MMSE-based beamforming techniques for relay broadcast channels

We propose minimum mean square error (MMSE)-based beamforming techniques for a multiantenna relay network, where a base station (BS) equipped with multiple antennas communicates with a number of single-antenna users through a multiantenna relay. We specifically solve three optimization problems, namely, 1) the sum-power minimization problem, 2) the mean-square-error (MSE) balancing problem, and 3) the mixed quality-of-service (QoS) problem. Unfortunately, these problems are not jointly convex in terms of beamforming vectors at the BS and the relay amplification matrix. To circumvent this nonconvexity issue, the original problems are divided into two subproblems, where the beamforming vectors and the relay amplification matrix are alternately optimized, whereas the other is fixed. Three iterative algorithms are developed based on convex optimization techniques and general MSE duality. Simulation results are provided to validate the convergence of the proposed algorithms

Energy levels and lifetimes of Gd IV and enhancement of the electron dipole moment

We have calculated energy levels and lifetimes of 4f7 and 4f6 5d configurations of Gd IV using Hartree-Fock and configuration interaction methods. This allows us to reduce significantly the uncertainty of the theoretical determination of the electron electric dipole moment (EDM) enhancement factor in this ion and, correspondingly, in gadolinium-containing garnets for which such measurements were recently proposed. Our new value for the EDM enhancement factor of Gd+3 is -2.2 +- 0.5. Calculations of energy levels and lifetimes for Eu~III are used to control the accuracy.Comment: Submitted to Phys. Rev. A 6 pages, 0 figures, 3 table

Modelling the Long-Term Impact on Herder Incomes and Environmental Services in an Uncertain World

Environmental, market and political influences affect herders’ livelihoods with the expectation that they maintain biologically and economically resilient systems. To balance these external influences and the trade-offs within a grassland system it involves the consideration of interactions between grassland ecology, technology use, environmental externalities, utilisation by grazing animals for food and fibre production, and the long-term profitability of the farming system. Many of these variables are slow-moving and are trade-offs are most efficiently studied with models. The StageTHREE Sustainable Grasslands Model, which utilizes the core functions and dynamics of more mechanistic tools, has been designed to minimize the skill and data required for parameterisation. It allows the key dynamics of the grassland systems to be incorporated along with the stochasticity of the system, in terms of both the uncertainty of the production and market environment. This enables an investigation into the sustainability and environmental impacts of alternative livestock management practices, so that these can be evaluated in relation to policy options. This paper presents an insight into the integration of herder level bioeconomic modelling for the analysis of grassland policy impacts in Mongolia and China. The research highlights that policy settings that reduce stocking rates can improve the environmental services from grasslands, and in most cases, also improve herder livelihoods and resilience

Management Changes and Strategies to Improve the Environmental Services from Grasslands in Northern China and Mongolia

The grasslands of Mongolia and northern China are part of the vast Eurasian grasslands that extend from east Asia to eastern Europe, with many common problems. Grassland degradation and herder livelihoods in the steppe regions of China and Mongolia are widely acknowledged as major issues that need to be improved. The core problem is too many animals are now grazing grasslands, initially driven by significant policy changes, and decisions that assumed more animals would lift herder incomes. Problems are accentuated by poorly defined property rights over the land. The effectiveness of current Government Programs aimed at reducing grazing pressures has been questioned, especially for their ability to deliver better environmental outcomes without impacting herder livelihoods. This panel session examines ways to understand the opportunities for improvement of grasslands. This first paper outlines some general aspects of the pastoral sectors, and management responses and strategies that can improve the services from grasslands

Cnidarian microRNAs frequently regulate targets by cleavage

In bilaterians, which comprise most of extant animals, microRNAs (miRNAs) regulate the majority of messenger RNAs (mRNAs) via base-pairing of a short sequence (the miRNA seed ) to the target, subsequently promoting translational inhibition and transcript instability. In plants, many miRNAs guide endonucleolytic cleavage of highly complementary targets. Because little is known about miRNA function in nonbilaterian animals, we investigated the repertoire and biological activity of miRNAs in the sea anemone Nematostella vectensis, a representative of Cnidaria, the sister phylum of Bilateria. Our work uncovers scores of novel miRNAs in Nematostella, increasing the total miRNA gene count to 87. Yet only a handful are conserved in corals and hydras, suggesting that microRNA gene turnover in Cnidaria greatly exceeds that of other metazoan groups. We further show that Nematostella miRNAs frequently direct the cleavage of their mRNA targets via nearly perfect complementarity. This mode of action resembles that of small interfering RNAs (siRNAs) and plant miRNAs. It appears to be common in Cnidaria, as several of the miRNA target sites are conserved among distantly related anemone species, and we also detected miRNA-directed cleavage in Hydra. Unlike in bilaterians, Nematostella miRNAs are commonly coexpressed with their target transcripts. In light of these findings, we propose that post-transcriptional regulation by miRNAs functions differently in Cnidaria and Bilateria. The similar, siRNA-like mode of action of miRNAs in Cnidaria and plants suggests that this may be an ancestral state

Contributions of inflammation and tumor microenvironment to neurofibroma tumorigenesis

Neurofibromatosis type 1 associates with multiple neoplasms, and the Schwann cell tumor neurofibroma is the most prevalent. A hallmark feature of neurofibroma is mast cell infiltration, which is recruited by chemoattractant stem cell factor (SCF) and has been suggested to sustain neurofibroma tumorigenesis. In the present study, we use new, genetically engineered Scf mice to decipher the contributions of tumor-derived SCF and mast cells to neurofibroma development. We demonstrate that mast cell infiltration is dependent on SCF from tumor Schwann cells. However, removal of mast cells by depleting the main SCF source only slightly affects neurofibroma progression. Other inflammation signatures show that all neurofibromas are associated with high levels of macrophages regardless of Scf status. These findings suggest an active inflammation in neurofibromas and partly explain why mast cell removal alone is not sufficient to relieve tumor burden in this experimental neurofibroma model. Furthermore, we show that plexiform neurofibromas are highly associated with injury-prone spinal nerves that are close to flexible vertebras. In summary, our study details the role of inflammation in neurofibromagenesis. Our data indicate that prevention of inflammation and possibly also nerve injury at the observed tumor locations are therapeutic approaches for neurofibroma prophylaxis and that such treatment should be explored