Category Archives: Health

Race and suicide

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Suicide is generally understood as a cry of desperation. If so, you’d expect that the poorer, less-powerful, less-mobile members of society — black people, Hispanics, and women — would be the most suicidal. The opposite is true. While black people and Hispanics have low savings, and mobility, they rarely commit suicide. White Protestants and Indians are the most suicidal groups in the US; Blacks, Hispanics, Jews, Catholics, Moslems, Orientals, are significantly less prone. And black, non-Hispanic women are the least suicidal group of all — something I find rather surprising.

US, Race-specific suicide, all ages, Center for Disease control 2002-2012

US, Race-specific suicide, all ages, Center for Disease control 2002-2012

Aha, I hear you say: It’s the stress of upward mobility that causes suicide. If this were true, you’d expect Asians would have a high suicide rate. They do not, at least not American Asians. Their rate (male + female) is only 6.5/100,000, even lower than that for Afro-Americans. In their own countries, it’s different, and Japanese, Chinese, and Koreans commit suicide at a frightening rate. My suspicion is that American Asians feel less trapped by their jobs, and less identified too. They do not feel shame in their company’s failures, and that’s a good, healthy situation. In Korea, several suicides were related to the Samsung phones that burst into flames. While there is some stress from upward mobility, suggested by the suicide rates for Asian-American females being higher than for other woman, it’s still half that of non-hispanic white women, and for women in China and Korea. This suggests, to me, that the attitude of Asian Americans is relatively healthy.

The only group with a suicide rate that matches that of white protestants is American Indians, particularly Alaskan Indians. You’d figure their rate would be high given the alcoholism, but you’d expect it to be similar to that for South-American Hispanics, as these are a similar culture, but you’d be wrong, and it’s worthwhile to ask why. While men in both cultures have similar genes, suffer financially, and are jailed often, American Indians are far more suicidal than Mexican Americans. It’s been suggested that the difference is religiosity or despair. But if Indians despair, why don’t Mexicans or black people? I find I don’t have a completely satisfactory explanation, and will leave it at that.

Age-specific suicide rates.

Age-specific suicide rates, US, all races, 2012, CDC.

Concerning age, you’d probably guess that teenagers and young adults would be most suicidal — they seem the most depressed. This is not the case. Instead, middle age men are twice as likely to commit suicide as teenage men, and old men, 85+, are 3.5 times more suicidal. The same age group, 85+ women, is among the least suicidal. This is sort-of surprising since they are often in a lot of pain. Why men and not women? My suspicion is that the difference, as with the Asians has to do with job identification. I note that middle age is a particularly important time for job progress, and note that men are more-expected to hold a job and provide than women are. When men feel they are not providing –or worse –see themselves as a drag on family resources, they commit suicide. At least, this is my explanation.

It’s been suggested that religion is the consolation of women and particularly of black women and Catholics. I find this explanation doubtful as I have no real reason to think that old women are more religious than old men, or that Protestants and Indians are less religious than Hispanics, Asians, Moslems, and Jews. Another difference that I (mostly) reject is that access to guns is the driver of suicide. Backing this up is a claim in a recent AFSP report, that women attempt suicide three times more often than men. That men prefer guns, while women prefer pills and other, less-violent means is used to suggest that removal of guns would (or should) reduce suicide. Sorry to say, a comparison between the US and Canada (below) suggests the opposite.

A Centers for Disease Control study (2012) found that people doing manual labor jobs are more prone to suicide than are people in high-strew, thinking jobs. That is, lumberjacks, farmers, fishermen, construction workers, carpenters, miners, etc. All commit suicide far more than librarians, doctors, and teachers, whatever the race. My suspicion is that it’s not the stress of the job so much, as the stress of unemployment between gigs. The high suicide jobs, it strikes me, are jobs one would identify with (I’m a lumberjack, I’m a plumber, etc. ) and short term. I suspect that the men doing these jobs (and all these are male-oriented jobs) tend to identify with their job, and tend to fall into a deadly funk when their laid off. They can not sit around the house. Then again, many of these jobs go hand in hand with heavy drinking and an uncommon access to guns, poison, and suicidal opportunities.

zc-percentage-total-suicides-by-method-2000-2003-ca-2007-us

Canadians commit suicide slightly more often than Americans, but Canadians do it mostly with rope and poison, while more than half of US suicides are with guns.

I suspect that suicide among older men stems from the stress of unemployment and the boredom of sitting around feeling useless. Older women tend to have hobbies and friends, while older men do not. And older men seem to feel they are “a burden” if they can no-longer work. Actor Robin Williams, as an example, committed suicide, supposedly, because he found he could not remember his lines as he had. And Kurt Gödel (famous philosopher) just stopped eating until he died (apparently, this is a fairly uncommon method). My speculation is that he thought he was no longer doing productive work and concluded “if I don’t produce, I don’t deserve to eat.” i’m going to speculate that the culture of women, black men, Hispanics, Asians, etc. are less bound to their job, and less burdened by feelings of worthlessness when they are not working. Clearly, black men have as much access to guns as white men, and anyone could potentially fast himself to death.

