70 research outputs found
For richer, for poorer: marriage and casualized sex in East African artisanal mining settlements
Migrants to Tanzania's artisanal gold mining sites seek mineral wealth, which is accompanied by high risks of occupational hazards, economic failure, AIDS and social censure from their home communities. Male miners in these settlements compete to attract newly arrived young women who are perceived to be diverting male material support from older women and children's economic survival. This article explores the dynamics of monogamy, polygamy and promiscuity in the context of rapid occupational change. It shows how a wide spectrum of productive and welfare outcomes is generated through sexual experimentation, which calls into question conventional concepts of prostitution, marriage and gender power relations
The Open Flux Problem
The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun's photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun's magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission
A História da Alimentação: balizas historiogråficas
Os M. pretenderam traçar um quadro da HistĂłria da Alimentação, nĂŁo como um novo ramo epistemolĂłgico da disciplina, mas como um campo em desenvolvimento de prĂĄticas e atividades especializadas, incluindo pesquisa, formação, publicaçÔes, associaçÔes, encontros acadĂȘmicos, etc. Um breve relato das condiçÔes em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biolĂłgica, a econĂŽmica, a social, a cultural e a filosĂłfica!, assim como da identificação das contribuiçÔes mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histĂłrica, foi ela organizada segundo critĂ©rios morfolĂłgicos. A seguir, alguns tĂłpicos importantes mereceram tratamento Ă parte: a fome, o alimento e o domĂnio religioso, as descobertas europĂ©ias e a difusĂŁo mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rĂĄpido balanço crĂtico da historiografia brasileira sobre o tema
Aquaporin-2: COOH terminus is necessary but not sufficient for routing to the apical membrane.
Item does not contain fulltextRenal regulation of mammalian water homeostasis is mediated by the aquaporin-1 (AQP1) water channel, which is expressed in the apical and basolateral membranes of proximal tubules and descending limbs of Henle, and aquaporin-2 (AQP2), which is redistributed from intracellular vesicles to the apical membrane (AM) of collecting duct cells with vasopressin. In transfected Madin-Darby canine kidney cells, AQP1 and AQP2 are regulated similarly, which indicates that routing elements reside in their primary sequences. We studied the role of the AQP2 COOH terminus in apical routing and AQP2 shuttling. An AQP1 chimera (AQP1 with an AQP2 tail: AQP1/2-N220) was located only in the AM independent of forskolin treatment. Forskolin increased the apical expression of AQP1 and AQP1/2-N220 less than twofold; that of AQP2 increased more than fourfold with concomitant changes in osmotic water permeabilities. The dimeric AQP2 tail coupled to placental alkaline phosphatase (AQP2-Plap) was retained in intracellular vesicles different from those of homotetrameric wild-type AQP2; the same protein without the AQP2 tail (TMR-Plap) was only expressed in the AM. The study shows that the AQP2 COOH tail is necessary but not sufficient for routing to the AM and suggests that other parts of AQP2 are needed for AQP2 accumulation in intracellular vesicles
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