Soil and Water Conservation Engineering (SWCE) is a specialized field of stud...
The Catalyst: November 2015 Issue
1. Catalyst
November 2016 1
November 2015 | novembre 2015
Volume 6: Issue 2
Student Science Journal - Journal étudiant scientifique
PAGE 18
Announcing the winners of
the Fall Illustration Contest
PAGE 6
stop seeing gmo as omg
PAGE 19
2. Catalyst
November 20162
THE TEAM | L’ÉQUIPE
Editor-in-Chief Vanessa Nzeribe
Poduction Manager Christine Wang
Rédacteur-en-chef Setti Belhouari
Deputy Editor-in-Chief Yen Tran
Assistant Production Manager Ashley Tenn
Website Manager Michael Leung
VP Media Ashley Chen
VP Promotions Ashley Tenn
Illustrations Manager Mariko Sumi
Authors | Auteurs
Kevin Amélété
Veronika Cencen
Winston Cheung
Angela Dou
Alanna Leale
Johanne Mathieu
Elizabeth Richardson
Hadjar Saidi
Alexander Satenstein
Cassidy Swanston
Ashley Tenn
Yen Tran
Tanya Yeuchyk
Editors | Editeurs
Nicole Auclair
Emily Huang
Natasha Kasulis
Alanna Leale
Olivia Magwood
Tatsiana Yeuchyk
Illustrations
Sanmeet Chahal
John Evans
Alanna Leale
Ashley Tenn
Translators | Traducteurs
Sanmeet Chahal
Laura Goodwin
Laila Fazal
Mihaela Tudorache
Featured | Sélectionné(e)s
Dawn Blair
Lina Liu
Nooria Rizvi
Saania Tariq
November Contents | Contenu de novembre
Illustration Contest Results
PAGE 6
Stop Seeing GMO as OMG
PAGE 6
Food Science: Yummy yogurt
PAGE 7
Ta b l e o f C o n t e n t s
4. Catalyst
November 20164
Why is yogurt healthier than milk?
A) Yogurt has higher nutritional content than milk.
B) Yogurt has denatured proteins which are easier to
digest.
C) Yogurt contains probiotic bacteria.
D) All of the above.
See answers online.
FOOD SCIENCE: YUMMY YOGURT
Historically, yogurt makers have fermented milk
spontaneously, yielding tremendous variation across
the globe. Yogurt today is made from milk and
bacteria, fermenting under specific, controlled
conditions. In the name of scientific curiosity and
knowledge, we have secured a tour to investigate the
making of yummy yogurt in a hypothetical, yogurt
manufacturing facility.
Let us begin our yogurt factory tour.
The
Yogurt Factory
Milk Modification:
Yogurt processing begins with milk composition.
In the first chamber, you can see our industrial
mixers pumping fats, milk solids, and other nutrients
into the milk mixture. This influences the texture and
nutrition of yogurt.
For creamier yogurt, higher fat content is desired,
but for thicker yogurt, non-fatty solids like proteins
are added. Typically for our commercial yogurts, we
reduce fat, increase lactose to 30-35%, and spike
proteins, minerals, and vitamins. Because sugars are
to be fermented by our yogurt bacteria later, sugars
and other sweeteners are not added at this stage.
Once our milk modification is completed, the mix
is sent to the pasteurization chambers next door.
Pasteurization:
Next, we have our yogurt pasteurized by the plate
heat exchangers, at 95°C for 8-10 min. According to
food scientists, Chandan and O’Rell, pasteurization
allows for the destruction of competitive
microorganisms in order to create an optimal
condition for yogurt culture growth. Also, the
denaturation of milk proteins refines yogurt texture.
At high heat, lactoglobulin in milk denatures to
form cross-links and gel, reducing unwanted bacteria
and retains water in the yogurt mix. By enhancing
the water absorption capacity up to 95%, the yogurt
base improves in viscosity, smoother consistency, and
stability.
Homogenization:
Following pasteurization, the yogurt base is then
homogenized for further refinement of its
consistency. At temperatures of 55-85°C, fat globules
are beaten down by 10-20 MPa of pressure to ensure
uniform fat distribution in the yogurt. An interest
fact to note is that heat treatment and
homogenization of yogurt are important to
digestibility in the stomach, by forming soft
coagulum.
Fermentation:
Upon cooling the homogenized yogurt base to
growth temperatures (41-43°C), starter yogurt
cultures are added for fermentation. The inclusion of
two main bacteria, Streptococcus salivarius
subspecies thermophilus (ST) and Lactobacillus
delbrueckii subspecies bulgaricus (LB), in the yogurt
starter is essential to the characteristic texture, taste
and aroma of yogurt.
The temperature is held at 41-43°C for starter
bacterial growth in the yogurt base. ST converts
lactose into lactic acid by fermenting glucose.
Technically, all other monosaccharides can be
fermented after ST isomerizes them into glucose. The
volatile by-products of fermentation, such as
acetaldehyde, diacetyl, and acetic acid, characterize a
complex, pleasant yogurt aroma. Meanwhile, the
accumulation of lactic acid contributes to the acidic,
refreshing taste of yogurt. Lactic acid also acts as a
preservative against unwanted microorganisms, but
does not hinder LB from enhancing the yogurt.
4th
year BCH
4th
year BIM
keep reading Z
F o o d S c i e n c e
Illustrated by Alanna Leale, M.Sc. candidate in BIO
5. Catalyst
November 2016 5
As lactic acid is produced, the pH drops to create
an acidic environment for LB to thrive. LB can
hydrolyze casein into smaller peptides, and with the
help of ST’s active peptidase, the resulting peptides
are converted into free amino acids.
