Thursday, March 29, 2012

Diversity in Science Carnival #14: Women’s History Month--Exploring the role of women in the STEM enterprise


Women in Science, via the Smithsonian.

“We must believe that we are gifted for something.” Marie Curie

Image of a real Rosie the Riveter from the
Women's History Month site.
It’s tempting to cast the role of women in STEM (Science, Technology, Engineering, and Math) as one of struggles and battles because of their sex, rather than as one of contributions because of their minds. But for Women’s History Month and this Diversity in Science Carnival #14, our focus is the role of women in the enterprise of STEM. There’s more to a woman than her sex and her struggles in science--there is, after all, the enormous body of work women have contributed to science.
 
Our history is ongoing, but we can start with a look back. Thanks to the efforts of the Smithsonian Institution Archives, we can put faces to the names of some of the female STEMmers of history. In a presentation of photographs in an 8 by 9 space, we can see the images of 72 women who contributed to the enterprise of STEM, many of them involved with the Smithsonian in some capacity. As their clothes and the dates on the photos tell us, these women were doing their work in a time when most women didn’t even wear pants.  
Some are Big Names--you’ve probably heard of Marie Curie. But others are like many of us, women working in the trenches of science, contributing to the enterprise of STEM in ways big and small. Women like Arlene Frances Fung, whose bio tells us she was born in Trinidad, went to medical school in Ireland, and by 1968 was engaged in chromosome research at a cancer institute in Philadelphia. From Trinidad to cancer research, her story is one of the millions we could tell about women’s historical contributions to science, if only we could find them all. But here there are 72, and we encourage you to click on each image, look at their direct gazes, ponder how their interest in science and knowledge trumped the heavy pressures of social mores, and discover the contributions these 72 women made, each on her own “little two inches wide of ivory.”

For more on historical and current women in science, you can also see Double X Science’s “Notable Women in Science” series, curated by Adrienne Roehrich.

And then there are the women STEMmers of today, who likely are, according to blogger Emma Leedham writing at her blog Pipettes and Paintbrushes, still underpaid. Leedham also mulls here what constitutes a role model for women--does it require being both a woman and a scientist, or one or the other?

Laurel L. James
Laurel L. James, writing at the University of Washington blog for the school’s SACNAS student chapter, answers with her post, “To identify my role as a woman in science: I must first honor my mother, my family and my past.” Her mother was the first “Miss Indian America,” and Laurel is a self-described non-traditional student at the school, where she is a graduate student in forest resources. She traces her journey to science, one that involved role models who were not scientists but who, as she writes, showed her “how to hang onto the things that are important with the expectation of getting something in return all the while, persevering and knowing who you are; while walking with grace and dignity.” I’d hazard that these words describe many a woman who has moved against the currents of her society to contribute something to the sciences.

A great site, Steminist.com, which features the “voices of women in science, tech, engineering, and math,” runs a series of interviews with modern-day STEMmers, including Double X Science’s own Jeanne Garbarino, and Naadiya Moosajee, an engineer and cofounder of South African Women in Engineering. You can follow Naadiya on Twitter here. Steminist is also running their version of March Madness, except that in honor of Women’s History Month, we can choose “Which historical women in STEM rock (our) world.” The 64 historical STEMinists in the tourney are listed here and include Emily Warren Robling (left), who took over completion of the Brooklyn Bridge when her husband's health prevented his doing so; she is known as the first woman field engineer. Double X Science also has a series about today’s women in science, Double Xpression, which you can find here.

Today, you can find a woman--or many women--in STEM just about anywhere you look, whether it is as a government scientist at NOAA like Melanie Harrison, PhD, or at NASA. It hasn’t always been that way, and it can still be better. But women have always been a presence in STEM. In the 18th and 19th centuries, astronomer Caroline Herschel labored away through the dark hours of just about every night of her adult life, tracking the night sky. Today, women continue these labors, and STEM wouldn’t be what it is today without women like Herschel willing to stay up all night with the skies or spend days on end in the field or lean over a microscope for hours just to add a tiny bit more to what we know about our world and our universe.
                            
