Is there sufficient Ensifer and Rhizobium species diversity in UK farmland soils to support red clover (Trifolium pratense), white clover (T. repens), lucerne (Medicago sativa) and black medic (M. lupulina)?

Rhizobia play important roles in agriculture owing to their ability to fix nitrogen through a symbiosis with legumes. The specificity of rhizobia-legume associations means that underused legume species may depend on seed inoculation with their rhizobial partners. For black medic (Medicago lupulina) and lucerne (Medicago sativa) little is known about the natural prevalence of their rhizobial partner Ensifer meliloti in UK soils, so that the need for inoculating them is unclear. We analysed the site-dependence of rhizobial seed inoculation effects on the subsequent ability of rhizobial communities to form symbioses with four legume species (Medicago lupulina, M. sativa, Trifolium repens and T. pratense). At ten organic farms across the UK, a species-diverse legume based mixture (LBM) which included these four species was grown. The LBM seed was inoculated with a mix of commercial inocula specific for clover and lucerne. At each site, soil from the LBM treatment was compared to the soil sampled prior to the sowing of the LBM (the control). From each site and each of the two treatments, a suspension of soils was applied to seedlings of the four legume species and grown in axenic conditions for six weeks. Root nodules were counted and their rhizobia isolated. PCR and sequencing of a fragment of the gyrB gene from rhizobial isolates allowed identification of strains. The number of nodules on each of the four legume species was significantly increased when inoculated with soil from the LBM treatment compared to the control. Both the proportion of plants forming nodules and the number of nodules formed varied significantly by site, with sites significantly affecting the Medicago species but not the Trifolium species. These differences in nodulation were broadly reflected in plant biomass where site and treatment interacted; at some sites there was a significant advantage from inoculation with the commercial inoculum but not at others. In particular, this study has demonstrated the commercial merit of inoculation of lucerne with compatible rhizobia

There and Back Again

John 1:29-4

And there was light

I discuss the use of light as a collection of real and virtual photons to study lingering questions in particle and nuclear physics.Comment: 9 pages, 5 figures, 4 tables, Invited Lecture at the Carpathian Summer School of Physics 2014, Exotic Nuclei and Nuclear/Particle Astrophysics (V), July 13-26, Sinaia, Romani

Lecture III: There are maps and there are maps – motives, markets and users

This is the third of three lectures given on 5,6 and 8 March 2007 as the Sandars lectures for that year at Cambridge University Library. The text is as read at the time, but includes some later revisions and citations to works used within the text. The slides shown are listed in a separate document.Cambridge University Library, Sandars Readership in Bibliograph

Whose there is there there? Queer Directions and Ecocritical Orientations

Key words: queer ecocriticism, environmental justice, ecophobia, performativity, normative heterosexuality This essay outlines the necessary role of queer ecocriticism as one of unsettling normative thinking about environmental issues and defamiliarizing some ecocritical practices. In particular, a queer ecocritic can propose a rethinking of what our reinhabitation of the world should be like. Other questions as the implications of the intersection between sex and nature or the rethinking of nature itself as queerly performative in the fact that species become themselves over and over again through a process of evolutionary “satisficing” according to the demands of their environment should also be addresssed. Likewise, queer ecocriticism can question the role of the senses and corporeal relations in experiencing place.  Palabras clave: ecocritica queer, justicia medioambiental, ecofobia, performatividad, heterosexualidad normativa Este ensayo esboza el papel necesario de la ecocrítica queer para cuestionar el  pensamiento normativo sobre temas medioambientales y como defamiliarización de algunas prácticas ecocríticas. En particular, un/a ecocrítico/a queer puede proponer un nuevo planteamiento de cómo debería ser nuestra re-habitación del mundo. Otras cuestiones son las implicaciones de los cruces entre sexo y naturaleza o el volver a pensar en la naturaleza como “performativa” desde una perspectiva queer en el sentido de que las especies se convierten en sí mismas una y otra vez a través de un proceso evolucionario de satisfacer en grado suficiente según las demandas de su entorno. De la misma manera, la ecocrítica queer puede cuestionar el papel de los sentidos y de las relaciones corporales al experimentar el lugar

Environmental Suffering, Here and There

Latin American Studie

GRBs as standard candles: There is no "circularity problem" (and there never was)

The 2002 discovery of the "Amati Relation" of GRB spectra created the possibility that this and other correlations of GRB phenomenology might be used to make GRBs into standard candles. One recurring apparent difficulty with this program has been that some of the primary observational quantities to be fit as "data" - the isotropic-equivalent prompt energy $E_{iso}$ and the collimation-corrected "total" prompt energy energy $E_{\gamma}$ - depend for their construction on the very cosmological models that they are supposed to help constrain. This is the so-called "circularity problem" of standard candle GRBs. This paper is intended to point out that the circularity problem is not in fact a problem at all, except to the extent that it amounts to a self-inflicted wound. It arises essentially because of an unfortunate choice of data variables, such as $E_{iso}$, which are unnecessarily model-dependent. If, instead, the empirical correlations of GRB phenomenology which are formulated in source-variables are {\it mapped to the primitive observational variables} (such as fluence) and compared to the observations in that space, then all circularity disappears. I also indicate here a set of procedures for encoding high-dimensional empirical correlations in a "Gaussian Tube" smeared model that includes both the correlation and its intrinsic scatter, and how that source-variable model may easily be mapped to the space of primitive observables and fashioned into a likelihood. I discuss the projections of such Gaussian tubes into sub-spaces, which may be used to incorporate data from GRB events that may lack some element of the data (for example, GRBs without ascertained jet-break times). In this way, a large set of inhomogeneously observed GRBs may be assimilated into a single analysis, so long as each possesses at least two correlated data attributes.Comment: 10 pages, to appear in New Astronom