The Role of Androgens in Life History Theories of Attachment

Life history theories (LHTs) of attachment address how attachments to caregivers in infancy/childhood and to romantic partners in adulthood are used to negotiate mating and reproductive choices. Greater insecure-avoidant attachment has been suggested to be associated with the adoption of a low-investment, short-term reproductive strategy. The role of sex hormones, including the androgen testosterone (T), in the development of attachment-related reproductive strategies has been speculated in some LHTs. This research tested an integrated-LHT model of early environment, attachment, and reproductive strategies in men, using structural equation modeling. Androgen-related effects were hypothesized to occur prenatally and/or in adulthood, consistent with various LHTs of attachment. A sample of 195 young men (M = 21.06 years) from the University of Western Ontario completed self-report paper-and-pencil questionnaires assessing their romantic attachment style, retrospective attachment to caregivers in childhood, sexual variables (e.g., sociosexuality, age at first intercourse), and personality variables such as aggression, impulsivity, and risk-taking. Testosterone was measured in saliva, while an indirect estimate of prenatal T was derived from the 2D:4D finger length ratio. Degree of androgen receptor (AR) sensitivity, as indexed by the CAG repeat polymorphism in the AR gene, was also obtained. Results showed that adult romantic attachment style (avoidant vs. anxious) mediated the relationship between childhood attachment insecurity and men’s sexual reproductive strategy. Greater avoidance predicted a more opportunistic sexual strategy and greater anxiety predicted lower levels of the same strategy. Degree of childhood attachment insecurity, as retrospectively reported, mediated the relationship between quality of early family structure and engagement in non-sexual evocative behaviours believed to be associated with a more opportunistic reproductive strategy (non-sexual reproductive strategy). Adult T was an independent positive predictor of avoidant attachment, and of the non-sexual reproductive strategy, while weaker AR responsivity predicted higher levels of romantic attachment anxiety. Furthermore, romantic attachment configurations were found to mediate the relationship between androgenic variables and sexual behaviour. These findings highlight the figural role of attachment in life history based models of mating strategies, and provide some of the first empirical support for the hypothesis that romantic attachment in men is, in part, sex-hormonally-based

Proceedings of the 24th Paediatric Rheumatology European Society Congress: Part three

From Springer Nature via Jisc Publications Router.Publication status: PublishedHistory: collection 2017-09, epub 2017-09-0

INFLUENCE OF TESTOSTERONE AND ANDROGEN RECEPTOR POLYMORPHISM ON VISUAL-SPATIAL COGNITION IN ADULT MEN

The nature of the relationship, if any, between visual-spatial cognition and androgens in humans remains controversial. Possible associations between spatial ability, testosterone (T), and the length of the CAG polymorphism in the androgen receptor gene were investigated in 106 healthy undergraduate males. Using multiple linear regression, T concentrations and CAG repeat length significantly contributed to the prediction of performance on the Paper Folding Test. Some differences between left- and right-handed participants were observed. A secondary objective was to study the association between salivary T, CAG repeat length, and depressive affect across the entire mood spectrum in the same sample of subjects. CAG repeat length and T levels significantly contributed to the prediction of somatic symptoms of depression, but not to overall depression scores. These findings suggest that taking CAG repeat status into consideration may be informative in studies looking at the associations between androgens and either spatial ability or mood

Extraction of lipids from microalgae using fluidisation

Microalgae are promising sources of lipids and are widely being investigated today for their capacity as a starting material for biodiesel production. One of the major constraints in handling algae and extracting lipids in large scale is the dewatering/drying step and the overall cost it incurs. This study proposes fluidisation as a new method for extracting lipids in the presence of water. The algal cells were exposed to different bubbling conditions; assisted with and without solids. The effects of the bubbles on cells and thus lipid extraction from the wet biomass were measured in terms of the amount of fatty acids obtained after trans-esterification determined using gas chromatography. The results were supported by scanning electron microscopic images which showed the morphological changes due to the hydrodynamic stress offered by the bubbles on the cells and on the introduction of solids. The results indicated that bubbling at higher velocities, 25cm/s has a positive effect towards lipid extraction in the presence of water, than operating at lower velocities. With the solids involved, cell disruption was clearly seen at relatively higher velocities; and short time exposure to fluidisation at that velocity was found to be effective in terms of lipid extraction.​Master of Science (Biomedical Engineering

Inflammatory demyelinating disorders of childhood: Experience with six children

Demyelinating disorders of the central nervous system (CNS) in children pose diagnostic and prognostic difficulties in clinical practice. In this report, we describe our experience with inflammatory demyelinating disorders of CNS in six children, classified as per the proposed criteria by the Pediatric Multiple Sclersois Study Group. We emphasize the importance of appropriate diagnosis and follow-up to distinguish transient inflammatory demyelinating diseases from chronic inflammatory demyelinating diseases