meet your profs one-on-one and develop a working relationship with them.Go to lab tutorials! They are absolutely worth the extra class time. The TAs explain important concepts behind the labs you have done, and how to structure your lab report. You’ll find them to be a major help!You may want to consider renting a locker in Marion from the SSA, especially if you live off campus. It’s not expensive to rent, and it’s a very convenient place to store your lab coat and books during the year. You can even share one with a friend and split the cost.Attend your DGDs! It’s tempting to skip a non-mandatory class, but they are very help-ful for your understanding of course material. Remember that the prof hand-picks what is discussed, and the TA often goes through mid-term-type questions.

Sometimes, your lab grade includes a TA eval-uation. Be sure to talk to your lab TA about their specific expectations - this might help you achieve a better grade.Actually do work and get caught up during reading week. Going on vacation might improve your mood, but probably not your GPA.Don’t rush to buy your textbooks. Some profs will highly recommend one, but then never use it. Wait until you actually need a textbook to buy it, and you might find yourself saving hun-dreds of dollars.Try getting involved with research at the uni-versity! There are some great scholarship oppor-tunities throughout your undergrad like UROP and NSERC that will look great on your resume - and contribute to your bank account. Join the Catalyst, uOttawa’s student science jour-nal! We’re looking for all sorts of contributors, giving you the chance to get involved on cam-pus, meet new people, and gain some experience in science communications.Join any other on-campus club or organization that catches your interest! Complete lists are available on the SSA and SFUO websites.Most of all, make sure to enjoy your first year. Yes, there are stressful times ahead, but it’s so important to take the time to make memories with your friends and explore the city as a uni-versity student. Take it seriously, but take breaks too.

Tips for Incoming Science Students

Good Luck!

By Editor-in-chief: Tanya Yeuchyk, 2nd year BIMIlustrated by: Meaghan De Jesus, 3rd year BIM


CRISPR/Cas9 is a genetic technology that allows for researchers to target and alter genes, specifically ones that cause disease and disorders.

CRISPR/Cas9, or clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9, comprises the adaptive immune system of bacteria against foreign DNA. It is used as a genome-editing tool through the integration of a viral genome into the CRISPR sequence to form CRISPR RNA. The latter can be employed as a guide to target and cleave a particular location within a genome using the Cas9 endonucle-ase. In a recent study, Junjiu Huang and his team used CRISPR/Cas9 to try and eradicate the human β-globu-lin gene (HBB) from a human embryo (Otienna, 2015). The mutation of this gene causes β-thalassaemia, a dangerous disorder of the blood characterized by low hemoglobin (β-thalassemia, 2016). Huang’s goal was to use this system on other genetic diseases such as cystic fibrosis in order to eliminate them from the embryonic genome. The attempt was only partially successful and faced several scientific and ethical challenges which led to it being abandoned in the preliminary stages (Otien-na, 2015). One major concern was the resulting numer-ous, unpredicted off-target mutations, which can lead to cell death or modification.

There are vast number of applications for the CRISPR/Cas9 technology. We must, however, consider the as-sociated benefits and disadvantages. A major ethical issue arises in the event of this technology being used on germ cells, as well as a significant loss of diversity in a population. For example, CRISPR/Cas9 has al-ready been used to modify rat coat pigmentation. The problem lies in the fact that the same method could po-tentially be used to modify human skin pigmentation (Otienna, 2015). Such actions would not only reduce genetic diversity, but lead to an important ethical di-lemma.

A possible problematic application of gene editing is parents’ ability to choose their child’s genetic features. Since parents often wish for their child to be intelligent, beautiful, and athletic, the frequency of genes associ-ated with these characteristics would rapidly increase in the population. This would lead, again, to a marked decrease in genetic diversity. Modifications could even lead to development of new genes if parents demand for their children to have purple eyes or blue hair, for example. It is arguable that children should have the right to be born naturally and not be genetically mod-ified without their consent. Many scientists firmly believe that such genetic technologies should only be used therapeutically and be kept under strict control.

