scholarly journals The Human Female Paradox: Biological Disadvantage Preimplantation, Biological Advantage, Thereafter

2021 ◽  
Vol 4 (1) ◽  
pp. 397-404
Author(s):  
Migeon BR
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
In Utero ◽  
Vital Statistics ◽  
Significant Loss ◽  
Human Female ◽  
X Chromosomes ◽  
Fetal Survival ◽  
Biological Advantage ◽  
Eighth Decade

The vital statistics show that human females outlive males at every biological stage. Once the embryo arrives in the uterus, more males die at every stage, at least until the eighth decade when the majority of survivors are female. Unexpectedly, the same statistics also show that more boys are born than girls, which is difficult to explain, because the sperm that determine the sex of the fetus, are not skewed toward males. Recently, new data reveal the reason for the increased number of male births; they imply the significant loss of females before the fetus arrives in the womb. Thereafter, there is an excessive loss of males – not only in utero but throughout their lives. One likely reason for the sex differences in fetal survival is the way that humans compensate for the sex difference in number of X chromosomes.

Human female exogamy is supported by cross-species comparisons: Cause to recognise sex differences in societal policy?

2009 ◽  
Vol 32 (5) ◽  
pp. 400-400 ◽  
Author(s):  
Guy Madison
Keyword(s):  
Sex Differences ◽  
Sexual Assault ◽  
Sex Difference ◽  
Empirical Support ◽  
Human Female ◽  
Species Comparisons

AbstractA sex difference in the tendency to outbreed (female exogamy) is a premise for the target article's proposed framework, which receives some support by being shared with chimpanzees but not with more distantly related primates. Further empirical support is provided, and it is suggested that recognition of sex differences might improve effective fairness, taking sexual assault as a case in point.

Competition in utero between twin lambs

1956 ◽  
Vol 48 (2) ◽  
pp. 245-249 ◽  
Author(s):  
H. P. Donald ◽  
A. F. Purser
Keyword(s):  
Sex Differences ◽  
Birth Weight ◽  
Sex Difference ◽  
In Utero ◽  
Sex Distribution ◽  
Sources Of Variation ◽  
Males And Females ◽  
Limited Supply ◽  
Image Position

1. The weights at birth of 822 pairs of twin lambs have been studied with respect to the differences between males and females. Data were obtained during five lambing seasons from various breeds and crosses in five flocks.2. The sex distribution of twin pairs came close to the ratio .3. Analyses made within season and within the major breed categories showed that sex differences were small relative to other sources of variation, but that there was a significant effect of sex of co-twin on birth weight. The following average differences were found (the sex of co-twin being indicated in brackets):These differences had an average S.E. of 0·078 lb. (Table 3). The sex difference in litters of mixed sex was twice as large as that obtained from like-sexed litters.4. The data for particular flocks and seasons suggest that in addition to these average effects, there may be some interaction between sex and breed or season which can cause deviations from the averages.5. These results are interpreted to mean that there is competition between twins for some element of growth in limited supply; and that in twins of mixed sex, the result tends to favour the male.

The Relationship of Compliance with Coping Strategies and Self-Esteem

2003 ◽  
Vol 19 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Gisli H. Gudjonsson ◽  
Jon Fridrik Sigurdsson
Keyword(s):  
Sex Differences ◽  
Coping Strategies ◽  
Multiple Regression ◽  
Sex Difference ◽  
Test Scores ◽  
Self Esteem ◽  
Stressful Situation ◽  
Men And Women ◽  
Relationship Of ◽  
The Relationship

Summary: The Gudjonsson Compliance Scale (GCS), the COPE Scale, and the Rosenberg Self-Esteem Scale were administered to 212 men and 212 women. Multiple regression of the test scores showed that low self-esteem and denial coping were the best predictors of compliance in both men and women. Significant sex differences emerged on all three scales, with women having lower self-esteem than men, being more compliant, and using different coping strategies when confronted with a stressful situation. The sex difference in compliance was mediated by differences in self-esteem between men and women.

Sex Differences in Time Production Revisited

2012 ◽  
Vol 33 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Joseph Glicksohn ◽  
Yamit Hadad
Keyword(s):  
Sex Differences ◽  
Individual Differences ◽  
Sex Difference ◽  
Absolute Error ◽  
Internal Clock ◽  
Target Duration ◽  
Log P ◽  
Men And Women ◽  
Time Production ◽  
T Score