For additional flavour and nutritional benefits,
optional bacteria, such as Lactobacilus acidophilus
and genus Bifidobacterium, can be added. Examples of
probiotic effects, as identified by Takano and
Yamamoto, include the enhancement of protein
digestibility, mineral absorption, and immunity.
Cooling:
Once the desired viscosity, aroma and plain yogurt
taste is attained, the yogurt is placed into the 4°C
fridge for cooling. The cooling stops fermentation and
culture growth.
Flavouring:
Pure yogurt can taste very sour due to the
accumulation of lactic acid during the fermentation
stage. To appropriate taste for consumers, yogurt can
be flavoured and sweetened. Some of our factory’s
most popular flavours include fruits such as
strawberry and honey. Depending on the type of
yogurt, the fruits can be added at the bottom of the
cup (set style yogurt) or blended into the fermented
yogurt mix (Swiss style yogurt).
After our yogurt is fully processed and flavoured,
it is time to move onto the packaging facility.
Packaging:
From the fermentation vat, the yogurt is pumped
into the packaging containers. As mentioned, soft-
served yogurt is packaged into two styles: set style
yogurt and Swiss style yogurt. Alternatively, we have
hard pack frozen yogurt which has been textured at
0-4°C, agitated, and crystallized for frozen storage.
We have reached the end of our tour of the
production of yogurt. Available in the next room are
free samples and activities. Please be welcomed to
make Greek yogurt or yogurt-dipped pretzels with us!
Your Own
Yogurt-covered
Pretzels
1. Preheat the oven to 120°C (250°F).
2. Mix 5 cups of confectionary sugar with 2
cups of low fat yogurt, one cup at a time.
3. Dip the pretzels, one at a time, until they
are thoroughly covered in yogurt.
4. After coating all the pretzels in yogurt,
place them on a wire cooling rack, with a
baking sheet beneath, and into the oven,
turned off.
5. Wait 3-4h for the coating to harden.
6. Remove the pretzels from the oven, and
store them in an airtight container.
Adapted from Stonyfield’s recipe.
What is Greek yogurt?
Greek yogurt is a type of strained yogurt,
where we filter out water and sugars.
How is Greek yogurt content
different?
The yogurt thickens as the protein ratio rises.
Although vitamins are filtered out with the fats,
nutrients can be re-added after filtration.
F o o d S c i e n c e
6. Catalyst
November 20166
The Catalyst’s First Annual Fall Illustration Contest
First Place:
Christine Wong,
2nd year BPS
First Place
$100 gift certificate to DeSerres
Runner up
$50 gift certificate to DeSerres
Runner up:
Lina Liu,
1st year BIM
F a l l I l l u s r a t i o n C o n t e s t
7. Catalyst
November 2016 7
The Catalyst’s First Annual Fall Illustration Contest
First Place: Winston Cheung, 4th year BIM
Runner up: Kevin Li, 4th year BCH
Email production.uocatalyst@gmail.com for more instructions to receive your prize!
F a l l I l l u s t r a t o n C o n t e s t
9. Catalyst
November 2016 9
Check out our website https://uocatalyst.wordpress.com/ for articles translated in French
Runner up: Lina Liu, 1st year BIM
Nooria Rizvi,
3rd year BCH
10. Catalyst
November 201610
T i m i n g i s E v e r y t h i n g
Timing is Everything:
Finding an adaptive basis for synchronized malarial infections
, M.Sc.
candidate in BIO
keep reading Z
Alanna Leale, M.Sc.
candidate in BIO
12. Catalyst
November 201612
→
That these were not all
named after the same
man?
Bernoulli differential equation
Bernoulli distribution
Bernoulli number
Bernoulli polynomials
Bernoulli process
Bernoulli Society for Mathe-
matical Statistics and Proba-
bility
Bernoulli trial
Bernoulli's principle
The Bernoulli family
contributed to mathe-
matics and science to-
gether spanning from
1654 to 1789.
Imagining having that
family reputation!
T i m i n g i s E v e r y t h i n g
13. Catalyst
November 2016 13
H
andling human heart samples and extracting their
cells is a science student’s fantasy, but this was
my reality this summer working at the University of
Ottawa Heart Institute. As a recipient of the Undergradu-
ate Research Scholarship, I was given the opportunity to
spend two summers working in a lab of my choice. I was
lucky enough to find a position in the lab of Dr. Darryl Da-
vis, where I discovered a whole new world of scientific re-
search.
Before being allowed to work with more valuable hu-
man-derived cells, I had first started out practicing cell
culture processes using inexpensive and rapidly-growing
cells. Once I learned the concepts, I was able to assist with
more finite procedures, including the extraction of cardiac
stem cells. We would receive a fresh biopsy of a human
heart, mince it into tiny pieces, and then incubate them in
cardiac explant medium until the individual cells migrated
out onto the plate. The cells were then harvested and fro-
zen in freezing media for future use.
Why did we investigate cardiac stem cells? Great prog-
ress within the last decade has been made towards a new
treatment for heart failure using these cells. It was previ-
ously thought that the heart, like the brain, was a post-mi-
totic organ - meaning its cells lack the capacity to regener-
ate. However, a study in 2003 proved otherwise. It followed
that a small number of cardiac stem cells exist were able
to differentiate into mature cardiomyocytes in the event of
minor cell death or damage. An estimated total of 50% of
cardiomyocytes are renewed over the human lifetime, but
the regenerating capacity decreases with age. Heart failure
is a condition where damage to the heart muscle renders
it unable to provide sufficient circulation of blood and nutri-
ents. After a heart attack for example, a patient is left with
scar tissue on the heart, consequently impairing its efficien-
cy. A patient with heart failure has typically lost over one
billion cardiomyocytes, and so native stem cells are not nu-
merous enough to be able to significantly repair the tissue.
A novel treatment for heart failure involves the admin-
istration of cardiac stem cells at the site of the damage.
