Friday, July 04, 2008

On the value of peer review

Just thought I'd post this comment that I excerpted from a message board. It discusses the value and limitations of the peer review process.

I don't think its the peer review that is the problem, but rather our perception of what it means.

Peer review is just a way of vetting an article to make sure it's not whacked out. The reviewers don't repeat experiments, recalculate all the data, etc.

Being published in a peer reviewed journal simple means that the author has made a respectable argument. Kinda of like a indictment.

The actual court case doesn't happen until after it's been published. When others may dispute the results, repeat the experiment, etc.

But the simple fact that the article has been published in a peer review journal does not make it inherently correct, just like being indicted for crime doesn't mean you are actually guilty.

Sunday, June 15, 2008

Tobacco mosaic

Adapted from the book, Scientists and Discoveries:

In 1892, Dmitry Ovanovsky, a Russian botanist, investigated the sap from tobacco plants affected by mosaic disease. This is a condition that stunts the growth of tobacco plants and mottles their leaves in a characteristic mosaic pattern (hence the name). He passed the sap through filters so fine that they would trap all known bacteria. The sap retained its ability to produce the disease in new plants. Ovanovsky thought there was some flaw in his experiment, not realizing that viruses (which had not yet been discovered) were at work.

Friday, May 30, 2008

Bull snake

I captured a bull snake recently -- twice, in fact. It was a pet snake that had escaped, and I found it in my closet three days later. I placed it in a temporary travelling cage so that I could show him to some children, but after I brought him home, he managed to pop the lid off the cage overnight.

That does it. Next time, I'm placing him directly in his permanent cage. Ugh.

Wednesday, May 28, 2008

Inaccurate assay description

I just discovered that this site says, "ELISpot assays employ the sandwich enzyme-linked immunosorbent assay (ELISA) technique." That is not very accurate. To be sure, there are some undeniable similarities between the ELISPOT method and the ELISA assay technique, but it's a bit of a misrepresentation to say that the former uses the latter. I would certainly be extremely uncomfortable making such a claim.


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).

Friday, March 21, 2008

Microplate readers

The following has been excerpted from Biotechnology 101 by Brian Robert Shmaefsky. Some grammatical issues have been corrected. Also, please note that the description provided in this excerpt is a bit simplistic. It's accurate when it comes to ELISA assays, but not for assays in which specific structures are generated, such as FluoroSpot and ELISpot assays or colony counting applications.

"The microplate reader works by shining a particular type of light at each of the samples in [a] microwell plate. It can be adjusted to[sic] in various ways. It can read a few to all [of] the samples in a particular sequence or it can read several samples at a time. A particular type of light is selected based on the type of analysis being done. Some chemicals absorb a particular color of light. Their presence or quantity can be determined by measuring how much of the light is absorbed by the sample. This is called absorbance detection. Hence, a scientist looking for the production of a particular chemical made by a cell would notice more and more light being absorbed by the reader as the chemical is produced. Some chemicals glow when exposed to a particular light. This is called fluorescence detection. The amount of chemical is measured by the intensity of glowing. Microplate readers feed the absorbance or fluorescence measures into a computer program that analyses the particular information being collected."

BTW, this guy could have used a better editor.

Tuesday, February 26, 2008

Groups of animals

I came across teh follwoing list of unusual names for animal groupings. Thought I'd post it here.

A convocation of eagles
A prickle of porcupines
A charm of finches
An unkindness of ravens
A skulk of foxes
A shiver of sharks
A troubling of goldfish
A pod of whales
A smack of jellyfish
A descent of woodpeckers
A mob of kangaroos
A zeal of zebras
A shrewdness of apes
An exaltation of larks
A battery of barracudas
A troop of monkeys
A kaleidoscope of butterflies
A parliament of owls
A quiver of cobras
An ostentation of peacocks
A murder of crows
A rookery of penguins