Friday, February 12, 2016

How teachers are getting it wrong on climate change

There is, sadly, nothing surprising in the results of “a major new survey of U.S. middle school and high school science teachers” regarding the teaching of climate change.

While it is being taught, most teachers don’t understand that there is an overwhelming (greater than 95%) consensus that it is due to human activities, many are teaching it as if it is or might be “a natural process,” and some “science” teachers are teaching the line of the oil companies.

One of the most striking findings: 30 percent of teachers said in the survey that they tell students that the current warming “is likely due to natural causes” — contradicting major scientific assessments of the matter. Thirty-one percent of teachers also said that they include both the scientific consensus position — that global warming is human-caused — but then also a “natural causes” position that contradicts it, thus presenting “both sides,” in the study’s words.

…  The study also found that most teachers are unaware of the strength of the scientific consensus about the human causes of climate change. The survey asked them “what proportion of climate scientists think that global warming is caused mostly by human activities?” For middle school teachers, 30 percent chose the option “81 to 100%,” which the researchers identified as the correct answer. High school teachers were only a little better, at 45 percent.

In addition, many teachers seemed misinformed about the subject matter. When asked what they would include in their courses on climate change, almost half selected off-topic items like “pesticides, ozone layer, or impacts of rocket launches.”

A key problem, (lead author Eric) Plutzer emphasizes, is how many teachers are presenting climate change as something to be debated in class.

“I think the message that students take away is that this is unsettled, that this is a matter of opinion and everyone is entitled to their opinion, and the details of evidence are not being presented in a way that is consistent with the scientific record,” he says.

If we paid teachers to teach well, this problem would likely go away. The problem is that we pay teachers to just stick around, even if they never go in a classroom

Saturday, February 6, 2016

Relying on BMI as a health metric is a bad idea

While it may be generally true that an exceedingly high body-mass index score suggests poor health, it is not always true, and a UCLA study, according to an LA Times story, suggests relying on BMI as a health metric is a bad idea:

“A new study from UCLA finds that some 54 million Americans who are labeled as obese or overweight according to their body mass index are, when you take a closer look, actually healthy. The findings, published in the International Journal of Obesity, reveal that employers could potentially saddle people with unfairly high health insurance costs based on a deeply flawed measure of actual health.”

The article explains BMI:

“Body mass index is calculated by dividing a person’s weight in kilograms by the square of the person’s height in meters. According to the Centers for Disease Control and Prevention, a “healthy” BMI is 18.5-24.9, an overweight BMI is 25-29.9 and an obese BMI is 30 or higher.”

The problem with using that number for “health” is that it can mask serious ailments — like high blood pressure — in people with a low BMI and wrongly presume that individuals who are overweight or obese also have those sorts of ailments. They may be true in general, but wrong in a lot of specific cases. BMI is, the research suggests, too crude a measure to apply to any one individual.

“Researchers have begun to suspect that people with so-called “healthy” BMIs can be very unhealthy, and those with high BMIs can actually be in very good shape.”

The inaccuracy of BMI on an individual basis might have actual financial consequences:

“… the U.S. Equal Employment Opportunity Commission recently proposed rules that would allow employers to penalize employees for up to 30% of their health insurance costs if they don’t meet 24 health criteria — which include meeting a specific BMI. If body mass index doesn’t accurately reflect health, then those with high BMIs potentially could be overcharged for no reason.”

After examining data from more than 40,000 individuals, here is what was discovered:

“(The UCLA researchers) found that nearly half (47.4%) of overweight people and 29% of obese people were, from a metabolic standpoint, quite healthy. On the flip side, more than 30% of individuals with “normal” weights were metabolically unhealthy.” 

My own belief is that a better, or maybe just a less crude measure of body size is a person’s waist-to-height ratio. Generally, the number of inches around your waist (at its widest point) should be under half the number of inches you are tall. 

In my case, I weigh 200 pounds, my waist is 33.5 inches and I am 74 inches tall. So my waist-to-height ratio is .453. That is in the healthy category. A man who is my same height and weight, but has a 39 inch waist is overweight, because his waist-to-height ratio is .527. Yet the two of us would have the same BMI score, and that would be misleading.

The basic idea behind waist-to-height ratio is that it does not matter so much how much you weigh relative to your height. What matters is where you are carrying that weight, and to that extent whether your weight is muscular or lipidic. 

From WebMD: 

“This visceral fat in your middle makes toxins that affect the way your body works, says Samuel Dagogo-Jack, MD, president of the American Diabetes Association. Among them are chemicals called cytokines that boost your chances of heart disease and make your body less sensitive to insulin, which can bring on diabetes.

“Cytokines also cause inflammation, which can lead to certain cancers, says Eric Jacobs, PhD, a researcher at the American Cancer Society. In recent years, he says, scientists have uncovered links between belly fat and cancers of the colon, esophagus, and pancreas.”

If you are slim all over but fat in your gut, you are probably much less healthy than a person who is the same height and weight but carries his weight in thick, muscular legs, butt, back, chest and arms with a slim waist. 

Thursday, February 4, 2016

We cannot “Take control of Davis’ mean streets,” if we don't “Take control of Davis’ mean labor costs”

Quin Denvir, a lawyer who lives in Davis and became nationally famous when he defended Ted Kaczynski, wrote a letter to The Davis Enterprise today titled, “Take control of Davis’ mean streets.”

After expressing outrage that “the streets of downtown Davis have become dangerous on weekend and holiday nights, including a murder, stabbings, beatings and sexual assaults,” Mr. Denvir makes two suggestions:

“First, impose a 10:30 last drink and 12:30 closing for drink establishments on those nights.”

I have no idea why anyone thinks closing earlier will make any difference. If the problem is the admixture of insobriety and a predisposition to violence, criminal mayhem can break out at any time. It’s not as if no one can get drunk by 10:30 pm; or that a propensity to misbehave does not start until 1 am.

“Second, the mayor should direct the police chief to increase patrols in those areas on those nights.”

This is a more sensible suggestion. However, there is a problem. The Davis City Councils that Davis residents have repeatedly elected have overpaid all city employees by so much that there is no money to “increase patrols.” 

Mr. Denvir needs to qualify his call for increased patrols by calling for a halt to increases in employee compensation.

The City is now operating with about 75% of a full staff, because employee compensation increases keep breaking the budget. And yet, every year the City Council keeps raising employee compensation more and more, always faster than tax revenues can grow.

Among the most overpaid employees are our police officers. They cost taxpayers around $200,000 to $250,000 a year. So it is no wonder that our police department is understaffed.

Yet Mr. Denvir ignores that crucial point in his suggestion. And oddly enough, he calls for “the mayor” to request more cops on this beat, when it is the current mayor (along with his hand-picked city manager) who has been so friendly to city workers, jacking up their compensation without any regard to how we can afford those hikes.