In conclusion, CRISPR/Cas9 is a very powerful ge-nome-editing tool with a promising future for disease eradication. However, it should be highly regulated in order to prevent unethical uses like on human embry-os. Although funding for human embryonic genome editing has been banned in the United States, it is still permitted in other countries. If the technology is pursued in these areas, what will be the future conse-quences on the human genome?

Figure 1. CRISPR RNA binding to genomic DNA leads to recruit-ment of the Cas9 endonuclease to the binding site. Cas9 can subse-quently cleave the genomic DNA at highly specific location

Ethical considerations with the CRISPR/Cas9 systemBy: Émilie Vaillancourt, 4th year BPS

References:Otieno, M. (2015). CRISPR-Cas9 Human Genome Editing: Challenges, Ethical Concerns and Implications. Journal of Clinical Research

& Bioethics 6(6), 253-255.Beta-thalassemia. (2016). U.S. National Library of Medicine: Genetics Home Reference. Retrieved from https://ghr.nlm.nih.gov/condi-

tion/beta-thalassemia

Photo Source:Chemical and Engineering News. 2014. CRISPR/Cas9 Gene Editing Systems. American Chemical Society. 92: 37.

“CRISPR/Cas9 is a very powerful ge-nome-editing tool with a promising future for disease eradication.


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FOOD SCIENCE: Ice Cream Winston Cheung 4th year BIM; Yen Tran 4th year BCHPhotographs by: Katherine Power, 2nd year BIO

Nothing hits the spot like good old ice cream on a hot summer day. The kid in you might think that ice cream is

made from cold, sweet, and creamy fluff. Yet what is ice cream really made of? Well, that kid is not too far off. Cream, sugar, and air are the three key ingredients that give rise to ice cream’s taste and texture. Inspired by Ottawa’s Ice Cream Festival, this issue’s Food Science will educate you on this tasty frozen treat called ice cream.

What is ice cream? What exactly is ice cream? Would you classify ice cream as a solid, liquid, or gas? Ice cream is actually an interesting mix-ture of all three phases- there is ice, cream, and air. As a colloid (a substance with very small in-soluble particles suspended), ice cream contains ice crystals and air bubbles suspended in the ice cream serum. The ice cream serum, which dis-solves sugars, salt, and proteins, acts as the ma-trix which holds the whole ice cream structure together.

What makes ice cream? What exactly is in ice cream? What do we put in ice cream to make it so savoury and sweet? The cream and milk in the ice cream pro-vide three vital components: fat, non-fat sol-ids, such as milk proteins, and water. The sugar sweetens the ice cream. Other flavourings and additives, like egg yolk and vanilla, can be dab-bled in to improve the taste.

FatsFat in ice cream mostly comes from milk fat, which contributes to its richness by increasing the creamy texture. This is because triglycerides in dairy fat melt at the right temperature range for us to eat. If the fats were to melt at a high-er temperature, the ice cream would feel waxy rather than creamy. Fat in ice cream usually organizes in drop-lets, but at times can form larger fat clusters or even partial clusters. Fat helps to stabilize the ice cream foam and slows down the melting rate of ice cream, while also helping to deliver flavours that might otherwise be insoluble in water. Due to the fat content, we are able to indulge in the soothing and savoury melt of ice cream.

ProteinsProteins found in the milk can improve the tex-ture of the ice cream via the emulsification of the fat and the water. Emulsification helps keep the fat droplets small to stabilise the air that will dif-fuse into our ice cream. Milk proteins surround each fat droplet and form a membrane, prevent-ing fat droplets from forming fat cluster that are too large.

WaterWater forms ice crystals inside the ice cream and influences the structure. The crystals should be miniscule in size to prevent the ice cream from feeling grainy. Hard ice creams that are smooth


and melt in your mouth have ice crystals that are around 35-45µm in size. Soft ice creams have a lower ice content. Most of the water transforms into ice after the ice cream hardens. Wait, why is the water not all ice if water freezes at 0˚C? Perhaps this phenomenon can be explained by the next ingredient which affects the ice cream in more ways than just taste.