Individual differences in time production should indicate differences in the rate of functioning of an internal clock, assuming the existence of such a clock. And sex differences in time production should reflect a difference in the rate of functioning of that clock between men and women. One way of approaching the data is to compute individual regressions of produced duration (P) on target duration (T), after log transformation, and to derive estimates for the intercept and the slope. One could investigate a sex difference by comparing these estimates for men and women; one could also contrast them by looking at mean log(P). Using such indices, we found a sex difference in time production, female participants having a relatively faster internal clock, making shorter time productions, and having a smaller exponent. The question is whether a sex difference in time production would be found using other methods for analyzing the data: (1) the P/T ratio; (2) an absolute discrepancy (|P-T|) score; and (3) an absolute error (|P-T|/T) score. For the P/T ratio, female participants have a lower mean ratio in comparison to the male participants. In contrast, the |P-T| and |P-T|/T indices seem to be seriously compromised by wide individual differences.

scholarly journals Tower Running—Participation, Performance Trends, and Sex Difference

2020 ◽  
Vol 17 (6) ◽  
pp. 1902 ◽  
Author(s):  
Daniel Stark ◽  
Stefania Di Gangi ◽  
Caio Victor Sousa ◽  
Pantelis Nikolaidis ◽  
Beat Knechtle
Keyword(s):  
Sex Differences ◽  
Statistical Model ◽  
Sex Difference ◽  
Random Effects ◽  
Age Groups ◽  
Repeated Measurements ◽  
Stair Climbing ◽  
Age Group ◽  
Performance Trends ◽  
The Difference

Though there are exhaustive data about participation, performance trends, and sex differences in performance in different running disciplines and races, no study has analyzed these trends in stair climbing and tower running. The aim of the present study was therefore to investigate these trends in tower running. The data, consisting of 28,203 observations from 24,007 climbers between 2014 and 2019, were analyzed. The effects of sex and age, together with the tower characteristics (i.e., stairs and floors), were examined through a multivariable statistical model with random effects on intercept, at climber’s level, accounting for repeated measurements. Men were faster than women in each age group (p < 0.001 for ages ≤69 years, p = 0.003 for ages > 69 years), and the difference in performance stayed around 0.20 km/h, with a minimum of 0.17 at the oldest age. However, women were able to outperform men in specific situations: (i) in smaller buildings (<600 stairs), for ages between 30 and 59 years and >69 years; (ii) in higher buildings (>2200 stairs), for age groups <20 years and 60–69 years; and (iii) in buildings with 1600–2200 stairs, for ages >69 years. In summary, men were faster than women in this specific running discipline; however, women were able to outperform men in very specific situations (i.e., specific age groups and specific numbers of stairs).

scholarly journals Sex differences in the association between major cardiovascular risk factors in midlife and dementia: a cohort study using data from the UK Biobank

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jessica Gong ◽  
Katie Harris ◽  
Sanne A. E. Peters ◽  
Mark Woodward
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Sex Differences ◽  
Cardiovascular Risk ◽  
Cardiovascular Risk Factors ◽  
Sex Difference ◽  
Incidence Rates ◽  
Cox Proportional Hazards ◽  
Uk Biobank ◽  
The Uk

Abstract Background Sex differences in major cardiovascular risk factors for incident (fatal or non-fatal) all-cause dementia were assessed in the UK Biobank. The effects of these risk factors on all-cause dementia were explored by age and socioeconomic status (SES). Methods Cox proportional hazards models were used to estimate hazard ratios (HRs) and women-to-men ratio of HRs (RHR) with 95% confidence intervals (CIs) for systolic blood pressure (SBP) and diastolic blood pressure (DBP), smoking, diabetes, adiposity, stroke, SES and lipids with dementia. Poisson regression was used to estimate the sex-specific incidence rate of dementia for these risk factors. Results 502,226 individuals in midlife (54.4% women, mean age 56.5 years) with no prevalent dementia were included in the analyses. Over 11.8 years (median), 4068 participants (45.9% women) developed dementia. The crude incidence rates were 5.88 [95% CI 5.62–6.16] for women and 8.42 [8.07–8.78] for men, per 10,000 person-years. Sex was associated with the risk of dementia, where the risk was lower in women than men (HR = 0.83 [0.77–0.89]). Current smoking, diabetes, high adiposity, prior stroke and low SES were associated with a greater risk of dementia, similarly in women and men. The relationship between blood pressure (BP) and dementia was U-shaped in men but had a dose-response relationship in women: the HR for SBP per 20 mmHg was 1.08 [1.02–1.13] in women and 0.98 [0.93–1.03] in men. This sex difference was not affected by the use of antihypertensive medication at baseline. The sex difference in the effect of raised BP was consistent for dementia subtypes (vascular dementia and Alzheimer’s disease). Conclusions Several mid-life cardiovascular risk factors were associated with dementia similarly in women and men, but not raised BP. Future bespoke BP-lowering trials are necessary to understand its role in restricting cognitive decline and to clarify any sex difference.

