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 to the Sign Test

Introduction to the Sign Test

The sign test is an important tool in nonparametric statistics, offering a straightforward yet effective method for analyzing matched pairs, nominal data, or hypotheses concerning the median of a population. It transforms data points into positive or negative signs, avoiding the need for assumptions about data distribution and instead focusing on the direction of change. It is particularly valuable when data does not conform to the normal distribution requirements of many parametric tests. For...

Sign Test for Nominal Data

Sign Test for Nominal Data

The sign test is a nonparametric method used to evaluate hypotheses about the median of a single sample or to compare the medians of two related samples. The sign test is particularly useful when dealing with nominal data, which includes distinct categories without an inherent order, such as names, labels, and preferences. Nominal data restricts statistical analysis to evaluating population proportions rather than mean or median values that require continuous data.
For example, consider a...

Sign Convention

Sign Convention

When analyzing a beam subjected to various loads, it is crucial to understand the internal forces and moments generated within the structure. These internal forces can be broadly classified into normal forces, shear forces, and bending moments. To determine these forces and moments, we use the method of sections and apply a specific sign convention based on their direction and the side of the section being analyzed.
The normal force acts perpendicular to the beam's cross-section and can cause...

Sign Test for Matched Pairs

Sign Test for Matched Pairs

The sign test for matched pairs offers a robust method for comparing two paired samples, often for the effects of an intervention in one of them. This method is very useful in situations where the underlying distribution of the data is unknown. The test compares two related samples—often pre- and post-treatment measurements on the same subjects—to determine if there are significant differences in their median values.
To conduct the sign test, we first calculate the differences in value between...

Nuclear Localization Signals and Import

Nuclear Localization Signals and Import

Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...

Sympathetic Signaling

Sympathetic Signaling

Sympathetic signaling, a vital part of the autonomic nervous system, plays a crucial role in mobilizing the body's resources in response to stress or emergencies. It involves the transmission of nerve impulses from sympathetic preganglionic fibers to postganglionic fibers. This results in the release of specific neurotransmitters and activation of adrenergic receptors.
Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the...

You might also read

Related Articles

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

Sort by

Same author

Domenico Mistichelli (1675-1717).

Journal of neurology·2025

Same author

The history of the European Neurological Society (1986-2014)-10 years later.

European journal of neurology·2024

Same author

Pioneers in neurology: a silver anniversary perspective.

Journal of neurology·2024

Same author

A (delayed) history of the brain lymphatic system.

Nature medicine·2019

Same author

[Are mental and neurological disorders related?]

Nederlands tijdschrift voor geneeskunde·2019

Same author

Macdonald Critchley (1900-1997).

Journal of neurology·2017

Search research articles

Related Experiment Video

Updated: Jun 2, 2026

Assessment of Social Interaction Behaviors

Assessment of Social Interaction Behaviors

Published on: February 25, 2011

[Nikolsky and his sign].

Jan van Gijn¹, Joost P Gijselhart

¹Nederlands Tijdschrift voor Geneeskunde, Amsterdam, the Netherlands. jan@vangijn.com

Nederlands Tijdschrift Voor Geneeskunde

|April 21, 2011

Summary

The Nikolsky sign, a skin wrinkling phenomenon, aids in diagnosing pemphigus foliaceus and vulgaris. It occurs when gentle rubbing causes the stratum corneum to slide over deeper skin layers.

Area of Science:

Dermatology
Venereology

Background:

Piotr Vasiliyevich Nikolsky, a dermatologist and venereologist, described a unique skin sign in his 1896 doctoral dissertation.
This sign involves skin wrinkling upon gentle rubbing, a characteristic observed in certain blistering diseases.

Discussion:

The Nikolsky sign results from the superficial stratum corneum sliding over deeper skin layers, observed in pemphigus foliaceus and pemphigus vulgaris.
The sign's absence in approximately 60% of patients and its differentiation from pemphigoid diseases highlight its specific diagnostic utility.

Key Insights:

The Nikolsky sign is a clinical finding related to the structural integrity of the epidermis.
Its presence or absence helps distinguish between different types of blistering dermatoses, particularly pemphigus variants.

More Related Videos

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis

Published on: November 21, 2013

Whisker-signaled Eyeblink Classical Conditioning in Head-fixed Mice

Whisker-signaled Eyeblink Classical Conditioning in Head-fixed Mice

Published on: March 30, 2016

Related Experiment Videos

Last Updated: Jun 2, 2026

Assessment of Social Interaction Behaviors

Assessment of Social Interaction Behaviors

Published on: February 25, 2011

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis

Published on: November 21, 2013

Whisker-signaled Eyeblink Classical Conditioning in Head-fixed Mice

Whisker-signaled Eyeblink Classical Conditioning in Head-fixed Mice

Published on: March 30, 2016

Outlook:

Further research could explore the precise biomechanical properties underlying the Nikolsky sign.
Standardization of the Nikolsky sign's elicitation could enhance its reliability in clinical practice.