SugarSugar is added to enhance the ice cream’s taste, giving ice cream its iconic sweetness that we crave, and furthermore affecting its structure. Much like how salt ions can lower the freezing point of snow in the winter, sugar molecules can lower the freezing point of ice cream. This is known as freezing point depression, where adding solutes can decrease the freezing point of solvents. It is important to be aware that adding sug-ar in moderate amounts is important. If there is too little sugar, the freezing point will not be low-ered enough and you will end up with a hard ice cube. Too much sugar, you have ice cream gloop as the melting point would be too high.

AirAir is whipped into the ice cream as the final in-gredient to give ice cream its light texture. Each little air bubble is 20-25µm. To further fluff up the ice cream, more air is added, whereas richer ice cream has less air content. The ice cream is now flavoured and textured.

How do we make ice cream? Hopefully good notes of the ice cream’s composition were taken, as we now move onto ice cream making. The manufacturing process for ice cream is made up of the following steps. See if you can spot the similarities between these ice cream machines and our yogurt factory (Read the November 2015 issue!). The manufacturing process of these prod-ucts is similar and involves:

- preparing a liquid mix,- whipping and freezing this mix dynamical-ly, into a soft, semi-frozen slurry,- adding flavouring ingredients,- packaging or shaping, - and further freezing (hardening) of the product under static conditions.

Ottawa Tips: Visit the Food and Agriculture Museum to further investigate the ice cream making pro-cess. Other processed foods, from cheese to jam to ham, are also on exhibition for your enrich-ment. There are so many museums to explore for the scientists, studious or curious, who study in the National Capital Region.

To see the French translations of our articles, visit our website at

uocatalyst.wordpress.com/

***

Do you have personal research you want to share? Send it to The Catalyst!

Submit your articles [email protected]

and see your name in print!


What an odd statement, you might think. How could humans come from fish? Better yet, how could fish possi-

bly walk?

Well, in Dr. Emily Standen’s lab, right here at U of O, a primitive, air-breathing species of fish called Polypterus senegalus is being raised on land! The lab is testing how adaptive these fish are to novel ter-restrial environments. Earlier work by Standen et al. (2014) raised Polypterus on land for 8 months and the results were stunning: they showed substantial improvements in their walking abilities on land. It was seen that a terrestrial environment compared to an aquatic one caused changes in the fish’s morphology and triggered skeletal changes which helped them in locomotion.

These results illustrated how, around 400 million years ago, some fish used their regular fins to walk when transitioning from water to land (Standen et al. 2014). Remarkably, the anatomical changes observed in the Polypterus seem to mirror what is seen in the fossil record. This gives us insight into how fossil fish-es with similar morphologies may have taken their first steps onto land.

Taxonomically, Polypterus are considered to be the most basal of the ray-finned fishes and are the most closely related to the common fish ancestor that led to the evolution of land animals called tetrapods. (Standen et al.2014). Polypterus are long and possess lungs and big bony scales. At the front of their body, they have large pectoral fins used for routine swim-ming and walking on land. Unverified reports also suggest Polypterus voluntarily walk between ponds as the waters dry up (Pennisi, 2014). In this way, they

are very similar to the fossil fishes that paleontologists think may have been the first fish to explore land.

Dr. Standen showed that land-raised fish walked more effectively by lifting their heads slightly high-er from the ground, holding their fins closer to their body as well as slipping less than fish that were raised in water (Standen et al. 2014). The terrestrial fish also showed changes to their fin anatomy that pro-vided more stability and mobility, both crucial factors when moving about on land. These changes are the result of plasticity, the ability of an animal to show anatomical, behavioural, biochemical or physiological changes (Standen et al. 2014).

