Fecundity, brood loss and egg development through embryogenesis of Armases cinereum (Decapoda: Grapsidae)

The present work is a comprehensive study of reproduction and embryonic development of Armases cinereum. Ovigerous A. cinereum (Bosc, 1802) females from Sebastian Inlet, Florida (9.88–19.4 mm CW) lay 2,000–12,000 eggs per brood, depending on their CW (mm): fecundity = 24.662 CW1.9432. A. cinereum displayed significant brood loss through development (ca. 500 eggs per brood) independently from their CW (no senescence). However, since smaller females lay fewer eggs than larger ones, the percentage of eggs lost during embryonic development is greater in smaller females. The number of eggs carried on a later stage of development (potential fertility = 5.5593 CW2.4417) is a more accurate estimate of the reproductive output and subsequent recruitment. Egg volume increased during development (64%, 0.025–0.041 mm3 or 0.36–0.43 mm of diameter, N = 270) and was strongly correlated with egg water content increase (19.21%, r = 0.89). Lipids, particularly fatty acids, seem to be the major energy source for embryonic development, decreasing 56.31 and 37.08% (respectively) during embryonic development; both are negatively correlated with egg volume (r = −0.90). The utilization of fatty acids through the different developmental stages of A. cinereum is presented. The most consumed fatty acids are the monounsatured (43.33 μg mg−1 dw), followed by the saturated (29.91 μg mg−1 dw) and polyunsaturated (24.03 μg mg−1). Palmitic (16:0) and linoleic (18:2n-6) acids are preferentially consumed (19.5 and 17.9 μg mg−1 dw, respectively). The high proportion of essential polyunsaturated fatty acids of C18 and C20 reflects the consumption of primary producers such as mangrove leaves. EPA/DHA ratio (2.85–3.84) and low DHA content indicated that this species appears in a medium-low level of the trophic chain. The low ratio of 18:1n-7/18:1n-9 and high percentage of 18:1n-9 (marker of carnivory) may be a sign of the consumption of juvenile invertebrates. The high percentage of odd-numbered FA indicated the occurrence of detritivores/scavenger behaviours. The fatty acid composition of the eggs reflects adult feeding ecology (omnivorous) and habitat

Hair disorders induced by external factors

• External factors may result in hair loss, increased hair growth, or changes in the color and texture of the hair. • External factors responsible for hair loss are drugs, radiation, traction, fungi, pesticides, plant toxins, heavy metals, and several other chemicals. • Several groups of drugs may be responsible for unintentional induction of hair growth. • Texture and color of hair may be changed by drugs, metals, and ultraviolet and other radiation. • Full recovery is the rule after elimination of the responsible factor

Paraglacial rock-slope failure following deglaciation in western Norway

© 2020 Springer-Verlag.The paraglacial framework describes the geomorphological response to glaciation and deglaciation, whereby non-renewable, metastable, glacially-conditioned sediment sources are progressively released by a range of nonglacial processes. These include slope failures that directly modify the bedrock topography of mountain landscapes. This chapter synthesises recent research on the paraglacial evolution of western Norway’s mountain rock-slopes, and evaluates the importance of glaciation, deglaciation, and associated climatic and non-climatic processes. Following an introduction to the concept of paraglacial landscape change, current understanding of rock-slope responses to deglaciation are outlined, focussing on the spatial distribution, timing, duration and triggers for rock-slope failure (RSF). Preliminary analysis of an inventory of published ages for 49 prehistoric RSFs indicates that the great majority of activity occurred in the Late Weichselian / Early Holocene transition (~13-9 ka), within 2 ka of deglaciation. Subsequent RSFs were much smaller, though event frequency increased again at 8-7 ka and 5-4 ka BP. The majority of RSFs were not directly triggered by deglaciation (debuttressing) but were preconditioned for more than 1000 years after ice withdrawal, until slopes collapsed. It is proposed that the primary causes of failure within 2 ka of ice retreat were stress redistribution, subcritical fracture propagation, and possibly seismic activity. Earthquakes may have triggered renewed RSF in the Late Holocene, though it seems likely that permafrost degradation and water supply were locally important. Priority avenues for further research are briefly identified.Peer reviewe