The goal of this approach is to increase the number of ac-
tive cells, and therefore improve heart function. Clinical tri-
als have shown that this method is safe and results in the
improvement of contractile function in the heart. Despite
promising results, a major issue remains in the difficult
retention of injected stem cells. More than 90% of inject-
ed cells are lost from the target area due to leakage into
the lymphatic or circulation systems. Additionally, many of
those that do remain die within weeks from low nutrient
content. One method of improving engraftment is encap-
sulation, which is something I also had the opportunity to
work over the summer. We used biocompatible proteins to
make microscopic capsules that mimic the natural domain
of cells in the body. This process aids in cell survival by
providing a stabilizing, three-dimensional environment to
live and grow in. Early work from the Davis lab shows that
encapsulation can improve cell retention, which brings im-
portant future clinical applications. Stem cell therapies are
not yet approved for clinical use, but continuing trials and
growing data are bringing researchers closer to this goal.
When working with cell culture, you need to use all ster-
ile materials extremely carefully and meticulously, to avoid
the slightest contamination. It was an eye-opening experi-
ence to see the sheer amount of work which researchers
put in each day, spanning many years, to make the discov-
eries we read about later in the news. I look forward to next
summer to keep learning and make any contribution I can
towards this life-saving technology!
Special thanks to Dr. Darryl Davis, M.D, Pushpinder
Kanda, Audrey Mayfield, and Bin Ye.
Working Hard, Heart-ly Working
Written by Tatsiana Yeuchyk, 1st
year BIM
14. Catalyst
November 201614
By: Sanmeet Chahal, 4th year PHY
By: John Evans, 3rd year PHY (top left, top right, bottom right)
Email production.uocatalyst@gmail.com for a chance to have your own comics published!
C o m i c C o r n e r
16. Catalyst
November 201616
B
ehind the day-to-day
monotony of lec-
tures and studying
at the University of Otta-
wa, there exists a world of
research that runs with the
help of both graduate and
undergraduate students.
For these students, it is a
sprawling other life filled
with hard work, long days,
and professors working
closely to guide them
along the way. While this
is not just the reality within our Faculty of Science, it is
here that we see work done in countless fields which
could further benefit humanity. Still, this research of-
ten goes unnoticed by the rest of our student popu-
lation. Even after publication, it is rare that students
will see that their peers have contributed to certain
papers, let alone know these papers existed. Con-
necting Young Minds (CYM) is a conference aimed to
remedy this low awareness.
The Catalyst was invited to the event, and as I
found myself a seat among the audience, I grew cu-
rious to see what sort of research was being done by
other undergraduate students. Would the level be as
advanced as those done by Master’s and PhD stu-
dents? What fields would be showcased? What year
were these students in? I leafed through the program,
eagerly waiting for the conference to start.
CYM was a bilingual undergraduate research con-
ference that held its first event on August 28th, 2015.
The opening remarks were delivered by co-presidents
Aida Ahrari and Anabel Bergeron, filled with referenc-
es to the human connectome – the neurological paths
that one’s neurons take in order to process thought.
It was here, they said, that our brains were able to
take in and process new information, where each
addition would add itself to the connectome. Activi-
ties that enhance the connectome included studying
and, of course, research.
The goal was to open
ourselves up to the idea
of enriching our minds
with the opportunities pre-
sented by research at our
school.
This sentiment was
shared by the professors
who carried on the open-
ing remarks, speaking
about their experiences
and benefits in undergrad-
uate research. I found my-
self keen to listen to their stories of their success and
further intrigued by what they were able to accom-
plish at such a young age. But these were current
professors, tenured and well-respected. How did the
current undergraduates compare?
The answer to my question came soon enough,
once the presentations started. Presentations were
15 min each, with accompanying slideshows and
varying levels of complexity. Subjects ranged from
possible treatments of acute myeloid leukemia to the
importance of citizen science in ecological research.
Most impressively, each student knew their research
by heart with passion. Elevator pitches of 5 min were
also presented at CYM, each competing for a cash
prize at the end, as determined by the judges.
The talks were clear and concise, overall impres-
sive, and reminded me that important research is nev-
er limited to just Master’s or PhD students. It is possi-
ble to get involved without a degree; opportunities just
need to be sought out. Connecting Young Minds was
put together exactly for this purpose – to bring togeth-
er and present the research done by our peers in the
Faculty of Science, to show that research does not
have to be a long, distant dream, years away from be-
ing fulfilled. Research is being done right now through
hard work and dedication by other undergraduates
having the passion for what they love.
Showcasing Undergraduate Research with CYM
Written by Ashley Tenn, 2nd year BCH
Photos taken from the CYM conference photography (https://www.facebook.com/CYMresearchconference)
C Y M
17. Catalyst
November 2016 17
A
u-delà de la vie mono-
tone d’un étudiant à
l’Université d’Ottawa, il
existe un monde peu connu de
recherche scientifique menée
par des étudiants gradués,
mais aussi par des étudiants
de premier cycle. Pour ceux
qui en font partie, leurs se-
maines sont occupées par de
longues journées de travail et
la chance de travailler côte à
côte avec des professeurs de notre université. Bien
que ce concept n’est pas propre à la faculté des sci-
ences, c’est dans ce domaine qu’on peut retrouver des
projets de recherche qui pourraient êtres bénéfiques
à l’humanité. Malgré ça, la plupart de la population
étudiante n’est pas au courant de la recherche im-
portante en cours dans son propre campus et encore
moins des articles publiés qui en résultent. La con-
férence CYM (Connecting Young Minds) cherche à
remédier cette lacune.