Caroline Herschel
For women in science, we’re there--at night, in the lab, in the field--because we love science. But as the non-science role models seem to tell us, we stick to it--and can stick with it--because we had role models in and out of science who showed us that regardless of our goals, our attitudes and willingness to move forward in spite of obstacles are really what drive us to success in STEM careers. Among the links I received for this carnival was one to Science Club for Girls, which is sponsoring a “Letter to My Young Self” roundup for Women’s History Month. The letters I’ve read invariably have that “stick with it” message, but one stood out for me, and I close with a quote from it.

It’s a letter by Chitra Thakur-Mahadik, who earned her PhD in biochemistry and hemoglobinopathy from the University of Mumbai and served as staff scientist a Mumbai children’s hospital for 25 years. She wrote to her younger, “partially sighted” self that, “The future is ahead and it is not bad!” She goes on to say, “Be fearless but be compassionate to yourself and others… be brave, keep your eyes and ears open and face the world happily. What if there are limitations? Work through them with awareness. --Yours, Chitra”


Links and resources for women in STEM, courtesy of D.N. Lee

Stay tuned for the April Diversity in Science Carnival #15: Confronting the Imposter Syndrome. This topic promises to resonate for many groups in science. I’m pretty sure we’ve all felt at least of twinge of imposter syndrome at some point in our education and careers.  Your editor for this carnival will be the inimitable Scicurious, who  blogs at Scientific American and Scientopia.


UPDATE: Carnival #15 is now available! Go read about imposter syndrome, why it happens, who has it, and what you can do about it. 


By Emily Willingham, DXS managing editor 

Saturday, March 24, 2012

Why don’t more girls get the HPV vaccine??


Double X Science is pleased to be able to repost, with permission, this important piece courtesy of author Kate Prengaman and her Xylem blog, focused on spreading science and new ideas.


Imagine if there was a vaccine that could prevent cancer. Everyone would want it, right?
Surprisingly, no. There IS a vaccine to prevent cervical cancer, which, according to the CDC, affects about 12,000 women every year. Unlike most cancers, cervical cancer is caused by a sexually transmitted virus, Human Papillomavirus, also known as HPV. The virus can cause abnormal cell growth in the cervix, which can turn cancerous. The vaccine, approved in 2006, works against many common strains of HPV.
The vaccine is recommended for girls ages 11-12, and also provided to women up through their early twenties.  The goal is to protect girls long before they are ever sexually active, so that they never contract HPV in the first place. As of 2011, the vaccine is also recommended for adolescent boys.
Contracting HPV is so common that more than half of all sexually active men and women in the United States will become infected with HPV at some point in their lives. According to a CDC factsheet on the HPV vaccine, “about 20 million Americans are currently affected, and 6 million more are infected every year.” In most people, HPV infections never lead to symptoms but the virus can cause development of cervical cancer and, more rarely, cancers of the vagina and anus, as well as genital warts. Furthermore, men can develop cancer from HPV. The virus is transmitted through skin to skin contact, which reduces the efficacy of condoms at preventing the spread of this disease.

Yet, despite the dangers associated with HPV, only 33.9% of American girls, ages 13-17, reported to the CDC in 2010 that they had been fully vaccinated (3 doses) against HPV.  When I mapped the state by state rates of vaccination, I found a dramatic distribution, from only 19% of girls in Idaho to nearly 60% in South Dakota and Rhode Island.
Map created by Kate Prengaman
Much of the resistance to vaccinating adolescent girls against cancer-causing HPV comes from  many people who are uncomfortable with or resistant to the fact that adolescent girls will grow up and have sex. I expected to see a strong correlation between states with Abstinence-only sex education and low vaccination rates, but the pattern in the map is weaker than I had anticipated. I also considered that the cost of the vaccines might play a role, although if they are not covered by a family’s health insurance, there are federal programs in place to subsidize the cost. There’s also some correlation there, but again, not as strong as you see, for example, when mapping teenage birthrates.
Map created by Kate Prengaman
Clearly, the pink map, lovely as it is, does not provide an answer for why more adolescent girls are not receiving the HPV vaccine. There is an unfortunate anti-vaccination movement in this country, with people choosing not to protect their kids from dangerous diseases because of unfounded fears that vaccines can cause autism, among other things. Last fall, Michelle Bachmann even used a presidential debate to stir up more fears that the HPV vaccines could cause mental disabilities, a enormous error that the medical community quickly tried to correct.
The truth is that these vaccines are safe. The truth is that HPV is really common, and it can cause cancer, and if you ever have sex, you have a good chance of getting it. Why aren’t more parents of adolescents taking the lead on protecting their kids’ future health?  If you have any ideas for other factors that might explain the patterns of vaccination, let me know in the comments and I  will try adding to my map.  Thanks!

