Archive for the ‘Life Science’ Category

Making Box Plots on Ti-84

August 15, 2017

Quick graphs on the Ti-84 is a good way to  see how data is distributed.  The attached document gives step by step instructions along with an example to practice.

Making a Box Plot on the TI 84


Maybe It’s Okay to Eat Before Surgery

July 13, 2017

Not eating before surgery was long considered one of those “absolute” rules that was not debatable.  Now comes an article that tells us that in Europe carbohydrate-rich drinks before surgery are not only allowed, they lead to improved outcomes!  Who knew?  Less risk of infection and faster recovery are two positives, along with resultant cost savings.  Click below for full article.

Don_t Hold Fast to This Surgical Rule – WSJ

20% error rate found in study of published genetics research papers

September 13, 2016

In a recent study 20% of genetics research papers using Microsoft Excel have been found to have data errors due to improper data entry.  It turns out that gene names such as SEPT2 and MARCH1 (these are actual gene name abbreviations used by scientists) get converted to dates by Excel and then result in rejected data.  The problem is resolvable if the scientists would make sure the data cells were formatted as “Text,” prior to entering the data.

For the full article in the Washington Post click on the link below.

Early Bedtime May Fight Fat

July 19, 2016

Scientists studying sleep time of preschoolers and obesity in teenages have observed some interesting correlations, but they are not conclusively cause and effect.  As reported in the New York Times, July 19, 2016.

Early Bedtime May Fight Fat NYT 7_19_16

Metric System of Measurements – Conversions

June 8, 2016

Centigrade and Fahrenheit conversions in addition to table of conversions between the Metric System and the British System of Measurements.

click here:  Metric system of measurements


Popular graph types

March 26, 2015

Seven of the most common graphs in statistics are listed below:

  1. Pareto Diagram or Bar Graph– A bar graph contains a bar for each category of a set of qualitative data. The bars are arranged in order of frequency, so that more important categories are emphasized.
  2. Pie Chart or Circle Graph– A pie chart displays qualitative data in the form of a pie. Each slice of pie represents a different category.
  3. Histogram– A histogram in another kind of graph that uses bars in its display. This type of graph is used with quantitative data. Ranges of values, called classes, are listed at the bottom, and the classes with greater frequencies have taller bars.
  4. Stem and Left Plot– A stem and left plot breaks each value of a quantitative data set into two pieces, a stem, typically for the highest place value, and a leaf for the other place values. It provides a way to list all data values in a compact form.
  5. Dot plot – A dot plot is a hybrid between a histogram and a stem and leaf plot. Each quantitative data value becomes a dot or point that is placed above the appropriate class values.
  6. Scatterplots – A scatterplot displays data that is paired by using a horizontal axis (thex axis), and a vertical axis (the y axis). The statistical tools of correlation and regression are then used to show trends on the scatterplot.
  7. Time-Series Graphs– A time-series graph displays data at different points in time, so it is another kind of graph to be used for certain kinds of paired data. The horizontal axis shows the time and the vertical axis is for the data values. These kinds of graphs can be used to show trends as time progresses.

Typing Subscripts on an iPad

March 23, 2015


via Typing Subscripts on an iPad.

Fire sensors for the attic…best advise I didn’t get.

February 26, 2015

Heat sensors in an attic can warn of a fire way before a smoke alarm on an upper floor would trigger an alert. This year two friends had very serious fires that started in the attic and worked their way down. By the time the smoke alarms went off the sleeping families had time to get out, but no more.

Smoke alarms in the attics are not a good idea because the dust interferes with their proper operation. I inquired of the experts and found out that heat sensors in an attic are the best way to detect a fire, and they are not affected by the dust. For some reason I had never heard that, not even from the company that sold me an alarm system, complete with a unit that can autodial a central station.

The wiring in the attic in an older home can start a fire, and no, fuses and circuit breakers will not always trip to prevent a catastrophe. Attic fans and air handlers can also start a fire when they malfunction. In the case of one of my friends who lived in an attached home, his house caught fire when the neighbor’s house caught fire, and the flames traveled across the attics, and down.

Adding two heat sensors to my system cost $159, well worth the price.

Home Monitoring of Patients by Doctors

February 18, 2015

As electronics applications get more sophisticated, and the pressure keeps increasing to keep medical costs down, doctors will more and more rely on home monitoring of patients. Electronic devices at home, such as blood-pressure monitors, digital scales, pulse and oxygen monitors, and EKG recorders to name a few, can easily be monitored remotely by doctors using a home “telestation.” Home telestations can also be programmed to ask relevant questions which can be answered with push button responses.

Monitoring of diabetics’ sugar levels is one of the early applications of this technology, where the data is not always relayed to the doctor, but sometime to a parent via cell phone or to the patient herself. Alarms can wake up a patient, or a parent to advise of an otherwise unnoticed medical situation.

This is just the beginning of what we can be looking forward to in the future.

For a comprehensive treatment of this subject see the Wall Street Journal article, “Stay Home. The Doctor is Watching You.” published February 17, 2015.

The “proxy,” an easier way to count.

February 10, 2015

The number of new car registrations can be used as a proxy for new car sales in cases where the new car sales numbers are not available, or the new car registration statistics are easier or cheaper to get.

In an article about the European car sales, the Wall Street Journal reports, “Last year, new passenger car registrations, a proxy for new car sales, rose 5.7% to 12.6 million, according to figures released by the European Automobile Manufacturers’ Association, or ACEA.”

Why is the number of new car registrations a good proxy for new car sales numbers? It is based on the assumption that people who buy new cars will register them and use them right away, so it is reasonable to assume a one to one relationship, with a very high degree of accuracy.

Another example of a proxy would be using the sales of various commodities as a measure of the strength of an economy, i.e., the sale of certain luxury goods. Some proxies are better at mimicking the underlying statistic than others.