2,307 research outputs found
Postnatal depression and reproductive success in modern, low-fertility contexts
Background and objectives: Postnatal depression (PND) presents a puzzling phenomenon to evolutionary
anthropologists as it is highly prevalent and yet detrimental to child development and maternal
health. Adaptive explanations have been proposed, but have not been tested with data that directly link
PND to female fertility.
Methodology: A survey was designed to gather complete reproductive histories and retrospective measures
of PND to measure the effects of PND on fitness. Respondents were born between 1930 and 1967,
with the majority based in the UK during their childrearing years. The hypothesis that PND is detrimental
to fitness is assessed using Mann–Whitney U tests on completed fertility. Binary logistic regression
modelling is used to test the hypothesis that PND reduces the likelihood of parity progression.
Results: Women experiencing PND at their first or second birth have lower completed fertility, with PND
at the first birth leading to lowered fertility. Logistic regression analyses show that this is the result of
reductions in the likelihood of parity progression to a third birth when PND is experienced at the first
birth or when repeat bouts occur.
Conclusions and implications: Our results call into question adaptationist arguments, contribute to the
growing understanding of the importance of emotional wellbeing to fertility decision making, and given
the economic consequences of markedly below replacement fertility, highlight a potential new source of
financial incentive to invest in screening and preventative measures to ensure good maternal mental
health
Mechanical characterization of disordered and anisotropic cellular monolayers
We consider a cellular monolayer, described using a vertex-based model, for
which cells form a spatially disordered array of convex polygons that tile the
plane. Equilibrium cell configurations are assumed to minimize a global energy
defined in terms of cell areas and perimeters; energy is dissipated via dynamic
area and length changes, as well as cell neighbour exchanges. The model
captures our observations of an epithelium from a Xenopus embryo showing that
uniaxial stretching induces spatial ordering, with cells under net tension
(compression) tending to align with (against) the direction of stretch, but
with the stress remaining heterogeneous at the single-cell level. We use the
vertex model to derive the linearized relation between tissue-level stress,
strain and strain-rate about a deformed base state, which can be used to
characterize the tissue's anisotropic mechanical properties; expressions for
viscoelastic tissue moduli are given as direct sums over cells. When the base
state is isotropic, the model predicts that tissue properties can be tuned to a
regime with high elastic shear resistance but low resistance to area changes,
or vice versa.Comment: 9 figure
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Estimating the proportion of Medicaid-eligible pregnant women in Louisiana who do not get abortions when Medicaid does not cover abortion.
BackgroundTo estimate the proportion of pregnant women in Louisiana who do not obtain abortions because Medicaid does not cover abortion.MethodsTwo hundred sixty nine women presenting at first prenatal visits in Southern Louisiana, 2015-2017, completed self-administered iPad surveys and structured interviews. Women reporting having considered abortion were asked whether Medicaid not paying for abortion was a reason they had not had an abortion. Using study data and published estimates of births, abortions, and Medicaid-covered births in Louisiana, we projected the proportion of Medicaid births that would instead be abortions if Medicaid covered abortion in Louisiana.Results28% considered abortion. Among women with Medicaid, 7.2% [95% CI 4.1-12.3] reported Medicaid not paying as a reason they did not have an abortion. Existing estimates suggest 10% of Louisiana pregnancies end in abortion. If Medicaid covered abortion, this would increase to 14% [95% CI 12, 16]. 29% [95% CI 19, 41] of Medicaid eligible pregnant women who would have an abortion with Medicaid coverage, instead give birth.ConclusionsFor a substantial proportion of pregnant women in Louisiana, the lack of Medicaid funding remains an insurmountable barrier to obtaining an abortion. Forty years after the Hyde Amendment was passed, lack of Medicaid funding for abortion continues to have substantial impacts on women's ability to obtain abortions
Male infants and birth complications are associated with increased incidence of postnatal depression
Rationale: A growing body of literature links both depressive symptoms generally, and those specifically in the postnatal period, with an inflammatory immune response. Evolutionary medical approaches, such as the Pathogen Host Defence Theory of Depression (PATHOS-D), have likened depression to sickness behaviour in other mammals, and propose that the characteristics associated with depression are protective when an individual is experiencing pathogenic threat. Many known risk factors for depressive symptoms are associated with activation of inflammatory pathways, opening up the potential for identifying novel risk factors based on their inflammation causing effects.
Objective: Both the gestation of male foetuses and the experience of birth complications have documented associations with increased inflammation, yet their relationships with postnatal depression (PND) are currently unclear.
Method: Here we use the complete reproductive histories of 296 women from contemporary, low fertility populations gathered by retrospective survey to assess whether the odds of PND increased when mothers gave birth to male infants or experienced birth complications, using generalised estimating equation models controlling for individual effects of the mother and other known PND risk factors.
Results: We found the odds of PND increased by 71–79% when male infants were born compared to female infants. The occurrence of birth complications increased the odds of PND by 174% compared to having no complications. Testing for interaction effects found that, while always at increased risk of PND, women with a tendency towards symptoms of depression, anxiety, and stress at other points in the life course had reduced odds of PND when experiencing birth complications, suggesting such women may elicit greater support.