The findings provide evidence for developmental plasticity, which could have given our earliest tetra-pod ancestors the ability to transition onto land. Over a very (very) long period of time, adapting to life on land may have accelerated evolutionary transforma-tion from fins used for swimming into limbs used for walking (Baker, 2014). It was speculated that these changes would later be genetically fixed by natural selection (Standen et al. 2014).

Many of the anatomical changes observed in Polypterus reflect the fossil record of land-transition-ing fish from roughly the same time period. Thus, Dr. Standen’s team was able to hypothesize that, if ana-tomically similar, the fossil fish could also have similar behavioural characteristics when they first walked us-ing their fins on land.

So, as strange as it sounds, 400 million year old fish may have evolved into our very distant ancestors on land!

Humans Evolved From Walking Fish? Yes, You Read That Right!

By Alek Tirpan, 3rd Year BIM


My Involvement with the Standen Lab

I have been involved with Dr. Standen’s lab since last year. I was fascinated by the research she is lead-ing and what it could signify for the field of evolutionary biomechanics. I first started by creating 3-D models of the gill arches of Polypterus from their micro CT scans to visually represent anatomical differences between the terrestrial and aquatic types. I then moved on to a project on testing vision in Polypterus. Dr. Standen and I were interested in understanding how terrestriality affects vision in this normally aquatic fish.

This summer, I worked in the lab on an exper-imental design to investigate the optokinetic reflex in Polypterus. The project will consist of running the Polypterus through optokinetic reflex tests to examine if different environmental adaptations cause changes to their visual acuity. We also hope to gain insight into

the advantages and disadvantages this would have brought from an evolutionary standpoint.

The project underway is very exciting, and I hope to share more results in the months to come.

References:Baker, N. (2014, August 27). How fish can learn to walk. Retrieved August 04, 2016, from http://www.nature.com/news/how-fish-can-

learn-to-walk-1.15778

Pennisi, E. (2014, August 27). Fish raised on land give clues to how early animals left the seas. Retrieved August 04, 2016, from http://www.sciencemag.org/news/2014/08/fish-raised-land-give-clues-how-early-animals-left-seas

Standen, E. M., Du, T. Y., & Larsson, H. C. (2014, August 27). Developmental plasticity and the origin of tetrapods. Nature, 513(7516), 54-58. doi:10.1038/nature13708

Image header source:https://www.reddit.com/r/evolution/comments/3dmgbk/human_evolution_timeline_picture/?st=irxkxoic&sh=cf853468

2nd year BIO

Follow her on:

Facebook: @kpowerartInstagram: @kpowerart

Image source: Dr. Emily Standen

THE ACCIDENT

BY KATHERINE POWER


Prostate cancer caused 27,540 deaths in the United States in 2015 alone, and is one of the most common causes of death due to cancer in men (Siegel et al, 2015). Since tumors tend to be complex and heterogeneous, current therapies which employ antibodies or small kinase inhib-itors are able to only selectively inhibit a single signaling pathway or molecule (Liu et al, 2016). Luckily, in 2016, a team of researchers led by Liu and colleagues from Augus-ta University engineered a novel strategy using aptamers to suppress prostate cancer by targeting multiple oncogenic signaling pathways concurrently.

Aptamers are oligonucleotides composed of short, synthetic single-stranded DNA or RNA (ssDNA/ssRNA), which can form unique secondary or tertiary structures. They use structural recognition to bind to and interact spe-cifically with target molecules (Ni et al, 2011). Aptamers were coined from the Latin word aptus, meaning “to fit”, since they bind to their targets with such a high affinity and specificity, like a key fitting into a lock (Ellington and Szostak, 1990). In fact, aptamers can be developed to bind to a variety of targets, ranging from large molecules, such as nucleic acid structures and proteins, to small molecules like antibiotics and amino acids (Pestourie et al, 2005). Since aptamers can be chemically synthesized and modi-fied according to their desired applications and targets (Ni et al, 2011), they are named “chemical antibodies” (Sun et al, 2016). In comparison to antibodies, aptamers are much more thermally stable with a longer shelf life; unlike an-tibodies, they can be repeatedly denatured and renatured (Jayasena, 1999). Most importantly, the non-immunoge-nicity of aptamers make them ideal alternatives to antibod-ies for in vivo applications (Ni et al, 2011).

