Optimizing propagating spin wave spectroscopy

The frequency difference between two oppositely propagating spin waves can be used to probe several interesting magnetic properties, such as the Dzyaloshinkii-Moriya interaction (DMI). Propagating spin wave spectroscopy is a technique that is very sensitive to this frequency difference. Here we show several elements that are important to optimize devices for such a measurement. We demonstrate that for wide magnetic strips there is a need for de-embedding. Additionally, for these wide strips there is a large parasitic antenna-antenna coupling that obfuscates any spin wave transmission signal, which is remedied by moving to smaller strips. The conventional antenna design excites spin waves with two different wave vectors. As the magnetic layers become thinner, the resulting resonances move closer together and become very difficult to disentangle. In the last part we therefore propose and verify a new antenna design that excites spin waves with only one wave vector. We suggest to use this antenna design to measure the DMI in thin magnetic layers.Comment: 12 pages, 4 figure

Mechanisms of arsenate removal and membrane fouling in ferric based coprecipitation-low pressure membrane filtration systems

Ferric based coprecipitation-low pressure membrane filtration is a promising arsenic (As) removal method, however, membrane fouling mechanisms are not fully understood. In this study we investigated the effect of feed water composition and membrane pore size on arsenate [As(V)] removal and membrane fouling. We observed that As removal efficiency was independent of the membrane pore size because the size of the Fe(III) particles was larger than the pore size of the membranes, attributed to a high calcium concentration in the feed water. Arsenic coprecipitation with Fe(III) (oxyhydr)oxides rapidly reached equilibrium before membrane filtration, within 1 min. Therefore, As removal efficiency was not improved by increasing residence time before membrane filtration. The removal of As(V) was strongly dependent on feed water composition. A higher Fe(III) dose was required to reduce As(V) to sub-mu g/L levels for feed water containing higher concentration of oxyanions such as phosphate and silicate, and lower concentration of cations such as calcium. Cake-layer formation was observed to be the predominant membrane fouling mechanism

Mechanisms of arsenate removal and membrane fouling in ferric based coprecipitation–low pressure membrane filtration systems

Ferric based coprecipitation–low pressure membrane filtration is a promising arsenic (As) removal method, however, membrane fouling mechanisms are not fully understood. In this study we investigated the effect of feed water composition and membrane pore size on arsenate [As(V)] removal and membrane fouling. We observed that As removal efficiency was independent of the membrane pore size because the size of the Fe(III) particles was larger than the pore size of the membranes, attributed to a high calcium concentration in the feed water. Arsenic coprecipitation with Fe(III) (oxyhydr)oxides rapidly reached equilibrium before membrane filtration, within 1 min. Therefore, As removal efficiency was not improved by increasing residence time before membrane filtration. The removal of As(V) was strongly dependent on feed water composition. A higher Fe(III) dose was required to reduce As(V) to sub-µg/L levels for feed water containing higher concentration of oxyanions such as phosphate and silicate, and lower concentration of cations such as calcium. Cake-layer formation was observed to be the predominant membrane fouling mechanism.</p

Methods of genetically altering a plant nin-gene to be responsive to cytokinin

Aspects of the present disclosure relate to genetically modified plants comprising NODULE INCEPTION (NIN) and NIN-LIKE PROTEIN (NLP) that have been genetically altered to be responsive to cytokinin so that the NIN or NLP protein can induce root nodulation upon appropriate signaling

Pseudogenization of the rhizobium-responsive EXOPOLYSACCHARIDE RECEPTOR in Parasponia is a rare event in nodulating plants

Background: Nodule symbiosis with diazotrophic Frankia or rhizobium occurs in plant species belonging to ten taxonomic lineages within the related orders Fabales, Fagales, Cucurbitales, and Rosales. Phylogenomic studies indicate that this nitrogen-fixing nodulation trait has a single evolutionary origin. In legume model plants, the molecular interaction between plant and rhizobium microsymbiont is mapped to a significant degree. A specific LysM-type receptor kinase, LjEPR3 in Lotus japonicus and MtLYK10 in Medicago truncatula, was found to act in a secondary identity-based mechanism, controlling intracellular rhizobium infection. Furthermore, LjEPR3 showed to bind surface exopolysaccharides of Mesorhizobium loti, the diazotrophic microsymbiont of L. japonicus. EPR3 orthologous genes are not unique to legumes. Surprisingly, however, its ortholog EXOPOLYSACCHARIDE RECEPTOR (EPR) is pseudogenized in Parasponia, the only lineage of non-legume plants that nodulate also with rhizobium. Results: Analysis of genome sequences showed that EPR3 orthologous genes are highly conserved in nodulating plants. We identified a conserved retrotransposon insertion in the EPR promoter region in three Parasponia species, which associates with defected transcriptional regulation of this gene. Subsequently, we studied the EPR gene of two Trema species as they represent the sister genus of Parasponia for which it is assumed it lost the nitrogen-fixing nodulation trait. Both Trema species possess apparently functional EPR genes that have a nodulation-specific expression profile when introduced into a Parasponia background. This indicates the EPR gene functioned in nodulation in the Parasponia-Trema ancestor. Conclusion: We conclude that nodule-specific expression of EPR3 orthologous genes is shared between the legume and Parasponia-Trema lineage, suggesting an ancestral function in the nitrogen-fixing nodulation trait. Pseudogenization of EPR in Parasponia is an exceptional case in nodulating plants. We speculate that this may have been instrumental to the microsymbiont switch -from Frankia to rhizobium- that has occurred in the Parasponia lineage and the evolution of a novel crack entry infection mechanism

Methods of genetically altering a plant nin-gene to be responsive to cytokinin

Aspects of the present disclosure relate to genetically modified plants comprising NODULE INCEPTION (NIN) and NIN-LIKE PROTEIN (NLP) that have been genetically altered to be responsive to cytokinin so that the NIN or NLP protein can induce root nodulation upon appropriate signaling.</p

Extending paradigm with data

We discuss an extension of the coordination modeling language Paradigm. The extension is geared towards data-dependent interaction among components, where the coordination is influenced by possibly distributed data. The approach is illustrated by the well-known example of a bakery where tickets are issued to serve clients in order. Also, it is described how to encode Paradigm models with data in the process language of the mCRL2 toolset for further analysis of the coordination

Extending paradigm with data

We discuss an extension of the coordination modeling language Paradigm. The extension is geared towards data-dependent interaction among components, where the coordination is influenced by possibly distributed data. The approach is illustrated by the well-known example of a bakery where tickets are issued to serve clients in order. Also, it is described how to encode Paradigm models with data in the process language of the mCRL2 toolset for further analysis of the coordination

Gene phylogenies based on Bayesian analysis

Phylogenetic analyses of genes of interest (EPR, HB, NFP, HCT, EPR, NIN, and RPG). Amino acid sequence alignments were generated using MAFFT version 7.017. Analyses were performed using MrBayes version 3.2.6 running 2.2 million generations, setting gamma-distributed rate variation and integrating over different models of amino acid sequence evolution (aamodelpr=mixed). For NFP analyses were based on the full-length sequences as well as separately on the kinase domain only