Increased dry matter yield of alfalfa following inoculation with plant growth promoting rhizobacteria

Non-Peer Reviewe

Colonization of the alfalfa rhizosphere by plant growth promoting rhizobacteria

Non-Peer ReviewedPlant growth promoting rhizobacteria (PGPR) were evaluated for their ability to colonize the alfalfa rhizosphere and increase dry matter yield of alfalfa. Field trials at Beaverlodge, AB., Sun Prairie, WI. and Outlook, SK. demonstrated that PGPR's Pseudomonas 31-12 (Ps.) and Serratia 2-68 co-inoculated with Rhizobium meliloti increased the dry matter yield by 11, 9 and 7%, respectively. In the first year of a three year field study planted in May 1993 at Outlook, the effect of formulation carriers on colonization of the alfalfa rhizosphere by spontaneous rifampicin resistant mutants (rif+) of PGPR's Ps. 31-12 and Serratia 2-68 was measured. No rif+ microorganisms were detected in the rhizosphere of uninoculated alfalfa. plants. Ps. 31-12 was the better colonizer of the rhizobacteria examined with populations exceeding 1 o6 cells per root 169 days after planting. The population of Ps. 31-12 was 10 times greater 35 and 169 days after planting in the peat formulation than in the clay formulation. Similarly, the population of Serratia 2-68 in the alfalfa rhizosphere was 1000 times greater in the peat formation than in the clay formulation. The populations of these microorganisms will be measured over the next two growing seasons

Does nature conservation enhance ecosystem services delivery?

Whilst a number of studies have examined the effects of biodiversity conservation on the delivery of ecosystems, they have been often limited by the scope of the ecosystem services (ES) assessed and often suffer from confounding spatial issues. This paper examines the impacts of nature conservation (designation) on the delivery of a full suite of ES across nine case-studies in the UK, using expert opinion. The case-studies covered a range of habitats and explore the delivery of ES from a ‘protected site’ and a comparable ‘non-protected’ site. By conducting pair-wise comparisons between comparable sites our study is one of the first to attempt to mitigate confounding cause and effect factors in relation to spatial context in correlative studies. Protected sites delivered higher levels of ecosystem services than nonprotected sites, with the main differences being in the cultural and regulating ecosystem services. Against expectations, there was no consistent negative impact of protection on provisioning services across the case-studies. Whilst the analysis demonstrated general patterns and differences in ecosystem delivery between protected and non-protected sites, the individual responses in each case-study highlights the importance of the social, biophysical, economic and temporal context of individual protected areas and the associated management

Congruent responses to weather variability in high arctic herbivores

Assessing the role of weather in the dynamics of wildlife populations is a pressing task in the face of rapid environmental change. Rodents and ruminants are abundant herbivore species in most Arctic ecosystems, many of which are experiencing particularly rapid climate change. Their different life-history characteristics, with the exception of their trophic position, suggest that they should show different responses to environmental variation. Here we show that the only mammalian herbivores on the Arctic islands of Svalbard, reindeer (Rangifer tarandus) and sibling voles (Microtus levis), exhibit strong synchrony in population parameters. This synchrony is due to rain-on-snow events that cause ground ice and demonstrates that climate impacts can be similarly integrated and expressed in species with highly contrasting life histories. The finding suggests that responses of wildlife populations to climate variability and change might be more consistent in Polar regions than elsewhere owing to the strength of the climate impact and the simplicity of the ecosystem

Integrin activation - the importance of a positive feedback

Integrins mediate cell adhesion and are essential receptors for the development and functioning of multicellular organisms. Integrin activation is known to require both ligand and talin binding and to correlate with cluster formation but the activation mechanism and precise roles of these processes are not yet resolved. Here mathematical modeling, with known experimental parameters, is used to show that the binding of a stabilizing factor, such as talin, is alone insufficient to enable ligand-dependent integrin activation for all observed conditions; an additional positive feedback is required.Comment: in press in Bulletin of Mathematical Biolog

Investigating the loss of recruitment potential in red grouse (Lagopus lagopus scoticus) : the relative importance of hen mortality, food supply, tick infestation and louping-ill

Ticks and their pathogens cause significant disease and economic loss in many animal populations. Despite this, experiments that test the impact of ticks and tickborne diseases on wild animal populations are rare. Here, we report on an experiment assessing the effect of ticks on red grouse productivity and chick growth in relation to other causes of poor recruitment at two sites in the Scottish uplands during 2005. Treated hens received two leg bands impregnated with the acaricide permethrin, while controls hens were untreated. Chicks were captured at c.2 weeks of age and fitted with a metal patagial tag, and chicks from treated hens also received a permethrinimpregnated strip. Mean tick burdens in treated chicks were close to zero compared with a mean of around 12 in the control group. Although treatment reduced tick infestations, it did not increase brood size. Growth rates in chicks from control and treated hens were similar during the first 10 days and comparable with chicks fed an ad-lib invertebrate-based diet. These results suggest that in this case, neither ticks (and the tick transmitted louping-ill virus) nor food shortages was the main cause of chick mortality. However, mortality in the adult hens was around 35 %, and predation accounted for 62 % of these losses before broods fledged. Our results indicate that on our study sites, predation may have a more important impact on grouse population dynamics than ticks and tick-borne disease. We suggest that it may be more cost effective to determine the causes of poor grouse population performance before implementing popular but expensive tick control measures such as the culling of alternative hosts and running acaracide treated sheep ‘tick-mop’ flocks.http://link.springer.com/journal/10344hb201

Role of dynamical particle-vibration coupling in reconciliation of the d3/2d_{3/2} puzzle for spherical proton emitters

It has been observed that decay rate for proton emission from $d_{3/2}$ single particle state is systematically quenched compared with the prediction of a one dimensional potential model although the same model successfully accounts for measured decay rates from $s_{1/2}$ and $h_{11/2}$ states. We reconcile this discrepancy by solving coupled-channels equations, taking into account couplings between the proton motion and vibrational excitations of a daughter nucleus. We apply the formalism to proton emitting nuclei $^{160,161}$Re to show that there is a certain range of parameter set of the excitation energy and the dynamical deformation parameter for the quadrupole phonon excitation which reproduces simultaneously the experimental decay rates from the 2$d_{3/2}$, 3$s_{1/2}$ and 1$h_{11/2}$ states in these nuclei.Comment: RevTex, 12 pages, 4 eps figure

Systematics of proton emission

A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.Comment: 4 pages, 3 figure

Deep Underground Science and Engineering Lab: S1 Dark Matter Working Group

A study of the current status of WIMP dark matter searches has been made in the context of scientific and technical planning for a Deep Underground Science and Engineering Laboratory (DUSEL) in the U.S. The table of contents follows: 1. Overview 2. WIMP Dark Matter: Cosmology, Astrophysics, and Particle Physics 3. Direct Detection of WIMPs 4. Indirect Detection of WIMPs 5. Dark Matter Candidates and New Physics in the Laboratory 6. Synergies with Other Sub-Fields 7. Direct Detection Experiments: Status and Future Prospects 8. Infrastructure 9. International Context 10. Summary and Outlook 11. AcknowledgmentsComment: Final working group report of 17 Feb 2007 updated to address reviewer comments (Latex, 32 pages