So, how have the researchers from Augusta Univer-sity employed aptamers to suppress prostate cancer? They developed a novel chimera in which two small interfering RNAs (siRNAs) specific to survivin and epidermal growth

factor receptor (EGFR) are fused between two aptamers (Liu et al, 2016). The aptamers on both ends of the chimera can bind specifically to prostate-specific membrane anti-gen (PSMA), which is a protein expressed on the surface of prostate cancer cells (Liu et al, 2016). Essentially, the aptamers on either end of the chimera act like “two arms” that grip PSMA in order to deliver the two siRNAs to the prostate cancer cell for internalization. Once internalized, the two siRNAs can inhibit EGFR and survivin. siRNAs silence genes by binding to the messenger RNA (mRNA) of specific genes and degrading them, which ensures that there is no transcription. Hence, the gene will not be ex-pressed.

“Prostate cancer caused 27,540 deaths in the United States in 2015 alone, and is one of the most com-mon causes of death due to cancer in men.

Overexpression of EGFR signaling pathway and survivin signaling pathway increases metastasis and can-cer cell proliferation (De Luca et al, 2008; Altieri, 2013). Since these two signaling pathways intersect at multiple networks, targeting both simultaneously can lead to a more global pathway inhibition for cancer cell growth (Liu et al, 2016). In fact, tumors which are resistant to EGFR inhibi-tors can switch to the survivin pathway for recurrence and survival (Altieri, 2008). Since these two proteins are inde-pendently required by cancer cells for proliferation, block-ing their production will be detrimental to the survival of cancer cells.

Research conducted by Liu and colleagues in 2016 has indicated that the novel chimera suppresses the ex-pression of survivin and EGFR by inducing apoptosis of prostate cancer cells and inhibits the growth of tumor cells in mouse models. Their models emulated middle and late stages of prostate cancer, which are the most common stag-es found in American males when they are diagnosed with

Novel Aptamer-based Therapeutic System against CancerBy: Zerin Khan, 5th year Biotech


prostate cancer (Medical College of Georgia at Augusta University, 2016). Since many cancer promoters do not re-side exclusively on the surface of cancer cells, but rather can hide inside where drugs are unable to reach them, siR-NAs can target these “undruggable” targets (Medical Col-lege of Georgia, 2016). Thus, the researchers have opened the avenue for designing combinational therapy and treat-ments to suppress cancer growth. For clinical applications, this research has indicated that the toxicity and immuno-genicity need to be further examined in higher species of animal models (Liu et al, 2016).

Aptamers can be used for a variety of medical ap-plications, ranging from molecular recognition probes to their roles as therapeutic agents. If aptamer research inter-ests you, then you should consider the research conducted at the Bioanalytical and Molecular Interaction laboratory under Dr. Maxim Berezovski here at the University of Ot-tawa. Dr. Berezovski’s lab encompasses many aspects of aptamer research, including developing aptamers against viruses and cells to create sensors and bioassays, as well as using them to discover new surface biomarkers for live cancer cells.

References:Altieri, D. C. (2013). Targeting survivin in cancer. Cancer Lett, 332(2),

225–228.Altieri, D. C. (2008). Opinion-Survivin, cancer networks and path-

way-directed drug discovery. Nature Reviews Cancer, 8(1), 61–70.

De Luca, A., Carotenuto, A., Rachiglio, A., Gallo, M., Maiello, M. R., Aldinucci, D., Pinto, A., Normanno, N. (2008). The role of the EGFR signaling in tumor microenvironment. J Cell Physiol, 214(3), 559–567.

Ellington, A. D., Szostak, J. W. (1990). In vitro selection of RNA mol-ecules that bind specific ligands. Nature, 346(6287), 818 – 822.