I should also note that people tend to commit suicide when they lose their wife or husband; girlfriend or boyfriend. My thought is that this is similar to job identification. It seems to me that a wife, husband, or loved one is an affirmation of worth, someone to do for. Without someone to do for, one may feel he has nothing to live for. Based on the above, my guess about counseling is that a particularly good approach would be to remind people in this situation that there are always other opportunities. Always more fish in the sea, as it were. There are other women and men out there, and other job opportunities. Two weeks ago, I sent a suicidal friend a link to the YouTube of Stephen Foster’s song, “there are plenty of fish in the sea” and it seemed to help. It might also help to make the person feel wanted, or needed by someone else — to involve him or her is some new political or social activity. Another thought, take away the opportunity. Since you can’t easily take someone’s gun, rope, or pills — they’d get mad and suspicious –I’d suggest taking the person somewhere where these things are not — a park, the beach, a sauna or hot-tub, or just for a walk. These are just my thoughts, I’m a PhD engineer, so my thinking may seem odd. I try to use numbers to guide my thought. If what I say makes sense, use it at your own risk.

Robert Buxbaum, June 21, 2017.Some other odd conclusions: that Hamilton didn’t throw away his shot, but tried to kill Burr. That tax day is particularly accident prone, both in the US and Canada, and that old people are not particularly bad drivers, but they drive more dangerous routes (country roads, not highways).

bicycle helmets kill

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There is rarely a silver lining that does not come with a cloud, and often the cloud is bigger than the lining. A fine example is bicycle helmets. They provide such an obvious good that, at first glance, you’d think everyone would wear one, even without a law mandating it. Why would anyone risk their skull in a bicycle accident if injury were prevented by merely wearing a particular hat? Yet half the people ride without, even when there are laws and fines. There are some down-side to helmets, but they are so small that even mentioning them seems small. Helmets are inconvenient, and this causes people to ride a little less, so what?

hospital admissions for bicycle related head injuries, red, left; and bicycle related, non-head injuries, blue, right. Victoria Australia.

Hospital admissions for bicycle-related, head injuries, red, left scale, and bicycle-related, non-head injuries, blue, right scale. The ratio is 1:2 before and after the helmet law suggesting that helmet law did nothing but reduce ridership.

As to turns out, helmets hardly stop accidental injury, yet cause people to ride a lot less, and this lack of exercise causes all sorts of problems — far more than the benefits. In virtually every city where it was studied, bicycle ridership dropped by 30-40% when helmets were required, and as often as not, those who still rode, rode unhelmeted. There was a 30-40% decrease in head-trauma injuries, but it appears that this was just the result of 30-40% less ridership. You’d expect a larger decrease if the helmet helped, as such.

Take the experience of Victoria, Australia; head and non-head bicycle injury data plotted above. Victoria required bicycle helmets in January 1990. Before then, in the peak summer months, hospital records show some 50 bicycle-related head injuries per month, and 100 bicycle-related, non-head injuries — a 1:2 proportion. Later, after the law went into effect, each summer month saw about 35 bicycle-related, head injuries, and 70 bicycle-related, non head injuries. This proportion, 1:2, remained the same suggesting the only effect of the helmet law was to reduce ridership, with no increase in safety. The same 30% decrease was seen by direct count of riders on major streets, though now a greater proportion of those still riding were flaunting the law, and not wearing helmets.

One reason that helmets don’t help much is that the skull is already a very good helmet. As things stand, the main injury in a bicycle flip does not come from your skull cracking, it comes from your brain hitting the inside of your skull, and a second helmet doesn’t help stop that. There’s no increase in safety, and perhaps a decrease as the helmet appears to decrease vision. In a study of bicycle-injury-related highway deaths, Piet de Jong found that countries with the highest helmet use had the highest highway death rates. The country with the highest helmet use (the USA, 38% helmeted) had the highest cyclist death rate, 44 deaths per 1,000,000,000 km. By comparison, the nation with the least helmet use (Holland, 1% helmeted) had among the lowest death rates, only 10.7 deaths per 1,000,000,000 km. There are many explanations for this finding, one sense is that the helmets hurt vision making all types of injury and death more likely.

An hour or three of exercise per week adds years to your life -- especially among the middle aged.

From the national cancer institute. An hour or three of exercise per week adds years to your life — especially among the middle aged. Note these are healthy weight individuals. 

Worse than the effect on visibility, may be the effect on exercise. Exercise is tremendously beneficial, especially for middle-aged people in a sedentary population like the US. The lack of exercise is a lot more deadly, it turns out, than any likelihood of flying over the handlebars. How do I know? From studies like the National Cancer institute, shown at right. To calculate the cost/benefit of a little riding, less say you ride 3 hours per week at 10 mph (slow roll). The chart at right suggests a middle-aged person will add 3.4 years to your life, or about 10% life extension. Now consider the risks. This person will ride 30 miles per week, or 2400 km per year. Over 35 years the chance of death is only 0.36%. In order to get a 10% chance of death, you’d have to ride, over 2.3 million km, or 1000 years. Clearly the life extension benefit far outweighs the risk from fatal accident.

But life extension isn’t the total benefit of exercise. Exercise is shown to improve metal health, reducing depression and ADD in children, and likely in adults. Exercise also helps with weight loss, and that is another big health benefit (the chart above was for healthy body weight riders). So my first suggestion is get rid of bicycle helmet laws. I would not go so far as to ban helmets, but see clear disadvantages to the current laws.

The other suggestion: invent a better helmet. While most helmets are vented, and reasonably cool while you ride. They become uncomfortably hot when you stop. And they look funny in a store or restaurant. You can’t easily take them off, either: Restaurants no longer have hat racks, and stores never had them. What’s needed is a lighter, cooler helmet. Without that, and with helmet laws in place, people in the US tend to drive rather than ride a bicycle — and the lack of exercise is killing them.