Étant donné que le Catalyst a été invité à cette
conférence, j’ai pris un siège dans l’assemblée, ayant
hâte de voir quel genre de recherche menaient les
étudiants de premier cycle, et dans quelle année
d’études ces jeunes scientifiques se retrouvaient. Je
me suis mise à feuilleter le programme en me deman-
dant si la recherche qui allait être présentée serait du
même calibre que celle des étudiants gradués.
La CYM est une conférence bilingue de recher-
che aux études de premier cycle, mise en place pour
la première fois le 28 août 2015. Quelques mots
d’ouverture ont été donnés par co-présidents Aida
Ahrari et Anabel Bergeron qui ont fait référence au
«connectome» humain - soit l’ensemble des connec-
tions neuronales du système nerveux. C’est par l’en-
tremise de ce système que nous pouvons assimiler
de nouvelles informations. Celles-ci nous parviennent
de nos études bien sûr, mais aussi par l’entremise de
la recherche. En fin de compte, ce mot d’introduction
visait à nous encourager à avoir l’esprit ouvert lors
des présentations des projets de recherche.
Ce dialogue a continué grâce à quelques pro-
fesseurs qui ont eux aussi donné un court discours
d’introduction sur leurs expériences en recherche
au niveau de premier cycle et comment cet appren-
tissage a été bénéfique pour
eux. J’ai été fascinée par leurs
succès académique et profes-
sionnel, mais en particulier
par ce qu’ils ont été capables
d’accomplir à un jeune âge.
Mais où sont les étudiants qui
n’ont pas encore gradué?
J’ai eu ma réponse dès le
début des présentations. Elles
étaient d’une durée de quinze
minutes, portant sur des su-
jets de niveaux de complexité différents et étaient
accompagnées de présentations PowerPoint. Les
projets, présentés avec beaucoup de passion, étaient
variés : d’une discussion sur des traitements possi-
bles de leucémie myéloïde aiguë jusqu’à l’importance
de la participation des citoyens en science dans le
domaine de la recherche écologique. Il y avait aussi
une catégorie de présentations de cinq minutes, avec
des prix pour les gagnants, sélectionnés par un comi-
té de juges.
Les présentations m’ont vraiment épatées, et elles
ont servies à me rappeler que ce n’est pas seulement
les étudiants gradués qui contribuent au monde de la
recherche scientifique. Il est possible d’en faire partie
en tant qu’étudiant de premier cycle, il suffit de vouloir
s’y aventurer. En fin de compte, c’est la raison que
la conférence CYM a été conçue : pour rassembler
les étudiants et démontrer que faire sa marque dans
le domaine des recherches ne devrait pas être qu’un
rêve distant pour les jeunes étudiants en science.
Plusieurs étudiants de premier cycle atteignent déjà
ce rêve, grâce à leurs efforts, leur dévouement à la
recherche et leur passion pour leur domaine.
La conférence CYM met en vedette la recherche pendant les études de premier cycle
Traduit par: Laura Goodwin
C Y M
18. Catalyst
November 201618
S h e d d i n g L i g h t o n t h e B r a i n
Shedding
Light on
the Brain:
High in complexity and
one of most awesome-
known machine is the hu-
man brain. With this mag-
nificence comes a lot of un-
certainty; to this day, we
have barely unraveled the
mystery that is the mind,
and as a result, there con-
tinues to be many gaps in
developing neurological
treatments. One sorely un-
met need that scientists
faced in neuroscience was
the need to control specific
cells in the brain, especially
at specific times. Frequently
used electrodes and drugs
could not meet this need, as
they are neither precise nor
fast-acting enough. In the
face of this challenge, the
science of optogenetics aris-
es – the use of light pulses
in order to activate or inhib-
it specific brain cells with
lightning accuracy.
The complex technolo-
gies used in optogenetics
today arose from humble
inspiration, such as from the
microorganism Chlamydo-
monas reinhardtii. The algae
have an organelle called an
‘eyespot’ which contains
proteins that open in re-
sponse to blue light. From
there, researchers extracted
DNA that codes for these
proteins, and inserted it into
neurons. Now, there are sev-
eral proteins which are used
for this purpose, namely
halorhodopsin, bacteriorho-
dopsin, and channelrhodop-
sin. They can be controlled
by connecting the organism
to a fiber optic cable.
However, optogenetics is
only just a budding field
within the last decade. It was
a latecomer in science be-
cause many believed that
this sort of technology
would never be feasible. One
of the reasons is because the
proteins were predicted to
be toxic to mammalian cells.
As well, scientist were
searching for a method
without any dependence on
any other factors, and these
microbial opsins require a
chemical co-factor called all-
trans retinal to absorb the
photons. However, both of
these concerns were proven
to be trivial since these mi-
crobial opsins have been
shown to be non-toxic, and
experimentation has indi-
cated that vertebrate tissue
already naturally contains
all-trans retinal.
One of the many reasons
why optogenetics is taking
the field of neuroscience by
the storm is due to the myr-
iad of neuropsychiatric dis-
eases to which it has the po-
tential to tackle. Patients
with disorders such as
schizophrenia and autism
have been shown to have
altered gamma oscillations
in the brain. Through con-
trolling parvalbumin neu-
rons, it is possible to regu-
late these oscillations with
the use of light. Additionally,
symptoms of anxiety have
been alleviated by optoge-
netically resolving a specific
intra-amygdala pathway.
Even extremely complex
symptoms of depression
have been simply alleviated
when tested with this new
research. As a precise and
rapidly-responsive branch of
science, the applications of
optogenetics are endless – it
is just a matter of time until
this explosive new tech-
nique in neuroscience could
become a treatment stand-
ard in neuropsychiatric care.
The Emergence
of Optogenetics
Cassidy Swanson, 1
st
year
BIO
Cassidy Swanston, 1st year BIO
19. Catalyst
November 2016 19
C o m m e n t a r i e s
Opinion and Commentaries:
Even if someone is not centered at the Faculty of Science, they’ve prob-
ably heard of genetically modified organisms (GMO) by now. We see
“GMO-free” labels on food products, read about the March Against Mon-
santo protests, and hopefully, see the applications of the medical technol-
ogy brought to us through research involving genetic modification (GM).
