Female sex inversion as a reason for an unbalanced sex ratio in the neotropical species Brycon orbignyanus

2021 ◽  
Author(s):  
Patricia Postingel Quirino ◽  
Maria Luiza Ribeiro Delgado ◽  
Luciane Gomes‐Silva ◽  
Cristiane Fernanda Benevente ◽  
Maiara Luzia Grigoli‐Olivio ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Neotropical Species ◽  
Female Sex ◽  
Sex Inversion

scholarly journals The Effect of China’s Two-Child Policy on the Child Sex Ratio: Evidence From Shanghai, China

2022 ◽  
Vol 59 ◽  
pp. 004695802110679
Author(s):  
Di Tang ◽  
Xiangdong Gao ◽  
Jiaoli Cai ◽  
Peter. C. Coyte
Keyword(s):  
Sex Ratio ◽  
Sex Ratio At Birth ◽  
Difference In Differences ◽  
Female Sex ◽  
One Child Policy ◽  
Child Policy ◽  
Pregnancy Status ◽  
The One ◽  
Male To Female ◽  
Municipal Level

Objective: The bias towards males at birth has resulted in a major imbalance in the Chinese sex ratio that is often attributed to China’s one-child policy. Relaxation of the one-child policy has the potential to reduce the imbalance in the sex ratio away from males. In this study, we assessed whether the bias towards males in the child sex ratio was reduced as a result of the two-child policy in China. Medical records data from one large municipal-level obstetrics hospital in Shanghai, East China. Design: Matching and difference-in-differences (MDID) techniques were used to investigate the effect of the two-child policy on the imbalance in the sex ratio at birth after matching for pregnancy status and socioeconomic factors. Results: Analyzing 133,358 live births suggest that the relaxation of the one-child policy had a small, but statistically significant effect in reducing the imbalance in the male to female sex ratio at birth. Conclusion: The results demonstrate that relaxation of the one-child policy reduced the imbalance in the male to female sex ratio at birth from 1.10 to 1.05 over the study period at one of the major obstetrics and gynecology hospitals in China.

scholarly journals Relapsing and progressive MS: the sex-specific perspective

2020 ◽  
Vol 13 ◽  
pp. 175628642095649
Author(s):  
Paulus Stefan Rommer ◽  
David Ellenberger ◽  
Kerstin Hellwig ◽  
Judith Haas ◽  
Dieter Pöhlau ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Sex Ratio ◽  
Demographic Data ◽  
Age At Onset ◽  
Symptomatic Treatment ◽  
Decisive Factor ◽  
Disease Course ◽  
Male Ratio ◽  
Female Sex

Background: Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease whose aetiology is not fully understood. The female sex is clearly predominant, with a sex ratio between 2 and 3. In primary progressive MS the sex ratio almost balances out. Since the age at onset is higher for patients with progressive onset (POMS) than for relapsing onset (ROMS), it can be hypothesized that the age at onset is a decisive factor for the sex ratio. Methods: To address this aspect, we compare clinical and demographic data between females and males for the different disease courses within the population of the German MS Register by the German MS Society. Only patients with complete details in mandatory data items and a follow-up visit since 01. Jan 2018 were included. Results: A total of 18,728 patients were included in our analyses, revealing a female-to-male ratio of 2.6 (2.7 for patients with ROMS and 1.3 for POMS). The age at diagnosis is higher in patients with POMS (43.3 and 42.3 years for females and males versus 32.1 and 33.2 years, respectively). Females irrespective of disease course are statistically significantly more often affected by cognitive impairment (POMS: p = 0.013, ROMS: p = 0.001) and depression (POMS: p = 0.002, ROMS: 0.001) and suffer more often from pain (POMS and ROMS: p < 0.001). Fatigue is significantly more often seen in females with ROMS ( p < 0.001) but not in POMS. Females with ROMS retire significantly ( p < 0.001) earlier (42.8 versus 44.2 years) and to a greater extent than males (28 versus 24%). Disease progression was similar for women and men. Conclusion: Our analysis shows that clinical and demographic data differ more between disease courses than between men and women. For pain, depression and cognitive impairment the female sex is the decisive factor. Whether these factors are responsible for the earlier retirement of females with ROMS is not clear. Appropriate measures for optimization of symptomatic treatment as well as to promote employment should be taken.