Robert Buxbaum, January 19, 2017. One of my favorite writing subjects is the counter-intuitiveness of health science. See, eg. on radiation, or e-cigarettes, or sunshine, or health food. Here is a general overview of how to do science; I picked all the quotes from Sherlock Holmes.

Rethinking fluoride in drinking water

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Fluoride is a poison, toxic tor a small child in doses of 500 mg, and toxic to an adult in doses of a few thousand mg. It is a commonly used rat poison that kills by robbing the brain of the ability to absorb oxygen. In the form of hydrofluoric acid, it is responsible for the deaths of more famous chemists than any other single compound: Humphrey Davy died trying to isolate fluorine; Paul Louyet and Jerome Nickles, too. Thomas Knox nearly died, and Henri Moissan’s life was shortened. Louis-Joseph Gay Lussac, George Knox, and Louis- Jacques Thenard suffered burns and similar, George Knox was bedridden for three years. Among the symptoms of fluoride poisoning is severe joint pain and that your brain turns blue.

In low doses, though, fluoride is thought to be safe and beneficial. This is a phenomenon known as hormesis. Many things that are toxic at high doses are beneficial at low. Most drugs fall into this category, and chemotherapy works this way. Diseased cells are usually less-heartythan healthy ones. Fluoride is associated with strong teeth, and few cavities. It is found at ppm levels many well water systems, and has shown no sign of toxicity, either for humans or animals at these ppm levels. Following guidelines set by the AMA, we’ve been putting fluoride in drinking water since the 1960s at concentrations between 0.7 and 1.2 ppm. We have seen no deaths or clear evidence of any injury from this, but there has been controversy. Much of the controversy stems from a Chinese study that links fluoride to diminished brain function, and passivity (Anti-fluoriders falsely attribute this finding to a Harvard researcher, but the Harvard study merely cites the Chinese). The American dental association strongly maintains that worries based on this study are groundless, and that the advantage in lower cavities more than off-sets any other risks. Notwithstanding, I thought I’d take another look. The typical US adult consumes 1-3 mg/day the result of drinking 1-3 liters of fluoridated water (1 ppm = 1 mg/liter). This < 1/1000 the toxic dose,

While there is no evidence that people who drink high-fluoride well water are any less-healthy than those who drink city water, or distilled / filtered water, that does not mean that our city levels are ideal. Two months ago, while running for water commissioner, I was asked about fluoride, and said I would look into it. Things have changed since the 1960s: our nutrition has changed, we have vitamin D milk, and our toothpastes now contain fluoride. My sense is we can reduce the water concentration. One indication that this concentration could be reduced is shown below. Many industrial countries that don’t add fluoride have similar tooth decay rates to the US.

World Health Organization data on tooth decay and fluoridation.

World Health Organization data on tooth decay and fluoridation.

This chart should not be read to suggest that fluoride doesn’t help; all the countries shown use fluoride toothpaste, and some give out fluoride pills, too. And some countries that don’t add fluoride have higher levels of cavities. Norway and Japan, for example, don’t add fluoride and have 50% more cavities than we do. Germany doesn’t add fluoride, and has fewer cavities, but they hand out fluoride pills, To me, the chart suggests that our levels should go down, though not to zero. In 2015, the Department of Health recommend lowering the fluoride level to 0.7 ppm, the lower end of the previous range, but my sense from the experience of Europe is that we should go lower still. If I were to pick, I’d choose 1/2 the original dose: 0.6 to 0.35 ppm. I’d then revisit in another 15 years.

Having picked my target fluoride concentration, I checked to see the levels in use in Oakland county, MI, the county I was running in. I was happy to discover that most of the water the county drinks, that provided by Detroit Water and Sewage, NOCWA and SOCWA already have decreased levels of 0.43-0.55 ppm. These are just in the range I would have picked, Fluoride concentrations are higher in towns that use well water, about  0.65-0.85 ppm. I do not know if this is because the well water comes from the ground with these fluoride concentrations or if the towns add, aiming at the Department of Health target. In either case, I don’t find these levels alarming. If you live none of these town, or outside of Oakland county, check your fluoride levels. If they seem high, write to your water commissioner. You can also try switching from fluoride toothpaste to non-fluoride, or baking soda. In any case, remember to brush. That does make a difference, and it’s completely non-toxic.

Robert Buxbaum, January 9, 2017. I discuss chloride addition a bit in this essay. As a side issue, a main mechanism of sewer pipe decay seems related to tooth decay. That is the roofs of pipe attract acid-producing, cavity causing bacteria that live off of the foul sewer gas. The remedies for pipe erosion include cleaning your pipes regularly, having them checked by a professional once per year, and repairing cavities early. Here too, it seems high fluoride cement resists cavities better.

Skilled labor isn’t cheap; cheap labor isn’t skilled

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Popular emblem for hard hats in the USA. The original quote is attributed to Sailor Jack, a famous tattoo artist.

Popular emblem for hard hats in the USA. The original quote is attributed to Sailor Jack, a famous tattoo artist.

The title for this post is a popular emblem on US hard-hats and was the motto of a famous, WWII era tattoo artist. It’s also at the heart of a divide between the skilled trade unions and the labor movement. Skilled laborers expect to be paid more than unskilled, while the labor movement tends to push for uniform pay, with distinctions based only on seniority or courses taken. Managers and customers prefer skilled work to not, and usually don’t mind paying the skilled worker more. It’s understand that, if the skilled workers are not rewarded, they’ll go elsewhere or quit. Management too tends to understand that the skilled laborer is effectively a manager, often more responsible for success than the manager himself/herself. In this environment, a skilled trade union is an advantage as they tend to keep out the incompetent, the addict, and the gold-brick, if only to raise the stature of the rest. They can also help by taking some burden of complaints. In the late 1800s, it was not uncommon for an owner to push for a trade union, like the Knights of Labor, or the AFL, but usually just for skilled trades for the reasons above.

