Recently, I got a new computer and I had to install the Apache Web Server on a Windows platform to be able to test my CGI scripts locally before publishing them on the internet.  The installation went well and I could test CGI executables without problems, but HTML pages that used Perl scripts displayed the dreaded HTTP Status 500 – Internal Server Error.  My Apache error.log file had the entry:

[client 127.0.0.1] (OS 3)The system cannot find the path specified.
: couldn’t create child process: 720003: echo1.pl

This type of error occurs more frequently in Windows systems than in Linux or Unix systems.  The reason is that the shebang line of the Perl script (#!/usr/bin/perl) is used by the Apache web server to find a program to interpret the script.  In Windows systems, the Perl interpreter is normally installed as C:\Perl\bin\perl.exe, whereas in Linux/Unix systems the path is usually /usr/bin/perl, as indicated in the shebang line.  Although there are several ways of telling the web server where to find the Perl interpreter, I have found that the simplest solution is to leave the Apache configuration alone and store a copy of the Perl interpreter as C:\usr\bin\perl.exe.

In this way, I can test my Perl scripts in the Windows system with exactly the same code that will run in the Linux systems.  In the event that I upgrade to a new version of Perl, I have to remember to also change the copy in the local C:\usr\bin\ directory, or install the new version of Perl in directory C:\usr instead of the default directory C:\perl.

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Example of a Declarative Sentence

This web site has a formal description of an English Grammar that I have used for many years for my computational linguistics work.  The problem with formal descriptions is that they are very terse, and it takes a lot of study to understand how the constituents interact with each other.

I have developed an Interactive Syntax Worksheet that displays the interaction of the grammatical components, and gives the user an intuitive feeling for the process involved in constructing English sentences.  I hope that this is useful to students learning English as a second language, and to native speakers interested in English syntax.  The program is written in JavaScript and it operates entirely within the web browser, so there is nothing to download.  The only requirement is that the browser should be running with JavaScript enabled.

Several studies have found that people with excess abdominal fat have a greater chance of dying from cancer or heart disease than people with smaller waistlines.  A Harvard study of 44,000 women in the Nurses’ Health study found that women with a waist size equal to or greater than 35 inches (89 cm) were approximately twice as likely to die of heart disease as were women with a waist size less than 28 inches (71 cm), regardless of their Body Mass Index (BMI). Similarly, women with a waist size equal to or greater than 35 inches also were twice as likely to die of cancer as were women with a waist size less than 28 inches.

Another study examined the association between waist circumference and mortality among 154,776 men and 90,757 women aged 51-72 years in the NIH-AARP Diet and Health Study.[1]  A large waist circumference was associated with an approximately 25% increased mortality risk for both men and women.  The waist circumference-mortality association was found in persons with and without prevalent disease, in smokers and nonsmokers, and across different racial or ethnic groups (non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Asians).

People with a normal BMI and a large waist circumference, 40 inches (102 cm) for men, and 34.6 inches (88 cm) for women, had approximately 20% higher mortality risk than those with normal BMI and normal waist size.

Many scientific studies focus on the absolute size of the waist instead of calculating a measure that provides the anthropomorphic proportions of the subjects.  The average height of persons in the U.S.  is 176.3 cm (69.4 inches) for males, and 162.2 cm (63.8 inches) for females.[2]  From these measurements, we can calculate that the Waist-to-Height ratio associated with 20% higher mortality is 0.58 for males and 0.54 for females.  In general, a normal Waist-to-Height ratio is less than 0.50.  Waist-to-Height ratios of 0.55 and over indicate excess abdominal fat which is associated with early death.

[1] Koster A, Leitzmann MF, Schatzkin A, Mouw T, Adams KF, van Eijk JT, Hollenbeck AR, Harris TB, Waist circumference and mortality, Am J Epidemiol. 2008 Jun 15;167(12):1465-75. PMID: 18417494

[2] Human Height

Fear of the number 13 is called Triskaidekaphobia.  Although the origins of this superstition have been lost in antiquity, they still persist in our modern world.  In Hispanic and Greek cultures Tuesday the 13th is considered an “unlucky” day, but in English folklore it is Friday the 13th.  The superstitions about the number thirteen are so ingrained in society that they even affect architectural decisions.  The building in which I live does not have a 13th floor, as you can see in the elevator panel above.