scholarly journals Subjecting Holstein Heifers to Stress During the Follicular Phase Following Superovulatory Treatment May Increase the Female Sex Ratio of Embryos

2009 ◽  
Vol 55 (5) ◽  
pp. 529-533 ◽  
Author(s):  
Atsushi IDETA ◽  
Koh HAYAMA ◽  
Chiho KAWASHIMA ◽  
Manami URAKAWA ◽  
Akio MIYAMOTO ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Follicular Phase ◽  
Female Sex

scholarly journals Hodgkin’s Disease

Blood ◽  
1955 ◽  
Vol 10 (12) ◽  
pp. 1214-1227 ◽  
Author(s):  
MICHAEL B. SHIMKIN
Keyword(s):  
United States ◽  
Sex Ratio ◽  
Hodgkin's Disease ◽  
Death Rate ◽  
Hodgkin’S Disease ◽  
The United States ◽  
Age At Death ◽  
Male Predominance ◽  
Female Sex ◽  
The Mean

Abstract Mortality from Hodgkin’s disease in the United States during the period 1921 through 1951 was analyzed with respect to race, sex and age incidence and distribution. The findings were compared with those reported for leukemia. The recorded death rate from Hodgkin’s disease rose from 6.9 in 1921 to 17.0 per million in 1951. During this period, the death rate from leukemia rose from 14 to 61 per million. The death rate among males is higher than among females for both diseases; the male predominance is more marked in Hodgkin’s disease than in leukemia. The rate is higher among whites than non-whites for both diseases; the white predominance is more marked in leukemia than in Hodgkin’s disease. There is no peak in rate during childhood for Hodgkin’s disease as there is for leukemia, and the increase in rate with age is much less steep for Hodgkin’s disease than for leukemia. The mean age at death of adults dying from Hodgkin’s disease and from leukemia increased by 3.5 and 8.0 years, respectively, between 1925 and 1950. The male-female sex ratio for Hodgkin’s disease decreased slightly, and increased slightly for leukemia between 1925 and 1950.

scholarly journals SEX INVERSION IN CULTIVATED MUSSELS MYTILUS GALLOPROVINCIALIS LAM. (CRIMEA, BLACK SEA) UNDER INFLUENCE OF EXTERNAL ENVIRONMENTAL FACTORS

2018 ◽  
Vol 19 ◽  
pp. 26-31
Author(s):  
Natalya Chelyadina ◽  
Natalya Pospelova ◽  
Mark Popov ◽  
Ludmila Smyrnova ◽  
Irina Kharchuk ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Sex Ratio ◽  
Black Sea ◽  
Diesel Fuel ◽  
Hormonal Regulation ◽  
Anthropogenic Impact ◽  
Mytilus Galloprovincialis ◽  
The Black Sea ◽  
Sex Inversion ◽  
Anionic Detergents

In the last decade, there has been a shift in the sex ratio of the mussel Mytilus galloprovincialis in the Black Sea towards increase of males. In modern literature, focus is mainly on mechanisms of sex inheritance in mussels and hormonal regulation of the reproduction, and there is no information on sex inversion in M. galloprovincialis under the influence of environmental factors. The goal of this work is to establish the fact of sex change in mussels cultivated near the coast of Crimea under the influence of some external environmental factors. We establish that mussels change sex from female to male, but some specimens become hermaphrodites, with their fraction reaching 13%. Under unfavorable environmental conditions, mussel females change sex, and their mortality rises up to 69%. In water areas subject to anthropogenic impact, the proportion of sex inversion in the mollusks may be as high as 58%. The influence of various adverse   environmental factors on sex inversion in mussel females is unequal, and its strength decreases in the following order: diesel fuel > hypoxia > anionic detergents > starvation.