An unskilled labor union, like the CIO is a different animal. The unskilled laborer would like the salary and respect of the skilled laborer without having to develop the hard-to-replace skills. Management objects to this, as do the skilled workers. A major problem with unions, as best I can tell, is a socialist bent that combines the skilled and unskilled worker to the disadvantage of the skilled trades.

Not all unionists harbor fondness for welfare or socialism.

Also popular. Few workers harbor a fondness for welfare or socialism. Mostly they want to keep their earnings.

Labor union management generally prefer a high minimum wage — and often favor high taxes too as a way of curing societal ills. This causes friction, both in wage-negotiation and in political party support. Skilled workers tend to want to be paid more than unskilled, and generally want to keep the majority of their earnings. As a result, skilled laborers tend to vote Republican. Unskilled workers tend to vote for Democrats. Generally, there are more unskilled workers than skilled, and the union management tends to favor Democrats. Many union leaders have gone further — to international socialism. They push for high welfare payments with no work requirement, and for aid the foreign socialist poor. The hard-hats themselves tend to be less than pleased with these socialist pushes.

During the hippie-60’s and 70’s the union split turned violent. It was not uncommon for unionized police and construction workers to hurl insults and bricks on the anti-war leftists and non-working students and welfare farmers. Teamster boss Jimmy Hoffa, supported Nixon, Vietnam, and the idea that his truckers should keep their high wages at the expense of unskilled. Rival teamster boss, Frank Fitzsimmons pushed for socialist unity with the non-working of the world, a split that broke the union and cost Hoffa his life in 1975. Eventually the split became moot. The war ended, US factories closed and jobs moved overseas, and even the unskilled labor and poor lost.

Skilled workers are, essentially managers, and like to be treated that way.

Skilled workers are, essentially managers, and like to be treated that way.

The Americans with Disability Act is another part of the union split. The act was designed to protect the sick, pregnant and older worker, but has come to protect the lazy, nasty, and slipshod, as well as the drug addict and thief. Any worker who’s censored for these unfortunate behaviors can claim a disability. If the claim is upheld the law requires that the company provide for them. The legal status of the union demands that the union support the worker in his or her claim of disability. In this, the union becomes obligated to the worker, and not to the employer, customer, or craft — something else that skilled workers tend to object to. Skilled workers do not like having their neighbors show them high-priced, badly made products from their assembly line. Citing the ADA doesn’t help, nor does it help to know that their union dues support Democrats, welfare, and legislation that takes money from the pocket of any one who takes pride in good work. We’ll have to hope this split in the union pans out better than in 1860.

Robert Buxbaum, June 5, 2016. I’m running for water commissioner. I’d like to see my skilled sewer workers rewarded for their work and skill. Currently experienced workers get only $18/hour and that’s too little for their expertise. If they took off, they’d be irreplaceable, and the city would likely fall to typhus or the plague.

The boon of e-cigarettes

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E-cigarette use is rising fast among US smokers, and have passed traditional cigarette smoking among US High Schoolers, according to a recent CDC survey. Among the advantages: e-cigarettes are less regulated and cheaper than regular cigarettes. The vapors smell better. The smoke is supposed to be 95% less unhealthy. And the vape (e-cigarette “smoke”) doesn’t stain teeth like regular cigarettes. Not everyone is thrilled to see a safer cigarette alternative, though. A 2014 Harvard Study, The E-cigarette Quandary, points out that 95% less dangerous is not the same as 100%, that kids might come to smoke who might not otherwise, and that one could still get unwelcome, second-hand nicotine from exhaled vape. To correct these issues, some 200 regulation and prohibition bills have been introduced in 40 states in the past year alone. Among these, prohibitions on selling to minors, prohibitions on vaping where smoking is prohibited, and a National Park Service prohibition on e-cigarette use anywhere in a national park. 

Inside an e-cigarette

Inside an e-cigarette

My sense is that, for some people, those who already smoke, a 95% less dangerous alternative has got to be a boon, unless (as seems unlikely) people come to smoke twenty times more e-cigarettes than regular. To the contrary, It appears that e-cigarettes seem to help smokers quit tobacco, even with no help from a smoking cessation service. And over time, e-smokers tend to reduce the amount of nicotine in the juice, in that way reducing the toxic burden of the e-cigarette too. This is an option that is not possible with traditional, combustion cigarettes.

The claim that e-cigarettes are 95% less harmful than combustion cigarettes is based on a comparison between the concentrations of poisonous vapors inhaled, as measured for a study published in the journal, Addiction. Sorry to say, you have to pay to read the whole article, but you can read the abstract for free, or read a blog post by the lead author, Dr. Konstantinos Farsalinos. A British study supports this too, as described in a more-recent report by Public Health England. While it is not 100% clear that a 95% reduction in harmful vapor means that e-cigarettes are 95% less dangerous, that would seem to be the conclusion on a puff-per-puff basis, assuming no change in the formulation of e-cigarette “juice”, and only if the smokers don’t end up smoking vastly more.

Have e-cigarettes caused the decrease of regular smoking, or is it a threat to the decrease in regular smoking?

