Cepheid Masses: FUSE Observations of S Mus

S Mus is the Cepheid with the hottest known companion. The large ultraviolet flux means that it is the only Cepheid companion for which the velocity amplitude could be measured with the echelle mode of the HST GHRS. Unfortunately, the high temperature is difficult to constrain at wavelengths longer than 1200 \AA because of the degeneracy between temperature and reddening. We have obtained a FUSE spectrum in order to improve the determination of the temperature of the companion. Two regions which are temperature sensitive near 16,000 K but relatively unaffected by H$_2$ absorption (940 \AA, and the Ly $\beta$ wings) have been identified. By comparing FUSE spectra of S Mus B with spectra of standard stars, we have determined a temperature of 17,000 $\pm$ 500 K. The resultant Cepheid mass is 6.0 $\pm$ 0.4 M$_\odot$. This mass is consistent with main sequence evolutionary tracks with a moderate amount of convective overshoot.Comment: accepted to Ap

VP25.24: Fetal ultrasound, MR imaging and MR autopsy in Cri du chat syndrome: two case reports and review of the literature

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Survival and growth of Nothofagus pumilio seedlings under several microenvironments after variable retention harvesting in southern Patagonian forests

Context: Variable retention prescriptions for Nothofagus pumilio forests provide for biodiversity conservation and natural regeneration by controlled opening of the canopy. Harvesting generates different microenvironments which present dissimilar conditions for seedling establishment, due to positive or negative influences over biotic and abiotic factors. Aims: This study evaluated seedling survival and performance in different microenvironments within the harvested stands. Tested hypotheses stated that seedling stress and performance were influenced by harvesting due to changes in forest structure, microclimate, soil properties, and nutrient availability. Methods: In the stands harvested by variable retention, five contrasting microenvironments were selected as treatments for the experiments and sampling. Environmental variables were related to ecophysiological, seedling survival, and performance. Results: The modification of forest structure (crown cover and tree density) and the presence of coarse woody debris greatly affect the effective rainfall and global radiation reaching understorey level, influencing seedling stress and consequently survival and performance. Harvesting also modifies soil properties (e.g., soil bulk density) and coarse woody debris accumulation which in turn influences soil moisture and/or solar radiation levels. Analyses showed that seedlings received benefits of microenvironment variation after harvesting. Areas covered with middle or fine woody debris presented regeneration with better ecophysiological response and seedling performance, although dispersed retention areas (far away from remnant trees) and roads could also present suitable conditions for seedling survival and performance. Conclusions: The proportion of different microenvironments in the harvested forests will determine the amount of natural recruitment of regeneration and consequently the success of proposed silvicultural management. Forest practices must be manipulated to increase the proportion of favorable microenvironments (e.g., woody debris), allowing greater natural regeneration success during the first years after harvesting.Laboratorio de Investigación de Sistemas Ecológicos y Ambientale

How important are supermarkets for the diets of the urban poor in Africa?

Many developing countries are undergoing a profound transformation of food systems and retail environments. Especially in urban areas, a rapid growth of supermarkets is observed, which can affect consumer food choices and diets. Supermarkets may improve access to diverse foods at affordable prices, but may also encourage a switch from unprocessed to highly-processed and energy-dense foods that contribute to obesity. However, the use of supermarkets is positively correlated with income. That supermarkets already play an important role for the diets of many urban consumers does not necessarily mean that this is also true for the poorest population segments that are of particular interest for development policy. This article analyzes the diets and food purchase patterns of poor urban consumers in Kenya and Uganda. Representative data were collected from households in the slums of Nairobi and Kampala. The data show that the majority of these households are undernourished. They buy most food items in unprocessed form from various traditional retail outlets, including mom-and-pop shops, local markets, and kiosks. Relatively few sample households buy any of their food in supermarkets. Supermarkets account for only 3% and 0.4% of all food expenditures of slum dwellers in Nairobi and Kampala, respectively. Reasons for the low supermarket use of these poor households are discussed. The findings suggest that a focus on the modern retail sector alone will not suffice to ensure food and nutrition security for all

Geochemistry of phosphatic nodules as a tool for understanding depositional and taphonomical settings in a paleolithic cave site (San teodoro, Sicily)

Interpreting depositional settings of cave sites is generally problematic, especially in absence of paleontological/archaeological evidence. This is the case of some deposits at San Teodoro Cave (Sicily), a key site for the Mediterranean Paleolithic. In a stratigraphic level interrupted by a carbonatic concretion, phosphatic nodules are present only in the part enclosed between the concretion and the cave wall. The discovery of these nodules combined with the punctual lack of fossils had initially suggested an erosion phenomenon and subsequent formation of nodules at a vadose level. Here we show the usefulness of an integrated, geochemical-paleoecological approach in defining stratigraphy and paleoenvironmental reconstructions. XRD, ICP-OES, ATR-FTIR and EDS analyses allowed the formulation of a new hypothesis regarding the origin of the nodules, the depositional dynamics, and the role played by the guano produced by an extensive colony of bats. The role of barium and rubidium in detecting taphonomical processes has been highlighted