About the guest author:

Kate Prengaman is a science writer and outdoor enthusiast currently based in Madison, WI. Formerly a botanist, Kate is pursuing her masters in science journalism at UW, reading and writing as much as possible.  She loves talking to people, telling stories, finding adventures,  geeking out over wildflowers, and eating delicious things. She blogs at Xylem

Monday, March 12, 2012

Everyday science: Why is the sky pink?


On Mars, the sky is pink during the day, shading to blue at sunset. What planet did you think I was talking about?

On Earth, the sky is blue during daytime, turning red at as the sun sinks toward night.

Scattering light

Well, it's not quite as simple as that: if you ignore your dear sainted mother's warning and look at the Sun, you'll see that the sky immediately around the Sun is white, and the sky right at the horizon (if you live in a place where you can get an unobstructed view) is much paler. In between the Sun and the horizon, the sky gradually changes hue, as well as varying through the day. That's a good clue to help us answer the question every child has asked: why is the sky blue? Or as a Martian child might ask: why is the sky pink?

First of all, light isn't being absorbed. If you wear a blue shirt, that means the dye in the cotton (or whatever it's made of) absorbs other colors in light, so only blue is reflected back to your eye. That's not what's happening in the air! Instead, light is being bounced off air molecules, a process known as scattering. Air on Earth is about 80% nitrogen, with almost all of the rest being oxygen, so those are the main molecules for us to think about.

As I discussed in my earlier article on fluorescent lights, atoms and molecules can only absorb light of certain colors, based on the laws of quantum mechanics. While oxygen and nitrogen do absorb some of the colors in sunlight, they turn right around and re-emit that light. (I'm oversimplifying slightly, but the main thing is that photons aren't lost to the world!) However, other colors don't just pass through atoms as though they aren't there: they can still interact, and the way we determine how that happens is again the color.

The color of light is determined by its wavelength: how far a wave travels before it repeats itself. Wavelength is also connected to energy: short wavelengths (blue and violet light) have high energy, while long wavelengths (red light) have lower energy. When a photon (a particle of light) hits a nitrogen or oxygen molecule, it might hit one of the electrons inside the molecule. Unless the wavelength is exactly right, the photon doesn't get absorbed and the electron doesn't move, so all the photon can do is bounce off, like a pool ball off the rail on a billiards table. Low-energy red photons don't change direction much after bouncing–they hit the electron too gently for that. Higher-energy blue and violet photons, on the other hand, scatter by quite a bit: they end up moving in a very different direction after hitting an electron than they moving before. This whole process is known technically as Rayleigh scattering, for the physicist John Strutt, Lord Rayleigh.

The blue color of the sky

Not every photon will hit a molecule as it passes through the atmosphere, and light from the Sun contains all the colors mixed together into white light. That means if you look directly at the Sun or the sky right around the Sun during broad daylight, what you see is mostly unscattered light, the photons that pass through the air unmolested, making both Sun and sky look white. (By the way, your body is pretty good at making sure you won't damage your vision: your reflexes will usually twitch your eyes away before any injury happens. I still don't recommend looking at the Sun directly for any length of time, especially with sunglasses, which can fool your reflexes into thinking everything is safer than it really is.) In other parts of the sky away from the Sun, scattering is going to be more significant.

The Sun is a long way away, so unlike a light bulb in a house, the light we get from it comes in parallel beams. If you look at a part of the sky away from the Sun, in other words, you're seeing scattered light! Red light doesn't get scattered much, so not much of that comes to you, but blue light does, meaning the sky appears blue to our eyes. Bingo! Since there is some green and other colors mixed in as well, the apparent color of the sky is more a blue-white than a pure blue.

