New paleomagnetic data from Late Neoproterozoic sedimentary successions in Southern Urals, Russia: implications for the Late Neoproterozoic paleogeography of the Iapetan realm

We present the results of paleomagnetic study of Ediacaran sedimentary successions from the Southern Urals. The analysis of the sedimentary rocks of the Krivaya Luka, Kurgashlya and Bakeevo Formations reveal stable mid-temperature and high-temperature remanence components.Mid-temperature components were acquired during Devonian (Bakeevo Formation) and Late Carboniferous–Early Permian remagnetization events. The high-temperature components in Kurgashlya and Bakeevo Formations are interpreted to be primar , because they are supported by a positive conglomerate test (Bakeevo Formation) and magnetostratigraphic pattern (Kurgashlya Formation). Thehigh-temperature component in the Krivaya Luka Formation is interpreted to be a Late Ediacaran overprint. Our new paleomagnetic poles together with some previously published Ediacaran poles from Baltica and Laurentia are used herein to produce a series of paleogeographic reconstructions of the opening of the Iapetus Ocean

Reproductive Aging, Sex Steroids, and Mood Disorders

Epidemiologic studies have documented that the majority of women do not become depressed during the menopause transition. However, recent longitudinal studies suggest that in some women, the events related to the menopause transition could play a role in the onset of depression. In this article we review evidence suggesting a relationship between the menopause transition and depression. Additionally, we describe several findings that suggest a role of ovarian hormones in the onset of these depressions, including the clustering of episodes of depression during the stage of the menopause transition that is accompanied by estradiol withdrawal, and the therapeutic effects of short-term estradiol in depressed perimenopausal women. Finally, we discuss possible causes of affective disturbances during the menopause transition

Pharmacologically Induced Hypogonadism and Sexual Function in Healthy Young Women and Men

Studies fail to find uniform effects of age-related or induced hypogonadism on human sexual function. We examined the effects of induced hypogonadism on sexual function in healthy men and women and attempted to identify predictors of the sexual response to induced hypogonadism or hormone addback. The study design used was a double-blind, controlled, crossover (self-as-own control). The study setting was an ambulatory care clinic in a research hospital, and the participants were 20 men (average ± SD age = 28.5 ± 6.2 years) and 20 women (average ± SD age = 33.5 ± 8.7 years), all healthy and with no history of psychiatric illness. A multidimensional scale assessing several domains of sexual function was the main outcome measure. Participants of the study received depot leuprolide acetate (Lupron) every 4 weeks for 3 months (men) or 5 months (women). After the first month of Lupron alone, men received (in addition to Lupron) testosterone enanthate (200 mg intramuscularly) or placebo every 2 weeks for 1 month each. Women received Lupron alone for 2 months, and then, in addition to Lupron, they received estradiol and progesterone for 5 weeks each. The results of the study: in women, hypogonadism resulted in a significant decrease in global measures of sexual functioning, principally reflecting a significant decrease in the reported quality of orgasm. In men, hypogonadism resulted in significant reductions in all measured domains of sexual function. Testosterone restored sexual functioning scores in men to those seen at baseline, whereas neither estradiol nor progesterone significantly improved the reduced sexual functioning associated with hypogonadism in women. Induced hypogonadism decreased sexual function in a similar number of men and women. No predictors of response were identified except for levels of sexual function at baseline. In conclusion, our data do not support a simple deficiency model for the role of gonadal steroids in human sexual function; moreover, while variable, the role of testosterone in sexual function in men is more apparent than that of estradiol or progesterone in women