Wednesday, March 25, 2015

Should high school and undergraduate students do internships in STEM?

Research internships for high school or undergraduate students can be an invaluable source of experience that will help propel the students further into or away from STEM (science, technology, engineering, and math). At the least, the student will get an idea of whether STEM is something that they want to continue pursuing and in what way. Laboratory research is not for everyone, so knowing this for yourself is an important step in finding your way into a STEM career or out of it. There is more to STEM than laboratory research. 

STEM careers are often presented as the answer to all of society's problems, but that is certainly not the case. Having worked with lawyers, teachers, social commentators, journalists, and community activists on various matters of society and justice, I have a deep appreciation for people who have skill sets that are derived from professions that are not in STEM. How many presidents and international ambassadors who prevented nuclear war had a career in STEM?

My own career in STEM began with internships at the University of Southern California (USC) Keck School of Medicine. The high school that I attended had a class that required you to volunteer in a STEM laboratory. I did an internship in the laboratory of Dr. Sue A. Ingles, Ph.D., and then that of Dr. Suraiya Rasheed, Ph.D. In both cases, I learned a lot about science, the process of science, laboratory research, how boring it could be, how exciting it could be, and what it takes to become a scientist. 

Aside from learning the "how to's" of science, an internship exposes you to great thinkers who provide valuable advice, future career connections, and funny stories to tell. During an internship, you may be able to hear different scientists within the department present their work. You learn about their passion -- and their complaints. You realize that there are many types of jobs within STEM fields, so you get a better idea of which ones you want to pursue. 

One of the highlights of my time at USC was the interaction that my fellow interns and I had with researchers outside of the laboratory. Several times a week, we ran into Dr. Samuel Bessman, M.D., and his colleagues in the lunch room. Dr. Bessman invented the first artificial pancreas and his license plate was the word "INSULIN." He was quite a character. "What do you want to be IF you grew up?" he would ask each new intern that he met. He would then explain that while he was growing up, there was a good chance of being drafted into World War II. So back then, he and his friends weren't sure that they would live to pursue a career. Dr. Bessman would ask us questions about our research, explain to us what we didn't understand, and encourage us to learn more. He would tell us about his fencing days in college, the poetry class that he taught at the medical school, and give a history lesson from time to time. He struck me as someone who spent a lot of time thinking about life, perhaps because he was also a poet. In many ways, those lunches with "Sam" would shape the kind of scholar that I would seek to become. What the interns appreciated most was that he treated us not as clueless high school students, but as people who would one day become bona fide scientists. He didn't have to do that, but he did. And it has shaped how I seek to mentor students today.

So, there is more to learn from an internship in STEM than just knowledge about a subject. 

Wednesday, December 3, 2014

When do good evidence and sound arguments fail?

In my teaching of science to high school and college students, I emphasize the need to have good evidence and sound arguments. However, at some point I also need to teach them that ultimately not everyone cares about these things. Those who oppress people don't care about evidence and arguments, but the oppressors will use such things to exploit people. Thus, the primary role of knowing good evidence and sound arguments isn't about changing the mind of the oppressor, but is about protecting yourself from oppressive tactics. Oppressors who have already made up their minds won't be swayed by evidence and argumentation, but that doesn't mean that they won’t be brought to justice or be disarmed by these tools.

People have the uncanny ability to deceive themselves, along with each other. This is why we say that people are "in denial" about their circumstances. As a human rights advocate, scientist, and science teacher, I know the importance of having good data and sound arguments in promoting the rights of exploited people. Good research papers can make a societal problem concrete, forcing opponents to face the facts – denial that the problem exists is a way of stalling progress. Good data can change policies and bring forth much needed funding from governments or private sources. But good data isn't enough. As the saying goes, "Statistics don't lie, but liars use statistics." Therefore, good data needs the help of sound arguments that correctly apply the data and to counter the misuse of good data. 


This article was originally published as part of my editorial for Cancer InCytes magazine: Volume 3, Issue 2, Winter 2014. URL: http://www.cancerincytes.org/#!when-do-good-evidence-and-sound-argument/c1v54

Sunday, November 2, 2014

Ventilation (Breathing), Blood pH, and Death by Forced Abortion

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.

----
Answer: d






Sunday, October 19, 2014

Ebola - How did the two nurses get infected?

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.

Answer: e

-------
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

How should I study for biology?

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

How Does the Chemical Structure of Water Explain Cohesion?

Introduction

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.

Electronegativity

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.

Hydrogen Bonding

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.

Surface Tension

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.


References


Monday, January 27, 2014

Why Must There Be So Much Memorization In Biology?

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

Saturday, December 28, 2013

Which Sub-Field of Biology Is The Best? (Does It Really Matter?)