(The Sun's light doesn't contain as much violet light as it does blue or red, so we won't see a purple sky. It also helps that our eyes don't respond strongly to violet light. The cone cells in our retinas are tuned to respond to blue, green, and red, so the other colors are perceived by triggering combinations of the primary cone cells.)

At sunset, light is traveling through a lot more air than it does at noon. That means every ray of light has more of a chance to scatter, removing the blue light before it reaches our eyes. What's left is red light, making the sky at the horizon near the Sun appear red. In fact, you see more gradations of color too: moving your vision higher in the sky, you'll note red shades into orange into yellow and so forth, but each color is less intense.

So finally: why is the Martian sky pink? The answer is dust: the surface of Mars is covered in a fine powder, more like talcum than sand. During the frequent windstorms that sweep across the planet, this dust is blown high into the air, where light (yes) scatters off of it. Since the grains are larger than air molecules, the kind of scattering is different, and tends to make the light appear red. (Actually, the sky's “true” color is very hard to determine, since there is a lot more variation than on Earth.) When there is less dust in the atmosphere, the Martian sky is a deep blue, when the Sun's light scatters off the carbon dioxide molecules in the air.

By DXS Physics Editor Matthew Francis

Wednesday, March 7, 2012

Colon Cancer Awareness Month: Get your ass screened. We mean it.

Don't want this growing in your colon?
Get screened. Via Wikimedia Commons.
It started a few months after I had my second son. A pain. Sharp, unrelenting, abdominal. Occasional blood from a place where blood isn't supposed to appear: the rectum. There. Got the R-word out of the way.

After I had laparoscopy for presumed endometrial scarring as the cause of the pain, the pain nevertheless persisted. So, I was referred to a gastrointestinal (GI) specialist, or gastroenterologist. The GI doc I saw first was a man who, I later, discovered, was the GI doctor for my uncle and my father. They loved him. There probably was a sort of "hail fellow well met" male camaraderie between doctor and patient there that made them sympatico. Me, not so much. He looked at me, looked at my age (36), and decided that all I needed was to take some ibuprofen. He literally sent me home with instructions to take some ibuprofen a few times a day and call him, not in the morning, but maybe in a couple of weeks.

Two years later, after more episodes of blood in the toilet, continued pain, and, pardon me, but I think this information is important, a whole lot of mucus coming out of there, I went to another GI doctor. For whatever reason--even though my symptoms weren't necessarily a match for colon cancer, even though I didn't, to my knowledge, have any risk factors for colon cancer, even though I was still quite young to have colon cancer--he decided to do a colonoscopy.

As I emerged from the anesthesia after the procedure, I saw my GI doctor talking with my husband. "How did it go?" I asked, groggy. He sort of smiled at me and said, "You're not going to remember any of this, but those symptoms you had saved your life." Unbeknownst to him, amnesia meds don't work on me--I've had ample subsequent opportunities to test that hypothesis--and I did remember it.

How did it save my life? 
What they found in my colon, near where it meets my lower small intestine, was a large, flat growth, about two inches (5 cm) by one inch (2.5 cm). In GI parlance, it was a large, flat (sessile) polyp, which is not a good kind of polyp. Closer analysis of the thing after my GI doctor deftly removed it during a second procedure revealed it to be a tubulovillous adenoma with cancerous tendencies. In fact, my medical records from that doctor now say the word "cancer" on them. 

Adenomas, the type of tumor this was, are "of greatest concern" in the colon. They come in three types: tubular, tubulovillous, and villous. The larger the size, the greater the cancer risk. Mine was large and on its way to becoming cancer. According to my GI doctor, I'd've been dead in another 5 years had I not had that colonoscopy and appropriate intervention. 

In other words, if I'd waited until the recommended age for a first colon cancer screening--age 50--I'd have already been dead for seven years. In fact, I would have died this year from colon cancer.

My mind was saying, "This would have been It. This would have been the thing, in a different time, that would have killed me. My potential death was growing inside of me, and I managed to put a stop to it." 