Jayasena, S. D. (1999). Aptamers: An emerging class of molecules that rival antibodies in diagnostics. Clinical Chemistry, 45(9), 1628 – 1650.

Liu, H., Yu, X., Liu, H., Wu, D., She, J. (2016). Co-targeting EGFR and survivin with a bivalent aptamer-dual siRNA chimera effectively suppresses prostate cancer. Nature Sci Rep, 6, 30346.

Medical College of Georgia at Augusta University. (2016, August 2). Treatment strategy has 2 arms for a secure grip on cancer. R & D Magazine. Retrieved from https://www.rdmag.com/news/2016/08/treatment-strategy-has-2-arms-secure-grip-cancer.

Ni, X., Castanares, M., Mukherjee, A., Lupold, S. E. (2011). Nucleic acid aptamers: clinical applications and promising new horizons. Curr Med Chem, 18(27), 4206 – 4214.

Pestourie, C., Tavitian, B., Duconge, F. (2005). Aptamers against ex-tracellular targets for in vivo applications. Biochemie, 87(9-10), 921 – 930.

Siegel, R. L., Miller, K. D. & Jemal, A. (2015). Cancer statistics. CA Cancer J Clin, 65(1), 5–29.

Sun, H., Zhu, X., Lu, P. Y., Rosato, R. R., Tan, W., Zu, Y. (2016). Ap-tamers: Versatile molecular recognition probes. Analyst, 141(2), 403 – 415.

Advice from Your Senior Advisor:

Enriching Your Undergrad Experienceby: Yen Tran, 4th year BCH

Dear fellow science students,Welcome to the 2016-2017 academic year.University is an experience that builds both character and

development. Expect to develop memorization, critical thinking, and time-priority management skills. Expect to handle multiple assignments at once, scramble through long labs, and write ex-ams under duress. Be challenged, but lest forget that your under-graduate education is more than just academics and grades.

Your undergraduate goal should also seek for skill devel-opment outside the classroom.

Think of some critical skills which you can apply just about anywhere. Can you write and summarize key information? Can you simplify and explain a concept to someone? Can you discover your passion? These are the real challenges students face, whether they are in a classroom, in a workplace, or chasing after a dream.

Your undergraduate experience may answer these ques-tions.

A significant part of learning is through discovery, so go take on different roles and responsibilities. Every time I faced a challenge, I learnt something new, whether it is a faster, better method of accomplishing something, or insight to passion and direction. For one thing, Winston and I have discovered pride and joy from founding our Food Science column. Through my di-verse CO-OP experiences, I have realized better career paths that suit my personality and strengths. There are many great oppor-tunities to seize and you will only know your preferences when you try them out.

Luckily for you, our Catalyst team has put together a spe-cial issue with success stories, suggested activities, and inspiring articles. More than just surviving the school year, we hope that you will enjoy reading and will find different ways to enrich your undergraduate experience

Passionate about Science and Art but not sure how to combine the two? The Catalyst is

looking for illustrators and photographers!Email: [email protected]


Zika: le nouveau fléaupar Hadjar Saidi, 3e année en BCH

**Cet article est écrit uniquement par Hadjar Saidi. Nous nous excusons pour toute confusion provoquée dans le numéro de Mars 2016.**

Depuis 2015, sévit en Amérique latine et dans quelques autres pays du monde une nouvelle flambée épidémique: le virus Zika.

Il a été pour la première fois découvert en Ou-ganda, en 1947, chez des singes rhésus, et en 1952, chez l’homme. Depuis, ce virus a infecté plus de 1.5 million de personnes à travers le monde, principalement en Amérique latine et en Afrique. Néanmoins, que savons-nous réellement sur ce virus et quelles sont les complications associées à ce-dérnier ?

“L’organisation mondiale de la santé (OMS) tire la sonnette d’alarme face à cette menace inconnue qui sepropage de façon explosive à l’échelle mondiale.