E-cigarette use among US High School students, 2014. The rise in e-cigarette use parallels a decrease regular smoking; perhaps it’s the cause of the decrease. From “The E-cigarette Quandary.”

For the reasons above, I gave an e-cigarette device to an employee who smokes. So far, it seems he likes it, and I’m happy that he doesn’t have to go outside to smoke. It also seems to have saved him some money and his teeth look a bit whiter as best I can tell. Interestingly, he claims he has less of a desire for regular cigarettes, too matching observations among high school use, and among the population in general. My first impression, the e-cigarette seems to be a boon, a good thing, for him at least.

Despite the sense that e-cigarettes are a boon, that sense is rooted in cæteris paribus, the assumption at all else remains static. Without regulations, I expect some nasty developments — in the content of e-cigarette juice, in the operation of the cigarette, and in the product marketing. Nicotine is a drug, cigarette makers are clever, and there is money to be had. I see regulation being needed over the acceptable composition of the juice, over the operating temperatures and flows of the cigarettes, and over sales and advertising to minors. With these put into place, I see no need for further prohibitions on e-cigarettes in the work-places or the national parks — or so it appears to me today.

Dr. Robert E. Buxbaum, November 8, 2015.

Zombie invasion model for surviving plagues

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Imagine a highly infectious, people-borne plague for which there is no immunization or ready cure, e.g. leprosy or small pox in the 1800s, or bubonic plague in the 1500s assuming that the carrier was fleas on people (there is a good argument that people-fleas were the carrier, not rat-fleas). We’ll call these plagues zombie invasions to highlight understanding that there is no way to cure these diseases or protect from them aside from quarantining the infected or killing them. Classical leprosy was treated by quarantine.

I propose to model the progress of these plagues to know how to survive one, if it should arise. I will follow a recent paper out of Cornell that highlighted a fact, perhaps forgotten in the 21 century, that population density makes a tremendous difference in the rate of plague-spread. In medieval Europe plagues spread fastest in the cities because a city dweller interacted with far more people per day. I’ll attempt to simplify the mathematics of that paper without losing any of the key insights. As often happens when I try this, I’ve found a new insight.

Assume that the density of zombies per square mile is Z, and the density of susceptible people is S in the same units, susceptible population per square mile. We define a bite transmission likelihood, ß so that dS/dt = -ßSZ. The total rate of susceptibles becoming zombies is proportional to the product of the density of zombies and of susceptibles. Assume, for now, that the plague moves fast enough that we can ignore natural death, immunity, or the birth rate of new susceptibles. I’ll relax this assumption at the end of the essay.

The rate of zombie increase will be less than the rate of susceptible population decrease because some zombies will be killed or rounded up. Classically, zombies are killed by shot-gun fire to the head, by flame-throwers, or removed to leper colonies. However zombies are removed, the process requires people. We can say that, dR/dt = kSZ where R is the density per square mile of removed zombies, and k is the rate factor for killing or quarantining them. From the above, dZ/dt = (ß-k) SZ.

We now have three, non-linear, indefinite differential equations. As a first step to solving them, we set the derivates to zero and calculate the end result of the plague: what happens at t –> ∞. Using just equation 1 and setting dS/dt= 0 we see that, since ß≠0, the end result is SZ =0. Thus, there are only two possible end-outcomes: either S=0 and we’ve all become zombies or Z=0, and all the zombies are all dead or rounded up. Zombie plagues can never end in mixed live-and-let-live situations. Worse yet, rounded up zombies are dangerous.

If you start with a small fraction of infected people Z0/S0 <<1, the equations above suggest that the outcome depends entirely on k/ß. If zombies are killed/ rounded up faster than they infect/bite, all is well. Otherwise, all is zombies. A situation like this is shown in the diagram below for a population of 200 and k/ß = .6

FIG. 1. Example dynamics for progress of a normal disease and a zombie apocalypse for an initial population of 199 unin- fected and 1 infected. The S, Z, and R populations are shown in (blue, red, black respectively, with solid lines for the zombie apocalypse, and lighter lines for the normal plague. t= t Nß where N is the total popula- tion. For both models the k/ß = 0.6 to show similar evolutions. In the SZR case, the S population disap- pears, while the SIR is self limiting, and only a fraction of the population becomes infected.

Fig. 1, Dynamics of a normal plague (light lines) and a zombie apocalypse (dark) for 199 uninfected and 1 infected. The S and R populations are shown in blue and black respectively. Zombie and infected populations, Z and I , are shown in red; k/ß = 0.6 and τ = tNß. With zombies, the S population disappears. With normal infection, the infected die and some S survive.

Sorry to say, things get worse for higher initial ratios,  Z0/S0 >> 0. For these cases, you can kill zombies faster than they infect you, and the last susceptible person will still be infected before the last zombie is killed. To analyze this, we create a new parameter P = Z + (1 – k/ß)S and note that dP/dt = 0 for all S and Z; the path of possible outcomes will always be along a path of constant P. We already know that, for any zombies to survive, S∞ = 0. We now use algebra to show that the final concentration of zombies will be Z∞ = Z0 + (1-k/ß)S0. Free zombies survive so long as the following ratio is non zero: Z0/S0 + 1- k/ß. If Z0/S0 = 1, a situation that could arise if a small army of zombies breaks out of quarantine, you’ll need a high kill ratio, k/ß > 2 or the zombies take over. It’s seen to be harder to stop a zombie outbreak than to stop the original plague. This is a strong motivation to kill any infected people you’ve rounded up, a moral dilemma that appears some plague literature.