Conclusions: These results highlight two novel PND risk factors, male infants and birth complications, which can be easily assessed by health professionals
Draft genome sequence of Pseudomonas aeruginosa ATCC 9027, originally isolated from an outer ear infection
Pseudomonas aeruginosa ATCC 9027 was isolated in 1943 from a case of otitis externa and is commonly employed as a quality control strain for sterility, assessment of antibiofilm agents, and in vitro study of wound infection. Here, we present the 6.34-Mb draft genome sequence and highlight some pertinent genes that are associated with virulence
Food taboos during pregnancy: meta-analysis on cross cultural differences suggests specific, diet-related pressures on childbirth among agriculturalists
Pregnancy is the most delicate stage of human life history as well as a common target of food taboos across cultures. Despite puzzling evidence that many pregnant women across the world reduce their intake of nutritious foods to accomplish cultural norms, no study has provided statistical analysis of cross-cultural variation in food taboos during pregnancy. Moreover, antenatal practices among forager and agriculturalists have never been compared, despite subsistence mode being known to affect staple foods and lifestyle directly. This gap hinders to us from understanding the overall threats attributed to pregnancy, and their perceived nutritional causes around the world. The present study constitutes the first cross-cultural meta-analysis on food taboos during pregnancy. We examined thirty-two articles on dietary antenatal restrictions among agricultural and non-agricultural societies, in order to: (i) identify cross-culturally targeted animal, plant and miscellaneous foods; (ii) define major clusters of taboo focus; (iii) test the hypothesis that food types and clusters of focus distribute differently between agricultural and non-agricultural taboos; and (iv) test the hypothesis that food types distribute differently across the clusters of taboo focus. All data were analysed in SPSS and RStudio using chi-squared tests and Fisher's exact tests. We detected a gradient in taboo focus that ranged from no direct physiological interest to the fear of varied physiological complications to a very specific concern over increased birth weight and difficult delivery. Non-agricultural taboos were more likely to target non-domesticated animal foods and to be justified by concerns not directly linked to the physiological sphere, whereas agricultural taboos tended to targed more cultivated and processed products and showed a stronger association with concerns over increased birth weight. Despite some methodological discrepancies in the existing literature on food taboos during pregnancy, our results illustrate that such cultural traits are useful for detecting perception of biological pressures on reproduction across cultures. Indeed, the widespread concern over birth weight and carbohydrate rich foods overlaps with clinical evidence that obstructed labor is a major threat to maternal life in Africa, Asia and Eurasia. Furthermore, asymmetry in the frequency of such concern across subsistence modes aligns with the evolutionary perspective that agriculture may have exacerbated delivery complications. This study highlights the need for the improved understanding of dietary behaviors during pregnancy across the world, addressing the role of obstructed labor as a key point of convergence between clinical, evolutionary and cultural issues in human behavior
Teenage pregnancy in the United Kingdom: A behavioral ecological perspective
In this paper we describe teenage pregnancy and motherhood in the United Kingdom. This has been regarded as a key social policy issue for some time and is the focus of policy intervention under the current administration. We argue that policy has been based on simple models of teenage pregnancy that have failed to take into account the complex biological nature of reproductive behavior. Our claim is that the U.K. government would be well advised to take a life-history approach to this issue, and we outline what this means and what is currently known as a consequence of research in this area, concluding with lessons that should be drawn by those working in policy
Deciduous enamel 3D microwear texture analysis as an indicator of childhood diet in medieval Canterbury, England
This study conducted the first three dimensional microwear texture analysis of human deciduous teeth to reconstruct the physical properties of medieval childhood diet (age 1-8yrs) at St Gregory's Priory and Cemetery (11th to 16th century AD) in Canterbury, England. Occlusal texture complexity surfaces of maxillary molars from juvenile skeletons (n=44) were examined to assess dietary hardness. Anisotropy values were calculated to reconstruct dietary toughness, as well as jaw movements during chewing. Evidence of weaning was sought, and variation in the physical properties of food was assessed against age and socio-economic status. Results indicate that weaning had already commenced in the youngest children. Diet became tougher from four years of age, and harder from age six. Variation in microwear texture surfaces was related to historical textual evidence that refers to lifestyle developments for these age groups. Diet did not vary with socio-economic status, which differs to previously reported patterns for adults. We conclude, microwear texture analyses can provide a non-destructive tool for revealing subtle aspects of childhood diet in the past
What drives sex toy popularity? A morphological examination of vaginally-insertable products sold by the world’s largest sexual wellness company
There is limited research into the morphology of sex toys, and specifically into (the often phallic-shaped) vibrators and dildos and what they may represent in terms of user preferences for male genital morphology. This study provides insight into consumer preference around vaginally insertable sex toys, their features, and what contributes to their popularity. Using a data set compiling information from the world’s largest online sexual wellness retailer Lovehoney, we examined the dimensions, price, and morphological features of 265 sex toys designed for vaginal insertion to determine what contributes to item popularity. Using regression models, we found that realistic features did not predict item popularity, whereas price (p < .001) and circumference (p = .01) significantly predicted the overall popularity of a toy. It appears that consumers show a preference for insertable sex toys that are not direct replicas of the male penis, which suggests they are not seeking a realistic partner substitute. Further, we found that the length of the toy did not significantly predict popularity which is consistent with other work showing that women do not place considerable emphasis on large phallus size. Our results can contribute to future product design and marketing, as well as reveal preferences toward particular characteristics of the phallus (whether real or toy)
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