Tuesday, September 30, 2014

We <3 Students!

Lu Loves Organic Chemistry

As September draws to a close, I’m inspired to reflect on the past month of working in Austin and how fortunate I have been.

Some of you may recall that my partner Paul and I relocated to Austin in August 2014.  We moved without “real jobs.”  Instead, our intention was to tutor full-time and make a living as freelancers.  We didn’t know how that plan would play out in the real marketplace; we just hoped that enough students would find us to make our lifestyle viable.

Paul and I had different ideas for our businesses.  Paul wanted to move his tutoring on-line so that he could continue to work with Texas A&M University students.  I planned to do a combination of in-person and on-line tutoring, working with students in the medium that worked best for them.  But regardless of the form, we were hoping for the best but preparing for the worst.  In my mind, the worst-case scenario was that we found no work in Austin and simply lived off of savings and/or credit cards while we hustled to find work.  I am happy to report that the results from our first month have been very, very good.

We know how much work we need in order to pay our bills.  To really make a freelance lifestyle work, you’ve got to be specific about your work and money goals.  To that end, it helps tremendously that Paul and I keep track of our spending.  We know exactly where our money goes.  That lets us see what we really value and how it fits into our vision of life.  (Wanna know what we love?  Food and our hydroponic garden are at the top of our list these days.)

In my first month of full-time tutoring, I’ve come really close to hitting my goal for weekly tutoring hours.  To be honest, this news comes as a delightful surprise to me.  I’m honored and humbled that so many of you have chosen to work with me, that you trust me to do this important work with you.  I’m inspired by your dedication to learning, to doing your best in challenging courses, to bouncing back after disappointing grades come back.  Being a student is hard work.  It’s my pleasure to join you on this journey, whether it’s for an hour or two or an entire semester of weekly tutoring sessions.

Thank you for everything, dear students.  I’m looking forward to the rest of the fall 2014 semester and continuing to do my best to help you do your best.  We <3 students, and we hope it shows.

Friday, September 19, 2014

The Learning Never Stops

“Lifelong learning” is a phrase you’ll hear educators say over and over again.  If you’ve been in school since the time you were five or six years old and have yet to live and work as a non-student, then the meaning of “lifelong learning” might be lost on you.  “Of course I’ve been a lifelong learner,” you say to yourself.  “I’ve been in school forever, and my job has been to learn.”

I too have spent most of my life in school, but this year I finally left academia to work as a private tutor.  I’m a freelancer now, which comes with a tremendous amount of freedom and no small amount of fear.  The most exciting thing about all this freedom is the near-constant opportunity to learn new things.  I thought I’d share some of those things with you, both as an illustration of lifelong learning as well as to document for myself how far I’ve come.

* My partner Tutor Paul developed our on-line tutoring platform earlier this year.  Paul is an engineer, which means that developing and utilizing technology is his bread and butter.  I am a biologist who does not have a natural affinity for new technology.  I’ve had to learn how to use the platform and get comfortable with the equipment set-up for on-line tutoring.  At this point, I think I’m mostly over the learning curve and have a much better handle on how to use the equipment.

* I have taught myself the course content for Texas A&M University’s Genetics 301 class.  Fun fact: I never took genetics as an undergrad.  Really, I wasn’t even interested in genetics until graduate school, when I learned how powerful it is.  So I arrived at genetics a bit older than my students, but I love teaching it.  My hope is to be one of the best genetics tutors in Austin.  It’s my favorite tutoring subject and it dovetails so nicely with molecular biology.

* I have been relearning general chemistry.  Gen chem is different now than it was when I took it.  That might be a function of my undergrad chemistry department; my professor friend tells me that their goal is to get students into organic chemistry after one semester of gen chem.  My reintroduction to general chemistry has given me new insights into the universe, new chances to experience wonder.  For example, now I better understand emission spectra and the idea of the electron as both a wave and a particle (just like light!).

* Finally, the most important thing I’ve had to learn is how to be in business for myself.  I’ve been really fortunate to have mentors who believed I could do it, who offered their insights and advice, who didn’t think I was crazy for wanting to be self-employed.  Without Paul and Jeremy, I don’t think I would have been brave enough to make the leap to full-time tutoring.  

