Wednesday, December 3, 2014
Sunday, November 2, 2014
Multiple Choice Question
China’s One Child Policy (each couple can only have one child) is secretly enforced by forced abortions. Late-term pregnant women are dragged kicking and screaming into filthy clinics, strapped down to a bed, induced to undergo labor, and forced to pay for the removal of the fetus’ carcass (or it is left next to her for her to discard). And no, local government officials do not provide grief counseling to these women – that is a privilege, not a right.
Learn more at Women’s Rights Without Frontiers, which was founded by Reggie Littlejohn, JD.
“It doesn’t matter whether you’re pro-life or pro-choice. Forced abortion is not a choice.”
-Reggie Littlejohn, JD
Some women die during these forced abortions. These events can be very violent and prolonged, during which the victim experiences physical and mental abuses. One cause of death in women who are not physically beaten may be because of acute acidosis, which is the drop in pH of the blood. Severe results of acute acidosis include coma, delirium, and tremors. Which of the following are reasons behind acute acidosis?
a. Being strapped down on her back for a prolonged period caused the fetus to squish the mother’s inferior vena cava against her spine, preventing deoxygenated blood from returning to the heart. (The inferior vena cava is the main vein that brings blood from the lower body back to the heart.)
b. An overdose of anesthesia impairs ventilation. The caregivers, if they can be called that, may not be properly trained.
c. Physical trauma to the head can impair ventilation.
d. All of the above.
Sunday, October 19, 2014
Ebola and Infection - Multiple Choice Question
The spread of ebola occurs through physical contact during which bodily fluids from the infected patient is transferred to the mucus membranes or skin lesions (breaks/tears) of another person. Nina Pham and Amber Vinson, the two nurses in Texas who were infected because they treated Thomas Eric Duncan, were infected even though there was no report of obvious unprotected physical contact between them and the patient. How might have this infection occurred?
(a) Bodily fluids such as saliva can become aerosols through coughing and sneezing. The microscopic aerosol particles cannot be seen with the naked eye, but persist on table surfaces, door knobs, arm rests, etc. The nurses touched these surfaces and then touched their faces, rubbed their eyes, or combed their hair (scraped their scalp) with their hands.
(b) The skin has many microscopic lesions (breaks/tears) due to day-to-day activities. A chip in your fingernail can cause a tear in the skin of your arms, face, etc. These lesions can become ebola's entry way. This is why it is important for healthcare providers who treat ebola patients to have protective gear that fully covers their entire body.
(c) When liquids (urine, diarrhea, blood, etc.) splash, they often produce aerosol particles. This is why when men urinate while standing, urine still gets outside the toilet even if the men did not miss the bowl. If you've had to clean toilets that were frequently used by men, you will know what I'm talking about.
(d) The nurses washed their hands (even though they wore gloves while treating the patient; standard procedure), but did not wash their wrists/forearms or face with soap and water.
(e) Something along the lines of all of the above.
Note: This question was written without full knowledge of the details of what happened at the hospital where the infections occurred.
Here is an article about dealing with ebola, written by a healthcare provider who has haz-mat (hazardous materials) training.
Abby Norman. “I'm a Hazmat-Trained Hospital Worker: Here's What No One Is Telling You About Ebola.” Huffington Post Blog. Posted: 10/17/2014 10:18 am EDT Updated: 10/18/2014 12:59 pm EDT
Saturday, July 19, 2014
Learning Biology is Like Learning a New Language
Biology may not be the most abstract and difficult science to understand, but it is the most complicated of the sciences to figure out. It's complexity becomes most apparent at the level of solving societal problems in healthcare and/or the environment. However, it's complexity can already be encountered by students early on in their schooling. If the sciences (i.e. math, chemistry, physics, psychology, etc.) are analogous to foreign languages, then biology has the largest alphabet and largest vocabulary among the sciences. So, learning biology is like learning a new language. You start with the alphabet, then build up a store of words, and then learn to put those words together according to grammatical rules -- the highest level of biology is like writing poetry and novels. Just like learning a new language, learning biology requires memorization, repetition, regular usage, and application.
The Four Main Challenges in Learning Biology
There are four main challenges that students face when they encounter biology.
Challenge 1. Remembering the vast vocabulary.
Challenge 2. Understanding the concepts behind how life forms work from the molecular level to the environmental level.
Challenge 3. Understanding the scientific process of how to learn by experimentation. Living things, and the stuff that makes them up, behave in ways that are more complicated (less predictable) than inanimate objects or materials.
Challenge 4. Putting 1, 2, and 3 together to make new discoveries or to gain deeper insights.
High school biology emphasizes 1 and 2, with a little bit of 3.
Undergraduate biology emphasizes 1 to 3, but with more intensity.
Graduate biology trains people to do 4, for which 1 to 3 are prerequisites.
Tips for Studying
The following tips have been very useful in my teaching of biology at all levels. My job as a teacher is to make remembering the vocabulary easier (Challenge 1), so that students can spend more energy on understanding the concepts of how things fit together (Challenge 2). Details are easily forgotten, since there are so many of them, and can be looked-up in a reference book or study. Concepts are the most important, since they can be applied to different situations, including those outside of "science*."
1. Mnemonics. These will help you organize and memorize complex things relatively quickly, saving your energy for understanding concepts.
2. Active note taking in class. Taking notes by writing and drawing (not typing) has been shown to increase retention. This is probably because the act of writing activates "motor memory," which helps you remember things better because you did them.
