Waves Basics

Basics

• A wave is a disturbance in a medium that carries energy.
• Two points are in phase if they have the same motion at all times
• Two points are completely out of phase if their motions are always opposite
• Superwaves are created when two identical waves move toward each other

Path Length and Path difference

• Path length: the distance from a point to the source of a wave
• Path difference(Δ): the difference between the path lengths of two different waves
• If two point sources vibrate in phase with each other, they would be in-phase at points where Δ is a whole number multiple of λ

Waves at Boundaries

• The frequency of a wave never changes
• Snell's law: n×sin(θ) is constant (n is the index of refraction)
• If a wave travels from a faster medium to a slower medium, the transmitted wave becomes inverted

Interference from two point-sources

• If a point P is very far away from the two sources, then Δ= d×sin(θ), where d is the separation between the sources, and θ is the angle between the perpendicular bisector of the sources and the line joining P and the midpoint of the two sources

Young's double slit experiment:

• Problem: to have two point sources of light that are coherent
• The first slit acted as a point source of light
• The double slit acted as two point sources of light
• On the screen, the bright fringes are where the antinodal lines are
• The dark fringes are where the nodal lines are

Interference of thin films:

• Use the theory of "waves at boundaries" and path difference to do these problems
• n₁×λ₁=n₂×λ₂

A Busy Winter Break

There are actually a lot of things that I need to do during this winter break. This means that I cannot just waste days playing games and doing nothing; I cannot afford to waste the valuable time.

So I decided to make this post to remind myself of all the things that I need to do:

University Applications:

• Engineering essay (600 words)
• Engineering extracurricular activities
• Engineering academic achievements
• What is a folly act?
• What defines you as you?
• What is an educated person?
• Write a reference letter for yourself

School

• Study for physics
• Study for calculus
• Prepare for physics presentation
• Work on philosophy essay

I Think, Therefore I Am

The quote "I think, therefore I am" is Rene Descartes' famous cogito argument, and it is extremely important in epistemology. Using his own Method of Doubt, Descartes doubted everything that was provided by the fallible senses, as well as anything that could be part of a dream or an illusion created by an evil genius. This left him with one thing that he could be sure of— his existence. He reasoned that even if everything around him was an illusion, his mind must exist because otherwise he would never have been fooled. This quote is an extremely important argument in rationalism— as it is purely based on reason— and it is also relevant to solipsism. It illustrates Descartes' method of doubt, which is to doubt anything that comes from our senses or anything that could be an illusion.

Not A Priority

A lot of things have happened last month. I dropped one of my courses, I started following a new television show, and I have encountered many thought-provoking things.

However, clearly I didn't take the time to document any of these onto this blog or anywhere else. Even when I had spare time, I would always choose another activity over writing a blog post.

Why? I think one reason is my preference for thoroughness. Whenever I thought of updating the blog, I would want to make a super-long post that would outline my thoughts with great detail; I would never allow myself to write a 2-sentence blog post. But thoroughness is costly— it takes time. I have time to make a post, but obviously not enough to spend 2-3 hours in a single session. And since I do not have the habit of writing a post chunk by chunk, I just never wrote anything.

Also, I have started to think that perhaps it's not always necessary to write everything down. Why can't I just go through everything in my head?

Besides, school really is busier than last year, and also a lot more important. In my final year, almost all my marks matter, and I have to spend a lot of time and effort to prepare for tests and to go over assignments.

So unfortunately, this trend probably wouldn't change until sometime next year. Blogging isn't a priority right now.

A Few Complaints

The administrative team of my school constantly brags about how the school is one of the highest-ranked schools in the school board. However, these rankings are merely based on the scores on standardized tests, and in actuality have little to do with how "good" the school is.

This post is going to outline all the major flaws that I find with the school.

Nightmare: Snakes and Death

September 27th
This dream was a bit more mystical than the one during the night before; it's a lot harder to put it into context.

For some reason I was walking in an area with a lot of trees, with many poisonous snakes on the ground. Of course, I couldn't actually tell whether they were poisonous or not, but they had black bodies plus some weird yellow patterns on their skin, so I assumed they were. Also, these snakes were all very large. They were perhaps as thick as a person's leg.

Nightmare: Failure

September 26th
That night, I had a bad dream in which I didn't win any awards at all during graduation. I'm not sure if there was any other "major failure" in the dream, such as not getting into the university program of choice, but I remember I was absolutely devastated during that dream; I think I literally cried. This goes on to show how much it means to me for me to win an award.

But why is it so important to me? Of course, there is a practical side: this year I have actually set goals to obtain awards just so that I can have more things to put onto my resume. However, I think it's mainly about pride and a confirmation of my ability, just like how I care so much about my marks.

The Catcher In The Rye by J. D. Salinger

I recently read the famous novel The Catcher in The Rye by J. D. Salinger, after seeing it in book stores and reading lists so frequently.

However, I really don't have much to say about this book, which is why it's five days after I finished the book and I still haven't written a post about it yet. This is probably because I don't have much connection with the narrator; we are simply two very different teenagers with different family backgrounds as well as values and concerns. Not to mention that Holden is a teen in the 1950s and lives in New York; even our societies are tremendously different.

The Asbestos Problem

This was an assignment for my economics course

Asbestos is a mineral fiber that has many wonderful properties— it's fire-resistant, flexible, and a good thermal and acoustic insulator. With these useful qualities, it became extremely popular in the early 1900's, when people used it for a variety of things, such as wall insulation, roofing tar, and fire blankets.

Unfortunately, as wonderful as asbestos may seem, it is responsible for a multitude of diseases: it has been proven that exposure to airborne asbestos can cause lung cancer and mesothelioma (a cancer of the pleura of the lung), as well as asbestosis and diffuse pleural thickening. Cancer is almost always fatal, and the other two conditions result in the difficulty in breathing— which, if not fatal, severely affects the quality of life.

The Murder of Roger Ackroyd by Agatha Christie



The murder of Roger Ackroyd is undoubtly one of the most famous works of Agatha Christie, with many stating that it is her masterpiece. However, I personally only liked it as much as many of her other works, perhaps because I accidentally read a spoiler of it while reading the review of another book.

(spoiler ahead)

Free Swimming Lesson

Whenever I have time and feel energetic, I would go downstairs and swim at the swimming pool in my building. However, I would always choose the time carefully to avoid having to swim in a crowded pool or with a lot of children (children swim sideways, so it's annoying to be in a pool that has children). For instance, I would never go down at 1:00 PM during weekends because at that time there are usually many families down there.