Figure 1, from the Cornell paper, gives a sense of the time necessary to reach the final state of S=0 or Z=0. For k/ß of .6, we see that it takes is a dimensionless time τ of 25 or to reach this final, steady state of all zombies. Here, τ= t Nß and N is the total population; it takes more real time to reach τ= 25 if N is high than if N is low. We find that the best course in a zombie invasion is to head for the country hoping to find a place where N is vanishingly low, or (better yet) where Z0 is zero. This was the main conclusion of the Cornell paper.

Figure 1 also shows the progress of a more normal disease, one where a significant fraction of the infected die on their own or develop a natural immunity and recover. As before, S is the density of the susceptible, R is the density of the removed + recovered, but here I is the density of those Infected by non-zombie disease. The time-scales are the same, but the outcome is different. As before, τ = 25 but now the infected are entirely killed off or isolated, I =0 though ß > k. Some non-infected, susceptible individuals survive as well.

From this observation, I now add a new conclusion, not from the Cornell paper. It seems clear that more immune people will be in the cities. I’ve also noted that τ = 25 will be reached faster in the cities, where N is large, than in the country where N is small. I conclude that, while you will be worse off in the city at the beginning of a plague, you’re likely better off there at the end. You may need to get through an intermediate zombie zone, and you will want to get the infected to bury their own, but my new insight is that you’ll want to return to the city at the end of the plague and look for the immune remnant. This is a typical zombie story-line; it should be the winning strategy if a plague strikes too. Good luck.

Robert Buxbaum, April 21, 2015. While everything I presented above was done with differential calculus, the original paper showed a more-complete, stochastic solution. I’ve noted before that difference calculus is better. Stochastic calculus shows that, if you start with only one or two zombies, there is still a chance to survive even if ß/k is high and there is no immunity. You’ve just got to kill all the zombies early on (gun ownership can help). Here’s my statistical way to look at this. James Sethna, lead author of the Cornell paper, was one of the brightest of my Princeton PhD chums.

you are what you eat?

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The simplest understanding of this phrase is that you should eat good, healthy foods to be healthy, and that this will make you healthy in body and mind.

The author of the study published this book against GM foods simultaneously with release of his paper.

The author of this book against unhealthy foods faked his analysis to support the book.

Clearly there is some truth to this. Crazy people look crazy and often eat crazy. Even ‘normal’ people, if they eat too much are likely to become fat, lazy, and sick. There is a socio- economic effect (fat people earn less), and a physiological evidence that gut bacteria affects anxiety and depression (at least in rats). My sense here is at the diet extremes though. There is little, or no evidence to suggest you can make yourself more intelligent (or kind or good) by eating more of the right stuff, or just the right foods in just the right amounts. A better diet can make you look better, but there is a core lie at work when you extend this to imply that the real you is your body, or so tied to your body that a healthy mind can not be found in a sickly body. But most evidence is that the mind is the real you, and (following Socrates) that beautiful minds are found in sickly bodies. I’ve seen few (basically, no) healthy poets, writers, or great artists. Neither are there scientists of note (that I can recall) who lived without smoking, drinking, and any bad habits. Many creative people did drugs. George Orwell smoked cigarette, and died of TB, but wrote well to the end. There is no evidence that bad writing or thinking can be improved by health foods. Stupid is as stupid does, and many healthy people are clearly dolts.

Not that it’s always clear what constitutes good health, or what constitutes good food for health, or what constitutes a good mind. Skinny people may be admired and may earn more, but it is not clear they are healthy. Yule Gibbons, the natural food guru died young of stomach cancer. Adele Davis, another the author of “eat right to be healthy,” died of brain cancer. And Jim Fix, “the running doctor” died young of a heat attack while running. Their health foods may have killed them, and that unhealthy foods, like chocolate and coffee can be good for you. It’s likely a question of balance. While a person will feel better who dresses well, the extreme is probably no good. Very often, a person is drawn after his self-image to be the person he pretends. Show me a man who eats only vegetarian, and I’ll show you someone who sees himself as spiritual, or wants to be seen as spiritual. And that man is likely to be drawn to acting spiritual. Among the vegetarians you find Einstein, George B. Shaw, and Gandhi, people who may have been spiritual from the start, but may have been kept to spirituality from their diets. You also find Hitler: spirituality can take all sorts of forms.

Ward Sullivan in the New Yorker

Ward Sullivan in the New Yorker. People eat, drink, and dress like who they are. And people become like those they eat drink and dress like.

Choice of diet also helps select the people you run into. If you eat vegetarian, you’re likely to associate with other vegetarians, and you will likely behave like them. If you eat Chinese, Greek, or Mexican food, you’re likely to associate with these communities and behave like them. Similarly, an orthodox Jew or Moslem is tied to his community with every dinner and every purchase from the kosher or halal store.

And now we come to the bizarre science of bio-systems. Each person is a complex bio-system, with more non-human DNA than human, and more non-human cells than human. A person has a vast army of bugs on him, and a similarly vast pool of bugs within him. Recent research suggests that what we eat affects this bio-system, and through it our mental state. For whatever the mechanism, show me someone who drinks only 30 year Scotch or 40-year-old French wine, and I’ll show you a food snob. By contrast, show me someone who eats good, cheap food, and drinks good, cheap wine or Scotch (Lauder’s or Dewar’s), and I’ll show you a decent person very much like myself, a clever man who either is a man of the people or who wants to be known as one.”Dis-moi ce que tu manges, je te dirai ce que tu es.” [Tell me what you eat and I will tell you what you are].

