Thursday, April 17, 2008

Originator of chaos theory dies

Edward Lorenz, the man who created the field of chaos theory, died on Wednesday at the age of 90. His name will be unfamiliar to most of the world, even among the well-educated, yet those of us who have studied his work will surely mourn.

As the cited article says, "His discovery of 'deterministic chaos' brought about 'one of the most dramatic changes in mankind's view of nature since Sir Isaac Newton,' said the committee that awarded Lorenz the 1991 Kyoto Prize for basic sciences. It was one of many scientific awards that Lorenz won."

Tuesday, April 15, 2008


Cytometers are used for counting cells. Biotech applications that involve various cell types use cytometers to keep track of the types and quantities of cells. For example, a hemocytometer is used in biotech applications that involve blood cells.

Traditionally, cytometry was performed using microscopes and special cytometry slides. This made it a tedious and laborious process. Even a skilled scientist can only count about 200 cells per minute.

Nowadays, much of cytometry is more thoroughly automated. For example, a flow cytometer employs monochromatic light (typically a laser beam) to enumerate, sort, and identify cells within a laminar flow of liquid.

Saturday, April 05, 2008


Dysthymia is basically low-grade depression, being less severe and pervasive than major depression.According to the APA, two or more of six possible symptoms must be present for a diagnosis of dysthymia. Symptoms can include the following:

Poor appetite or overeating
Insomnia or hypersomnia
Low energy or fatigue
Low self-esteem
Poor concentration
Difficulty in making decisions
Feelings of hopelessness.

For a proper clinical diagnosis, an individual must experience symptoms for at least two years and should have no longer than a two-month period without symptoms being present. These symptoms must result in clinically significant distress or impairment in social, occupational, academic, or other major areas of functioning (APA, 2000).