It's true: Colon cancer can be prevented
Finding and removing polyps in the colon can prevent colon cancer from developing. But first, you have to have the screening. Because more than 90% of cases of colorectal cancer happen in people ages 50 or older, the starting age for screening is currently set at age 50. 

If you have symptoms like the following, though, don't delay. If a GI doctor dismisses you as my first one did--that polyp of mine was probably growing in there for a few years--get a second opinion.

  • Blood in or on the stool (as I had)
  • Stomach pain or aches that do not go away (as I had)
  • Unexplained weight loss
  • A change in bowel habits (diarrhea, constipation, frequency)
  • A feeling of incomplete emptying


Colon cancer is associated with some risk factors. These include

  • Age 
  • Having previously had colon polyps or colorectal cancer yourself
  • A family history of polyps or colorectal cancer
  • A history of having inflammatory bowel disease (Crohn's or ulcerative colitis; not to be confused with irritable bowel syndrome or IBS)
  • A family history of inherited disorders related to polyps of the colon
Of these factors, I thought going into my GI doctors that I had none. Only later did I learn that my father also had had some polyps found and removed, although of the more typical and less-threatening variety and at a later age (in his 50s). In addition, in the past year, my octogenarian maternal grandmother had a large colorectal cancer removed that had likely begun its evolution from a polyp years ago, but she had never undergone screening. I cannot stress enough how important it is for a family to share health history so that these risks can be known and for anyone to have appropriate screening either at the recommended age or in the presence of symptoms.

Speaking of family, there is my own. My having been diagnosed with a precancerous growth at age 38 means that my first-degree relatives--siblings, parents, children--should have screening at least by that age and preferably years before.

There is some understandable reluctance to have a colonoscopy. Outside of the obvious ignominy of having someone shove a tube up your rectum while you lie anesthetized (I woke up during my second--yep, there's a tube in there), there is the preparation for it. I've done just about every prep known to modern medicine, having now had five colonoscopies--all my follow-ups have been clear, and I don't need another for four years now (!). Yes, they're unpleasant, and they take quite a bit of willpower. You have to drink what they tell you, take the pills that they tell you, not eat when they tell you, and consume only what they say is OK. You'll never want to see Jell-O or Gatorade again, and I can't stare down a bowl of clear bouillon any more without feeling a tad nauseated. 

But the goal of a prep is a completely clean colon. The cleaner you get it, the more accurate your findings will be and the less likely you'll have to do it again simply because you conducted--pardon me--a  crappy prep. 

March is Colon Cancer Awareness month. Be aware and embrace the reality that polyps happen and that so far, finding them requires this daylong unpleasantness. But also embrace the fact that the prep won't kill you. Instead, it will help you prevent a cancer that does, in fact, kill 50,000 people a year in the United States alone. 

This year, five years after that first colonoscopy would have been the year I'd've been one of those people. Thanks to that procedure, I am instead alive and well enough to tell you about it, and my three young sons still have their mother. I'd starve for a week and drink Gatorade until I puked to make sure of that outcome.
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By Emily Willingham, DXS Managing Editor

Monday, March 5, 2012

Hormonal birth control explainer: a matter of health


Politics often interferes where it has no natural business, and one of those places is the discussion among a teenager, her parents, and her doctor or between a woman and her doctor about the best choices for health. The hottest button politics is pushing right now takes the form of a tiny hormone-containing pill known popularly as the birth control pill or, simply, The Pill. This hormonal medication, when taken correctly (same time every day, every day), does indeed prevent pregnancy. But like just about any other medication, this one has multiple uses, the majority of them unrelated to pregnancy prevention.

But let's start with pregnancy prevention first and get it out of the way. When I used to ask my students how these hormone pills work, they almost invariably answered, "By making your body think it is pregnant." That's not correct. We take advantage of our understanding of how our bodies regulate hormones not to mimic pregnancy, exactly, but instead to flatten out what we usually talk about as a hormone cycle. 

The Menstrual Cycle
In a hormonally cycling girl or woman, the brain talks to the ovaries and the ovaries send messages to the uterus and back to the brain. All this chat takes place via chemicals called hormones. In human females, the ovarian hormones are progesterone and estradiol, a type of estrogen, and the brain hormones are luteinizing hormone and follicle-stimulating hormone. The levels of these four hormones drive what we think of as the menstrual cycle, which exists to prepare an egg for fertilization and to make the uterine lining ready to receive a fertilized egg, should it arrive. 

