Temperate and tropical brown macroalgae thrive, despite decalcification, along natural CO(2) gradients

Predicting the impacts of ocean acidification on coastal ecosystems requires an understanding of the effects on macroalgae and their grazers, as these underpin the ecology of rocky shores. Whilst calcified coralline algae (Rhodophyta) appear to be especially vulnerable to ocean acidification, there is a lack of information concerning calcified brown algae (Phaeophyta), which are not obligate calcifiers but are still important producers of calcium carbonate and organic matter in shallow coastal waters. Here, we compare ecological shifts in subtidal rocky shore systems along CO2 gradients created by volcanic seeps in the Mediterranean and Papua New Guinea, focussing on abundant macroalgae and grazing sea urchins. In both the temperate and tropical systems the abundances of grazing sea urchins declined dramatically along CO2 gradients. Temperate and tropical species of the calcifying macroalgal genus Padina (Dictyoaceae, Phaeophyta) showed reductions in CaCO3 content with CO2 enrichment. In contrast to other studies of calcified macroalgae, however, we observed an increase in the abundance of Padina spp. in acidified conditions. Reduced sea urchin grazing pressure and significant increases in photosynthetic rates may explain the unexpected success of decalcified Padina spp. at elevated levels of CO2 . This is the first study to provide a comparison of ecological changes along CO2 gradients between temperate and tropical rocky shores. The similarities we found in the responses of Padina spp. and sea urchin abundance at several vent systems increases confidence in predictions of the ecological impacts of ocean acidification over a large geographical range.Vivienne R. Johnson, Bayden D. Russell, Katharina E. Fabricius, Colin Brownlee and Jason M. Hall-Spence

Net primary productivity estimates and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models

The relative skill of 21 regional and global biogeochemical models was assessed in terms of how well the models reproduced observed net primary productivity (NPP) and environmental variables such as nitrate concentration (NO3), mixed layer depth (MLD), euphotic layer depth (Zeu), and sea ice concentration, by comparing results against a newly updated, quality-controlled in situ NPP database for the Arctic Ocean (1959-2011). The models broadly captured the spatial features of integrated NPP (iNPP) on a pan-Arctic scale. Most models underestimated iNPP by varying degrees in spite of overestimating surface NO3, MLD, and Zeu throughout the regions. Among the models, iNPP exhibited little difference over sea ice condition (ice-free vs. ice-influenced) and bottom depth (shelf vs. deep ocean). The models performed relatively well for the most recent decade and towards the end of Arctic summer. In the Barents and Greenland Seas, regional model skill of surface NO3 was best associated with how well MLD was reproduced. . Regionally, iNPP was relatively well simulated in the Beaufort Sea and the central Arctic Basin, where in situ NPP is low and nutrients are mostly depleted. Models performed less well at simulating iNPP in the Greenland and Chukchi Seas, despite the higher model skill in MLD and sea ice concentration, respectively. iNPP model skill was constrained by different factors in different Arctic Ocean regions. Our study suggests that better parameterization of biological and ecological microbial rates (phytoplankton growth and zooplankton grazing) are needed for improved Arctic Ocean biogeochemical modeling

Epigenetic mechanisms in virus-induced tumorigenesis

About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogenic viruses belong to different families, their strategies in human cancer development show many similarities and involve viral-encoded oncoproteins targeting the key cellular proteins that regulate cell growth. Recent studies show that virus and host interactions also occur at the epigenetic level. In this review, we summarize the published information related to the interactions between viral proteins and epigenetic machinery which lead to alterations in the epigenetic landscape of the cell contributing to carcinogenesis

Genetically engineered people: autonomy and moral virtue

I endorse Mark Walker’s thesis that there is no moral difference between genetic interventions to make it more likely that children will develop moral virtues, such as truthfulness, caring, and justice — however, exactly, these are understood — and environmental interventions aimed at the same outcome. In this response, I offer some further considerations that tend to support the thesis in the face of "loss of freedom" or "loss of autonomy" arguments

Post-Human Futures. "Transcension", by Damien Broderick and "Schild's Ladder", by Greg Egan. [review]

Since 1990 Australian science fiction (SF) has undergone an extraordinary renaissance. These new books by Broderick and Egan, "Transcension" and "Schild’s Ladder", are at the genre’s cutting edge. Both writers attempt to imagine worlds that have undergone truly radical change, as a result of which humanity itself has been superseded or deeply altered. Such post-human scenarios are now debated intensely within the genre, as its practitioners reflect upon the contemporary technological trajectory. Once the possibilities for powerful new technologies, such as nanotechnology and artificial intelligence (AI), become clearer, the debate will increasingly spill over into the intellectual mainstream, a process already underway. Today’s serious SF themes are tomorrow’s mainstream social and political issues

Freedom of religion & the secular state.

Focusing on the intersection of religion, law, and politics in contemporary liberal democracies, Blackford considers the concept of the secular state, revising and updating enlightenment views for the present day. Freedom of Religion and the Secular State offers a comprehensive analysis, with a global focus, of the subject of religious freedom from a legal as well as historical and philosophical viewpoint. It makes an original contribution to current debates about freedom of religion, and addresses a whole range of hot-button issues that involve the relationship between religion and the state, including the teaching of evolution in schools, what to do about the burqa, and so on

Rendezvous with Utopia: Two Versions of the Future in the Rama Novels

<div>Published in 1973, Arthur C. Clarke's <i>Rendezvous with Rama </i>won the Hugo, Nebula, and John W. Campbell Awards (and also the Jupiter Award, voted on by the Institute of Science Fiction in Higher Education). Its impressive collection of awards, outstanding commercial success, and intrinsic interest make it one of the few truly iconic works of hard science fiction. It depicts the work of astronauts in space, and shows an obvious concern for scientific accuracy and logic. In all, <i>Rendezvous with Rama </i>seems like an unlikely candidate for a utopian novel, and that expression would, in-deed, misdescribe it. Yet, it contains strong mythic, satirical, and utopian elements, which give it much of its interest.</div><div>Alas, many of those elements are discarded in the trilogy of novels that appeared much later as an extended sequel to the novel's action.</div

The mystery of moral authority /

The Mystery of Moral Authority argues for a sceptical and pragmatic view of morality as an all-too-human institution. Searching, intellectually rigorous, and always fair to rival views, it represents the state of the art in a tradition of moral philosophy that includes Thomas Hobbes, David Hume, and J.L. Mackie