Arabidopsis thaliana genome: All of the genetic information contained in Arabidopsis thaliana, a plant belonging to the mustard family.
The genomes of particular nonhuman organisms such as Arabidopsis have been studied for a number of reasons including the need to improve sequencing and analysis techniques. These nonhuman genomes also provide powerful sets of data against which to compare the human genome.
For example, Arabidopsis uses a chemical, glutamate, much as it is used in the human brain. The plant has genes that encode for glutamate receptors. In the human brain, glutamate acts as a chemical messenger, playing a role in acquiring and storing memories, and possibly contributing to certain mental health ailments. Glutamate also acts as a messenger in plants, communicating the presence of light and regulating light-dependent processes.
The Arabidopsis genome has been found to have 100 million base pairs to date and is estimated to have 25,000 genes to date. The sequencing of this genome was still in progress as of June 2000.
Arachnodactyly: Long spider-like fingers and toes, a frequent finding in Marfan syndrome, a heritable disorder of connective tissue. “Arachnodactyly” is derived from the Greek “arachne” (spider) and “daktylos” (finger). The Greek word was derived from the name “Arachne,” a maiden in Greek mythology whom the goddess Athena turned into a spider after the girl, a […]
Inflammation of the middle layer of membranes covering the brain and spinal cord. Arachnoiditis can occur as a complication of procedures such as myelograms, spinal operations, epidural steroid injections, and injury to the spine.
Arachnophobia: An abnormal and persistent fear of spiders. Sufferers from arachnophobia experience undue anxiety, even though they realize that the risk of encountering a spider and being harmed by it is small or nonexistent. They may avoid going barefoot and may be especially alert when taking showers or getting into and out of bed.
- Arbitration agreement
Arbitration agreement: An arrangement in which the patient waives the right to sue the physician and, instead, agrees to submit any dispute to arbitration. Arbitration agreements are legal and binding. The arguments in their favor are that, for patients, the case can be settled faster, and more money can go to the patient (rather than […]
- Arboviral encephalitis
Arboviral encephalitis: Inflammation of the brain (encephalitis) caused by infection with an arbovirus, a virus transmitted by a mosquito, tick or another arthropod. Infection of vertebrates, including humans, occurs when an infected arthropod feasts upon them for a blood meal. There are a number of types of arboviral encephalitis. Those that occur in the US […]