So a few days ago, I went down to the swimming pool at 10:30, a time at which most children would be at sleep. Indeed, there was no child at the pool that night . However, as soon as I got out of the change room, I heard a woman greeting me, and upon squinting my eyes— I had to because I was near-sighted—I realized that she was the pastor's wife!

Overheating Issue

Ever since I came back to Toronto from Vancouver, my computer has had a worsening overheating problem. It would suddenly shut down when I browse the internet, when I let it sit idle while a browser is open, and even when I let it sleep during safe mode!! I mean, doesn't safe mode use a lot less processing than normal mode? And for the computer to overheat while one safe mode and asleep? The problem was clearly not negligible.

Top 100 Books from BBC

I recently stumbled across Facebook's book list challenge, which (falsely) states that BBC claims the average person has only read 6 items out of a total of 100.  It's actually not a very good book list challenge, because items like "complete works of Shakespeare" simply don't make sense (especially when Hamlet is another item). Also, the book list itself is from the Guardian...

So I have decided to use BBC The Big Read's top 100 books for my book list challenge.

Here's where I stand as of August 2012:

Enduring Love by Ian McEwan

On a windy day, the pilot of a helium balloon fails to anchor it properly, causing the balloon to go afloat with a child still in it. Several men at the scene help out by holding onto the ropes of the balloon and weighing it down, but the pilot— who has been trying to get the child out— accidentally falls out of the basket when a strong wind comes, and this causes the balloon to rise up in the air. One of the man lets go of the rope, then three others follow suit, leaving only one man who hangs on with the balloon high up in the air. His grip eventually weakens, and he falls to his death.

After this accident, the narrator— who has been helping out— makes eye contact with Jed Parry, who has also been trying to help. At this moment, Jed Parry believes that the narrator is in love with him, and thus begin their unpleasant entanglement...

Fight Club by Chuck Palahniuk

Although Fight Club is both a popular movie and novel, I didn't know what it was about until roughly a week and a half ago, when I searched it up on Wikipedia after a friend of mine had recommended it to me. At the time I was quite intrigued by the psychological element of the book, and— fueled by my friend's recommendation—decided to borrow and read it.

Judging by the fact that I have actually finished the book already, you can guess that it isn't a bad book; normally it takes months for me to actually get to and finish a book on my book list. Indeed, I thought the book was interesting and reasonably fast-paced, and had a very good twist.  However, I can't say that I liked it very much, either.

Summary of Fight Club

The novel starts at a point very close to the ending, where Tyler and the unnamed narrator stand on a tilting building that is about to explode, and Tyler is pointing a gun into the unnamed narrator's mouth.  The narrator then goes on to describe his circumstances and all the events that have led to the final moment.

"Too Asian?"

Being an Asian, I was immediately drawn to the title of this book when I saw it in the UBC book store. This is why I have so quickly gotten a copy of it after I came back to Toronto. To clarify, the full name of the book is "Too Asian?": Racism, Privilege, and Post-Secondary Education, and it has several authors, who each writes one or more chapters/essays.

Volunteering Incident

Today when volunteering at the hospital gift shop, there was an unhappy incident which I thought I should reflect on.

Having only one short training session and three shifts volunteering at the hospital so far, I am still not very familiar with using the lottery terminal. Of course, I can do basic transactions such as selling and redeeming tickets, but there are still certain scenarios that I am no very sure how to deal with. For example, what should the retailer do if the customer wants to redeem tickets plus buying tickets using the selection slips? This problem was the cause of the unhappy incident today.

Atonement by Ian McEwan

To be honest, I was a little disappointed by Atonement by Ian McEwan. Not because it was a bad book— I thought it to be quite good— but because it was kind of over-hyped. When a book is listed under TIME magazine's 100 best novels of all time and named as one of the 10 best books of the decade by the Guardian, you would naturally expect a lot of it. And unfortunately, this book didn't live up to the high expectation that I had for it.

The Long Walk by Stephen King

The Long Walk by Stephen King was recommended to me by a friend, and upon hearing the premise of the story, I immediately wanted to read it.

The novel centers around 16-year-old Ray Garraty, who is a competitor of the Long Walk. The Long Walk is an annual walking competition consisting of 100 boys who have volunteered to be in it. Once the competition starts, the walkers have to keep a pace of 4 miles per hour, or else they get a warning. If a walker' speed drops below 4 MPH after his third warning, he will "buy a ticket," which is a euphemism for being shot dead. Then, the competition continues until there is only one walker alive...

Olympics— It Doesn't Have to be All Canadian

Today when I was flipping through the channels, I saw CTV broadcasting the elimination race of men's omnium, in which every two laps, the slowest person would be eliminated. It was actually very interesting to watch because it was a very close race and each cyclist was constantly trying to pass each other.

However, just as I was enjoying watching the tight race, the one and only Canadian got eliminated. The camera then zoomed over to the faces of the disappointed friends and families, and then there was a sudden commercial break. Yes, a commercial break when the race was going to finish in a few minutes!

Peril at End House by Agatha Christie

In Peril at End House, a young woman named Magdala Buckley— nicknamed Nick— has had three near escapes from death. Once a heavy painting fell off from the wall and almost hit her, once her car wouldn't brake, and another time a huge boulder fell and almost hit her car. Then, when she was talking to Poirot, a bullet went straight past through her hat, almost killing her...

Seeing that she was in danger, Poirot tried his best to protect her. However...

Spoiler/Plot development:

Full Dark, No Stars by Stephen King

The book Full Dark, No Stars contains four short stories by Stephen King, although two of them are so long that I think can be classified as novellas. In any case, the title perfectly indicates the mood of these stories— all four of them are extremely morbid, to a point that would make readers shiver.

Report Card (grade 11 final)

This year, I wasn't able to physically see my report card until July 27th— when I came back home from my summer camp. Therefore, in order to find out my marks earlier, I had to ask my mom via Skype.

Of course, my mom would not just tell me my marks without some fun— she made me guess what I got in each subject. The problem was, it was extremely hard to guess because I had no idea how I did on the exams or the final projects! So I just guessed a bunch of random numbers that were close to my marks going into the exam, hoping that she would say "correct!" at one of those numbers.

When Memory Fails

I'm not sure if I've always had such problems with my memory, but ever since grade 9 or 10, I have had trouble remembering things.

Of course, it's nothing as severe as not remembering my name or address (actually, it took me a while to remember my new address when I moved...), but it's significant enough to be noticeable. For example, when seeing the titles of books that I have read just a year ago, I would sometimes be unable to recall anything about it and would have to search up the plot summary to evoke any memory of it.

A Summer Update

I have only had one post in the past 40 days or so, and that post wasn't even something that required a lot of time— I merely copied and pasted one of my economics assignment.

