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Wednesday, March 21, 2012

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

Sunday, March 18, 2012

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.

Thursday, March 15, 2012

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.

Wednesday, March 14, 2012

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.

Friday, March 9, 2012

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.

Thursday, March 8, 2012

The Midwich Cuckoos by John Wyndham


Just like two of the other novels by the same author, The Day of the Triffids and The ChrysalidsThe 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

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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.

Wednesday, March 7, 2012

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.

Sunday, March 4, 2012

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.