Drink up - there's only a little weed killer in there...

A new study published has linked atrazine (an herbicide) to hormonal regularities in women.


"Women who drink water contaminated with low levels of the weed-killer atrazine may be more likely to have low estrogen levels, according to a new study."

"The newest research, which compared women in Illinois to women in Vermont, adds to the growing scientific evidence linking atrazine to altered hormones."

The company that makes atrazine disputes the results, saying that there are too many other factors that could contribute to the problem.

As you comment think about the study. How large was their sample size? Could that have an effect? Are there other studies confirming this data? Are there other factors that could account for these differences? As we move on in content you might also want to relate the use of atrazine to the use of glyphosate (Round-up) and think about what might happen if more and more plants become resistant to Round up.
 

Pepper protection?

We talked in biology about how some plants produce toxic compounds to protect themselves. Peppers have such a compound (although how much is natural, and how much is due to artificial selection is a question to be answered later). The compound in question is capsaicin. The amount of it is measured by the Scoville Scale (a measure of pepper hotness).

As you read the article, identify how peppers would benefit from this compound and also how it might hinder their distribution. The rest of the article deals with using isolated capsaicin in pepper spray by police and in personal safety devices. In your opinion, is this safe to continue?

More antibiotic resistance article

We will continually be dealing with articles like these. Here's another one to view and review.

Antibiotic resistance marching across Europe - Scientific American

New clues for improving antibiotics in tolerant bacteria - Scientific American

Useless - 10 million kid antibiotic prescriptions a year - MSNBC

What should be done about these issues? What do you think about the future if nothing is done?

White Nose, Black Death

This is an interesting article comparing the White Nose Fungus that is killing many North American bats to the Black Death of the middle ages. The idea is that neither affliction is tremendously dangerous on its own in healthy organisms, but when those organisms are stressed it changes their mortality tremendously. The White Nose Fungus affects the torpor of bats. The fungus has been found in European bats for years, but doesn't affect them as much. It was thought that it was moved to North America by spelunkers

Biology students you can comment upon the ecology of that and also how losing a predator in a food web will affect the overall ecosystem.

Wolfote?

It has long been known that coyotes, wolves, and dogs can interbreed. It seems that wolf and coyote hybrids are now roaming the East Coast.

What affect could hybrid coyotes have on the ecosystem. Are there positives? Are there negatives? How much do you trust the research?

Stem cells to pituitary gland

Japanese scientists have grown an entire organ outside of the body. They grew a pituitary gland from embryonic stem cells. This is a first because scientists have had success creating tissues, but entire organs have been difficult up until now.

Some ideas for comments are: How could this be used for medical advances? Is this ethical to work on for humans? How does this relate to class work?

Honeybees: Why are they decreasing?

Nature.com has an article about the decrease in animal pollinators (The pollinator crisis: what's best for bees) and the effect that has on the environment. Bees have been decreasing for years, as their graph shows, and these scientists based in California are looking for reasons why. As you comment upon the article think about the how this research could be used in different regions of the country. Also identify how this article connects the last few chapters that we have studied.

Update (11.16.11):
The European Parliament is getting involved by taking action to protect the bees as well. Is this an appropriate response, and should the government of the United States do something similar to this.

Why science majors change their minds

The New York Times has an article in it about why STEM (Science, Technology Engineering, Math) majors wash out and do not complete college in the same majors as they entered. It was determined that 40% do not complete the STEM major, either switching majors or dropping out. If premed students are included the dropout and transfer to other majors increases to 60%. There were a few quotes in this article that I found interesting.

But, it turns out, middle and high school students are having most of the fun, building their erector sets and dropping eggs into water to test the first law of motion. The excitement quickly fades as students brush up against the reality of what David E. Goldberg, an emeritus engineering professor, calls “the math-science death march.” Freshmen in college wade through a blizzard of calculus, physics and chemistry in lecture halls with hundreds of other students.

There is no doubt that the main majors are difficult and growing more complex. Some students still lack math preparation or aren’t willing to work hard enough.

Other deterrents are the tough freshman classes, typically followed by two years of fairly abstract courses leading to a senior research or design project. “It’s dry and hard to get through, so if you can create an oasis in there, it would be a good thing,” says Dr. Goldberg,

The latest research also suggests that there could be more subtle problems at work, like the proliferation of grade inflation in the humanities and social sciences, which provides another incentive for students to leave STEM majors...After studying nearly a decade of transcripts at one college, Kevin Rask, a professor at Wake Forest University, concluded last year that the grades in the introductory math and science classes were among the lowest on campus.

Other bright students may have breezed through high school without developing disciplined habits. By contrast, students in China and India focus relentlessly on math and science from an early age.

As you read the article it does identify that many schools are working on more authentic projects and hands on activities even at the college level. It still doesn't eliminate the fact that many times - SCIENCE IS CHALLENGING!

Update: The National Survey of Student Engagement (NSSE) identified that Engineering majors spent more time studying and preparing for their classes than other majors. Science majors were just behind them in terms of hours per week studying. That is above and beyond the extra class time that lab classes include.

One of my favorite Sundays - Fall Back - Some information about Daylight Savings Time.

Read the National Geographic Article about Daylight Savings Time. It covers the history and how the reasons behind it. Comment on whether we should continue to have DST or if it's something that has served its usefulness. The other article is discussing how DST affects of circadian rhythms. Tell me what you think.

Other DST articles
Why Daylight Saving Time should be abolished.
Permanent Daylight Saving Time? Might Boost Tourism, Efficiency

Why pioneers bred like rabbits...

A new study out of Canada has used data from church birth and death records and identified that the pioneers had more children and those children contributed more genes to the modern gene pool than those that came after them.
   

Families that colonized the Canadian frontier contributed more genetic material to the modern population than folks who stayed home, says a new study...According to new research, the desire to expand into new territory may have provided an evolutionary advantage to those who had it over those who lacked it.

The article also compares the pioneers of the Canadian frontier to the plants and animals that colonize new habitats.

What do you think of the research? What do you think of conclusions and comparisons. Is there a genetic component to fertility as is suggested in the article?

Got a fever? Sweat it out...

This MSNBC article references some research in which scientists studied the activity of different cells at different temperatures. In the controlled study they researched mice and immune cells effectiveness against viruses.This other article also reviews the study

Biology students, when you comment identify how this fits in with the information that you learned about viruses and how the body fights them off. Both biology and AP Biology students can comment upon how it's safe to allow the body temperature to rise to a certain level (102 Farenheit), but higher than than can cause issues with homeostasis. AP Biology students also can note how this ties in with positive feedback.

Hunger on the wing

This is a link to the Discover Magazine article that 5th hour is reading in class. No extra credit for this one, yet.