The question is— why? Shouldn't I have a lot of time due to summer vacation?

Well, throughout July, I have been in an intense camp called Shad Valley, where I participated in various activities from 9 o'clock in the morning to 10 at night. This is not to take into account the time for breakfast, showering, and Skyping my parents. So basically, I had nearly no time nor energy to update the blog.

For August, I probably won't be able to spend a lot of time on the blog either. I have an internship starting on August 7th, and it's from 9 to 5— it's longer than school! I am also volunteering at a hospital once every week, and there are just so many things that I want to fit into the tight summer schedule: applying for scholarships, reading novels, going to Bible studies, etc.

Still, I plan to write a blog post for every novel that I read, as well as one for my month-long experience at Shad Valley. I will do my best to make sure that I fulfill this goal!

Exclusive Interview With Adam Marx, on the Challenges Faced by University Graduates When Starting a Family

Note: This is my economic assignment, exactly as it was submitted onto the students works blog
Posted: Jun 14, 2012, by ___, New Life reporter

Nobel Prize winning economist Adam Marx is known for his studies about how different demographics make their economic decisions differently. In recent years, he has been focusing his studies on the challenges faced by the younger generation, especially university graduates.

Adam Marx speaks with New Life about the challenges that university graduates will face when they try to start a family. This is the first part of a series of exclusive interviews with economists to talk about the main challenges faced by different demographics.

To listen to the original interview, click here.

Plant Technology and Maintanence

Artificial Selection: selecting the desire traits of a plant, and only breed the plants that have the desired traits

• mass selection: selecting the largest and biggest
• pure line selection: selecting certain traits
• cross-breeding: breeding two plants that have two different desired traits

Tissue Culturing Technology

• Obtain cells from the meristem
• Grow the cells through mitosis. The mass of cell is called a callus
• Apply hormones such as auxin and cytokinin so that roots and shoots can grow

Gene transfer: splicing the genes of one species into another to get the desired traits

• Cold resistant gene: obtained from a kind of fish
• Bt gene: codes for proteins that paralyze and kill insects

Common Genetic Disorders

Inherited Disorders:
Autosomal dominant

• Progeria: characterized by rapid aging
• Huntington disease: characterized by involuntary arms and legs movements. Other symptoms include mild irritability and memory loss

Autosomal recessive

• Tay-Sachs Disease:  They lack a certain enzyme that would allow cells to digest lipids. This causes the lipids to build up in the brain cells and destroy, which further causes blindness, mental deterioration, and death
• Phenylketonuria: If untreated, children can be severely mentally handicapped
• Albinism: Lacks the brown pigment melanin

X-linked recessive

• Hemophilia: Reduced ability to clot blood.
• Colour blindness: Cannot distinguish between colours
• Duchenne muscular distrophy: Muscles waste away because the muscle cells are are engorged with fat and connective tissue

Codominance

• Sickle Cell Anemia: RBCs are shaped like sickles, causing reduced blood flow to various parts of the body.

Incomplete Dominance

• Hypercholesterolemia: high cholesterol, so higher chances of heart attack

Aneuploidy (Non disunction):
Down syndrome: trisomy of the 21st chromosome
Edwards syndrome: trisomy of the 13th chromosome
Patau's syndrome: trisomy of the 18th chromosome

Turner's syndrome: only one "x" chromosome
Kinefelter's syndrome: "XXY"
Jacob's syndrome: "XYY"

Common Digestive Diseases

Colon Polyps 
Description/ Symptoms: fleshy growth on the colon. Could cause rectum bleeding and could turn cancerous
Causes: genetic mutations of colon cells
Treatments: Surgeries


Gingivitis 
Description/ Symptoms: inflammation of the gums
Causes: bad oral hygiene, bacteria
Treatments: Better oral hygiene


Diabetes
Description/ Symptoms: not enough insulin; blood sugar too high
Causes: genetic factors, obesity
Treatments: injection of insulin

Exam Time

This semester passed by so fast; exams are already approaching. In fact, they are next week! I feel that the schedule this semester is a little bit tighter, because in previous years I have had a lot more time to study for exams.

Anyway,  below are the exams that I will have:

• Monday morning: Advanced Functions
• Tuesday morning: Biology
• Thursday afternoon: Data Management
• Friday morning: Economics

My main challenge would be advanced functions and biology, since they are on the first two days and I have less time to study for them.

However, the ones that are the most important are advanced functions and data management, as these two courses are most likely become part of my top six for university. 

I will need to start studying for the exams... today.

Note: This post was created in the second semester of grade 11.

Quick Review for Plants

Classification

• Plants can be classified as aquatic or terrestrial.
• Of the terrestrial plants, there are ones that are vascular and ones that are non-vascular.
• Of the vascular plants, there are seedless plants, and seed-bearing plants
• Of the seed bearing plants, there are gymnosperms and angiosperms
• Angiosperms can be classified as monocots or dicots

Organs

Leaves

Leaves are primarily responsible for photosynthesis. They are covered by cuticles, which are waxy layers that prevent water loss. They have stomata that allow for plants' gas exchange.

Palisade mesophyll are responsible for photosynthesis.

Four Tests On Monday

Oh my, I think this is first time that I would have four tests in one single day! This means that for the entire day, excluding lunch, I will be writing tests, that I would be writing tests for a total of five hours.

And I don't have that much time to prepare for these tests, because I also have two major projects due on Tuesday. So I will need to— as I always tell my self— not waste any time.

In addition, I will need to make preparations to  ensure that I have enough replenishment for my brain on that day...

No Time To Think

Many important things have arisen in the past few months, many of them worth some reflections. However, I have been so busy that I couldn't find time to write my thoughts down— this is demonstrated by the fact that almost all recent my posts are school-related. 

Even if I didn't have the time to write posts on the issues/topics, I always thought to myself: it's fine, I can just think about it. But I rarely did. I was always so occupied with other things that I'd only got time to think when on the bus or during the few minutes before I fall asleep each day. And I was always so tired during those times that I couldn't think properly.

So in short, I didn't spend nearly enough time thinking about those important things.

To make matters even worse, I seemed to have stopped thinking about the random and seemingly unimportant stuff. I no longer tried to imagine strangers' lives when I walked on streets. I no longer looked at the electric posts and thought about all the advertisements and scratches on them. I no longer wondered why things were the way they were.

I have become too preoccupied with all the things going on in my life.

This reminds me of Fahrenheit 451, in which the pace of life was so fast that people no longer thought critically. I remember (probably incorrectly) how Clarisse was lamenting the fact that people didn't have to time sit on their lawns and just think. And now, I am lamenting the fact that I do not have the time to sit down and just think.

