This is the second instalment of our Science to English dictionary. You can find our first instalment (with terms from A-C) here and our second instalment (D-I) here.
L
Latent Infection
A latent infection can happen when you’re infected by a virus that is able to ‘hide out’ in your cells in a dormant state without causing symptoms. HIV is an example of a virus capable of latent infections.
Law
A scientific law can be said to be a “description of an observed phenomenon”, but it doesn’t provide an explanation as to why the phenomenon exists or the causes of it. Unlike a fact, a scientific law is a general observation about some relationships between two or more things that occur in nature.
M
Model System
In science, a model system(also known as a model organism, or a model) is a representation of something that we’re trying to study. For example, in vaccine testing, we often use mouse models. Models systems make it possible to scientifically examine systems or concepts that can’t be ethically or economically examined directly. For example- mouse models are used for early vaccine research because we want to make very, very sure that the vaccine is safe before moving to humans. In science, model systems are chosen based on several different criteria, including:
- How useful information collected through this model is to human health
- How much we know about the model (how well characterized it is)
- How easy the model is to work with
Among others.
Multivalent
In the context of COVID19, ‘multivalent’ is generally referring to an antigen (or an antibody). A multivalent antigen has multiple sites on it that can be bound to by an antibody.
P
P-value
A P-value is a statistical measure. It gives the odds of your observed outcome having occurred by chance.
Here’s a slightly less convoluted explanation: If at the end of your experiment you find that there is a difference between your control and experimental groups, and that this difference has a P value of 0.05, there is a 99.5% chance that this is a real difference (caused by whatever your experimental variable was) and not a result of random chance.
Peer-reviewed
We did a whole article on peer review! Check it out here.
Simply, peer-review is a process where a paper submitted to a journal is read and critiqued by several other scientists in the field. The goal of peer-review is to make sure that the data is sound and that the experiments were conducted properly. Peer review is an external seal of approval that indicates that the research has been deemed worthy of publication by at least one set of experts. In other words, it’s a form of scientific quality assurance
Persistent Infection
Persistent infections are slightly different from latent infections. Latent infections will remain at low levels and “hang out” in an infected cell until an event of stress causes it to produce more copies of the virus. Think of it this way, a latent infection is like a “really slow” infection, like the herpes simplex virus (HSV) or the chicken pox. Persistent infections however, take place when the virus that infected the cells is not cleared by the immune system. Instead viral particles, proteins and its genetic material can continue to be made in the infected cell or simply stay in the cell for a very long time. For example, the Epstein-Barr Virus (EBV) causes persistent infections and will stay in the cell for a while before reproducing once more.
(Definition by M. Manolya Sag)
Phagocytosis
Phagocytosis is when a cell ‘eats’ a large particle, such as a bacterium or a virus particle. You can see a video of it here.
Principal Investigator
A Principal Investigator (PI) is the person in charge of a research project or clinical trial. Most of the time, it’s the person whose name is on the research grant. In academic settings, the principal investigator is often the head of the research group (the professor in charge). When looking at a paper, you can usually find the principal investigator’s name at the end of the author list.
Pre-clinical
Pre-clinical studies of a drug or treatment are used to show that the drug works and is safe for human trials. These studies are usually conducted in animal models.
Pre-print
A pre-print is a full research paper that’s been released online before it has been peer-reviewed or accepted for publication in a journal.
Precise
In science, ‘precision’ refers to how close repeated measurements are to each other. For example, if I measure a length of string three times and get 4.8, 4.81 and 4.79, that is more precise than if I measured 4.8, 4.7 and 5.It’s important to remember that, in science, precision is independent of accuracy. You can have a precise measurement that’s not very accurate, and you can have an accurate measurement that’s not very precise.
Presymptomatic
When a patient is presymptomatic they are infected with a disease and are capable of spreading it to others, but may not be showing symptoms yet. It is well known that COVID19 patients can still shed virus particles while presymptomatic.