Fig. 1. Female reproductive anatomy. Credit: Jeanne Garbarino.
In the theoretical 28-day cycle, fertilization (fusion of sperm and egg), if it occurs, will happen about 14 days in, timed with ovulation, or release of the egg from the ovary into the Fallopian tube or oviduct (see video--watch for the tiny egg--and Figure 1). The fertilized egg will immediately start dividing, and a ball of cells (called a blastocyst) that ultimately develops is expected to arrive at the uterus a few days later.

If the ball of cells shows up and implants in the uterine wall, the ovary continues producing progesterone to keep that fluffy, welcoming uterine lining in place. If nothing shows up, the ovaries drop output of estradiol and progesterone so that the uterus releases its lining of cells (which girls and women recognize as their “period”), and the cycle starts all over again.



A typical cycle
The typical cycle (which almost no girl or woman seems to have) begins on day 1 when a girl or woman starts her "period." This bleeding is the shedding of the uterine lining, a letting go of tissue because the ovaries have bottomed out production of the hormones that keep the tissue intact. During this time, the brain and ovaries are in communication. In the first two weeks of the cycle, called the “follicular phase” (see Figure 2), an ovary has the job of promoting an egg to mature. The egg is protected inside a follicle that spends about 14 days reaching maturity. During this time, the ovary produces estrogen at increasing levels, which causes thickening of the uterine lining, until the estradiol hits a peak about midway through the cycle. This spike sends a hormone signal to the brain, which responds with a hormone spike of its own.
Fig. 2. Top: Day of cycle and phases. Second row: Body temperature (at waking) through cycle.
Third row: Hormones and their levels. Fourth row: What the ovaries are doing.
Fifth row: What the uterus is doing. Via Wikimedia Commons
In the figure, you can see this spike as the red line indicating luteinizing hormone. A smaller spike of follicle-stimulating hormone (blue line), also from the brain, occurs simultaneously. These two hormones along with the estradiol peak result in the follicle expelling the egg from the ovary into the Fallopian tube, or oviduct (Figure 3, step 4). That’s ovulation.

Fun fact: Right when the estrogen spikes, a woman’s body temperature will typically drop a bit (see “Basal body temperature” in the figure), so many women have used temperature monitoring to know that ovulation is happening. Some women also may experience a phenomenon called mittelschmerz, a pain sensation on the side where ovulation is occurring; ovaries trade off follicle duties with each cycle.  

The window of time for a sperm to meet the egg is usually very short, about a day. Meanwhile, as the purple line in the “hormone level” section of Figure 2 shows, the ovary in question immediately begins pumping out progesterone, which maintains that proliferated uterine lining should a ball of dividing cells show up.
Fig. 3. Follicle cycle in the ovary. Steps 1-3, follicular phase, during
which the follicle matures with the egg inside. Step 4: Ovulation, followed by
the luteal phase. Step 5: Corpus luteum (yellow body) releases progesterone.
Step 6: corpus luteum degrades if no implantation in uterus occurs.
Via Wikimedia Commons.
The structure in the ovary responsible for this phase, the luteal phase, is the corpus luteum (“yellow body”; see Figure 3, step 5), which puts out progesterone for a couple of weeks after ovulation to keep the uterine lining in place. If nothing implants, the corpus luteum degenerates (Figure 3, step 6). If implantation takes place, this structure will (should) instead continue producing progesterone through the early weeks of pregnancy to ensure that the lining doesn’t shed.

How do hormones in a pill stop all of this?
The hormones from the brain--luteinizing hormone and follicle-stimulating hormone-- spike because the brain gets signals from the ovarian hormones. When a girl or woman takes the pills, which contain synthetics of ovarian hormones, the hormone dose doesn’t peak that way. Instead, the pills expose the girl or woman to a flat daily dose of hormones (synthetic estradiol and synthetic progesterone) or hormone (synthetic progesterone only). Without these peaks (and valleys), the brain doesn’t release the hormones that trigger follicle maturation or ovulation. Without follicle maturation and ovulation, no egg will be present for fertilization.