Oh, I wish life was less busy.

That's it for my rant. Meanwhile, I have to organize my time better, so that I can allocate more time to thinking, and to doing other more meaningful things.

Grace

During today's youth group, the leader— whom I'll refer as L.— talked about grace, the unmerited love that God gives to everyone. He explained how every part of us, including our bodies, is given to us by God; how everything we have is grace. God has not only created us, but has also bore our sins for us, despite the fact that we rejected him. He could easily have destroyed the human race when we did all the horrible things to him, but instead he chose to bore all the sins for us and to suffer for us. Not because we did anything deserving, but simply because he loved us.

Since everything we have is grace— we are all sinners and we don't actually deserve anything that we have  —there is no reason for us to be proud. That is, because we couldn't have accomplished anything without the gifts of God, nothing we do is great in God's eyes. This also means that we should never expect things from God just because we have done "good" deeds— to God, these things are like "polluted garments" and they are nowhere close to God's holiness and perfection.

At the end, L. said that when one truly understands what grace is, there should be a radical change in one's thoughts and behaviours. One would become humble, and one's actions would be spurred by one's love of god, not by an urge to please god and be saved.

Unfortunately, I can't remember exactly what L. has taught us during youth group; even the things above are formed from my fragmented memory (and this is probably why many things seem vague). However, when he was talking, I felt a stirring within my heart. I don't know why, but for the first time in my life, I felt God's presence, I believed in the existence of God!

Actually, to think of it now, I didn't really believe in the existence God at the moment. Instead, I simply started to accept the possibility that God exists. Still, it was a big moment for me, because it had always been difficult to accept this possibility— it had been too abstract to me.

Of course, the concept of God is still very abstract to me. But now a brand-new perspective is open to me, and I am confident that I have experienced some spiritual gains, however little it might be. At the same time, I am ready to adopt a different mindset, and change the way I think and act.

Tomorrow I will go to church as well. Hopefully I will get to understand God more.

Monopolistic Competition

What is a monopolistic competition?
A monopolistic competition is an imperfect competition in which many firms sell a product that has product differentiation. An example would be the hamburger market, where there are many stores selling hamburgers, but the taste and quality of the burgers from each store are slightly different. The firms in a monopolistic competition are not price-takers, but they face a very elastic demand due to the availability of substitutes.

Also, there's an ease of entry and exit for a monopolistic competition

Advertising
In order to differentiate their products, firms in a monopolistic often rely on advertisements to create brand names, to increase market share.

In the short Run
In the short run, the graph of a firm in monopolistic competition is very similar to that of a monopoly. The marginal cost curve is different from the average revenue curve, the firm produces at a point where MR=MC, and it can earn economic profit by charging the consumers at where the quantity intersects with the demand curve..

The only difference is that the demand is more elastic, and therefore the demand and MC curves look more "flat".

The Human Respiratory System

As mentioned in the post named Respiration, humans cannot rely on simple diffusion for gas exchange. Instead, we have to rely on a specialized respiratory system to do so.

In this post, I will be describing how the human respiratory system works.   

Nose

The nose (nasal cavity) is where the air comes into our body. The nostrils contain tiny hair that clean the air, and the epithelium lining have capillaries that warm the blood. Also, the turbinate bones are lined with a thin membrane that secrets mucus, which moistens the air.

(turbinate bones: thin bones in the nose that increase surface area, and warm and moisten the air)

Larynx

• The larynx house the vocal cords

Trachea 

• have mucous cells and cilia.
• mucous cells trap foreign particles, and cilia brush them away
• maintains its rigidity because of the cartilage rings

Bronchi

• like the trachea, they are also reinforced with cartilage
• lead to bronchiole, and then alveoli

Alveoli

• Spherical hollow cavities (grape-like structures) that are lined up with capillaries
• where gas exchange occurs

Lung surfactant: a complex substance that reduces the surface tension throughout the lung

Lungs

• The right lung has three lobes, while the left lung has only two lobes (to accommodate for the heart) 
• protected by a flexible membrane called pleura, which allows the lung to expand and contract

Types of respiration:

• Breathing: the act of drawing air into and then out of the lungs
• External respiration: gas exchange between the air and the blood
• Internal respiration: gas exchange between the blood and other cells
• Cellular respiration: the process in which cells convert oxygen and glucose into useful energy, creating carbon dioxide in the process.

Respiration

Cellular respiration: Almost every organism needs cellular respiration, as it allows cells to convert glucose and oxygen into useful energy.

Gas Exchange: As oxygen is a key component in cellular respiration, a cell needs to constantly bring in oxygen so that it can go through cellular respiration. Also, each cell needs to eliminate its carbon dioxide, a waste product of cellular respiration. Therefore, gas exchange— the process by which oxygen enters a cell and carbon dioxide leaves it— is necessary.

Requirements for gas exhange:

• large surface area: so that it can occur at a fast-enough speed
• moist environment

Diffusion

• Diffusion is a natural process in which molecules travel from areas of high concentration to low concentration
• It is only effective if an organism is only a few cells think
• Therefore, only uni-cellular organisms and very thin multi-cellular organisms (such as planarian) rely on diffusion

Specialized Respiratory Systems

• As organisms become larger, diffusion becomes inefficient.
• Also, many cells become specialized for other functions (e.g., reproduction)
• Therefore, a respiratory system is needed — a system that consists of respiratory surfaces, and muscles and tubes that allow air to contact the surface.
• Different types:
• Skin Respiration: The skin is lined with capillaries so that air can diffuse from the skin into the blood. The blood then transfers the oxygen to rest of the organism. Since diffusion must occur in a moist environment, organisms that rely on skin respiration must live in moist/damp environments. Examples: annelids (including earthworms, leeches)
• Gills: gills are organs that have high surface area and a lot of capillaries. They allow diffusion and gas exchange to occur efficiently for aquatic animals. 
• Tracheal Respiratory System: This is for insects. Many insects have spiracles (external pores) that allow the air to go into their trachea, which come in close contact to all the living cells.
• Lungs: organs that forcibly bring in air so that gas exchange can occur at the capillaries located on the lung surface. The blood then transports the oxygen to other parts of the body.

Oligopoly

What is an oligopoly?
An oligopoly market is one that is dominated by a few large firms. Firms in an oligopoly selling similar but branded products, and thus advertising plays an important role in the market. Also, there are high barriers to entry, and thus the small number of firms in the market.

Interdependence of Oligopoly
Since there are only a few firms in the market, the decisions of one firm can significantly affect all the other firms. Thus, the firms are interdependent on each other, and in many cases they might want to collude.