scholarly journals Influence of sex and gonadal status of sheep on cortisol secretion in response to ACTH and on cortisol and LH secretion in response to stress: importance of different stressors

2002 ◽  
Vol 173 (1) ◽  
pp. 113-122 ◽  
Author(s):  
AI Turner ◽  
BJ Canny ◽  
RJ Hobbs ◽  
JD Bond ◽  
IJ Clarke ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Restraint Stress ◽  
Cortisol Response ◽  
Blood Samples ◽  
Response To Stress ◽  
Lh Secretion ◽  
Gonadal Status ◽  
Major Mediator

There are sex differences in the response to stress and in the influence of stress on reproduction which may be due to gonadal steroids but the nature of these differences and the role of the gonads are not understood. We tested the hypotheses that sex and the presence/absence of gonads (gonadal status) will influence the cortisol response to injection of ACTH, insulin-induced hypoglycaemia and isolation/restraint stress, and that sex and gonadal status will influence the secretion of LH in response to isolation/restraint stress. Four groups of sheep were used in each of three experiments: gonad-intact rams, gonadectomised rams, gonad-intact ewes in the mid-luteal phase of the oestrous cycle and gonadectomised ewes. In Experiment 1 (n=4/group), jugular blood samples were collected every 10 min for 6 h; after 3 h, two animals in each group were injected (i.v.) with ACTH and the remaining two animals were injected (i.v.) with saline. Treatments were reversed 5 days later so that every animal received both treatments. Experiment 2 (n=4/group) used a similar schedule except that insulin was injected (i.v.) instead of ACTH. In Experiment 3 (n=5/group), blood samples were collected every 10 min for 16 h on a control day and again 2 weeks later when, after 8 h of sampling, all sheep were isolated and restrained for 8 h. Plasma cortisol was significantly (P<0.05) elevated following injection of ACTH or insulin and during isolation/restraint stress. There were no significant differences between the sexes in the cortisol response to ACTH. Rams had a greater (P<0.05) cortisol response to insulin-induced hypoglycaemia than ewes while ewes had a greater (P<0.05) cortisol response to isolation/restraint stress than rams. There was no effect of gonadal status on these parameters. Plasma LH was suppressed (P<0.05) in gonadectomised animals during isolation/restraint stress but was not affected in gonad-intact animals, and there were no differences between the sexes. Our results show that the sex that has the greater cortisol response to a stressor depends on the stressor imposed and that these sex differences are likely to be at the level of the hypothalamo-pituitary unit rather than at the adrenal gland. Since there was a sex difference in the cortisol response to isolation/restraint, the lack of a sex difference in the response of LH to this stress suggests that glucocorticoids are unlikely to be a major mediator of the stress-induced suppression of LH secretion.

scholarly journals Sex-Related Differences in the Effects of the Mediterranean Diet on Glucose and Insulin Homeostasis

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Alexandra Bédard ◽  
Louise Corneau ◽  
Benoît Lamarche ◽  
Sylvie Dodin ◽  
Simone Lemieux
Keyword(s):  
Sex Differences ◽  
Insulin Sensitivity ◽  
Mediterranean Diet ◽  
Sex Difference ◽  
Premenopausal Women ◽  
Nonesterified Fatty Acids ◽  
Time Interaction ◽  
Insulin Homeostasis ◽  
The Mediterranean ◽  
The Impact

Objective. To document sex differences in the impact of the Mediterranean diet (MedDiet) on glucose/insulin homeostasis and to verify whether these sex-related effects were associated with changes in nonesterified fatty acids (NEFA).Methods. All foods were provided to 38 men and 32 premenopausal women (24–53 y) during 4 weeks. Variables were measured during a 180 min OGTT before and after the MedDiet.Results. A sex-by-time interaction for plasma insulin iAUC was found (men: −17.8%,P=0.02; women: +9.4%,P=0.63;Pfor sex-by-time interaction = 0.005). A sex-by-time interaction was also observed for insulin sensitivity (Cederholm index,P=0.03), for which only men experienced improvements (men: +8.1%,P=0.047; women: −5.9%,P=0.94). No sex difference was observed for glucose and C-peptide responses. Trends toward a decrease in NEFA AUC (P=0.06) and an increase in NEFA suppression rate (P=0.06) were noted, with no sex difference. Changes in NEFA were not associated with change in insulin sensitivity.Conclusions. Results suggest that the more favorable changes in glucose/insulin homeostasis observed in men compared to women in response to the MedDiet are not explained by sex differences in NEFA response. This clinical trial is registered with clinicaltrials.govNCT01293344.