Assorted hormonal pills. Via Wikimedia Commons.
Most prescriptions of hormone pills are for packets of 28 pills. Typically, seven of these pills--sometimes fewer--are “dummy pills.” During the time a woman takes these dummy pills, her body shows the signs of withdrawal from the hormones, usually as a fairly light bleeding for those days, known as “withdrawal bleeding.” With the lowest-dose pills, the uterine lining may proliferate very little, so that this bleeding can be quite light compared to what a woman might experience under natural hormone influences.

How important are hormonal interventions for birth control?
Every woman has a story to tell, and the stories about the importance of hormonal birth control are legion. My personal story is this: I have three children. With our last son, I had two transient ischemic attacks at the end of the pregnancy, tiny strokes resulting from high blood pressure in the pregnancy. I had to undergo an immediate induction. This was the second time I’d had this condition, called pre-eclampsia, having also had this with our first son. My OB-GYN told me under no uncertain terms that I could not--should not--get pregnant again, as a pregnancy could be life threatening.

But I’m married, happily. As my sister puts it, my husband and I “like each other.” We had to have a failsafe method of ensuring that I wouldn’t become pregnant and endanger my life. For several years, hormonal medication made that possible. After I began having cluster headaches and high blood pressure on this medication in my forties, my OB-GYN and I talked about options, and we ultimately turned to surgery to prevent pregnancy.

But surgery is almost always not reversible. For a younger woman, it’s not the temporary option that hormonal pills provide. Hormonal interventions also are available in other forms, including as a vaginal ring, intrauterine device (some are hormonal), and implants, all reversible.
                                            
One of the most important things a society can do for its own health is to ensure that women in that society have as much control as possible over their reproduction. Thanks to hormonal interventions, although I’ve been capable of childbearing for 30 years, I’ve had only three children in that time. The ability to control my childbearing has meant I’ve been able to focus on being the best woman, mother, friend, and partner I can be, not only for myself and my family, but as a contributor to society, as well.

What are other uses of hormonal interventions?
Heavy, painful, or irregular periods. Did you read that part about how flat hormone inputs can mean less build up of the uterine lining and thus less bleeding and a shorter period? Many girls and women who lack hormonal interventions experience bleeding so heavy that they become anemic. This kind of bleeding can take a girl or woman out of commission for days at a time, in addition to threatening her health. Pain and irregular bleeding also are disabling and negatively affect quality of life on a frequent basis. Taking a single pill each day can make it all better. 


Unfortunately, the current political climate can take this situation--especially for teenage girls--and cast it as a personal moral failing with implications that a girl who takes hormonal medications is a "slut," rather than the real fact that this hormonal intervention is literally maintaining the regularity of her health.

For some context, imagine that a whenever a boy or man produced sperm, it was painful or caused extensive blood loss that resulted in anemia. Would there be any issues raised with providing a medication that successfully addressed this problem?

Polycystic ovarian syndrome. This syndrome is, at its core, an imbalance of the ovarian hormones that is associated with all kinds of problems, from acne to infertility to overweight to uterine cancer. Guess what balances those hormones back out? Yes. Hormonal medication, otherwise known as The Pill.  

Again, for some context, imagine that this syndrome affected testes instead of ovaries, and caused boys and men to become infertile, experience extreme pain in the testes, gain weight, be at risk for diabetes, and lose their hair. Would there be an issue with providing appropriate hormonal medication to address this problem?

Acne. I had a friend in high school who was on hormonal medication, not because she was sexually active (she was not) but because she struggled for years with acne. This is an FDA-approved use of this medication.

Are there health benefits of hormonal interventions?
In a word, yes. They can protect against certain cancers, including ovarian and endometrial, or uterine, cancer. Women die from these cancers, and this protection is not negligible. They may also help protect against osteoporosis, or bone loss. In cases like mine, they protect against a potentially life-threatening pregnancy.

Speaking of pregnancy, access to contraception is “the only reliable way” to reduce unwanted pregnancies and abortion rates [PDF]. Pregnancy itself is far more threatening to a girl’s (in particular) or woman’s health than hormonal contraception.