* * *
What have you learned lately?

Friday, September 12, 2014

On-Line Genetics Tutoring, Sundays 3-4 PM

Hey, hey!

Starting this Sunday, September 14 from 3-4 PM, I’ll be holding an on-line group tutoring session for genetics students.  Right now, my sessions will be geared toward Texas A&M University Genetics 301 students because I’ve worked with those students, and I know they can benefit from my services.  But if you are taking a genetics class from a different university, you are welcome too!  I’ll answer student questions on a first-come, first-serve basis.

The cost of the session is $20 per person, and you can pay easily through PayPal or Venmo.  This is a great opportunity to work with a professional tutor and experience on-line tutoring, where you can get the help you want without leaving the house.

Here’s how it works:

* You’ll need a Google+ account and the Google Hang-outs plug-in, which you can find here.

* You’ll need a good internet connection and the ability to see video and hear audio.

* Connect with me on Google+ by finding me (Rose-Anne Meissner) and adding me to a circle.  Send me a message on Google+ to tell me you’re interested in the group session, and I’ll add you to the Hang-out.  Or send me a text message to tell me you are interested: 847-644-0782.

* You’ll be able to see me, hear me, and see me working on a virtual whiteboard.  I can e-mail anyone a copy of the session notes after we wrap up.

* Ask me questions and learn some genetics!

* Pay before or after the session.  But either way, please pay.  The only way I’m able to do this work is if students honor their end of the bargain.

Want to learn more about on-line tutoring?  Watch this video from my partner, Tutor Paul.

* * *

A word about payment:

“What if I don’t pay you for the group session?”

I can already hear some students thinking this question, cynical as it may sound.  A few encounters with no-pays does make a tutor weary.

First of all, if you are truly strapped for cash but want to attend the group session, contact me first.

But if you simply don’t pay, you won’t be invited back to the next session.  And if most students don’t pay, I’ll stop offering a group session.  I’m still available for group tutoring, but my normal group rate is much higher ($30/person) than the special Sunday session.

* * *

Happy learning!  I hope to see you on Hang-outs on Sunday.

 

Saturday, September 6, 2014

Already feeling overwhelmed by your semester?

Hey, guys!  This post is not a marketing pitch, I promise.  I just wanted to share another quote with you as we start to dive deep into the fall semester.  If you are already feeling overwhelmed by your semester (and if you are, I feel you, because that was always me in college), remember this:

“Obstacles are things a person sees when he takes his eyes off his goal.” ~E. Joseph Cossman

Also, how about a visual reminder about perseverance?

We All Get Hungry Sometimes

You’re welcome.  Now get back to studying.

Thursday, September 4, 2014

LESSON: Selection Pressure, Part Two

In this lesson, we’re going to pick up where my last lesson on selection pressure left off.  Here’s the link to the first lesson if you’d like to familiarize yourself with that first.

Today’s lesson focuses on how selection pressure changes allele frequencies over many generations.  Our sample problem is a follow-up to the scenario in my first lesson:

Despite your good work in Capitol City last time, the strange epidemic persisted and all individuals who lack Factor G are now sterile.  Individuals who lack Factor G are genotype gg; individuals who produce Factor G are GG or Gg and have normal levels of fertility.  How many generations will pass until the recessive g allele has a frequency of less than 1%?

In my last lesson, we figured out that when gg individuals cannot reproduce, the frequency of g drops from 0.3 in the parent population to 0.231 in the first generation after selection.  The simple formula for figuring out g’ if gg individuals are not reproducing is g’ = g/(1+g).

Here, g’ refers to the frequency of g in the next generation.  (And if you want to see the derivation of that simple formula, see my last lesson.)

If we do the math, we see that after one generation of selection, g decreased by 23%:

Slide 1 cropped

So how do we find the generation at which allele g is less than 1%?

Before we jump to those calculations, let’s consider what these numbers really mean.  After the first round of selection, the frequency of g is 23.1% or 0.231.  This number includes the individuals who are gg, even though they are sterile.  Why is that?  Because when Gg heterozygotes mate, their children will be:

1 GG: 2 Gg: 1 gg

The fact that Gg individuals have normal fertility means that there will be gg children, even though those children are not able to reproduce.

