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A thin glacial diamicton, informally termed Granite drift, occupies the floor of central Beacon Valley in southern Victoria Land, Antarctica. This drift is Our results show that the surface of Granite drift is stable at polygon centers and that enclosed ash-fall deposits can be used to define the age of underlying glacier ice. In our model for patternedground development, active regions lie only above polygon troughs, where enhanced sublimation of underlying ice outlines high-centered polygons. The rate of sublimation is influenced by the development of porous gravel-and-cobble lag deposits that form above thermal-contraction cracks in the underlying ice. A negative feedback associated with the development of secondary-ice lenses at the base of polygon troughs prevents runaway ice loss. Secondary-ice lenses contrast markedly with glacial ice by lying on a [delta]D versus [[delta].sup.18]O slope of 5 rather than a precipitation slope of 8 and by possessing a strongly negative deuterium excess. The latter indicates that secondary-ice lenses likely formed by melting, downward percolation, and subsequent refreezing of snow trapped preferentially in deep polygon troughs. The internal stratigraphy of Granite drift is related to the formation of surface polygons and surrounding troughs. The drift is composed of two facies: A nonweathered, matrix-supported diamicton that contains >25% striated clasts in the >16 mm fraction and a weathered, clast-supported diamicton with varnished and wind-faceted gravels and cobbles. The weathered facies is a coarse-grained lag of Granite drift that occurs at the base of polygon troughs and in lenses within the nonweathered facies. The concentration of cosmogenic [sup.3]He in dolerite cobbles from two profiles through the nonweathered drift facies exhibits steadily decreasing values and shows the drift to have formed by sublimation of underlying ice. These profile patterns and the [sup.3]He surface-exposure ages of 1.18 [+ or -] 0.08 Ma and 0.18 [+ or -] 0.01 Ma atop these profiles indicate that churning of clasts by cryoturbation has not occurred at these sites in at least the past [10.sup.5] and [10.sup.6] yr. Although Granite drift is stable at polygon centers, low-frequency slump events occur at the margin of active polygons. Slumping, together with weathering of surface clasts, creates the large range of cosmogenic-nuclide surface-exposure ages observed for Granite drift. Maximum rates of sublimation near active thermal-contraction cracks, calculated by using the two [sup.3]He depth profiles, range from 5 m/m.y. to 90 m/m.y. Sublimation rates are likely highest immediately following major slump events and decrease thereafter to values well below our maximum estimates. Nevertheless, these rates are orders of magnitude lower than those computed on theoretical grounds. During eruptions of the nearby McMurdo Group volcanic centers, ash-fall debris collects at the surface of Granite drift, either in open thermal-contraction cracks or in deep troughs that lie above contraction cracks; these deposits subsequently lower passively as the underlying glacier ice sublimes. The fact that some regions of Granite drift have escaped modification by patterned ground for at least 8.1 Ma indicates long-term geomorphic stability of individual polygons. Once established, polygon toughs likely persist for as long as [10.sup.5]-[10.sup.6] yr. Our model of patterned-ground formation, which applies to the hyperarid, cold-desert, polar climate of Antarctica, may also apply to similar-sized polygons on Mars that occur over buried ice in Utopia Planitia. Keywords: Antarctica, cosmogenic-nuclide exposure dating, Dry Valleys, periglacial features, polygons.

Many rock glaciers contain massive ice that may be usefull in paleoclimate studies. Interpreting geochemical ice-core records from rock glaciers requires a thorough understanding of rock glacier structure and dynamics. High-precision surface-velocity data were obtained for the Galena Creek rock glacier, Absaroka Mountains, Wyoming. Surface velocities range from 0 to 1.00 m/yr and vary across the rock glacier in a manner similar to true glaciers. We used Glen's flow law to calculate the thickness of the deforming ice layer. The modeled ice thickness ranges from 0 to 50 m, and is confirmed by direct observations. This agreement shows that rock glacier movement can be entirely explained by deformation of massive ice within the rock glacier; neither basal sliding nor deformation of basal debris is necessary. Recovered ice cores (to depths of 25 m) contain thin debris layers associated with summer ablation in the accumulation zone. The ages of four samples of organic material removed from several debris layers in the southern half of the rock glacier range from 200 +/- 40 to 2250 +/- 35(super 14)C yr B.P., demonstrating that the rock glacier formed well before the Little Ice Age and may contain ice dating to the middle Holocene or earlier.

Vaginal dryness is common during and after menopause due to declining estrogen. It is one of the symptoms of vulvovaginal atrophy (VVA), which is part of the genitourinary syndrome of menopause. This can be distressing for women and cause pain, discomfort, and dyspareunia. Vaginal dryness affects over 50% of postmenopausal women but is under-reported and thus under-treated due to barriers to seeking help. Estrogen replacement can resolve symptoms, but may be contraindicated or not desired by all women. Over-the-counter vaginal moisturizers and lubricants can ease the symptoms of VVA. However, their chemical composition varies enormously and some are known to cause detrimental effects due to unphysiological pH, osmolality, and additives. The primary purpose of this review is to assess both their efficacy and safety. Women should be directed toward products that are as 'body-similar' as possible to vaginal secretions in terms of pH and osmolality. Products with potentially harmful ingredients should be avoided. Lubricants can be trialed for sexual activity and moisturizers for symptom control, even if topical or systemic menopause hormone therapy is being used. [ABSTRACT FROM AUTHOR]