Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Introduction and Methods of Leveling

Introduction and Methods of Leveling

Leveling is a surveying procedure used to determine elevation differences between distant points. Elevation refers to the vertical distance above or below a reference datum, typically mean sea level (MSL). In the United States, elevations are often referenced to the mean sea level station at Father Point Rimouski along the St. Lawrence Seaway. To make the datum accessible, permanent markers are established throughout the region. These markers, called benchmarks, have known elevations. If the...

Leveling Effect

Leveling Effect

In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the...

High-Level and Low-Level Awareness

High-Level and Low-Level Awareness

Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive...

Levels of Organization

Levels of Organization

Biological organization is the classification of biological structures, ranging from atoms at the bottom of the hierarchy to the Earth's biosphere. Each level of the hierarchy represents an increase in complexity that builds upon the previous level.
Molecules Are Composed of Atoms, and Biomolecules Are Assembled from Molecules:
The most basic levels include atoms, molecules, and biomolecules. Atoms, the smallest unit of ordinary matter, are composed of a nucleus and electrons. Molecules...

Fermi Level

Fermi Level

The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...

Ratio Level of Measurement

Ratio Level of Measurement

The way a set of data is measured is called its level of measurement. Correct statistical procedures depend on a researcher being familiar with levels of measurement. For analysis, data are classified into four levels of measurement—nominal, ordinal, interval, and ratio.
A set of data measured using the ratio scale takes care of the ratio problem and provides complete information. Ratio scale data are like interval scale data, except they have a zero point and ratios can be calculated....

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

The clinical value of commonly used spinal fluid diagnostic studies in the evaluation of patients with suspected multiple sclerosis.

The American journal of managed care·1998

Same author

Childhood allergy.

Southern medical journal·1980

Same author

Persistent eosinophilia with corticosteroid therapy.

Annals of allergy·1980

Same author

Localized heat urticaria.

Annals of allergy·1980

Same author

Wasp sting anaphylaxis with cerebral infarction.

Annals of allergy·1977

Same author

IgE suppressor T cells and atopy.

Lancet (London, England)·1977

Search research articles

Related Experiment Video

Updated: Feb 12, 2026

Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature

Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature

Published on: June 19, 2019

C1q levels in hereditary angioedema

The Journal of Allergy and Clinical Immunology

|March 1, 1977

Summary

Serum C1q levels are often depressed in hereditary angioedema patients, even below normal ranges. This finding does not rule out hereditary angioedema diagnosis.

Area of Science:

Immunology
Genetics

Background:

Hereditary angioedema (HAE) is a rare genetic disorder.
Complement system component C1q plays a crucial role in immune response.
Previous studies on C1q levels in HAE patients have yielded varied results.

Purpose of the Study:

To investigate serum C1q levels in individuals with hereditary angioedema.
To determine the correlation between C1q levels and disease activity.
To assess the stability of C1q in serum samples under different storage conditions.

Main Methods:

Serum samples were collected from 21 affected members across 4 kindreds with HAE.
Serum C1q and C4 levels were measured.
Statistical analysis was performed to compare C1q levels between patients, unaffected family members, and healthy controls.

More Related Videos

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Published on: June 15, 2019

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis

Published on: June 9, 2018

Related Experiment Videos

Last Updated: Feb 12, 2026

Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature

Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature

Published on: June 19, 2019

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Published on: June 15, 2019

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis

Published on: June 9, 2018

Serum samples were stored at -20°C and -70°C to assess C1q stability.

Main Results:

Serum C1q levels were significantly lower in HAE patients compared to unaffected family members and healthy controls.
A significant correlation was observed between serum C1q and serum C4 levels, a marker of disease activity.
C1q demonstrated stability in serum samples stored at -20°C for 60 days.

Conclusions:

Depressed serum C1q concentrations are a potential finding in patients with hereditary angioedema.
Low C1q levels in HAE patients do not exclude the diagnosis.
C1q measurement can be a valuable tool in understanding HAE, with stable storage conditions identified.