Model-Independent Bounds on R(J/ψ)R(J/\psi)

We present a model-independent bound on $R(J/\psi) \! \equiv \! \mathcal{BR} (B_c^+ \rightarrow J/\psi \, \tau^+\nu_\tau)/ \mathcal{BR} (B_c^+ \rightarrow J/\psi \, \mu^+\nu_\mu)$. This bound is constructed by constraining the form factors through a combination of dispersive relations, heavy-quark relations at zero-recoil, and the limited existing determinations from lattice QCD. The resulting 95\% confidence-level bound, $0.20\leq R(J/\psi)\leq0.39$, agrees with the recent LHCb result at $1.3 \, \sigma$, and rules out some previously suggested model form factors.Comment: 19 pages, 4 figures, JHEP format, revised to match published versio

Targeted short-term nutrient reduction to manage Ventenata dubia an invasive winter annual grass: soil and plant responses

Invasive winter annual grasses, IWAGs, have degraded extensive ecosystems around the world and continue to invade new ones yearly. IWAGs readily form large monocultures or near monocultures, thus management and restoration goals largely focus on maintaining or increasing plant diversity in impacted ecosystems. Unfortunately, common management methods also reduce native plant diversity and harm the soil microbiome. These effects require additional measures to be taken, like reseeding, and plant diversity is still usually well below remnant targets. Early season short-term nutrient reduction to manage IWAGs is largely unexplored and would potentially decrease IWAG abundance, active earlier than most plants, but impact later season species less. Low rates of labile carbon, as sucrose, were applied to soils in a Pacific Northwest semi-arid grassland in early spring to stimulate microbial growth and temporarily reduce nutrient availability to the IWAG Ventenata dubia. Inorganic nitrogen was tracked throughout the experiment and plant and soil microbial community changes were determined at the end of the growing season. Labile carbon application reduced nitrogen at the beginning of the year, but effects did not persist to mid may when most plants were still active and soil moisture was not limiting. Treatments reduced V.dubia cover, per area seed production, and seed mass with no corresponding impact on perennial or other annual plants, except at the highest application rate when annual cover was reduced by 2%. The soil microbial community, determined via PLFA and NLFA analysis, was largely unchanged at the end of the season with slightly higher bacterial biomass and, importantly, no reduction in AMF abundance. These results suggest that this method has few negative impacts on the plant and soil community aside from a reduction in V.dubia cover and possibly its seed bank. This short-term nutrient reduction method has the potential to not only target IWAGs, active early, but also any non-native plants targeted for management that are active earlier or later than the native plant community

Finding Near-Optimal Independent Sets at Scale

The independent set problem is NP-hard and particularly difficult to solve in large sparse graphs. In this work, we develop an advanced evolutionary algorithm, which incorporates kernelization techniques to compute large independent sets in huge sparse networks. A recent exact algorithm has shown that large networks can be solved exactly by employing a branch-and-reduce technique that recursively kernelizes the graph and performs branching. However, one major drawback of their algorithm is that, for huge graphs, branching still can take exponential time. To avoid this problem, we recursively choose vertices that are likely to be in a large independent set (using an evolutionary approach), then further kernelize the graph. We show that identifying and removing vertices likely to be in large independent sets opens up the reduction space---which not only speeds up the computation of large independent sets drastically, but also enables us to compute high-quality independent sets on much larger instances than previously reported in the literature.Comment: 17 pages, 1 figure, 8 tables. arXiv admin note: text overlap with arXiv:1502.0168

Response of Drought Tolerant and Conventional Corn to Limited Irrigation

The purpose of this study was to evaluate the response of two commercial hybrids (DKC 62-27 DGVT2PRO [drought tolerant trait (DT)] and DKC 62-98 VT2PRO [conventional]) to limited irrigation. Preliminary results from the 2014 and 2015 growing seasons at Southwest Research-Extension Center near Garden City, Kansas, indicate the effect of irrigation capacity on corn yield was significant (P \u3c 0.001) for both hybrids. The effect of the drought tolerance trait on yield was not significant (P \u3e 0.05) in both years. The effect of the interaction between irrigation capacity and corn hybrid on yield was also not significant (P \u3e 0.05). Hybrid type had a significant effect on crop water use (P \u3c 0.05). Crop water use ranged between 25.1 to 15.2 and 26.0 to 15.1 inches for the conventional and DT corn hybrids respectively. Averaged across treatments, the DT hybrid used approximately 3% more water compared to the locally adapted hybrid. It is worth noting that since the two hybrids were not isolines, any differences in crop water use could be attributed to differences in genetics and not the drought tolerant trait. The effects of the drought tolerant trait on water productivity were not significant in both years (P \u3e 0.05). Water productivity ranged between 10.9 to 3.6 and 11.2 to 5.6 bu/a/in for conventional and DT corn hybrids, respectively. As expected, DT and conventional corn hybrids had curvilinear yield response to irrigation and linear response to seasonal crop water use/evapotranspiration (ETc). The marginal water productivity for conventional and DT hybrids ranged from 18.4 to 14.5 bu/a/in and from 15.2 to 14.6 bu/a/in respectively. These preliminary results indicate no signifi­cant differences in yields and water productivity between DT and conventional hybrids under full and limited irrigation. More research is needed to confirm these findings

Unsafe/Unhealthy work? OH&S outcomes in Australian Call Centres

Call centres have attracted the attention of researchers globally due to their implementation of new forms of work organisation and the implications these represent for the workforce. While there has been a great deal written on the poor working conditions within the call centre industry, and some discussion on the impact of these conditions on the health and safety of workers, there is still little known about the occupational health and well being policies and practices used in these workplaces. There has also been scant research on the health and safety experiences of call centre workers. This paper aims to address these gaps by examining whether the tasks performed and the occupational health and well being policies and practices in call centres lead to unhealthy outcomes for workers. A case study methodology is applied to explore these questions in two Australian call centres which highlight the diversity that exists in the industry. Key findings based on interviews with case study participants and key stakeholders indicate a misalignment between policy and practice, which represent various immediate and ongoing risks for employees. A number of policy concerns are raised through the data, particularly where negative occupational health outcomes can be associated with the lack of organisational compliance with employment legislation

Foliations of asymptotically flat manifolds by surfaces of Willmore type

The goal of this paper is to establish the existence of a foliation of the asymptotic region of an asymptotically flat manifold with nonzero mass by surfaces which are critical points of the Willmore functional subject to an area constraint. Equivalently these surfaces are critical points of the Geroch-Hawking mass. Thus our result has applications in the theory of General Relativity