The strictest regulations are currently set in a predominant part of Europe,
while Canada allows a relatively less-restricted use of genetic modification,
though still appropriately regulated. In fact, Canada is one of the world’s largest producers and
the larger exporter of genetically modified canola.
While a certain extent of caution is appreciated by the public, some governments might be
taking the issue too sternly. In a recent example, the small central European country of Slove-
nia has just passed a law, majorly restricting the use of genetic modification in research itself,
despite the known benefits and crucial discoveries that have stemmed from this technology.
There are some very widespread misconceptions that underlie the hyped concerns with re-
gards to genetic modification. Some general ones that came up during the campaigns in Slove-
nia and their corresponding truths are summarized below:
The facts: Genetic engineering-assisted
agriculture is by far more efficient, and is
used by several countries that lead the
world economy. By falling back to tradi-
tional, “old-fashioned” farming methods,
it can be argued that Slovenia has further
hindered its productive capacity and must
now rely on imports from those exact
countries.
The facts: Several misleading articles
falsifying or overstating the effect of
GMOs on health (e.g. the famous Seralini
rat study) have been debunked. Unfortu-
nately, the negative perception printed in
people’s minds is difficult to reverse, and
the many medical breakthroughs they
helped achieve (e.g. insulin, antibiotics,
vaccines, and many more) are often ig-
nored.
● ● ●
Want to contribute? Veuillez contribuer? Find out more at/découvrez
comment à https://uocatalyst.wordpress.com/submissions/
● ● ●
X
N
Image source goes here if I need it
20. Catalyst
November 201620
Stop Seeing GMO as an OMG
The facts: Actually, using GM tech-
nology has allowed an improved efficien-
cy of production in industry, agriculture
and medicine, and reduced the need to
use more harmful processes. An example
of this is Bt-corn, where the genetically
inserted pest repellant eliminated the
need for harmful pesticides. Its sole ef-
fect is on the insects which it targets.
The facts: This type of gene transfer
has such an unlikely probability that it is
not quite worth fearing. Nevertheless, the
extent of preventative control currently
being practiced restricts even the smallest
chance.
The facts: With the growing popula-
tion and increasing environmental and
health concerns, genetic engineering can
provide some crucial solutions, from de-
veloping greener, more efficient industrial
production, to aiding and accelerating
medical research, to improving crop yield
and nutritional value. Golden rice, for ex-
ample, was actually a non-profit project
developed to combat health issues arising
from vitamin A deficiency in developing
countries. Medical technology and pre-
ventive information can help avoid ex-
pensive treatment.
This is certainly not a complete and in-
depth list of all the possible, usually un-
necessary fears associated with genetic
modification. To present the reality to a
wider audience, experts are reaching out
through various networks and social me-
dia. The “Truth About GMO” group was
recently created for uOttawa students on
Facebook, so please be welcomed to join
in on any interesting discussions that
might pop up there!
Want to read more
about GM foods?
Stay tuned for the
next Food Science
article!
By VERONIKA
CENCEN – M.Sc.
candidate in
Biomechanical
Engineering
C o m m e n t a r i e s
21. Catalyst
November 2016 21
L
es traitements anticancéreux modernes comme la chimiothérapie sont souvent ineffica-
ces et très toxiques. Par conséquent, la recherche se penche de plus en plus à inculquer
des méthodes moins dangereuses et invasives pour traiter le cancer. Par exemple, depuis
quelques décennies, la photothérapie est utilisée pour détruire les lymphomes T cutanés super-
ficiels. Le principe général de la photothérapie consiste à introduire dans le corps des matériaux
photosensibles capables de se fixer aux tumeurs puis de les illuminer à l’aide de faisceaux. Ils
vont alors générer des radicaux libres qui sont toxiques et mortels pour la cellule cancéreuse.
La présence d’oxygène et de lumière sont des conditions sine qua non à la photothérapie, son
utilisation se restreint donc aux zones superficielles du corps et celles accessibles par endoscope.
Ceci est pourquoi les progrès dans ce domaine ont stagné depuis des décennies.
Cependant, des chercheurs de l’école de Médecine de Université de St Louis à Washington,
ont réussi à contourner ce problème grâce à la nanotechnologie. Cette technique consiste non
plus à illuminer par faisceau la tumeur, mais plutôt à apporter la lumière in-vivo à l’aide de nano
livraison. Tout commence par un mélange de sucre radio-marqué appelé fluorodéoxyglucose
(FDG) et de nanoparticules de dioxyde de titane (TiO2
) sensibles à la lumière qui est ingéré par
le sujet malade. Suite à cela les cellules tumorales qui sont exigeantes en énergie consomment ce
sucre, et grâce au fluor radioactif contenu dans le FDG, elles deviennent fluorescentes en produi-
sant un rayonnement Tcherenkov. Ce rayonnement est assez puissant pour activer le TiO2
qui, en
bout de chaine, générera les radicaux libres anti-tumoraux. Malgré le fait qu’elle n’ait été testée
que sur des rats, cette nouvelle méthode a cependant prouvé son efficacité en doublant le taux de
survie des individus traités par rapport aux non traités. Les chercheurs ont aussi brillamment re-
marqué qu’un complexe moléculaire de FDG, de TiO2
et de médicaments anti-cancéreux accroit
la précision et la puissance thérapeutique en augmentant le taux de survie par 3 et en réduisant la
taille des tumeurs par un facteur de 8! Il faut aussi noter que cette nouvelle technique serait plus
saine et moins invasive puisque qu’elle requiert des doses de médicament largement plus faibles
que ce qui serait administré pendant une chimiothérapie.