Kinked Demand Theory (Non-collusive behavior)
If the firms do not collude, then for each individual firm, we will see a kinked demand curve. That is, at the current market price, the demand becomes elastic as price increases, and inelastic as price decreases.

Why? If a firm raises its price, then consumers are simply going to switch to the other firms. Thus, quantity will decrease drastically and the demand will be elastic. On the other hand, if a firm lowers its price, then all the other firms are going to follow suit. This, in the end, will mean that the firm doesn't get that much more quantity, and that the demand becomes sinelastic.

Digestive Tract #2

This is a continuation of Digestive Tract #1.


Small Intestines:

After turning into chyme, the food enters the small intestines, which are comprised of three parts:

• Duodenum: receives secretions from the gall bladder and the pancreas (pancreatic juice). It is where the majority of chemical digestion takes place
• Jejunum: absorption of carbohydrates and proteins takes place
• Ileum: absorption takes place, especially vitamin B-12 and bile salts

Large Intestines:
The large intestines absorb water, and they also contain bacteria that produce vitamin K and vitamin B-12. In addition, they pass waste material to the anus.

Anus:
The anus expels the wastes.

Pancreas:
The pancreas secretes bicarbonate ions, which neutralize the stomach acid and inactivates pepsin. The pancreas also secretes pancreatic juice, which is comprised of pancreatic amylase (breaks down starch), lipase and trypsin.

Gall Bladder:
The gall bladder stores bile, which emulsifies fat and allows a greater surface area for fat to be broken down .

Liver:
The liver produces bile and cholesterol. It also converts excess glucose to glycogen, detoxifies poisons, and stores fat-soluble vitamins.

Digestive Tract #1

The digestive tract (also called the alimentary canal or the gastrointestineal tract) consists of: mouth→ pharynx→ epiglottis→ esophagus→ stomach→ small intestine→ large intestine→ anus

This entire post will be used to describe each part of the digestive tract, as well as other organs in the digestive system, such as livers and gallbladders.

Mouth:
The mouth (oral cavity) is where the food enters our body, and in it, both physical and chemical digestion take place.

The teeth physically break down the food, with different types of teeth breaking the food down different ways:

The saliva contains mucus and enzymes, such as amylase (breaks down polysaccharides) and maltase. Saliva is produced by the salivary glands, which are the parotid gland, the sublingual gland, and the submandibular gland:

The tongue moves the food when the person is chewing. In addition, it has taste buds, which are receptors that send messages to our brain: 

In the mouth, with the chewing and the mixing with the saliva, the food becomes a food bolus, and it now travels to the pharynx.

Esophagus: 

The food bolus then goes through the pharynx and into the esophagus, and long muscular tube made up circular and longitudinal muscles. In the esophagus, food is moved along with peristalsis.

Stomach:
At the end of the esophagus, there's the cardiac sphincter, which controls the movement of the food from the esophagus to the stomach. The stomach is a J-shaped organ with a volume of 1.5L, and it has thick layers of smooth muscle (rugae) that allows it to stretch. The stomach uses its longitudinal, circular, and oblique muscles to churn the food, and it also secretes gastric juices to chemically digest the food.

With both physical and chemical digestion, the food bolus is turned into a thick liquid called chyme.

Some components of the gastric juice:

• Hydrochloric acid: destroys invading microbes, breaks down food bolus, and turns pepsinogen into pepsin
• Pepsinogen: In acidic environments, it turns into pepsin, which breaks polypeptides into dipeptides
• Lipases: enzymes that break down lipids
• Mucus: secreted by the rugae, it forms a protective coating for the stomach that prevents the hydrochloric acid from burning through

Monopoly

What is a monopoly?
Monopoly is a type of market where there is only one firm (monopolist) that supplies the good. The firm is very large, and has control of the market price (has a lot of market power).

Sources of Market Power
A monopoly has market power (the ability to set the prices higher than the marginal cost) because it has no competitors. Consumers have to either buy from the monopolist, or not have the good at all. As a result, there will be demand for the good even if the price is set high.

To maintain its market power, a monopolist has to avoid having competitions; once it has competitors, customers will no longer be willing to buy the highly-priced goods that it supplies. But how can it prevent competitors? High barriers to entry:

• Economic barriers: economies of scale, superior technologies, and large initial investments are all things that benefit the existing firm, allowing it to produce more efficiently.
• Legal barriers: patents and copy rights ensure that the monopolist is the only firm producing a good. Property rights may grant one firm the exclusive access to a certain resource.

Essential Nutrients

Nutrients are chemicals that an organism needs to carry out its life processes.

Out of all the nutrients, many of them need be obtained from our diet. This may be because our bodies do not synthesize enough of these nutrients, or because our bodies do not synthesize thems at all. We call these nutrients essential nutrients, and categorize them into the following: carbohydrates, fats, proteins, minerals, vitamins, and water.

Theory of Consumer Choice

When dealing with consumers' choices, it is important to think about utility, which is a measure of satisfaction. The more utility a consumer has, the more satisfied they are with the goods or services that they have received.

Total Utility and Marginal Utility
These two terms are relatively straightforward. Total utility refers to the total amount of satisfaction that a consumer has gained from a certain amount of goods or services. On the other hand, marginal utility refers to the additional satisfaction that a consumer gets for the consumption of one extra unit of good.

Having a positive marginal utility means that the total utility is increasing, since marginal utility is the additional satisfaction. Similarly, having a negative marginal utility will result in a decrease in total utility.

Diminishing Marginal Utility
In most situations, we experience a diminishing marginal utility. That is, as we consume more and more of one good, our additional satisfaction from each unit of the good begins to be less and less. For example, if a person consumes one unit of a food that they like, they would be extremely satisfied from that unit of food. However, suppose they go on and consume 100 more units of the food, then one can imagine the person growing more and more tired of that food as they continue to consume it. Their marginal utility decreases.

However, it is important to note that even if marginal utility decreases, the total utility would still be increasing if MU is positive. It's just that the consumer is getting more satisfied at a slower rate.

Utility Maximization

Perfect Competition

What is a Perfect Competition?
A perfectly competitive market is a market that has many small firms and many individual buyers. Each seller has a very small share of the market, and as a result is a price taker; they cannot control the market price. Also, the products are all identical, and the consumers have perfect information about the market. That is, as soon as one firm prices its goods higher than its competitors, consumers will know and will switch to buying from other firms.

Additionally, there no barriers for entering or exiting the market, thus new competitors can arise at any moment, and companies can easily leave the market if they are losing profit.

Individual firm in the short run...
As mentioned above, each individual firm has such a small share of the market that it doesn't affect the market price at all. This means that whatever quantity it produces, it can always sell all of them at the market price, and the marginal revenue is constant. As marginal revenue is constant, the average revenue is also constant. So P=MR=AR.

