Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology

notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations

The new JENSA gas-jet target for astrophysical radioactive beam experiments

To take full advantage of advanced exotic beam facilities, target technology must also be advanced. Particularly important to the study of astrophysical reaction rates is the creation of localized and dense targets of hydrogen and helium. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target has been constructed for this purpose. JENSA was constructed at Oak Ridge National Laboratory (ORNL) where it was tested and characterized, and has now moved to the ReA3 reaccelerated beam hall at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University for use with radioactive beams

Constraint of the Astrophysical 26g^{26g}Al(p;γ)27^{27}Si Destruction Rate at Stellar Temperatures

International audienceThe Galactic 1.809-MeV γ-ray signature from the β decay of $^{26g}$Al is a dominant target of γ-rayastronomy, of which a significant component is understood to originate from massive stars. The$^{26g}$Al(p; γ)$^{27}$Si reaction is a major destruction pathway for $^{26g}$Al at stellar temperatures, but the reactionrate is poorly constrained due to uncertainties in the strengths of low-lying resonances in $^{27}$Si. The$^{26g}$Al(d; p)$^{27}$Al reaction has been employed in inverse kinematics to determine the spectroscopic factors,and hence resonance strengths, of proton resonances in $^{27}$Si via mirror symmetry. The strength of the127-keV resonance is found to be a factor of 4 higher than the previously adopted upper limit, and the upperlimit for the 68-keV resonance has been reduced by an order of magnitude, considerably constraining the$^{26g}$Al destruction rate at stellar temperatures