Interpregnancy weight gain and the male-to-female sex ratio of the second pregnancy: a population-based cohort study

2008 ◽  
Vol 89 (5) ◽  
pp. 1240-1244 ◽  
Author(s):  
Eduardo Villamor ◽  
Pär Sparén ◽  
Sven Cnattingius
Keyword(s):  
Cohort Study ◽  
Weight Gain ◽  
Sex Ratio ◽  
Population Based ◽  
Female Sex ◽  
Male To Female

scholarly journals Fetal Female Sex Ratio

2020 ◽  
Author(s):  
Keyword(s):  
Sex Ratio ◽  
Female Sex

scholarly journals Reproductive aspects of the gulf pipefish, Syngnathus scovelli (Teleostei: Syngnathidae), from Southeastern Brazil

1999 ◽  
Vol 59 (1) ◽  
pp. 87-90 ◽  
Author(s):  
J. L. GASPARINI ◽  
R. L. TEIXEIRA
Keyword(s):  
Sex Ratio ◽  
Sandy Beach ◽  
Surf Zone ◽  
Southeastern Brazil ◽  
Immature Male ◽  
Female Sex ◽  
Total Length ◽  
Minimum Number ◽  
Males And Females ◽  
The Relationship

This study attempts to assess the relationship between fecundity and fertility of males and females of the gulf pipefish, Syngnathus scovelli. Specimens of this pipefish were collected in detached algae in the inner surf-zone of a dissipative sandy beach in southeastern Brazil. 97 specimens were collected, and they were associates to detached algae. From these, 14 were males, 36 females and 47 immature. Male-female sex ratio was 0.4:1, which was significantly different from the expected 1:1 ratio. Fish ranged from 43 to 98 mm TL (Fig. 1), and males and females showed similar size. Only 7 males were pregnants, while 9 females had hydrated oocytes. Minimum number of eggs/embryos in the pouch was 30 and the maximum 92. Minimum number of hydrated oocytes was 36, and the maximum was 165. The number of egg/embryos, and hydrated oocytes were weakly related to total length. It seems that the gulf pipefish occupy the inner surf-zone of the Praia do Iate are brought to the shallows accidentally when the specimens were inhabiting drifting vegetation.

scholarly journals Noninvasive genetic census of greater one-horned rhinocerosRhinoceros unicornisin Gorumara National Park, India: a pilot study for population estimation

Oryx ◽  
2016 ◽  
Vol 50 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Udayan Borthakur ◽  
Pranjal Kumar Das ◽  
Anjan Talukdar ◽  
Bibhab Kumar Talukdar
Keyword(s):  
Sex Ratio ◽  
National Park ◽  
West Bengal ◽  
Legal Protection ◽  
Population Estimation ◽  
Female Sex ◽  
Rhinoceros Unicornis ◽  
In The Wild ◽  
Genetic Techniques ◽  
Male To Female

AbstractThe greater one-horned rhinocerosRhinoceros unicornisis a flagship species for conservation in protected areas in India and Nepal. In India the species is afforded the highest level of legal protection under Schedule I of the Wildlife (Protection) Act 1972. Although censuses of greater one-horned rhinoceros have been carried out for decades using the traditional total count method, no advanced scientific approach has been adopted for population estimation of the species in India or elsewhere. We optimized noninvasive genetic techniques for identification of greater one-horned rhinoceros from dung samples, and applied these to estimate the number of rhinoceros in Gorumara National Park, in West Bengal, India. Our results confirmed the presence of 43 individuals from 60 dung samples collected throughout the Park in 2011. We confirmed a male-to-female sex ratio of 3.8 : 1, based on analysis of DNA from dung samples, using a y-chromosome linked marker. Our results are in concordance with a census carried out by the West Bengal Forest Department that found 42 rhinoceros in the Park, with a male-to-female sex ratio of 3.5 : 1. Our study thus demonstrates the feasibility of using a noninvasive genetic approach for population estimation of greater one-horned rhinoceros in the wild.

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