Yesterday, was Friday the 13th, and I had a particularly unlucky day.  Actually, it could have been worse, but I am glad that it wasn’t.  It all started with my usual TGIF celebration which consists of going to a restaurant for dinner and having a relaxing evening at home.  But not last night.

The French food was a complete disaster.  I ate only half of the food because it was too much, but nevertheless, I woke up in the middle of the night with a stomach ache.  I don’t think that the food was bad, it was just too salty and my organism is not used to so much salt.  I probably had dehydration cramps.  My girlfriend ordered something that had some crab meat and something else with a strange French name.  She should have heeded her instinct when the waiter asked if that was what she really wanted and whether she had had it before.  She asked “What is it?”, the waiter explained that if she liked sardines or anchovies she might like it.  mmhhh…  At this point I thought that she would change her mind, but no, she is an adventurous gourmand.

Too bad.  During the middle of her culinary adventure, it seemed to me that she looked a little bit green.  At about this time she offered to let me try her dish.  Having once been duped into tasting a horribly vile fishy morsel, I politely declined.  Then she confessed that she really didn’t like the dish, and that the mystery ingredient with the French name seemed to be some kind of raw roe or organ which was too fishy and unpleasant.  We left the restaurant in a less than pleasant mood.

But Friday the 13th had not worked its full magic yet.  The worst part was about to happen on the way home.  The first sign of trouble sounded like a pop as we passed a car that had been stopped by a police car.  I did not realize then that my rear tire had blown out and was leaking slowly.  As I turned into the cloverleaf to get on Washington’s outer belt, Route 495, I felt the car sway in an unusual way.  The steering became harder, and then I realized that I had to pull to the edge of the road.

Fortunately, the blowout was on the right wheel along the curb of the road, otherwise I would not have been able to change the tire without risking my life.  I fiddled in the dark with the jack and the spare tire while my girlfriend held a flashlight.  The flashlight gave up the ghost after a few minutes.  I managed to get the spare tire on in the dark.  When I tried to get back on the road, there were some strange noises from the wheel that I had changed.  I could not drive.  I called the Mercedes help line, and a knowledgeable assistant asked me if I had changed the tire myself.  When I said yes, he mentioned that the spare tire uses shorter wheel bolts than the regular wheels and suggested that this might be the problem.

I looked back through my toolkit using the cabin light of the car and there I found the five shorter bolts that I needed.  I jacked the car up again and replaced the bolts in the dark.  Now the car could move, but there was still some drag.  I drove home slowly, which was eight miles away, and I could hear that the rear brake calipers were dragging on the disk.  Evidently, the longer bolts had bent something.  The tire was under warranty.  I changed it on Saturday, but it cost me $101 Dollars to replace it after credit for residual value.  The brake repairs will have to be done on Monday, and they will probably be a lot more expensive than the tire.  This is a Friday the 13th that I will not soon forget.

The expanding waistlines of Americans have produced alarming increases in the rates of cardiovascular disease and diabetes.  Obesity increases the risk of Metabolic Syndrome, which is the combination of multiple symptoms that include high blood pressure, diabetes, and cardiovascular disease.

Scientists have tried to determine a person’s degree of obesity with measures such as the Body Mass Index (BMI) and the waist-to-hip ratio.  The BMI is calculated by dividing the weight in kilograms by the square of the height in meters. The BMI provides a way for identifying people who are too heavy for their height.  This is a good screening measure for finding fat people in the general population, but it fails for muscular bodybuilders who have large torsos and small waists.  The BMI does not take into consideration whether the excess weight consists of big biceps and pectoral muscles, or a large pot belly and a huge butt.

The waist-to-hip ratio is calculated by dividing the circumference of the waist by the circumference of the hips.  This measure determines if the abdomen is too big compared with the hips.  Unfortunately, as people gain weight, both their waist and their hips grow.  Recently, I posted pictures of Oprah Winfrey and her struggles with diet. Those pictures show that Oprah’s waist and hips increased substantially between 1988 and 2008.  Even though Oprah is a lot fatter now, her waist-to-hip ratio is about the same as it was when she was thin.  This is the basic defect of the waist-to-hip ratio.  A big butt cancels a big waist.  This is illustrated in the images above that show the shape of the typical female body for various weights.  Clearly, the evaluation of  the waist circumference as an anthropomorphic measure should not be done relative to the hips which also increase in size as a person gains weight.