Also, let’s consider the number of Gg heterozygotes in the population after one round of selection pressure.  Again, the frequency of g is 0.231.  The number of Gg hets = 2pq.

2pq = 2(0.769)(0.231) = 0.355 or 35.5%

35% of the population here is Gg, which means that g is being propagated by about a third of the population (a substantial fraction!).

Let’s move on to the calculations to determine when the frequency of g will be less than 1%.

I doubt that you’d be asked to solve a problem like this on an exam without being able to use Excel or a similar program.  The calculations are easy on a spreadsheet but very tedious to do by hand.  I used Excel to solve this problem.  Here’s what my spreadsheet looked like to set up the calculations:

Slide 2

Here are the entries I put into Excel to set up this spreadsheet: 

Cell B1: 0.3 (original value of g before selection)

Cell B6: =B1/(1+B1)

(this is the calculation for g after each round of selection: g’ = g/(1+g))

Cell B7: =B6/(1+B6)

Cells B8-B14: Copy/Paste from cell B7 down to B14.

From the image above, you can see that after 9 rounds of selection (Row 14), the frequency of g is 0.081 or 8.1%.  So we’re not done, and we can continue our calculations by copy/pasting Cells A14 and B14 until we reach…

Slide 3

…Cell 102!

We’re looking for the generation at which q drops below 0.01, which happens to occur at the 97th generation of selective pressure.  What’s so interesting to me as a geneticist is that g (or q, in Hardy-Weinberg terms) can persist for so long when gg individuals are sterile.  This example illustrates why recessive deleterious alleles are not easily eliminated from the population.  As long as Gg heterozygotes are healthy, then g will be in the allele pool for a long time.

So that was a lesson on selective pressure and Microsoft Excel techniques.  Got questions, comments, or something else to say?  Tell me in the comments below! 

Thanks for reading!

A Little Something Inspirational

As your new semester gets underway, remember that…

“Education is not filling a bucket, but lighting a fire.” ~William Yates

Happy learning to you!

Tuesday, September 2, 2014

A Personal Post

Found Heart

Today, as I write this post, my dad is in an operating room, where his team is working to save his life.

Dad is a rather private person (unlike me, who has three blogs and writes about her personal life on a regular basis), so I’m not going to share any details about his illness.  Instead, I want to talk about cynicism, service, and the meaning of one person’s life.

I’ve been working in the biomedical sciences for eleven years now—six years in grad school, another four-ish doing research, and less than a year of tutoring biology and chemistry students.  I often feel a sense of cynicism from my colleagues about premedical students and their behavior, which is ultimately motivated by a fear of not being good enough: the obsession with getting the best grades and the best test scores.  We lose track of the awesome, humbling goal of medicine: to save lives.  My dad’s surgical team, if they are successful, will save his life today.  How incredible is that?!

My dad has been receiving the best that modern medicine has to offer.  He is one person, and his life is worth the best.

As a tutor, I sometimes struggle with the feeling that my work doesn’t matter, that helping one person at a time isn’t really helping anybody.  It’s a cynical view, the same cynical view that sees premedical students as more concerned with their grades than with helping other people.  It’s an ego-driven view, one that says I’m too important to spend my time helping one student at a time.  I should be doing something BIGGER.

My dad: one person.  Each student: one person.  All of them, one person at a time, deserving of the best care that we can offer them, in our own ways.

Ultimately, some of my students will go on to be doctors, nurses, and other medical professionals.  They too will save lives, and how amazing is that?!  When I think about those career paths, I can see that we exist in a circle of service: we who teach help our students become health professionals, and they go on to take care of all of us, one life at a time.

“On my deathbed I will be grateful for each choice of connection, love, and service,” writes Charles Eisenstein in The More Beautiful World Our Hearts Know is Possible.  I think those of us who choose teaching or medicine intuitively know the truth in Eisenstein’s words.  We make the world a better place, helping one person at at a time.  If that’s the scale on which our work unfolds, then let us embrace that.  Let’s celebrate it!  We aren’t small just because our work happens on a small scale.  We are big because our work sends out ripples of love into the wider world.  Today, a group of medical professionals put all of their expertise together to save one life, my dad.  This semester, I will give each of my students the best I can offer, whether here on this website or sitting down together in a coffee shop, solving chemistry problems together.  Each act of service is an attempt at excellence, at meeting a real need coming from a real person.

