scholarly journals Insight into human sex ratio imbalance: the more boys born, the more infertile men

2007 ◽  
Vol 15 (5) ◽  
pp. 487-494 ◽  
Author(s):  
Hanhua Cheng ◽  
Xuan Shang ◽  
Yan He ◽  
Tao Zhang ◽  
Ya-Ping Zhang ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Infertile Men ◽  
Sex Ratio Imbalance ◽  
Insight Into

Single Embryo Blastocyst Transfer May Lead to An Altered Sex Ratio Imbalance

2005 ◽  
Vol 84 ◽  
pp. S89 ◽  
Author(s):  
J. Barritt ◽  
M. Duke ◽  
J. Klein ◽  
A. Devenuta ◽  
B. Sandler ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Blastocyst Transfer ◽  
Sex Ratio Imbalance

scholarly journals Causes and consequences of adult sex ratio imbalance in a historical U.S. population

2017 ◽  
Vol 372 (1729) ◽  
pp. 20160314 ◽  
Author(s):  
Ryan Schacht ◽  
Ken R. Smith
Keyword(s):  
Biological Sciences ◽  
Sex Ratio ◽  
Life History Traits ◽  
Male Mating ◽  
Age At First Birth ◽  
The Social ◽  
Adult Sex Ratio ◽  
Sex Ratio Imbalance ◽  
Animal Societies

The responsiveness of individuals to partner availability has been well-documented across the literature. However, there is disagreement regarding the direction of the consequences of sex ratio imbalance. Specifically, does an excess of males or females promote male–male mating competition? In an attempt to clarify the role of the adult sex ratio (ASR) on behaviour, here we evaluate both competing and complimentary expectations derived from theory across the social and biological sciences. We use data drawn from a historical, nineteenth century population in North America and target several life-history traits thought to be affected by partner availability: age at first birth, relationship status, completed fertility and longevity. Furthermore, we assess the role of various contributors to a population's ASR. We find that both the contributors to and consequences of sex ratio imbalance vary over time. Our results largely support predictions of greater male pairbond commitment and lesser male mating effort, as well as elevated bargaining power of women in response to female scarcity. After reviewing our findings, and others from across the literature, we highlight the need to adjust predictions in response to ASR imbalance by the: (i) culturally mediated mating arena, (ii) variable role of demographic inputs across time and place, (iii) constraints to behavioural outcomes across populations, and (iv) ability and accuracy of individuals to assess partner availability. This article is part of the themed issue ‘Adult sex ratios and reproductive strategies: a critical re-examination of sex differences in human and animal societies’.

Trophectoderm grade significantly affects the sex-ratio imbalance in favor of male offspring

2013 ◽  
Vol 100 (3) ◽  
pp. S463
Author(s):  
T. Habara ◽  
S. Terada ◽  
N. Yoshioka ◽  
N. Hayashi
Keyword(s):  
Sex Ratio ◽  
Male Offspring ◽  
Sex Ratio Imbalance

scholarly journals Up-regulation of Arl4a gene expression by broccoli aqueous extract is associated with improved spermatogenesis in mouse testes

Biomédica ◽  
2021 ◽  
Vol 41 (4) ◽  
Author(s):  
Omid Jazayeri ◽  
Setareh Farahmand Araghi ◽  
Tahereh A. Aghajanzadeh ◽  
Fereshteh Mir Moammadrezaei
Keyword(s):  
Gene Expression ◽  
Aqueous Extract ◽  
Sperm Count ◽  
Mrna Level ◽  
Treated Group ◽  
Sperm Number ◽  
Infertile Men ◽  
Anti Cancer ◽  
Insight Into ◽  
Mouse Body Weight

