38 research outputs found
Intraâclinothem variability in sedimentary texture and process regime recorded down slope profiles
Shelfâmargin clinothem successions can archive process interactions at the shelf to slope transition, and their architecture provides constraints on the interplay of factors that control basinâmargin evolution. However, detailed textural analysis and facies distributions from shelf to slope transitions remain poorly documented. This study uses quantitative grainâsize and sorting data from coeval shelf and slope deposits of a single clinothem that crops out along a 5 km long, dipâparallel transect of the Eocene Sobrarbe Deltaic Complex (Ainsa Basin, southâcentral Pyrenees, Spain). Systematic sampling of sandstone beds tied to measured sections has captured vertical and basinward changes in sedimentary texture and facies distributions at an intraâclinothem scale. Two types of hyperpycnal flowârelated slope deposits, both rich in mica and terrestrial organic matter, are differentiated according to grain size, sorting and bed geometry: (i) sustained hyperpycnal flow deposits, which are physically linked to coarse channelized sediments in the shelf setting and which deposit sand down the complete slope profile; (ii) episodic hyperpycnal flow deposits, which are disconnected from, and incise into, shelf sands and which are associated with sediment bypass of the proximal slope and coarseâgrained sand deposition on the medial and distal slope. Both types of hyperpycnites are interbedded with relatively homogenous, organicâfree and micaâfree, wellâsorted, very fineâgrained sandstones, which are interpreted to be remobilized from waveâdominated shelf environments; these waveâdominated deposits are found only on the proximal and medial slope. Coarseâgrained sediment bypass into the deeperâwater slope settings is therefore dominated by episodic hyperpycnal flows, whilst sustained hyperpycnal flows and turbidity currents remobilizing waveâdominated shelf deposits are responsible for the full range of grain sizes in the proximal and medial slope, thus facilitating clinoform progradation. This novel dataset highlights previously undocumented intraâclinothem variability related to updip changes in the shelf processâregime, which is therefore a key factor controlling downdip architecture and resulting sedimentary texture
Automatic and Deliberate Affective Associations with Sexual Stimuli in Women with Superficial Dyspareunia
Current views suggest that in women with superficial dyspareunia the prospect of penileâvaginal intercourse automatically activates fear-related associations. The automatic activation of negative associations is assumed to interfere with the development of sexual arousal. In turn, this may further aggravate the dyspareunia-related complaints. To assess whether automatic negative associations are involved in this sexual pain disorder, women with superficial dyspareunia (n = 35) and a control group (n = 35) completed a modified pictorial Affective Simon Task (AST). Questioning the role of dysfunctional automatic associations in superficial dyspareunia, the AST indicated that symptomatic women displayed relatively positive rather than negative automatic associations with sexual stimuli. At the self-report level, however, affective associations with sex cues were significantly more negative for women with dyspareunia than for controls. This discrepancy between âreflectiveâ and âreflexiveâ affective associations with sexual stimuli in women with dyspareunia points to the relevance of conscious appraisal and deliberate rather than automatic processes in the onset and maintenance of dyspareunia
Sex, hormones and the brain
The human sexual response is a complicated biopsychosocial phenomenon in which internal and external stimuli are modulated by the central and peripheral nervous system, resulting in a cascade of biochemical, hormonal and circulatory changes that lead to cognitive and physical sexual arousal. In this article, current knowledge of the relationships between central processes, mediated by neuropeptides and neurotransmitters, and the hypothalamo-pituitary-gonadal axis is explored. Hormonal aspects of sexual arousability and sexual excitement are mainly related to androgens. The possible influences of hormonal therapies such as hormonal contraception and perimenopausal hormone substitution are described. The main conclusion is that clinicians should be aware of possible sexual problems resulting from changes in circulating sex hormone binding globulin and free testosterone in men and women due to endogenous or exogenous hormonal change