A firm will always produce at a point where MR=MC. And since P=MR=AR, it will produce at a level where MC=P=MR=AR.

However, at this point, the price may be at, above, or below the average cost curve of the firm. If price is equal to average cost, then the company is making normal profit:

There is neither economic profit nor loss

Consumer and Producer Surplus

Basic Definitions:
Consumer surplus: The difference between what consumers are willing to pay and what they actually pay.
Producer surplus: The difference between what the producers are willing to supply a good for and the actual price at which they sell the good.

In a graph:
In a graph, consumer surplus is represented by the area that is above the price, but below the demand curve.

On the other hand, producer surplus is represented by the area that is below the price, but above the supply curve.

Response to an Economics Question

Article: http://articles.latimes.com/2012/mar/24/business/la-fi-home-rental-20120324

For my economics assignment, we have to go in pairs and make presentations. For each presentation, the presenters have to summarize an article about an article on a current economic event, and pose two discussion questions .

Today, the presenters summarized the above article, and asked: "Do you think this pilot program will be successful? Will homeowners and investors be interested?"

My Response
In my opinion, this program will be successful, as it will definitely attract both homeowners and investors.

Looking Back At Grade 11 English

Ha, semester one has been over for more than two months, and I still haven't written my personal reflections for English and physics. Such a procrastinator...

Anyway, grade 11 English was probably the most stressful course that I have had in my school career (so far). For one, its workload was a lot heavier than those of the other courses. For example, I remember that during December, we had this many things due:

• Speech 
• Macbeth culminating activity (mine was a story book)
• ISP essay

This may not seem like too much, but considering that the Christmas holidays started on December 16th, and the fact that these three big assessments were all due before the holidays, I really think that the schedule was a bit cramped.  

Preparing for AP Microeconomics Exam

For my AP economics class, I have go to an afternoon session every Tuesday to learn the AP material and prepare for the AP exam. 

However, for the past few weeks, I have been feeling that these afternoon sessions really aren't enough of a preparation for the exam. This is partly because the lessons are all taught by other students (so sometimes they don't know the materials themselves), and partly because each session is only 1 hour to 1.5 hours long.

Anyway, regardless of why the afternoon sessions are not effective, I will have to do quite a lot of studying on my own. So just a while ago, I have placed hold on several AP microeconomics books, and I am planning to go through all of them once they have arrived. In addition, I am planning on making a blog post on each of the topics that may be covered in the exam. These include:

• Consumer and Producer Surplus
• Income and Cross-price elasticity
• Perfect competition
• Monopoly
• Monopolistic competition
• Oligopoly 
• Collusion
• Game theory
• Factor markets
• Market failures

That's 10 topics that I have to cover in four weeks (the AP exam isn't actually that far away)! I must thoroughly study six for the next two weeks, and then the other four during the remaining two weeks. Ugh, such a busy studying schedule, considering that this is something "extra."

Early Ideas/Beliefs About Heredity

Hippocrates:
Greek philosopher Hippocrates believed that every part of the parents produced "seeds," which would fuse together to create the offspring

Aristotle:
Aristotle believed that male and female semen mixed upon conception.

George Harvey
English physician George Harvey theorized that individuals arose through the process of epigenesis; he believed that embryos formed in stages and that their development could be affected by factors inside and outside of the mother.  

Anton van Leeuwenhoek
This dutch scientist, who invented the microscope, believed that each sperm contained preformed embryos and that the development of the offspring was controlled by the male parent. On the other hand, mothers had almost no effect on the offspring, except providing an environment for the embroys to develop.

Charles Darwin
Charles Darwin believed that the offspring contained variations of traits from both parents. However, he couldn't explain why.

Pangenesis
The belief that each organ contains "genes," which travel through blood, the parents' genitals, and into the children.

Blending Traits:
The belief that offsprings are the "mix" of the parents. (e,g, red flowers and blue flowers would produce purple flowers)

Factoring Polynomials

A Review Of Some Concepts (for myself):
Remainder Theorem:
When dividing a polynomial expression p(x) by a linear polynomial expression x-b, the remainder is p(b).

Factor Theorem:
A linear expression x-b is only a factor of p(x) if p(b) is 0. (So there must not be any remainder)

Integral Zero Theorem:
If x=b is an integral zero of the polynomial P(x), then the constant term of P(x) must be divisible by 2.

Rational Zero Theorem:
If x=b/a is a rational zero of the polynomial P(x), then the constant term of P(x) must be divisible by b, and the leading coefficient must be divisible by a.

Becoming A Christian??

For the past few weeks, I have become quite involved with church activities.

I have been going to my ethnic United Church youth group for four weeks, and just this week, I went to the bible study session at my friend's church.

During these occasions, I have learnt quite a lot of basic information about Christianity. For example, I learned the differences between the Old Testament and the New Testament, I learned the stories in Exodus and Genesis, and I learned several teachings/principles of the religion.

So do I believe in god yet? Of course not. I have grown up in a family that doesn't have a religion, and the majority of the people around me were either atheists or agnostics. Therefore, I have never really thought about God's existence or non-existence, and have never imagined that there would be a superior being watching over me.

But will I ever become a believer? I don't know. I want to be a Christian— I really agree with many of their beliefs, and admire their virtues— but at this stage, it's still hard for me to just accept the existence of God as a fact. And I simply can't imagine how I may change my beliefs over time. So basically, there's no way to tell.

Meanwhile, I should try my best to attend youth groups and bible studies, to expand my knowledge on the bible and Christianity. And hopefully within a few months, I will begin to have a better understanding of my own beliefs.
---
If you find this post to messy and confusing, it simply reflects my state of mind. I am really confused about what my beliefs, and what they will be.

The Evolution of Cooperation by Robert Axelrod

image taken from here

In The Evolution of Cooperation, Robert Axelrod studies the evolution and nature of cooperation through his two computer tournaments of prisoner's dilemma. In both of his tournaments, the winning program employs the tit for tat strategy, and he attributes the success to:

• Being nice: it always cooperates unless the opponent defects
• Provocable: one provoked (being defected), it is quick to defect on the next turn. Thus it is not exploitable.
• Forgiving: it forgives the opponent for defecting as soon as the opponent switches to cooperating. This makes it easy for the two sides to restore to mutual cooperation
• Clarity: its strategy is very clear, allowing the opponent to know that it is best to cooperate with it

In the book, the author also discusses how this might come in play in many situations, the "stability" of such a strategy, as well as how to encourage or discourage cooperation.