Robert E. Buxbaum, February, 2015. My 16-year-old daughter asked me to write on this topic. Perhaps she didn’t know what it meant, or how true I thought it was, or perhaps she liked my challenges of being 16.

Statistics of death and taxes — death on tax day

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Strange as it seems, Americans tend to die in road accidents on tax-day. This deadly day is April 15 most years, but on some years April 15th falls out on a weekend and the fatal tax day shifts to April 16 or 17. Whatever weekday it is, about 8% more people die on the road on tax day than on the same weekday a week earlier or a week later; data courtesy of the US highway safety bureau and two statisticians, Redelmeier and Yarnell, 2014.

Forest plot of individuals in fatal road crashes over 30 years. X-axis shows relative increase in risk on tax days compared to control days expressed as odds ratio. Y-axis denotes subgroup (results for full cohort in final row). Column data are counts of individuals in crashes. Analytic results expressed with 95% confidence intervals setting control days as referent. Results show increased risk on tax day for full cohort, similar increase for 25 of 27 subgroups, and all confidence intervals overlapping main analysis. Recall that odds ratios are reliable estimates of relative risk when event rates are low from an individual driver’s perspective.

Forest plot of individuals in fatal road crashes for the 30 years to 2008  on US highways (Redelmeier and Yarnell, 2014). X-axis shows relative increase in risk on tax days compared to control days expressed as odds ratio. Y-axis denotes subgroup (results for full cohort in final row). Column data are counts of individuals in crashes (there are twice as many control days as tax days). Analytic results are 95% confidence intervals based on control days as referent. Dividing the experimental subjects into groups is a key trick of experimental design.

To confirm that the relation isn’t a fluke, the result of well-timed ice storms or football games, the traffic death data was down into subgroups by time, age, region etc– see figure. Each groups showed more deaths than on the average of the day a week before and after.

The cause appears unrelated to paying the tax bill, as such. The increase is near equal for men and women; with alcohol and without, and for those over 18 and under (presumably those under 18 don’t pay taxes). The death increase isn’t concentrated at midnight either, as might be expected if the cause were people rushing to the post office. The consistency through all groups suggests this is not a quirk of non-normal data, nor a fluke but a direct result of  tax-day itself.Redelmeier and Yarnell suggest that stress — the stress of thinking of taxes — is the cause.

Though stress seems a plausible explanation, I’d like to see if other stress-related deaths are more common on tax day — heart attack or stroke. I have not done this, I’m sorry to say, and neither have they. General US death data is not tabulated day by day. I’ve done a quick study of Canadian tax-day deaths though (unpublished) and I’ve found that, for Canadians, Canadian tax day is even more deadly than US tax day is for Americans. Perhaps heart attack and stroke data is available day by day in Canada (?).

Robert Buxbaum, December 12, 2014. I write about all sorts of stuff. Here’s my suggested, low stress income tax structure, and a way to reduce/ eliminate income taxes: tariffs– they worked till the Civil war. Here’s my thought on why old people have more fatal car accidents per mile driven.

Change your underwear; of mites and men

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The underware bomber mites make it right.

Umar, the underwear bomber.

For those who don’t know it, the underwear bomber, Umar Farook Abdulmutallab, wore his pair of explosive underwear for 3 weeks straight before trying to detonate them while flying over Detroit in 2009. They didn’t go off, leaving him scarred for life. It’s quite possible that the nasty little mites that live in underwear stopped the underwear bomber. They are a main source of US allergens too.

Dust mite, skin, and pollen seen with a light microscope. Gimmie some skin.

Dust mite, skin, and pollen seen with a light microscope. Gimmie some skin.

If you’ve ever used an electron microscope to look at household objects, you’ll find them covered with brick-like flakes of dried out skin-cells: yours and your friends’. Each person sheds his or her skin every month, on average. The outer layer dries out and flakes off as new skin grows in behind it. Skin flakes are the single largest source of household dust, and if not for the fact that these flakes are the main food for mites, your house would be chock full of your left over skin. When sunlight shines in your window, you see the shimmer of skin-flakes hanging in the air. Under the electron microscope, the fresh skin flakes look like bricks, but mite-eaten skin flakes look irregular. Less common, but more busy are the mites.

The facial mite movie. They live on in us, about 1 per hair follicle, particularly favoring eyelashes. Whenever you shower, your shower with a friend.

The facial mite movie. They live on in us, about 1 per hair follicle, particularly favoring eyelashes. Whenever you shower, you shower with a friend.

Dry skin is mostly protein (keratin), plus cholesterol and squalene. This provides great nutrition for dust mites and their associated bacteria. In warm, damp environments, as in your underwear or mattress, these beasties multiply and eat the old skin. The average density of dust mites on a mattress is greater than 2500/gram of dust.[1]  The mites leave behind excrement and broken off mite-limbs: nasty bits that are the most common allergens in the US today.

An allergy to dust shows up as sneezing, coughing, clogged lungs, and eczema. The most effective cure is a high level of in-home hygiene; mites don’t like soap or dry air. You’ve go to mop and vacuum regularly. Clean and change your clothing, particularly your undergarments; rotate your mattresses, and shake the dust out of your bedding. Vacuuming is less-effective as a significant fraction of the nasties go through the filter and get spread around by the vacuum blower.