Are there health risks with hormonal interventions?
Yes. No medical intervention is without risk. In the case of hormonal interventions, lifestyle habits such as smoking can enhance risk for high blood pressure and blood clots. Age can be a factor, although--as I can attest--women no longer have to stop taking hormonal interventions after age 35 as long as they are nonsmokers and blood pressure is normal. These interventions have been associated with a decrease in some cancers, as I’ve noted, but also with an increase in others, such as liver cancer, over the long term. The effect on breast cancer risk is mixed and may have to do with how long taking the medication delays childbearing. ETA: PLoS Medicine just published a paper (open access) addressing the effects of hormonal interventions on cancer risk.
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By Emily Willingham, DXS Managing Editor
Opinions expressed in this piece are my own and do not necessarily reflect the opinions of all DXS editors or contributors.

Friday, March 2, 2012

Book Review: Science Myths Unmasked: Exposing the misconceptions and counterfeits forged by bad science books



 By DXS Biology Editor Jeanne Garbarino

Do you remember that old candle experiment involving a lit candle in a jar? You know, the one where you place a lit candle in a bowl of water, then place a jar over the candle, and rather quickly, the candle extinguishes? If you were like me, you probably learned that the candle goes out because all of the oxygen gets used up (oxygen is a requirement for combustion).  However, according to David Isaac Rudel in his multi-volume series Science Myths Unmasked, this is one of the many science demonstrations that are wholly misinterpreted.

Unfortunately, the science textbooks used by thousands of schools across the US are chock-full of what Rudel calls “pseudo-explanations” for many complicated scientific phenomena. Instead of presenting clear explanations, including the establishment of a basic scientific foundation, many science textbooks present certain concepts using shortcuts, with the assumption that these so-called shortcuts make it easier for kids to understand science. 

Rudel argues that these shortcuts, which are often associated with an “abuse of [scientific] language,” only confuse students. In fact, included on the back cover of Science Myths Unmasked, Volume 2: Physical Sciences is a quote from Richard Feynman regarding science textbooks: “They said things that were useless, mixed-up, ambiguous, confusing, and partially incorrect. How anybody can learn science from these books, I do not know, because it’s not science.”

My husband, a public high school chemistry and biology teacher, is wholeheartedly aligned with this particular opinion of Feynman and Rudel and for many years, has not used a textbook to teach science. When I asked why, he simply stated, “They just confuse the kids.” 

As an example to what is wrong with science textbooks, let’s get back to the candle-in-a-jar experiment. In Science Myths Unmasked Volume 2: Physical Science, this very common scientific demonstration is thoroughly dissected, explaining why “the candle goes out when the oxygen content of the air is no longer high enough to support combustion” is an incorrect conclusion found in many textbooks, especially since it overlooks how the products of combustion affect the candle flame. After elaborating on the precise conditions point by point, and providing an outline for easy demonstrations to “expose the myth,” the following is stated:

Candles in closed containers do not go out because they use up all the oxygen.  Rather, the hot carbon dioxide (and to a lesser extent water vapor) given off in combustion accumulates at the top, pushing down other gases (most importantly, oxygen), and eventually stifles the flame. 
If the jar’s rim is submerged in water, the liquid rises not because water is replacing the oxygen used up in combustion.  Rather, the air inside the jar cools as the flame dies down and hot gases offload heat to the glass container.  As the air cools, it applies less pressure to the water than it did when the jar was first put over the candle.  The water rises as a result of the decreasing pressure from the air against it.           

In the Science Myths Unmasked series, a great number scientific factoids and processes that are often misrepresented in the classroom are correctly explained, and in great detail.  In addition to the candle experiment described above, Rudel tackles simple machines, circuits, phase change, and waves, just to name a few. However, this book is not for those without at least some background in science, as it does get technical. I would, though, recommend that these books find a way onto the shelves of science educators, as it seems they would benefit the most from the lessons and demonstrations covered. It is also good for people who, like me, have a scientific background and wish to properly explain scientific concepts to their kids, as I am sure those questions are bound to come up.  

For more on the Science Myths Unmasked series, go here.