There is a better measure: the waist-to-height ratio.[1] Unlike the hips which increase when a person gains weight, a person’s height remains constant. The waist-to-height ratio is a better measure of the relative size of the abdomen.  For a person like Oprah Winfrey, whose height is 66.5 inches, a change of waist size from 28 inches to 36 inches would result in waist-to-height ratios of 0.42 and 0.54, respectively.

[1] S.D. Hsieh, H. Yoshinaga, T. Muto, Int. J. Obes. Relat. Metab. Disord., 2003 May;27(5):610-6. Waist-to-height ratio, a simple and practical index for assessing central fat distribution and metabolic risk in Japanese men and women.

If you are on a diet and you are thinking about pizza, here is a dish that will satisfy your cravings and help you limit your calories.  This recipe uses eggplant slices instead of bread crust as the foundation for the pizza.

Our metabolism slows down as we age, and if we keep eating like when we were young, we eventually get fat.  Many studies have shown that people over the age of 50 appear to gradually lose muscle mass and gain weight. Paul Williams of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) investigated the question of whether vigorous exercise can prevent weight gain with age.  The study showed that in 4,769 runners between the ages of 18 and 50, weight gain occurred at the same rate regardless of the number of miles run per week. The average six-foot-tall man gained about 3.3 pounds and about 3/4 inches around the waist every 10 years.

So, exercise is not the answer to keeping weight off.  But we already knew that.  Moderately vigorous exercise burns up only around 400 calories per hour which is about the number of calories in a medium size serving of McDonald’s French Fries.  We can eat more calories in five minutes than we can lose in one hour of exercise.  The way to keep the weight off is to limit what we eat.

I read a recent post in Mary Robinson’s CRON Diary. Mary has been a practitioner of Calorie Restriction with Optimum Nutrition (CRON) for many years, but over the past couple of years her life has changed substantially.  Her son moved away to go to college, she retired, moved from the Washington, D.C. area to Austin, Texas, and she took in her mother to live with her.  All these changes destabilized the predictable routine that made it possible for her to control her diet.  The weight gain sneaked up on her.  She says:

“I am going to return to square one on CR – well maybe square three. I’ve just gotten lazy about it and have let the vacation atmosphere of my current situation, my mom’s slightly bad influence, Austin cuisine, and being home all day with easy access to the kitchen all derail me to some extent. The level of vigilance that was working reasonably well when I was working in Washington just does not work for me here. I’ve continued to slowly gain weight and now I weigh 8 pounds more than I did during my “golden” period of 3 or 4 years, when my weight was very stable.”

Can you count the number of excuses in that paragraph?  Vacation atmosphere, mom’s influence, Austin cuisine, being at home all day, access to the kitchen…  Weight gain happens so slowly that we hardly notice it.  An extra 50 calories per day will result in a weight gain of one-pound in just over two months.  That is just one extra slice of bread per day!  The 3.3 pounds that the runners gained over 10 years corresponds to a gain of only 1/3 of a pound per year which is really imperceptible.  It corresponds to 3.2 extra calories per day or about an extra teaspoon of sugar.

Here is Mary’s impression of weight gain:

“What’s interesting to me is that I don’t seem fatter to myself. I still look slim, as far as I can see. I guess I’ve gained it so slowly that I am used to it, and my weight is still good for my height. Some of my clothes are a little tight, though, which always provides good incentive to get back on careful CR!”

What is the secret to keeping weight off?  The answer is simple: An accurate scale that can show tenths of a pound.  Weigh yourself every morning after going to the bathroom and before eating or drinking anything.  This is how you can monitor how your diet affects your weight.  If you pig out, the scale will show it.  If you stay a little bit hungry, the scale will show your weight loss.  Don’t expect to see big changes from day to day. Variations of half a pound may occur due to water retention or dehydration.  It is the trend that matters.  You will probably find that you have to be hungry several hours per day in order to maintain a constant weight as you age.

Learn about Weight Control