As it turns out, dust mites and their bacteria eat more than skin. They also eat dried body fluids, poop residue, and the particular explosive used by Umar Farook, pentaerythritol tetra nitrate, PETN (humans can eat and metabolize this stuff too — it’s an angina treatment). The mites turn PETN into less-explosive versions, plus more mites.

Mighty mites as seen with electron microscopy. They eat more than skin.

Mighty mites as seen with electron microscopy. They eat more than skin.

There are many varieties of mite living on and among us. Belly button mites, for example, and face mites as shown above (click on the image to see it move). On average, people have one facial mite per hair follicle. It’s also possible that the bomber was stopped by poor quality control engineering and not mites at all. Religion tends to be at odds with a science like quality control, and followers tend to put their faith in miracles.

Chigger turning on a dime

Chigger turning on a dime

larger than the dust mite is the chigger, shown at left. Chiggers leave visible bites, particularly along the underwear waste-band. There are larger-yet critters in the family: lice, bed bugs, crabs. Bathing regularly, and cleaning your stuff will rid yourself of all these beasties, at least temporarily. Keeping your hair short and your windows open helps too. Mites multiply in humid, warm environments. Opening the windows dries and cools the air, and blows out mite-bits that could cause wheezing. Benjamin Franklin and took air-baths too: walking around naked with the windows open, even in winter. It helped that he lived on the second floor. Other ways to minimize mite growth include sunlight, DOT (a modern version of DDT), and eucalyptus oil. At the very minimum, change your underwear regularly. It goes a long way to reduce dust embarrassing moments at the jihadist convention.

Dr. Robert E. Buxbaum, Sept 21, 2014. Not all science or life is this weird and wonderful, but a lot is, and I prefer to write about the weird and wonderful bits. See e.g. the hazards of health food, the value of sunshine, or the cancer hazard of living near a river. Or the grammar of pirates.

Marijuana, paranoia, and creativity

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Many studies have shown that marijuana use and paranoid schizophrenia go together, the effect getting stronger with longer-term and heavy use. There also seems to be a relation between marijuana (pot) and creativity. The Beetles and Stones; Dylan, DuChaps, and Obama: creative musicians painters, poets and politicians, smoked pot. Thus, we can ask what causes what: do crazy, creative folks smoke pot, or does pot-smoking cause normal folks to become crazy and creative, or is there some other relationship. Dope dealers would like you to believe that pot-smoking will make you a creative, sane genius, but this is clearly false advertising. If you were not a great artist, poet, or musician before, you are unlikely to be one after a few puffs of weed.

The Freak Brothers, by Gilbert Shelton. While these boys were not improved by dope, It would be a shame to put the artist in prison for any length of time.

The Freak Brothers, by Gilbert Shelton. What’s the relationship?

When things go together, we apply inductive reasoning. There are four possibilities: A causes B (pot makes you crazy and/or creative), B causes A (crazy folks smoke pot, perhaps as self medication), A and B are caused by a third thing C (in this case, poverty culture, or some genetic mutation). Finally, it’s possible there’s no real relationship but a failure to use statistics right. If we looked at how many golf tournaments were won by people with W last names (Woods, Wilson, Watson) we might be fooled to think it’s a causal relationship. Key science tidbit: correlation does not imply causation.

The most likely option, I suspect is that some of all of the above is going on here: There is an Oxford University study that THC, the main active ingredient in pot, causes some, temporary paranoia, and another study suggests that pot smoking and paranoid insanity may be caused by the same genetics. To this mix I’d like to add another semi-random causative: that heavy metals and other toxins that are sometimes found in marijuana are the main cause of the paranoia — while being harmful to creativity.

marijuana -paranoia

Pot cultivation is easy — that’s why it’s called weed– and cultivation is often illegal, even in countries with large pot use, like Jamaica. As a result, I suspect pot is grown preferentially in places contaminated with heavy metal toxins like vanadium, cadmium, mercury, and lead. No one wants to grow something illegal on their own, good crop-land. Instead it will be grown on toxic brownfields where no one goes. Heavy metals are known to absorb in plants, and are known to have negative psychoactive properties. Inhalation of mercury is known to make you paranoid: mad as a hatter. Thus, while the pot itself may not drive you nuts, it’s possible that heavy metals and other toxins in the pot-soil may. The creativity would have to come from some other source, and would be diminished by smoking bad weed.

I suspect that creativity is largely an in-born, genetic trait that can be improved marginally by education, but I also find that creative people are necessarily people who try new things, go off the beaten path. This, I suspect, is what leads them to pot and other “drug experiments.” You can’t be creative and walk the same, standard path as everyone else. I’d expect, therefore, that in high use countries, like Jamaica, creative success is preferentially found in the few, anti-establishment folks who eschew it.

Robert E. (landslide) Buxbaum, September 4, 2014. The words pot, marijuana, dope, and weed all mean the same but appear in different cultural contexts. To add to the confusion, Jamaicans refer to pot as ganja or skiff, and their version of paranoid schizophrenia is called “ganja psychosis”. I’m not anti-pot, but favor government regulation— perhaps along the lines of beer regulation, or perhaps the stricter regulation of Valium. My most recent essay was on the tension-balance between personal freedom and government control. I was recently elected in Oak Park’s 3rd voting district. My slogan: “A Chicken in every pot, not pot in every chicken”. I won by one vote. For those who are convinced they’ve become really deep, creative types without having to create anything, let me suggest the following cartoon about talent. Also, if pot made you smart, Jamaica would be floating in Einsteins.