Whenever you hear a question in the form of which so-and-so of so-and-so is the best, be prepared to see that the question may be misguided (sometimes it isn't). There is room for debating whether one Olympic sport, such as track & field, is better or harder than another sport, such as swimming -- Carl Lewis or Michael Phelps? These questions can be fun and very informative. I think they are best understood in the context of companion questions, such as "How do we define best?" and "What is the big picture purpose of this 'best'?" Allow me to illustrate.

The field of biology includes many sub-fields. Broadly defined, biology is the study of life or of stuff that interacts with living things. It ranges from sub-fields that study very small things, such as biochemistry and biophysics, to very large things such as psychology and ecology. There is an unspoken pecking order within the fields of biology, likely due to the amount of abstract thinking that is required in that field. Why is it unspoken? Because people usually don't claim such things to be absolutely true, but I have heard many scientists talk about this "pecking order" based on their experience as professionals. At the top of the biology totem pole is biochemistry, and at the bottom would be something like psychology, which some call a "soft science." The irony is that many of the biochemists are so stressed that they need to see psychologists and psychiatrists just to be functional people. Then there is the field of public health. If the goal of biology -- or medical science, to be exact -- is to save lives, then public health researchers have probably saved more lives than all the sub-fields of biology put together. "Who ya gonna call after a disastrous typhoon? Ghost Busters?"

Take-away point #1. If you're deciding which field of biology to study, don't bother yourself too much with which one is the best. Find the one that interests you, that you enjoy, and that you can be good at with some effort. Leave the bickering and posturing for jokes among friends. 

Take-away point #2. Becoming an effective leader -- in business, science, whatever -- requires the ability to respect everyone on the team or in the company. People who do this well are those who get promoted -- I know, because I vote for those type of people. Being ruthless and selfish will get you to the top faster, but being generous and respectful is what keeps you there (or at least helps you sleep better and decreases your risk of unhealthy addictions). I've worked in retail companies, IT companies, educational companies, university laboratories, and national laboratories. I see this again and again... But here are some other interesting questions. Where is this top? And what is success?

Category: Lessons From Science

   

Tuesday, December 17, 2013

Science Must Learn From The Humanities

The other day I was teaching about the cell cycle and mitosis, when a colleague of mine who teaches history walked in and saw the whiteboard. "Wow, this is so technical," he said, "I just teach history." Assuming that he thought that history was less important than biology, I seized the moment and reminded him of the crucial role of historians. Scientists create technologies that improve life, but historians remind scientists not to destroy the world with that technology -- we call them "whistle blowers." 

The scary thing is that history repeats itself. Nuclear energy is great, but then we now have nuclear weapons. Biotechnology is great, but now we have exquisitely refined chemical and biological warfare. Chemical engineering is great for extracting oil and natural gas from the ground, but unregulated hydrofracking pollutes the environment and causes cancer (1) in those who live nearby. You see, science is just a tool. How humans use science is what makes it great or terrible.  

My recent editorial (2) for Cancer InCytes magazine discusses some lessons we learned from reading the historical accounts of a Nazi concentration camp during World War II. These concentration camps not only killed millions of people, they were places where cruel and unethical medical experiments were done on prisoners (3). 

As a science teacher, it's my job to help my students understand science and to move along the course -- if they so choose later on -- of becoming a scientist. If they don't learn to respect the value of the humanities (i.e. literature, history, sociology, etc.), then they risk becoming scientists who wield science in a very destructive way. 


References

[1] Karen J. Miller. PREVENTION IS THE CURE. Cancer InCytes 2012, 2(1):e.

[2] David H. Nguyen. CAN MORALITY BE LEGISLATED? Cancer InCytes 2013, 2(2):e. 

[3] Methodist Hospital, Houston (2012, December 6). Survivor of Nazi 'twin experiments' talks to doctors about human subjects research. 
http://cancerincytes.blogspot.com/2013/02/survivor-of-nazi-twin-experiments-talks.html


Category: Lessons From Science


Friday, December 6, 2013

Tips for Transferring Small Volumes in PCR (or Other) Experiments

This article is for those who are learning how to do PCR. Other articles that describe PCR are in the "Further Reading" section after the text. 

PCR stands for Polymerase Chain Reaction, a technique in biomedical research that is used to make copies of a certain length of DNA. 

PCR, reverse-transcription PCR (RT-PCR), and quantiative PCR (qPCR; qRT-PCR) involve handling sub-microliter volumes of liquids that need to be mixed.  One major source of experimental error is when people re-use one pipette tip for aliquot-ing small volumes of the same reagent, thinking that as long as they avoid contamination with the other reagents their experiment will be fine.  What they don’t realize is that the volume increases with each use of a micropipette tip. Thus, they will see trends in their replicates that should not be there, or the readings between replicates will be very sporadic.  The optimal way to do it is to use a new tip every time.  Also, to minimize user-introduced trends in the data, they should not aliquot a reagent into all replicates for treatment group A, and then to treatment group B.  There is no way to completely get rid of user imprecision, so one way around this is to aliquot sample A1, then B1; A2, then B2; A3, then B3, etc. (See Figure 1). These suggestions would apply to other assays that require distribution of small volumes from the same source. 