En ce qui concerne les effets toxiques que pourraient engendrer la lumière et le matériel
photosensible, Nalinikanth Kotagiri le premier auteur de l’étude affirme qu’ils sont minimes.
En effet, la lumière et le composant photosensible sont tous deux conçut pour viser la tumeur
de manière très précise et éviter ainsi les tissus sains aux alentours. Les chercheurs préparent
prochainement un essai clinique sur des sujets humains en combinant le FDG et le TiO2
à des
médicaments anticancéreux expérimentaux, dans le but de valider cette nouvelle technique qui
semble d’ores et déjà très prometteuse.
La nanotechnologie photoémettrice
au profit de la lutte contre le cancer
Par Kevin Amélété, 3ème année BIM; Johanne Mathieu, 3ème année BIM; Hadjar Saidi 3ème année BCH
L a n a n o t e c h n o l o g i e
22. Catalyst
November 201622
The issue of climate change has been
highly publicized as a cataclysmic and global
phenomenon. The focus has been on the major
contributors, like carbon dioxide emissions
from burning fossil fuels. Other contributors
however, which one might consider to be fairly
minor and less impactful, can be much more
problematic when observed on the regional
scale. The amount of green space in our cities
may seem almost inconsequential when com-
pared to the large scale de-forestation and
desertification seen around the world, but the
real time impact on human health is becoming
increasingly apparent (Stone Jr. & Rodg., 2001).
Beating the Heat by Greening the Street
Battre la chaleur par l’écologisation de la rue
Le problème du changement climatique a
été grandement médiatisé comme un phéno-
mène cataclysmique et mondial. L’accent a été
mis sur les contributeurs majeurs, tels que les
émissions de dioxyde de carbone provenant de
la combustion de combustibles fossiles. Cepen-
dant, d’autres contributeurs que l’on pourrait
considérer mineurs et ayant moins d’impact
peuvent être beaucoup plus problématiques
lorsqu’ils sont observés à l’échelle régionale. La
quantité d’espaces verts dans nos villes peut
sembler presque sans conséquences par rap-
port à la déforestation et la désertification à
grande échelle vu partout dans le monde, mais
l’impact en temps réel sur la santé humaine
est de plus en plus apparent (Stone Jr. & Rodg.,
2001).
4th
year GEO traduit par
keep reading Z
Traduit par: Laila Fazal
B e a t i n g t h e H e a t
23. Catalyst
November 2016 23
The problem arises from urban areas being
covered with impervious surfaces, which are
surfaces that do not allow water to pass
through them. This is important since moisture
can help alleviate heat. These surfaces include
paved sur-faces like roads, sidewalks, as well as
buildings, which are all generally dark in col-
our. Dark colours absorb more light energy
than lighter colours, causing them to be hotter.
In the northwestern United States, it has been
found that cities are 7-9°C hotter than their
rural neighbors (Voil., 2010). This is because
vegetation holds moisture, and thus diffuses
some of the heat. Vegetation plays such a large
role that in cities surrounded by arid or desert
regions, the measured heat island effect is sig-
nificantly reduced because temperatures inside
the cities more closely match those outside.
To better understand this issue, the US Na-
tional Aeronautics and Space Ad-ministration
(NASA) compiled temperature data from thou-
sands of cities and population settlements
world-wide. Data was initially inadequate, com-
ing from land-based sensors that were prone to
local bias, due to an uneven distribution of
these sensors. NASA responded to this problem
by doing what they do best: launching some-
thing into space. They utilized the Moderate
Resolution Spectroradiometer (MODIS), an in-
strument on their Aqua Terra satellite, and in
cooperation with the United States Geological
Survey (USGS) Land-Sat satellite, they used in-
frared Imaging to detect heat in and around
cities around the world (Lo, Quatt.. & Luva.,
1996.) They found that climatic factors did not
account for all discrepancies. For example,
Providence, Rhode Island and Buffalo.
Le problème survient des zones urbaines
recouvertes de surfaces imperméables, qui sont
des surfaces qui ne permettent pas l’eau de
passer à travers la surface. Ceci est grave car
l’humidité peut aider à diminuer la chaleur. Ces
surfaces incluent les surfaces pavées comme
les routes et les trottoirs, ainsi que les bâti-
ments, qui sont aussi généralement de couleur
foncée. Les couleurs foncées absorbent davan-
tage l’énergie lumineuse que les couleurs
claires, les obligeant à être plus chauds. Dans le
nord-ouest des États-Unis, il a été constaté que
les villes sont 7 à 9°C plus chaudes que leurs
voisins ruraux (Voil., 2010). En effet, cela est dû
à la végétation qui retient l’humidité, diffusant
ainsi une partie de la chaleur. La végétation
joue un si grand rôle que dans les villes entou-
rées par des régions désertiques ou arides,
l’effet d’îlot de chaleur mesuré est significati-
vement réduit puisque les températures à
l’intérieur des villes correspondent de plus près
à ceux de l’extérieur.
