Changes in biomass and elemental composition during early ontogeny of the Antarctic isopod crustacean Ceratoserolis trilobitoides

Changes in biomass and elemental composition (dry mass, DM; carbon, C; hydrogen, H; nitrogen, N) were studied throughout the early ontogeny in the serolid isopod Ceratoserolis trilobitoides from a population off the South Shetland Islands (62°24.35?S, 61°23.77?W). Specimens of C. trilobitoides were sampled using an Agassiz trawl during the expedition ANT XXIII-8 of RV Polarstern in January 2007. Classification of embryos into six developmental stages followed previous studies. No clear size-dependant fecundity relationship was found in ovigerous C. trilobitoides. Egg volume increased by about 160 and 400% from stage I to IV and stage IV to VI, respectively. DM, C, N, and H continuously decreased throughout the early ontogeny from stage I to VI, but DM showed significant increase on reaching the late-V stage and premanca stages. The C:N ratio remained relatively stable throughout stages I to V, followed by a significant drop from about 6.17 to 5.5 in subsequent stages, indicating depletion of lipid resources of maternal origin. The results coincide with previous studies and indicate a shift from a lipid-based metabolism throughout early embryo stages to a protein-based metabolism in the late-V and premanca stage, which requires external energy supply. Given the steep increase in DM in the final phase of embryo development (late-V stage to premanca) and the need for external food supply to exert growth, the possibility of external food supply or cannibalism in early offspring of C. trilobitoides is discussed

Ethics and Decisions in Distributed Technologies: A Problem of Trust and Governance Advocating Substantive Democracy

The distributed architecture of applications such as blockchains, wireless sensor networks, multi-agent platforms, and the Internet of Things charges technological development to face, by default, with two aspects of responsibility that were usually accorded to human beings: the “decision” (Who is enabled to make decisions in a decentralized system? What about the mechanism for deciding? Authorized by whom? With what kind of consensus?) and “ethics” (To which principles must respond the decision-making mechanism? And, if decisions are distributed, what is the role of ethics? To guide or to laissez-faire? Permissive or restrictive? For everyone or only for those who are authorized?). Responding to these epochal questions can lead to rethinking the distributed technologies in view of a game-changing transformation of models of trust-in-governance. From a model signed by centralization of trust, we have come to progressively more decentralized forms until the contemporary “distributed trust”. This paper constitutes an endeavor to introduce and address the main philosophical foundations of this historical passage

Ancient crustal metamorphism at low pH2O: Charnockite formation at Kabbaldurga, South India

Arrested charnockitic conversion of amphibolitic gneiss at Kabbaldurga, Karnataka State, south India, was studied mineralogically. Iron-rich pyroxenes were generated from amphibole in patches and stringers without melting. The dark colour of charnockite arises from numerous tiny veins of chlorite and manganese-bearing calcite, particularly in feldspars. The metamorphism was effected by very local, mainly grain-boundary, migration of volatiles low in H2O, and probably dominantly CO2. This was followed by vein alteration at lower temperatures from volatiles richer in H2O. The volatiles are ascribed to massive liberation from the mantle in upwelling areas, and this may have been an important process in the evolution of the deep continental crust. © 1979 Nature Publishing Group