My Sister's Keeper by Jodi Picoult

In My Sister's Keeper by Jodi Pocuolt, 13-year-old Anna Fitzgerald was born with the intent that her cord blood would cure her sister, Kate, of Leukemia. However, Kate started relapsing five years after Anna's birth, requiring Anna to donate her blood, bone marrow, and— finally— kidney. This prompts her to sue her parents so that she can get medical emancipation from them.

From this, it is quite clear that the book centers on the issue of organ transplantation. It raises many questions regarding the ethics of organ transplantation, and lets the readers to deliberate over them. For example, should parents be able to genetically screen the embryos of their children, to ensure that the children can become matching donors for their older siblings?

What amazed me, though, was how the author managed to show the dynamics and complexity of Anna's household. By including narrations from each of the family members (except Kate), Picoult successfully illustrated the complicated relationships between each pair of family members and the conflicting emotions of them. To me, this was great because it demonstrated the extent to which a family could be affected by the issue; it showed the human and emotional— as opposed to the legal —side of the story.

In my opinion, though, the book had some flaws. For one, I found it entirely unnecessary to include Julia's and Campbell's (the lawyer's) relationship— I just don't see how it's relevant! Also, I quite disliked the ways in which Anna interacted with Campbell. She was always extremely rude and disrespectful, which didn't seem to match her personality depicted throughout the other parts of the novel.

Overall, I definitely think that this is a novel that is worth reading. It has a unique theme, as well as a good storyline. There were some parts that I didn't like, but for the most part it was good and thought-provocative.

Life Cycle

Fertilization:

• Male and female gametes (egg and sperm) combine to form a zygote. 
• Gonads are organs that produce gametes (male: testes, female: ovaries)

Incubation

• Embryos→ fetus→ infant
• growth through cell division and differenciation

Growth

• Cell division of somatic cells (non-sex cells).  

Reproduction

• Puberty: parts of body begin to be able to make sex cells
• Meiosis: make more gametes

The Cell Cycle

Interphase

• G1: The cell grows and duplicates its contents (except the chromosomes).
• S: The cell duplicates its chromosomes
• G2: The cell checks for error in the duplicated chromosomes

Mitosis

• Prophase: the cell's chromosomes become visible, and nuclear membranes begin to dissolve. Also, centrioles migrate to opposite poles of the cell, and spindle fibres begin to form between the two centrioles.
• Metaphase: The chromotids move to the center of the cell, and form the metaphase plate.
• Anaphase: The centromere splits apart, and the chromotids move to the opposing poles of the cell.
• Telophase: nuclear membrane begins to reappear. Chromosomes begin to uncoil. The spindle fibres begin to disappear

Cytokinesis: 

- The two daughter cells separate

How to Lie With Statistics by Darren Huff

From its title, one would probably guess that the book is about how statistics can be misleading. Indeed, the book discusses the various forms of bias that we may see in statistics, including sampling bias (unrepresentative population), data-collection bias, misleading representations/uses of data, etc. It uses real-life examples to show how data can be distorted with various techniques.

The things discussed in the book are all quite straightforward. In fact, I have learnt all of them in my data management class already. Nevertheless, I liked the succinctness and clearness of the book as well as the humourous illustrations used to demonstrate the concepts. In short, How to lie with statistics is a stress-less and light read that may teach you some important and useful things.

The Remains of the Day by Kazuo Ishiguro

 

In The Remains of the Day by Kazuo Ishiguro, Stevens, an old English butler, goes on a journey to the countryside and reflects on the events and decisions that he has made in the past.

Because of his devotion to his profession— and his belief in "dignity"— Stevens has been holding back his emotions for his entire life. This includes the time when he didn't properly morn for his father's death because of an important event in the gentleman's house, as well as the time when went against his personal belief and fired two Jewish maids under his master's will. In short, Stevens chose the "professional" path, and sacrificed his own emotions and private life; all his concerns were those of his professionalism, and none of which is of his own well-being.

When reading the novel, I could sense the narrator's sadness, his melancholy. However, due to my young age and inexperience in life, I could never fully appreciate the extent of the sadness. So, if it's possible, I would like to read this novel again a few years later, and perhaps get a deeper understanding of the novel. Also, just as an afterthought, this book was beautifully written and very compelling.

The Hunger Games by Suzanne Collins

 

When I heard about this book last October, I immediately reserved a library copy of it. However, the book was so popular that there were more than one thousand people waiting in line before me, and consequently I have only gotten my copy a few days ago (that's a 5-6 months wait!).

Fortunately, the book didn't disappoint me. In fact, it was better than I had expected! Before I started reading the book, I had imagined this book to be children-oriented and perhaps quite like Rick Riordan's Percy Jackson and the Olympians series. However, a few pages into the novel, I was already struck by the sophistication of the narrator. Also, this book was unimaginably fast-paced and suspenseful; I simply couldn't stop reading it until I was on the very last page.

One thing that disappointed me a bit, though, was that the author had twisted the plot such that Katnis never had to kill Peeta or Rue. For me, this was the moment that I was looking forward to the most, for I really wanted to see how the author would portray Katnis's conflicting emotions over killing them. But I suppose this was too hard a task for the author, for it would be difficult for her to do so without somehow destroying Katnis's character.

Anyway, I really liked this novel. I was not only drawn to the intense plot, but also the characters, who were believable and likable. I am looking forward to reading the novel in the series, Catching Fire.

The Positive Power of Negative Thinking by Julie K. Norem

As the title indicates, the book discusses the ways and benefits of thinking negatively. Basically, when a person is feeling anxious about something, one way to combat this anxiousness would be to think of all the negative possibilities of the thing and to plan to prevent (or to know how to react to) those negative possibilities. This way, the person can feel more in control of the situation, and can often react well to obstacles.

Obviously, the things discussed in the book don't apply to everyone, and many of them don't apply to me. However, when reading the book, I did find some parts of it to be important to me. For example, the book describes procrastination as a self-handicapping action, where the person handicaps themselves so that if they fail, they can attribute the failure to "doing the task last minute," rather than their own inability. And although this may seem like a working strategy, it definitely has many drawbacks, including being constantly behind schedule, being viewed as undependable, and— obviously— having poor quality work. So next time I want to procrastinate, I shall think about the negative consequences of doing so.

Also, part of the book talks about how confidence and positive illusions can have negative effects on a person's performance. I should watch out for them in the future.

Overall, I think this book an interesting book for quick-reading, and at the same time one that contains helpful information. Read it, especially if you consider yourself as a pessimist.