Pour mieux comprendre ce problème,
l’Administration nationale de l’aéronautique et
de l’espace (NASA) a compilé les données de
température à partir de milliers de villes et co-
lonies de la population à travers le monde. Les
données étaient initialement inadéquates, pro-
venant de capteurs terrestres qui étaient su-
jettes à des préjugés locaux en raison d’une ré-
partition inégale de ces capteurs. NASA a ré-
pondu à ce problème en faisant ce qu’ils font le
mieux; lancer quelque chose dans l’espace. Ils
ont utilisé le Radiomètre spectral pour image-
rie de résolution moyenne (MODIS), un instru-
ment sur leur satellite Aqua Terra, et en coopé-
ration avec le satellite Land-Sat de l’Institut
d’études géologiques des États-Unis (USGS), ils
ont utilisé l’imagerie infrarouge pour détecter
la chaleur dans et autour des villes à travers le
monde (Lo, Quatt.. & Luva., 1996). Ils ont consta-
té que, bien que les facteurs climatiques soient
importants, ils ne tiennent pas compte de tous
les écarts. Par exemple, Providence, IR et Buffa-
lo.
continuer à lire Z
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check out our website: www.uocatalyst.wordpress.com
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B e a t i n g t h e H e a t
24. Catalyst
November 201624
NY sont deux villes du nord-est des États-
Unis avec une taille similaire et milieux écolo-
giques, mais Buffalo a tout de même une tem-
pérature moyenne supérieure de 7.2°C. La NASA
a isolé la couverture végétale et le modèle ur-
bain comme le déterminant majeur sur la for-
mation des îlots de chaleur. Avec l’aide de
l’imagerie par satellite et les dossiers fiscaux
municipaux, il a été constaté que les villes à
faible densité et d’agencements tentaculaires
ont un plus grand îlot de chaleur urbain que
celles à haute densité. Une mauvaise planifica-
tion de la ville augmente aussi les problèmes de
circulation, ce qui produit beaucoup de chaleur.
Plus de végétation (en particulier des grands
espaces verts, des arbres bordant les rues et
des jardins) sur les toits peut aider à refroidir
ces villes en fournissant de l’humidité et en
couvrant les couleurs sombres. Benedicte
Dousset, un scientifique qui étudie ce problème
à l’Université de Hawaii croit que « il n’y pas
une seule solution, et ça va être différent pour
chaque ville. Les îlots de chaleur sont des phé-
nomènes complexes3
».
Cependant, il vaut la peine de trouver des
solutions, puisque ce phénomène affecte à la
fois la consommation d’énergie et la santé hu-
maine, avec des conséquences potentiellement
mortelles. Certaines populations sont plus à
risque que d’autres pendant les vagues de cha-
leur, comme les personnes souffrant d’asthme,
de maladies cardiaques, et les personnes âgées.
La vague de chaleur à Paris en 2003 a causé une
hausse de la moyenne du taux de mortalité de
la ville, allant de 50 décès/jour à presque 350
décès/jour, alors que les températures avaient
dépassé 45°C. L’utilisation accrue du climati-
seur produit plus de chaleur à l’extérieur, exa-
cerbant le problème pour les personnes sans
climatiseur. Il est estimé qu’il y avait 4800 dé-
cès évitables à Paris et plus de 70 000 en Eu-
rope l’été de la tragédie, les personnes âgées
étant les plus touchées. L’Agence américaine de
protection de l’environnement (EPA) estime que
plus d'Américains sont tués dans des vagues de
chaleur que dans des ouragans, des foudres, des
tornades, des inondations et des tremblements
de terre combinés2
. Avec de telles consé-
quences terribles, il vaut la peine de planter
quelques arbres.
,New York are both northeastern US cities
similar in size and ecological backgrounds, yet
Buffalo is 7.2°C higher in average temperature.
NASA has identified vegetative cover and urban
design as the major determinant on the for-
mation of heat islands. With the help of the
satellite imaging and municipal tax records, it
was found that cities with low density and
sprawling layouts have a greater urban heat
island than those with high density. Poor city
planning also increases traffic problems, which
output significant excess heat. More vegetation,
particularly from large greenspaces, trees lin-
ing streets, and rooftop gardens can help cool
these cities by providing moisture and cov-
ering up dark colours. Benedicte Dousset, a sci-
entist on this issue at the University of Hawaii,
believed “there’s no one solution, and it’s go-ing
to be different for every city. Heat islands are
complex phenomena” (Voil., 2010).
Solutions are worth pursuing since the heat
island phenomenon affects both energy con-
sumption and human health, with some poten-
tially deadly consequences. Certain populations
are at a higher risk than others during heat
waves, such as those with asthma, heart condi-
tions, and the elderly. The 2003 Paris heat wave
saw the city’s average mortality rate jump from
50 deaths per day to almost 350 deaths per day,
as temperatures surpassed 45°C. The increased
use of air conditioning (AC) generated more
heat outdoors, exacerbating the problem for
those with-out AC. It is estimated that there
were 4 800 preventable deaths in Paris and
over 70 000 in Europe that summer, with the
elderly being the most impacted. The US Envi-
ronmental Protection Agency (EPA) estimates
more Americans were killed in heat waves than
in hurricanes, lightning, tornados, floods, and
earthquakes combined (Stone Jr. & Rodgers,
2001). With such dire consequences and need to
reduce the heat density, it is worth planting a
few trees.
B e a t i n g t h e H e a t
25. Catalyst
November 2016 25
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26. Catalyst
November 201626
Hello Scarcely Sleeping Student,
Even though the odd all-nighter here and there will not kill you, it is not likely to help you out as much
as you think. That bad case of the munchies you will get throughout the night and the next day are not
just boredom, they are actually hormones such as ghrelin, an appetite stimulant, and leptin, an appetite
suppressant, that have been thrown for a loop. As a result, you may feel hungry, over eat, and potentially
result in weight gain.
While you are probably planning on using your all-nighter productively to cram for a mid-term or final,
the lack of sleep actually negatively impacts your ability to form and retrieve memories, so you will be less
likely to remember your studied material on the exam.
Additionally, all-nighters trigger an elation effect, otherwise known as a natural chemical high from the
neurotransmitter serotonin, which will give you a false sense of confidence, and potentially lead to risky
behaviours. Your body’s adrenaline and cortisol levels also rise from lack of sleep and the stress that it
induces. This makes it even tougher to concentrate! Stimulatory drugs such as caffeine or Adderall may
seem like tempting solutions to these problems, but they only temporarily relieve your feeling of drowsi-
ness before leaving the rest of your brain impaired.
