Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans05:40

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans

3.5K
This study aims to show that the Progressive-Ratio Computer-assisted Alcohol-Infusion System (CAIS) paradigm is a reliable and sensitive method that can be used to examine the motivating properties associated with alcohol self-administration in...
3.5K
Self-Concept01:19

Self-Concept

1.5K
Self-concept is the cognitive and emotional understanding individuals hold about their identity. It evolves through various developmental stages, beginning in infancy and maturing as children grow. This concept influences how individuals perceive their abilities, interact with others, and manage challenges throughout life.
Infancy and Emerging Recognition
During infancy, self-concept is virtually nonexistent. Babies do not distinguish themselves as separate entities and often mistake their...
1.5K
Sex-linked Disorders01:43

Sex-linked Disorders

108.4K
Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
108.4K
Concepts and Prototypes01:24

Concepts and Prototypes

515
The human nervous system handles vast amounts of information by translating sensory stimuli into neural impulses, which the brain processes, creating thoughts expressed through language or stored as memories. The brain also synthesizes information from emotions and memories, which significantly influence thoughts and behaviors. This intricate process creates a comprehensive mental picture.
The brain organizes this information using concepts, which are mental categories grouping linguistic data,...
515
Formula Mass and Mole Concepts of Compounds02:56

Formula Mass and Mole Concepts of Compounds

80.6K
Formula Mass of Covalent Compounds
80.6K
Understanding Self-Concept01:20

Understanding Self-Concept

227
The self-concept encompasses individuals' beliefs about themselves, structured through cognitive frameworks known as self-schemas. These schemas function as mental representations of specific traits or behaviors, influencing how self-relevant information is perceived, processed, and remembered. For example, individuals who are schematic for body weight are more likely to interpret routine experiences—such as dining out or shopping—through the lens of that trait. Conversely, those...
227

You might also read

Related Articles

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

Sort by
Same author

Rectal shedding of SARS-CoV-2 in patients with negative COVID-19 nasopharyngeal RT-PCR test.

The International journal of risk & safety in medicine·2025
Same author

Sex Ratio at Birth in Northern Ireland During the COVID-19 Pandemic: A Comparison With Published Data From the Republic of Ireland, England and Wales.

American journal of human biology : the official journal of the Human Biology Council·2025
Same author

Forecasting with Excel.

Acta medica (Hradec Kralove)·2025
Same author

The Impact of the COVID-19 Pandemic on the Sex Ratio at Birth in Ireland.

American journal of human biology : the official journal of the Human Biology Council·2024
Same author

Two World Wars and Belgium: Missing Births and Birth Sex Ratio Changes.

Acta medica (Hradec Kralove)·2024
Same author

Sporting tournaments and changed birth rates 9 months later: a systematic review.

PeerJ·2024

Related Experiment Video

Updated: Jan 19, 2026

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans
05:40

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans

Published on: April 28, 2022

3.5K

The human sex ratio at conception.

William H James1, Victor Grech2

  • 1Galton Laboratory, Department practice guidelinesof Genetics, Evolution and Environment, University College London, United Kingdom.

Early Human Development
|September 8, 2019
PubMed
Summary

This study challenges previous research, finding a male bias at conception, not an equal sex ratio. Historical birth data suggests more males are conceived, miscarried, and survive to birth.

More Related Videos

Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR
10:16

Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR

Published on: February 14, 2016

10.4K
Self-Concept
01:19

Self-Concept

1.5K

Related Experiment Videos

Last Updated: Jan 19, 2026

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans
05:40

The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans

Published on: April 28, 2022

3.5K
Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR
10:16

Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR

Published on: February 14, 2016

10.4K
Self-Concept
01:19

Self-Concept

1.5K

Area of Science:

  • Human reproduction
  • Developmental biology
  • Population studies

Background:

  • Estimating the primary sex ratio (sex ratio at conception) is complex.
  • Previous studies projected back from birth data, estimating fetal loss.
  • One recent study concluded an equal sex ratio at conception.

Purpose of the Study:

  • To re-evaluate the primary sex ratio using historical birth records.
  • To challenge the conclusion of an equal sex ratio at conception.
  • To investigate factors influencing sex ratio at conception and birth.

Main Methods:

  • Analysis of two large, accurately recorded 19th-century birth datasets.
  • Utilizing data from a period with limited contraception and sex selection.
  • Statistical projection and analysis of fetal loss and survival rates.

Main Results:

  • A substantial excess of males at conception was observed.
  • Evidence suggests male fetuses are preferentially miscarried under stress.
  • More males than females are conceived, miscarried, and survive to birth.

Conclusions:

  • The primary sex ratio at conception shows a significant male excess.
  • Parental hormone levels may influence the primary sex ratio (hormonal hypothesis).
  • Pregnancy stress can lead to preferential culling of frail male fetuses.