CLINICAL CONFERENCE

PEDIATRICS ◽  
1957 ◽  
Vol 20 (4) ◽  
pp. 740-746
Author(s):  
Melvin M. Grumbach
Keyword(s):  
Sex Difference ◽  
Sex Chromosome ◽  
Good Evidence ◽  
Polymorphonuclear Neutrophils ◽  
Vaginal Mucosa ◽  
Simple Method ◽  
X Chromosomes ◽  
Cytologic Examination ◽  
Sex Development ◽  
Sex Chromatin

Dr. Grumbach: Barr and associates have demonstrated that in the human the majority of somatic cells of females contain a conspicuous, heterochromatic mass of chromatin in the resting nuclei. Their discovery of a sex-difference in intermitotic nuclei of a number of vertebrate species, including man, has provided a relatively simple method for assessing the sex-chromosome constitution. This chromatin mass is about 1 micron in diameter and often plano-convex in configuration. It is usually located against the inner surface of the nuclear membrane and contains desoxyribonucleic acid. In males, a comparable chromatin mass is rarely found, never in more than a few per cent of the nuclei. There is good evidence that this so-called "sexchromatin" represents the fusion of heterochromatic portions of two X-chromosomes. The sex chromatin can be conveniently determined by examination of specimens of skin obtained by biopsy (Fig. 1). Recently, more practical methods for determining cytologic sex have been described employing smears from readily available tissues, such as the oral and vaginal mucosa (Fig. 2) and the blood. Davidson and Smith have shown that there is a sex difference in the morphology of polymorphonuclear neutrophils. Cytologic examination of chromosomal sex has provided an important tool for the investigation of anomalies of sex development. Apart from its ancillary role in diagnosis, cytologic examination of sex chromatin has made a significant contribution to our understanding of the disordered development in these afflictions. However, the results of this determination should not be regarded as an especial indication of the psychosexual orientation of patients with such abnormalities, nor, in the case of infants, of the sex to which they should be assigned.

Abstract 302: Sex Differences In Nonlinear Dynamics And Their Circadian Variation In Control Dogs And In A New Arrhythmogenic Canine Model Of Heart Failure

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Yujie Zhu ◽  
Steven M Pogwizd
Keyword(s):  
Nonlinear Dynamics ◽  
Heart Failure ◽  
Sex Differences ◽  
Sex Difference ◽  
Circadian Variation ◽  
Holter Monitoring ◽  
Canine Model ◽  
Nonlinear Parameters ◽  
Arrhythmogenic Substrate ◽  
Males And Females

Introduction: Females can be more arrhythmogenic than males, and this sex difference can persist with development of chronic heart failure (CHF). The aim of this study was to investigate sex differences in the arrhythmogenic substrate in control dogs and in a new arrhythmogenic canine model of CHF. Methods: CHF was induced in 30 dogs by aortic insufficiency and aortic constriction. Holter monitoring assessed VT and PVCs from 30 dogs, as well as traditional HRV measures and nonlinear dynamics (including correlation dimension (CD), detrended fluctuations analysis α1 (DFAα1), and Shannon entropy (SE)) at baseline, 240 days (240d) and 720 days (720d) after CHF induction. Results: At baseline, females had lower LF/HF (0.27±0.03 vs 0.33±0.02, p=0.04), CD (1.60±0.17 vs 2.21±0.15, p=0.01), DFAα1 (0.62±0.03 vs 0.72±0.03, p=0.03), and SE (2.99±0.02 vs 3.10±0.03, p=0.03 vs males). Females lacked circadian variation in LF/HF, DFAα1, and SE while males had circadian variation in all of these. Of 11 dogs with frequent runs of VT and PVCs, 95% and 91% of total VT runs and total PVCs, respectively, were in females. With CHF, all these linear and nonlinear parameters progressively declined in males and females. CHF females had less decline in LF/HF than males so that by 720 days there was no more sex difference (0.24±0.06, 0.17±0.03 in females vs 0.22±0.05, 0.18±0.01 in males at 240d, 720d). However, for nonlinear parameters of CD, DFAα1, and SE, CHF females had lower values than males (CD: 1.56±0.21, 0.99±0.32 vs 1.87±0.24, 1.50±0.34; DFAα1: 0.51±0.05, 0.43±0.04 vs 0.54±0.07, 0.48±0.04; and SE 2.93±0.08, 2.76±0.08 vs 3.01±0.11, 2.91±0.04 in females vs males at 240d, 720d). With CHF, circadian variation in CD, DFAα1, and SE were lost in both males and females. Conclusions: There are sex differences in the arrhythmogenic substrate in control dogs and in this new arrhythmogenic canine model of moderate CHF. At baseline, females have lower sympathetic stimulation, reduced cardiac chaos, and loss of circadian variation in nonlinear dynamics. With CHF, sex differences in nonlinear dynamics persist; this reflects a loss of complexity and fractal properties that could contribute to increased arrhythmias in female CHF dogs.

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