Figure 1














Further Reading


Excerpt from "What You Need to Know About the International Test Scores"

What You Need to Know About the International Test Scores
Huffington Post,12/03/2013 3:24 pm

By Diana Ravitch, Historian, NYU Professor

The myth persists that once our nation led the world on international tests, but we have fallen from that exalted position in recent years. 
Wrong, wrong, wrong.
The U.S. has never been first in the world, nor even near the top, on international tests.

In my recent book, Reign of Error, I quote extensively from a brilliant article by Keith Baker, called "Are International Tests Worth Anything?," which was published by Phi Delta Kappan in October 2007. Baker, who worked for many years as a researcher at the U.S. Department of Education, had the ingenious idea to investigate what happened to the 12 nations that took the First International Mathematics test in 1964. He looked at the per capita gross domestic product of those nations and found that "the higher a nation's test score 40 years ago, the worse its economic performance on this measure of national wealth-the opposite of what the Chicken Littles raising the alarm over the poor test scores of U.S. children claimed would happen." He found no relationship between a nation's economic productivity and its test scores. Nor did the test scores bear any relationship to quality of life or democratic institutions. And when it came to creativity, the U.S. "clobbered the world," with more patents per million people than any other nation.
Baker wrote that a certain level of educational achievement may be "a platform for launching national success, but once that platform is reached, other factors become more important than further gains in test scores. Indeed, once the platform is reached, it may be bad policy to pursue further gains in test scores because focusing on the scores diverts attention, effort, and resources away from other factors that are more important determinants of national success." What has mattered most for the economic, cultural, and technological success of the U.S., he says, is a certain "spirit," which he defines as "ambition, inquisitiveness, independence, and perhaps most important, the absence of a fixation on testing and test scores." 
Baker's conclusion was that "standings in the league tables of international tests are worthless."


Tuesday, December 3, 2013

Excerpt from "Policy: Twenty tips for interpreting scientific claims"

This article by Sutherland, Spiegelhalter, and Burgman in the journal Nature is great for understanding the limitations of science and the importance of knowing how to interpret science.

-------------------

Policy: Twenty tips for interpreting scientific claims
William J. Sutherland, David Spiegelhalter & Mark Burgman
Nature, 20 November 2013



And there is rarely, if ever, a beautifully designed double-blind, randomized, replicated, controlled experiment with a large sample size and unambiguous conclusion that tackles the exact policy issue.

In this context, we suggest that the immediate priority is to improve policy-makers' understanding of the imperfect nature of science. The essential skills are to be able to intelligently interrogate experts and advisers, and to understand the quality, limitations and biases of evidence. We term these interpretive scientific skills. These skills are more accessible than those required to understand the fundamental science itself, and can form part of the broad skill set of most politicians.

Politicians with a healthy scepticism of scientific advocates might simply prefer to arm themselves with this critical set of knowledge.

We are not so naive as to believe that improved policy decisions will automatically follow. We are fully aware that scientific judgement itself is value-laden, and that bias and context are integral to how data are collected and interpreted. What we offer is a simple list of ideas that could help decision-makers to parse how evidence can contribute to a decision, and potentially to avoid undue influence by those with vested interests. The harder part - the social acceptability of different policies - remains in the hands of politicians and the broader political process.


The 20 SSB Tips (Sutherland-Spiegelhalter-Burgman)
1. Differences and chance cause variation.
2. No measurement is exact.
3. Bias is rife.
4. Bigger is usually better for sample size. 
5. Correlation does not imply causation.
6. Regression to the mean can mislead. 
7. Extrapolating beyond the data is risky.
8. Beware the base-rate fallacy.
9. Controls are important.
10. Randomization avoids bias.
11. Seek replication, not pseudoreplication.
12. Scientists are human.
13. Significance is significant.
14. Separate no effect from non-significance.
15. Effect size matters.
16. Study relevance limits generalizations.
17. Feelings influence risk perception. 
18. Dependencies change the risks.
19. Data can be dredged or cherry picked.
20. Extreme measurements may mislead.


Friday, November 22, 2013

Why Study Biology?

This is the introduction to a high school Advanced Placement Biology course that I taught. It's short, but dense. Each part of each sentence can be unpacked into entire articles, which I will do over time as I generate more mini-lessons. As you will see, much biology and science can be learned by unpacking the parts of each statement and seeing how all parts are ultimately united as one.


"Put on your seat belts! We will be embarking on a wild ride through AP Biology. Biology is becoming an ever more important subject of study. As the other sciences progress, we find that new technologies can interact with life forms and environments in unintended ways. Thus, because of things like disease, environmental protection, and the need for renewable energy, the science of biology must also progress just as fast. Building a fuel-efficient space ship is one thing, but the viable mass migration of sentient, carbon-based life forms across the solar system is a whole different ball game. Welcome to biology."  


Category: Biology Lessons