Des moustiques du genre Aedes portent le virus et le transmettent à leur tour. Les sujets atteints présentent généralement une fièvre modérée, des éruptions cutanées, une conjonctivite et des dou-leurs musculaires. Ces symptômes, assez bénins, dis-paraissent en 2 à 7 jours. La virulence du virus Zika provoque plutôt des complications neurologiques et auto-immunitaires, signalées dès 2013 par les au-torités de la santé lors de l’épidémie en Polynésie française.

Parmi les complications auto-immunaitres, le virus Zika pourrait potentiellement être responsable du syndrome de Guillain-Barré. Plus fréquente chez les adultes de sexe masculin, cette infection provo-que une réaction auto-immunitaire contre le système nerveux périphérique du patient. Le syndrome peut atteindre les nerfs moteurs, qui comman-dent le mouvement musculaire, ce qui entraine des paralysies réversibles. La nature auto-immune du syndrome exige un traitement immunothéra-peutique visant à éliminer les anticorps du sang. Par ailleurs, des sessions thérapeutiques plus

régulières seraient nécessaires pour soulager les symptômes. Par contre, ce virus entraine des conséquences encore plus calomnieuses pour les femmes enceintes et atteintes parce qu’il provoque une sérieuse malformation fœtale, la microcéphalie. Celle-ci se caractérise par une croissance insuffisant-edu cerveau chez le nouveau-né qui pourrait entrainer dans les cas graves, des retards de développement très dévastateurs et irréversibles. Aucun traitement spécifique de la microcépha-lie n’est disponible aujourd’hui. Les nouveau-nés doivent être pris en charge dès la naissance par des équipes pluridisciplinaires pour maximiser leur dévelopment cérébrale.

Aujourd’hui, les connaissances scientifiques con-cernant le virus Zika sont très restreintes. Les autorités de la santé essayent de déterminer les caractéristiques de ce virus telles que sa période d’incubation, le rôle des moustiques dans sa transmission. Il est aussi primordial d’élaborer au plus vite des traitements et des vaccins ainsi que des tests diagnostiques plus spécifiques visant à réduire les erreurs liées à la présence d’autres types de virus. La recherche s’active aussi autour du lien potentiel entre le virus et les complications neurodégénératives et auto-im-munes. Selon les statistiques, le nombre de diag-nostiques du virus Zika coïncident parfaitement avec une recrudescence inexpliquée du syndrome de Guillain-Barré et de la microcéphalie chez les nou-veau-nés.

L’organisation mondiale de la santé (OMS) tire la sonnette d’alarme face à cette menace inconnue qui se propage de façon explosive à l’échelle mon-diale. Face à ce fléau présentement incurable, la prévention reste le seul moyen de protection. Selon l’OMS, il est vital d’éviter les piqûres de moustiques étant les vecteurs de cette mala-die. Pour ce fait, l’utilisation de produit répulsifs et de moustiquaires est fortement recommandée dans les zones à risque. Ces conseils s’appliquent


particulièrement aux femmes enceintes en vue des conséquences possibles sur les nou-veau-nés. Les gouvernements de pays touchés par le virus recommandent aussi aux couples de repousser leurs projets de grossesses de plu-sieurs mois. Néanmoins, cette épidémie a créé une véritable crise sociale notamment dans beaucoup de pays d’Amérique latine, où l’accès aux contraceptives est très limité et l’avortement prohibé pour des raisons religieuses (sauf en cas de viol ou de risques pour la santé de la mère

dans certains pays). Cette flambée de maladie du virus Zika permet aujourd’hui à de plus en plus de voix de se lever et de crier au changement des mœurs et du code pénal dans ces pays notamment pour le droit à l’avortement dans le cas de diagnostic de microcéphalie. Le virus Zika a dévoilé la faiblesse des services de la santé face à une épidémie de cette envergure, mais il a aussi permis de soulever des débats socio-cul-turels nécessaires.

Funky Fungiby Ashley Tenn, 3rd year BCH