Introduction: Broccoli (Brassica oleracea) is well recognized due to its properties as an anti-cancer, antioxidant and scavenging free radicals. However, its benefit in enhancing spermatogenesis is not well understood. Objectives: To investigate the effect of broccoli aqueous extract on sperm factors and also expression of the involving genes (Catsper1, Catsper2, Arl4a, Sox5 and Sox9) in sperm factors in mice. Material and methods: Male mice were divided randomly into six groups: (1) Control, (2) Cadmium (3 mg/kg mouse body weight), (3) Orally treated with 200 broccoli aqueous extract (1 g ml-1), (4) Orally treated with 400 µl of broccoli aqueous extract, (5) Orally treated with 200 broccoli aqueous extract plus cadmium, and (6) Orally treated with 400 µl of broccoli aqueous extract plus cadmium. Sperms factors and also gene expression in Catsper1, Catsper2, Arl4a, Sox5 and Sox9 genes were studied. Results: An obvious improvement in sperm number and slight enhancement in sperm motility was observed in mice treated with broccoli extract with and without cadmium. While sperm viability was reduced by broccoli extract, except for 200 µl of broccoli extract with cadmium that was significantly increased. Interestingly, Arl4a gene expression showed an increase in 400 µl broccoli-treated group. Likewise, the Arl4a mRNA level in mice treated with cadmium along with 200 µl broccoli extract was higher than in cadmium-treated mice. Furthermore, broccoli extract enhanced the mRNA level of Catsper2 and Sox5 genes in mice treated with both 200 and 400 µl broccoli extract along with cadmium than the only cadmium-treated group. Conclusion: Generally, improvement in sperm count in broccoli-treated mice provides insight into the pharmaceutical industry to make new products available to infertile men.

scholarly journals Sex-Ratio Imbalance: Impending Feminity

2013 ◽  
Vol 13 (4) ◽  
pp. 76-79
Author(s):  
Pragyan Mohanty ◽  
Keyword(s):  
Sex Ratio ◽  
Sex Ratio Imbalance

Sex ratio imbalance and Down’s syndrome newborns

2001 ◽  
Vol 29 (3) ◽  
Author(s):  
Sebastiano Bianca ◽  
Marco Bianca ◽  
Giuseppe Ettore
Keyword(s):  
Sex Ratio ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Sex Ratio Imbalance

scholarly journals Biodiversity and seasonal distribution of Cullicoides spp. examined in NIVS Belgrade during 2019

2020 ◽  
Vol 13 (2) ◽  
pp. 105-115
Author(s):  
Ivan Pavlović ◽  
Slobodan Stanojević ◽  
Nemanja Zdravković ◽  
Oliver Radovanović
Keyword(s):  
Sex Ratio ◽  
Geographical Distribution ◽  
Seasonal Dynamics ◽  
Seasonal Distribution ◽  
Valuable Data ◽  
Entomological Monitoring ◽  
Novi Sad ◽  
Insight Into

Continuous entomological monitoring of Cullicoides spp., which is being conducted starting from 2014 have so far yielded significant results related to biodiversity and seasonal dynamics of these insects Serbia. The research we have done so far has contributed to mapping the geographical distribution of the species we encounter as well as the variations in the number of populations in different years. As monitoring continues, we receive new valuable data every year that will help predict the movement of these insects on the basis of biclimatograms and enable preventative action to be taken to counteract them. Unfortunately, starting in 2019, monitoring has been split into three institutions (NIVS Belgrade, NIV Novi Sad and VSI Kraljevo) so that this has lost insight into the biodiversity, sex ratio, and most importantly the age of the females that are the primary vectors. In our work, therefore, we can provide only the results of testing the biodiversity and seasonal dynamics of Cullicoides spp. during 2019 in the epizootiological area of NIVS Belgrade, VSI Šabac, VSI Pančevo, VSI Požarevac, and VSI Zaječar, while we did not divide samples from VSI Jagodina for the fourth consecutive year.  Culicoides spp. from Obsoletus complexes were established at 59.91%, from the Pulicaris complex were established at 34.06% and other types of culicoids have been established in less than 10% of the examined samples.

Sign in / Sign up

Export Citation Format

Share Document