How amazing is that!

Monday, September 1, 2014

LESSON: Selection Pressure and Changing Allele Frequencies

We’ve used Hardy-Weinberg equilibria to determine phenotype frequencies in a population.  The Hardy-Weinberg equations assume that a population is stable.  In other words, allele frequencies are not changing—there’s no selection pressure.

But what happens when selection is acting upon a population?  Theoretically, we understand that selection will favor certain alleles or allele combinations over others.  This will shift the balance of alleles toward a new equilibrium.  If we know the magnitude of the selection pressure, we can calculate the effect of selection on allele frequencies.

Let’s work through a sample problem to unpack this set of questions. 

You and your medical team are summoned to Capitol City, where a strange epidemic has rendered 9% of the population sterile. Working rapidly, you discover that there’s a strong correlation between Factor G, a protein found in blood, and the fertile residents: all the fertile residents test positive for Factor G, but all the infertile residents test negative for Factor G. Later genetic and biochemical tests reveal that the population of Capitol City carries two alleles for a gene that is necessary for the production of Factor G such that G is dominant to g. All the fertile residents are genotypically GG or Gg. All gg individuals are now sterile. The original frequencies of G and g were as follows:

G = 0.7

g = 0.3

After the epidemic, what are the allele frequencies of G and g in the next generation?

Let’s define a new term first.

* Fitness, W.  Fitness is a measure of reproductive success and should be a value between 0 and 1.  If there is no selection pressure reducing the reproductive success of a genotype, then W = 1.  If a genotype cannot reproduce (as in our sample problem above, where gg individuals are sterile), then W = 0.

So for our sample problem:

For GG, W = 1

For Gg, W = 1

For gg, W = 0.

We’ll make use of these values below. 

Now we need to dive deeper into the math to connect s to Hardy-Weinberg equilibria.

Slide1 cropped

Slide2

We could have predicted that if q2 = 0, then p2 + 2pq = 1.  So that set of calculations confirms our prediction, but we still have no idea what p and q are after selection.  We need another set of equations for that task.

Slide3

Slide4 cropped

Slide5 cropped

Slide6

Slide 7 redo cropped

Slide 8 cropped

And there you have it!  Now it’s your turn: what if the epidemic, rather than making gg individuals sterile, reduced their fertility by 50%  What would the frequency of G and g be after one round of selection pressure?  (I’ll provide or confirm the answer in the comments when someone asks for it.) 

References:

Comprehensive Genetics coursepack, 2014 version, published by Dr. John Ellison, Texas A&M University

TAMU Genetics 301 Tutoring for Fall 2014

Happy first day of classes, TAMU students!

I’ll be offering on-line tutoring this semester for Genetics 301, as taught by Dr. John Ellison.  I have tutored several students in this class, and my students have been really happy with their sessions.  I love this challenging class, and I love helping students better understand the material.  I recently acquired the book containing class Powerpoint slides and practice exams, so that will facilitate easier tutoring sessions for my next batch of students.

I’m located in Austin, TX, having recently moved from College Station.  My Genetics 301 sessions will be on-line.  As a recent student commented, being able to do tutoring sessions at home in your pajamas is awesome!  My partner, Tutor Paul, has set up on-line tutoring for both of us.  (Some of you might know Tutor Paul; he’s the guy you want to see for tutoring in mechanical engineering, math, or physics.  He’s awesome.)

So what do you need for on-line tutoring?

* A high-speed internet connection, a computer, and a microphone.  If you want me to be able to see you, you’ll need a webcam as well.

* A Google+ account

* The plug-in for Google+ Hang-outs

During an on-line tutoring session, you’ll be able to see my face, hear my voice, and see my whiteboard in which I work out problems and illustrate concepts.  Paul and I are dedicated to creating an awesome on-line tutoring experience for our students, so we invite you to try it out with us.  Contact me for more information!  Call or text 847-644-0782.  (You can also e-mail me at r-meissner@u.northwestern.edu)

Happy learning and have a great semester!