Microstructure and Magnetic Properties of Bulk Nanocrystalline MnAl

MnAl is a promising rare-earth free permanent magnet for technological use. We have examined the effects of consolidation by back-pressure, assisted equal channel angular extrusion processing on mechanically-milled, gas-atomized Mn-46% at. Al powder. X-ray diffraction showed both that the extruded rod consisted mostly of metastable τ phase, with some of the equilibrium γ2 and β phases, and that it largely retained the as-milled nanostructure. Magnetic measurements show a coercivity of ≤4.4 kOe and a magnetization at 10 kOe of ≤40 emu/g. In addition, extrusions exhibit greater than 95% of the theoretical density. This study opens a new window in the area of bulk MnAl magnets with improved magnetic properties for technological use

Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon.We thank the European Union (EU) Marie-Curie International Outgoing Fellowship Program (FP7-PEOPLE-2010, ADAPT-ENVGENOME, project code #271485) to J.M., A.J. Green and L.J.W., and the U.S. National Science Foundation (NSF-IOS-OEI) collaborative grants #0924289 and #1256881 to L.J.W. and grant #09244019 to P.D. Jeyasingh for funding this project. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the U.S. National Science Foundation. J.M. was also supported by the European Science Foundation (ConGenOmics, project code #4810) to develop the bioinformatics part of this study. L.J.W. also acknowledges the support of the KU Leuven Research Fund (fellowship SF/12/009), which allowed him to visit KU Leuven during the course of this project. A.C. was financed by the KU Leuven Research Fund excellence center financing PF/2010/07 during this project.EUR 1,165 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe

Ethnobotanical knowledge and socioeconomic potential of honey wine in the Horn of Africa

299-303The traditional honey wine is a ceremonial drink made locally in Ethiopia and Eritrea. The drink is known as Tej in Amharic (a widely spoken language in Ethiopia) and Mess in Tigrigna (a widely spoken language in Eritrea). It is consumed mostly during social and religious ceremonies, albeit sold in honey wine bars. It is easy to prepare with varied tastes by local people from its main components; honey, chopped stems of Rhamnus prinoides or roots of R. staddo and water. Honey and the shrubs used for the preparation of the wine are recognized for their medicinal importance worldwide. Particularly, after the isolation of geshoidin, a bitter glycoside from R. prinoides, that is currently being investigated for its role in providing novel-pharmacological leads for Alzheimer’s treatment. On the other hand, R. staddo has been investigated for potential antimalarial candidate. These with other beneficial metabolites from the shrubs call for a wider investigation into the medicinal benefits of the honey wine. Furthermore, considering its declining consumption, limited efforts to preserve the indigenous knowledge of preparing the drink and lack of adequate promotion, further research is needed to lead into the sustainability of drink for generations and its global usage

Origin of the magnetic anomaly and tunneling effect of europium on the ferromagnetic ordering in Eu8-xSrxGa16Ge30 (x = 0,4) type-I clathrates.

Systematic dc magnetization studies using the Banerjee criterion, Kouvel-Fisher, and magnetocaloric effect methods provide physical insights into the origin of themagnetic anomaly and the tunneling effect of europium on the ferromagnetic ordering in Eu8Ga16Ge30 type-I clathrates.We showthat Eu8Ga16Ge30 undergoes a second-order magnetic transition (SOMT) at TC ∼ 35 K, resulting from the magnetic interaction between the Eu2+ ions at the Eu2 sites, followed by a secondary magnetic transition at TL ∼10 K (indicated as amagnetic anomaly in previous studies), as a result of the magnetic interaction between the Eu2+ ions at the Eu1 and Eu2 sites. The critical exponent β = 0.388 is close to that predicted from the three-dimensional Heisenberg model (β = 0.365), while the critical exponent γ = 0.956 is close to that predicted from the mean-field model (γ = 1). The substitution of Sr2+ for Eu2+ retains the SOMT but largely reduces the transition temperatures (TC ∼ 15 K and TL ∼ 5 K), with the critical exponents β = 0.521 and γ = 0.917 close to those predicted from the mean-field model (β = 0.5 and γ = 1). These results point to the important fact that the tunneling of Eu2+ between the four equivalent sites in the tetrakaidecahedral cage tends to prevent the occurrence of a long-range ferromagnetic ordering in the type-I clathrate materials

Magnetocaloric effect and refrigerant capacity in Sr-doped Eu8 Ga16 Ge30 type-I clathrates

Magnetic properties, the magnetocaloric effect (MCE) and refrigerant capacity (RC) were investigated in Eu8Sr8−xGa16Ge30 (x=0,4) type-I clathrates. The substitution of Sr for Eu decreases the Curie temperature (TC) and saturation magnetization (MS) from 35 K and 65 emu/g for the x = 0 composition to 15 K and 35 emu/g for the x = 4 composition. This is attributed to the increase in the Eu–Eu distance with Sr substitution. The large MCE and RC are achieved in both specimens. For a field change of 3 T, the MCE and RC reach the largest values of 5.8 J / kg K and 127.6 J/kg for x = 0 composition and 4.3 J / kg K and 72.1 J/kg for x = 4 composition. The broadening of the MCE curves is likely associated with the ordering of the magnetic moments of Eu that occurs below 10 K. The large values of MCE and RC, in addition to the absence of thermal and field hysteresis indicate that these clathrate materials are very interesting for cryogenic magnetic refrigeration applications

Adaptive divergence under gene flow along an environmental gradient in two coexisting stickleback species

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