3. Review notes daily, even if for only 20 minutes per day.
4. Ask yourself questions about the subject while you're listening to a lecture, doing an experiment, or reading a book. Seek the answers to these questions from fellow classmates, the instructor, books, or the internet. This is part of "active learning."
5. Talk to your instructor during office hours. Bring questions about things that were unclear.
6. Write your own questions while you're learning. Being able to write good multiple choice questions or short-essay questions is GREAT preparation for tests AND helps you understand the material better. This is a skill that will improve with practice over time. Do this throughout the course, while reading, while reviewing notes, and while listening to the instructor.
7. Learn the teacher's testing style. Different teachers like to ask different types of questions. Ask the teacher to give some sample questions during the lecture, so you get a flavor of how the teacher likes to write tests. This will guide your studying strategy.
*I put the word science in quotation marks because science is both a subject of knowledge and a way of thinking. As a way of thinking, of course it applies to subject areas that are not considered science subjects.
Last updated on 10/19/14
Friday, February 28, 2014
A water molecule is like a weak magnet that momentarily attaches to other water molecules. This process of continuous momentary attractions is what makes cohesion possible. A water molecule is made of one big oxygen atom that holds onto two smaller hydrogen atoms -- shaped like an L. The oxygen atom gives the corner the L a slightly negative electrical charge, while the hydrogen atoms at the tips have slightly positive charges. These charges give each water molecule a mini-magnet-like quality.
Cohesion and Adhesion
Cohesion is defined as the attraction of water molecules to other water molecules. This is in contrast to adhesion, which is the attraction of water molecules to a solid surface. Cohesion is done by water molecules that are in the middle of a drop or body of water. Adhesion is done by water molecules that are at the outer edges of a volume of water. In trees, cohesion and adhesion work together to move water that is absorbed in the roots all the way up to the leaves. Adhesion and cohesion allows water to climb up the narrow water tunnels that are inside of plants.
Water has bent shape, like a boomerang. The oxygen atom sits between two hydrogen atoms and forms the corner of the boomerang. Cohesion is possible because water has what is called a polar nature, meaning it has a north pole and a south pole. As previously described, these poles give water a magnet-like property. But why does water behave like a magnet? It is because of a chemical principle called electronegativity. Electronegativity is the ability of an atom to attract electrons towards it. Atoms are made of particles called protons, neutrons and electrons. Protons and neutrons cluster at the center of an atom and give the atom its weight. Electrons barely weigh anything and float around in a cloud around the protons and neutrons. Protons have positive electrical charges while electrons have negative electrical charges. The attraction between them is what keeps the electrons from floating away. Water has poles because the oxygen atom is more electronegative than the hydrogen atoms. Oxygen is bigger and has more positive protons, so it pulls the shared electrons closer to it.
Electronegativity is what allows a water molecule to have north and south poles, but hydrogen bonding is what makes cohesion possible. Hydrogen bonding describes the interactions between two or more water molecules. The rule of electrostatic attraction is that opposite charges attract each other. Since a cup of water contains many water molecules floating inside of it, the slightly negative oxygen atoms of water are constantly bumping into and momentarily attaching to the slightly positive hydrogen atoms of other water molecules. When two oxygen atoms run into each other they move away because of their similar slightly negative charge. The same goes for two hydrogen atoms from different molecules that bump into each other.
Ever wonder why a drop of water on a table looks like sphere? Water can do that because of cohesion at the surface of the droplet. The water molecules are constantly hydrogen bonding with each other within the droplet. However, the molecules in the middle of the droplet are busier than the molecules at the surface. This is because the molecules in the middle are being pulled from all sides, while the molecules at the surface are exposed to air on one side and only need to deal with other water molecules on their other side. Each water molecule has a certain amount of strength to pull on its neighbors. Since the molecules at the surface have less neighbors to pull on, their strength is divided among fewer neighbors. This means they can pull harder on their fewer neighbors, resulting in an extra tight packing of water molecules at the surface of the droplet.
Monday, January 27, 2014
This is the first installment of the answer to the question (or complaint!), "Why must there be so much memorization in biology?" [The second installment of the answer can be found in the post entitled "How should I study for biology?"]
A Funny Analogy - American Football
Biology studies living organisms (or living organisms that have died). Living organisms happen to be very (VERY) complicated things. Here is a male-centric, modern-day American analogy: American football (sorry, gals). A football game is played by two teams, each with 11 players on the field. There are many rules in the game of football. With anything that has many moving parts and rules to govern those movements, understanding that thing is aided by names and definitions. When a football player breaks a rule, the referee will stop the game and describe the violation. "Personal foul on the offense. Number 17. Ten yard penalty." This means that player number 17 on the team that has possession of the ball made an illegal move against his opponent. If the game of football did not have an established definition for the terms, "personal foul," "offense," and "number (referring to the number on the player's jersey)," then the referee might have to say something like the following. "The guy who's 6 ft. 2 in., with three tattoos on his arm, who is on the team that is standing near the fans who are drinking coke. Yeah, that guy. He was unnecessarily aggressive against the other team. I will penalize his team by making them move 10 yards away from their goal." Now, compare that to: "Personal foul on the offense. Number 17. Ten yard penalty."
To work off of this football analogy, studying a biological life form or process is like trying to understand a game of football where there are 100 players on each team, four balls, four end zones in which to score points, 50 conditions under which certain rules of football do not apply, and another 50 conditions under which players switch teams for a few minutes. Mind boggling isn't it? Which is why learning biology takes effort and the right strategy. I will describe that strategy in another post.
Category: Science Lessons