The Midwich Cuckoos by John Wyndham

Just like two of the other novels by the same author, The Day of the Triffids and The Chrysalids, The Midwich Cuckoos by John Wyndham has a very interesting premise. The story is set in a British village called Midwich, where all the women become impregnated with alien children after a mysterious event known as the "Day Out" (in which people become unconscious for an entire day). The Children (capitalized to indicate that they are aliens) have different physical properties from human children; they have golden eyes and grow at a much faster rate. But more importantly, they are capable of exerting control on human minds, and seem to have two distinct group minds (one for boys and one for girls). And when they begin to harm and kill other humans because of some small offences, the community starts feeling endangered and begins to try to eliminate them.

The Sea of Monsters by Rick Riordan

Just like its prequel The Lightning Thief, The Sea of Monster is fast-paced and eventful. However, when I was reading this book, I found it to be quite repetitive and predictable; every nice person that Percy encounters turns out to be evil, and whenever Percy is in danger, someone else saves him. Also, the mythology part of it doesn't seem as intriguing as that of the first book— how interesting are these one-eyed cyclops?

Furthermore, I got a bit tired of the overly-simplistic way that the narrator uses to describe everything. For example, I remember Percy simplifying the dynamics between the gods down to "Zeus and my father are angry at each other." I mean, even though this is a children's book, many things could still be stated and described in some more elegant, insightful manner!

Nevertheless, as a book for entertainment, it serves its purpose. It's a light read that doesn't require a lot of thinking, and one that doesn't get boring.

Income and Cross-Price Elasticities of Demand

In regular economics class, we have learned that buyers’ incomes and prices of other goods are both demand determinants that shift the demand curve. Now, income elasticity and cross-price elasticity are measures that tell us “how much” the demand is shifted. In other words, income elasticity of demand gives us information about how responsive the demand (for a good) is to a change in income . Cross-price elasticity tells us how responsive the demand (for a good) is to a change in the price of another good.

Income Elasticity:

• Definition: the measure of how much the demand for one good responds to a change in consumers’ income.
• How to calculate: see “formulas”
• Other important information:
• A good is inferior if it has a negative income elasticity
• A good is normal if it has a positive income elasticity
• The greater the absolute value of the income elasticity, the more income-elastic the good is (the more the demand is affected by the income)
• If income elasticity is between zero and one, the good is income-inelastic, and can be classified as a normal necessity
• If income elasticity >1, the good is income- elastic, and can be classified as a luxury good.

Reproduction of Bactriophage (Lytic and Lysogenic Cycle)

Information taken from:  http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/index.html#charvir
Note: this post is very poorly written...

Lytic Cycle:

1) Adsorption: the virus attaches to the surface of the host cell

2) Entry: the virus injects its nucleic acid into the bacterial cell

3) Replication: Viral DNA is transcribed and then translated by the host cell.

4) Assembly: The protein parts are then assembled to form new viruses
5) Lysis and Release: the host cell then breaks open, and the viruses are now able to infect other cells

Lysogenic Cycle:
1) Adsorption: the virus attaches to the surface of the host cell
2) Entry
3) Integration: the virus inserts its DNA into the host cell's genome, forming a provirus
4) At this point, whenever the virus undergoes mitosis, the provirus would be replicated as well
5) Spontaneous induction: at some point, the provirus would break out of the host chromosome
6) In each of the infected cells, 3) 4) 5) from the lytic cycle would occur

Advantages/ Disadvantages:
- Lytic cycle is fast is slow, whereas lysogenic is slow
- With the lysogenic cycle, a virus can reproduce more offspring, since the viral DNA is passed onto future generations of the host cell

Beware of Email Filters

My economics teacher likes to use online resources for her course, and this means that she often has us go onto her blogs to post our assignments or do online discussions.

Recently, she created a new blog for us to post our assignments, and told us that she had sent invitations to the blog to all of us. However, when I got home, I couldn't find her invitation email anywhere— including the spam box— so I sent an email to her, asking her to resend the invitation.

Then, after two days, I still didn't get her reply— which was strange, considering that she usually checks her email every day. So I sent another email to her, asking her to just add my username to her blog.

Ten minutes after, I somehow noticed that I have an email folder named "BG," where all emails containing the word "blog" would be redirected to. And guess what? The two emails from my teacher— as well as 7-8 other emails that I mysteriously didn't receive a few months/years ago— were all there.

So I have learned my lesson— never use email filters, for they can cause a lot of trouble. I now recall from grade 10 that there was once when my classmate couldn't get any email from me and we had to create a shared email account so that we could send each other our information on a history project. And the culprit of the inconvenience was, obviously, email filters. This, along with what my email filter has done to me, clearly proves that email filters are evil and disastrous.

Stapler- My New Friend

Until grade 11 semester 2, I have never really used my stapler. Not only did school not require a lot of stapling, I also did all the stapling at school whenever I actually needed to. 

However, everything is changed. Now, everyday I have to use the stapler twice or thrice. To staple my math notes/printouts, my data management homework, and my economics handouts. And there hasn't been a day in a past week when I didn't use my stapler.

So, in a way, the stapler has become my new friend. I now become attached to it, feeling anxious whenever I don't see it around. =D

Looking Back at Grade 11 Mathematics (Functions)

I don't really have much to say about this course, since there was nothing particularly memorable to me; I moved through the course rather effortlessly. Did pretty well (98), but worse than grade 10 (100).

However, this is not to say that this course was unimportant. Many concepts introduced in this course are actually ones that frequently appear on contests or ones that just come up a lot when solving math questions. For example, trigonometry with radians and geometric and arithmetic series are all things that one must know.

Also, it was through this course that I realized my greatest problem: I often misread the questions. On five out of eight tests, I misread the question somehow, and as a result got 2-4% lower (per test) than I could have gotten. This obviously served as an important lesson to me, and I now make sure that I underline the key information in each question so that I don't make any mistakes.

Looking Back at Grade 12 Chemistry

When I took grade 11 chemistry in grade 10, I got a high mark with a relatively small amount of effort. As a result, I grew a bit overconfident and thought that, hey, grade 12 chemistry would probably be just as easy as the grade 11 course!

Unfortunately, I was wrong. Grade 12 chemistry was — though not by a lot— more difficult than grade 11 chemistry. We received labs which we had to hand in on the day of the experiments, there were more theory-based questions on tests (as opposed to calculation-based questions), and the teacher just seemed to mark harder. For example, for the communication questions on the tests, I would lose 0.5 to 1 mark no matter how much detail I tried to provide.

Anyway, I didn't really study hard until after the second test, when I realized that my mark for the course was a meager 93. But even after that, I didn't work that hard; I rarely did any of my daily homework, since I thought the questions were all very similar anyway. And in retrospect, this lack of practice was probably what caused me to make so many careless mistakes on the tests.