When you take all of this together, the lack of sleep prevents your brain from working as well as it can
while rested. There is a reason they say that driving tired can be just as dangerous as driving impaired;
writing exams or assignments are no different. While it is tempting to think you can catch up on sleep the
next night, sleep specialists say it could take weeks to make up for your lost sleep, and that returning to
a normal sleep schedule is the most important way to recover.
Finally, a regular sleep schedule is also the best way to save your GPA. According to sleep research-
ers at St. Lawrence University, sleep deprived students had lower GPAs than their well-rested class-
mates. So hit the hay, your body and your GPA will thank you.
-Darwin
Dear Darwin, are all-nighters really all that bad for you, aside from being tired in the morning?
-Sincerely, Scarcely Sleeping Student
Dear Anonymous,
In the world of anatomy and physiology, abomasum is the fourth chamber of the stomach in ruminant
animals, which are mammals with four compartments of the stomach instead of one. Examples of rumi-
nants include cattle, sheep and goats. Through the use of their specialized stomachs, ruminants are capa-
ble of obtaining the nutrients they need from plant-based foods. These plant products undergo fermentation
in the stomach before digestion.
Thus, the function of the abomasum is to perform the chemical breakdown of food, and to do so it must
secrete hydrochloric acid and pepsinogen. The abomasum structure is found on the abdominal floor of ru-
minants and is composed of simple columnar epithelial tissue. A fun fact about the abomasum structure is
that it is particularly large in newborn ruminants.
-Darwin
Dear Darwin, what is an abomasum?
-Anonymous
By: Tianyue Angela Dou, 1st Year, BIM and
Elizabeth Anne Richardson, 5th Year Co-op Option, BIM
27. Catalyst
November 2016 27
Dear Fizzy Friend,
I feel that it is important to first and foremost elaborate on what exactly consists of a carbonated bever-
age. Strictly speaking, a carbonated beverage is defined as a drink that contains carbon dioxide dissolved
in the liquid. Typically, properties of carbonated drinks would include its fizzy texture, bubbling in the liquid,
and last but not least, that incredible feeling of an ice cold carbonated drink running down your throat on a
hot summer day.
Now you might be asking Fizzy Friend, why I am reciting all this information that you most likely already
know? The reason is simple, that the term ‘carbonated drink’ is simply too general to deem it good or bad
for your body. There are many types of carbonated drinks in the world, from sodas, to root beer, to ginger
ale, to carbonated water, and it is certain to say that certain types of those beverages are more harmful to
the body than others.
I’m sure you have been told that Coke or Sprite is bad for you, but is the dissolved carbon dioxide inside
truly the cause? The answer leans towards: NO. Despite myths that carbonated water leeches calcium from
bones or teeth, there is yet to be much real, concrete evidence to suggest the validity of such statements.
However, studies related to the consumption of carbonated soda drinks have been linked to low bone
mineral density. Thus, it is safe to say that among carbonated drinks, there is no harm in enjoying a bottle
of Perrier every so often, especially if you enjoy the texture of bubbly as opposed to plain water. Yet, my
advice to you, Fizzy Friend, would be to cut back on the Coke, Sprite, or root beer as such drinks have been
consistently found to contain too much sugar. Additionally, its high phosphoric acid content is likely a bigger
factor for low bone mineral density than carbonated water.
Hope this helped and have a great day!
-Darwin
Dear Darwin, why are carbonated beverages bad for me?
-Sincerely Fizzy Friend
Salut Éudiant privé de sommeil,
Même si passer une nuit blanche de temps en temps ne te tue pas, ceci ne t’aide en rien. Manger trop de
casse-croûte le lendemain d’une nuit blanche n’est pas forcément à cause de l’ennuie– en fait, les hormones
ghréline, un stimulant de l’appétit, et leptine, un inhibiteur de l’appétit, sont entièrement déséquilibrées, dû à
un manque de sommeil, ce qui te donne envie de manger. Il se peut même que tu grossisses. Bien que tu
croies bien faire en étudiant tard pour un intra ou examen final, tu ne fais qu’altérer ta mémoire. Ainsi, lors de
l’examen, tu auras beaucoup de difficulté à te rappeler ce que tu as lu le soir précédent.
En plus, les nuits blanches déclenchent un effet d’exaltation associé à la libération de sérotonine qui te
donne un faux sentiment de confiance ce qui peut mener à des comportements risqués. Le manque de som-
meil augmentera aussi les niveaux d’adrénaline et du cortisol ce qui provoque le stress, rendant la concentra-
tion encore plus difficile ! Les drogues stimulantes comme la caféine et l’Adderall semblent être les solutions à
ces problèmes (fatigue, stress, etc…), mais elles offrent un soulagement temporaire et provoquent la détério-
ration du cerveau. Mettons tout ensemble, le manque de sommeil empêche ton cerveau de bien travailler. On
considère que la conduite en état de fatigue est aussi dangereuse que la conduite en état d’ivresse. En quoi
écrire un examen quand on manque de sommeil est-il différent?
Bien que tu croies être capable de compenser ton manque de sommeil, les scientifiques disent que cela
pourrait prendre des semaines pour compenser le sommeil perdu. Bref, un horaire de sommeil régulier est la
meilleure façon de sauver sa santé ainsi que sa moyenne (scolaire). Selon les chercheurs à l’université St.
Lawrence – les étudiants privés de sommeil avaient des moyennes inférieures par rapport à leurs camarades
bien reposés.
Alors, va au lit, ton corps et ta moyenne te remercieront.
-Darwin
Cher Darwin, à part de se sentir fatigué le lendemain matin, passer des nuits blanches, est-il grave pour la santé?
-Cordialement, Étudiant privé de sommeil
