107 research outputs found

    Zero field ambient pressure quantum criticality in the stoichiometric non fermi liquid system CeRhBi

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    We present the spin dynamics study of a stoichiometric non-Fermi liquid (NFL) system CeRhBi, using low-energy inelastic neutron scattering (INS) and muon spin relaxation (Ī¼SR) measurements. It shows evidence for an energy-temperature (E=T) scaling in the INS dynamic response and a time-field (t=HĪ·) scaling of the Ī¼SR asymmetry function indicating a quantum critical behavior in this compound. The E=T scaling reveals a local character of quantum criticality consistent with the power-law divergence of the magnetic susceptibility, logarithmic divergence of the magnetic heat capacity and T-linear resistivity at low temperature. The occurrence of NFL behavior and local criticality over a very wide dynamical range at zero field and ambient pressure without any tuning in this stoichiometric heavy fermion compound is striking, making CeRhBi a model system amenable to in-depth studies for quantum criticality. Ā©2018 The Physical Society of Japa

    Chirality scenario of the spin-glass ordering

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    Detailed account is given of the chirality scenario of experimental spin-glass transitions. In this scenario, the spin glass order of weakly anisotropic Heisenberg-like spin-glass magnets including canonical spin glasses are essentially chirality driven. Recent numerical and experimental results are discussed in conjunction with this scenario.Comment: Submitted to J. Phys. Soc. Japan "Special Issue on Frustration

    Harnessing genetic potential of wheat germplasm banks through impact-oriented-prebreeding for future food and nutritional security

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    The value of exotic wheat genetic resources for accelerating grain yield gains is largely unproven and unrealized. We used next-generation sequencing, together with multi-environment phenotyping, to study the contribution of exotic genomes to 984 three-way-cross-derived (exotic/elite1//elite2) pre-breeding lines (PBLs). Genomic characterization of these lines with haplotype map-based and SNP marker approaches revealed exotic specific imprints of 16.1 to 25.1%, which compares to theoretical expectation of 25%. A rare and favorable haplotype (GT) with 0.4% frequency in gene bank identified on chromosome 6D minimized grain yield (GY) loss under heat stress without GY penalty under irrigated conditions. More specifically, the ā€˜Tā€™ allele of the haplotype GT originated in Aegilops tauschii and was absent in all elite lines used in study. In silico analysis of the SNP showed hits with a candidate gene coding for isoflavone reductase IRL-like protein in Ae. tauschii. Rare haplotypes were also identified on chromosomes 1A, 6A and 2B effective against abiotic/biotic stresses. Results demonstrate positive contributions of exotic germplasm to PBLs derived from crosses of exotics with CIMMYTā€™s best elite lines. This is a major impact-oriented pre-breeding effort at CIMMYT, resulting in large-scale development of PBLs for deployment in breeding programs addressing food security under climate change scenarios

    The gendered impact of the financial crisis:Struggles over social reproduction in Greece

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    The global financial crisis has triggered a dramatic transformation of employment in the weakest Eurozone economies. This is evidenced in deteriorating work conditions, limited employee negotiating power, low pay, zero-hours contracts and, most importantly, periods of prolonged unemployment for most of the working population, especially women. We offer a critical analysis of the boundaries of formal and informal, paid and unpaid, productive and reproductive work, and explore how austerity policies implemented in Greece in the aftermath of the global financial crisis have transformed womenā€™s everyday lives. In contributing to critical discussions of neoliberal capitalism and recent feminist geography studies, our empirical study focuses on how womenā€™s struggles over social reproduction unfold in the public and private spheres. It proposes that womenā€™s temporary retreat to unpaid work at home constitutes a form of resistance to intensifying precarisation, and, at times, contributes to the emergence of new collective forms of reproduction.</p

    The Role of Atypical Protein Kinase C in CSF-1-Dependent Erk Activation and Proliferation in Myeloid Progenitors and Macrophages

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    Colony stimulating factor-1 (CSF-1 or M-CSF) is the major physiological regulator of the proliferation, differentiation and survival of cells of the mononuclear phagocyte lineage. CSF-1 binds to a receptor tyrosine kinase, the CSF-1 receptor (CSF-1R). Multiple pathways are activated downstream of the CSF-1R; however, it is not clear which pathways regulate proliferation and survival. Here, we investigated the role of atypical protein kinase Cs (PKCĪ¶) in a myeloid progenitor cell line that expressed CSF-1R (32D.R) and in primary murine bone marrow derived macrophages (BMMs). In 32D.R cells, CSF-1 induced the phosphorylation of PKCĪ¶ and increased its kinase activity. PKC inhibitors and transfections with mutant PKCs showed that optimal CSF-1-dependent Erk activation and proliferation depended on the activity of PKCĪ¶. We previously reported that CSF-1 activated the Erk pathway through an A-Raf-dependent and an A-Raf independent pathway (Lee and States, Mol. Cell. Biol. 18, 6779). PKC inhibitors did not affect CSF-1 induced Ras and A-Raf activity but markedly reduced MEK and Erk activity, implying that PKCĪ¶ regulated the CSF-1-Erk pathway at the level of MEK. PKCĪ¶ has been implicated in activating the NF-ĪŗB pathway. However, CSF-1 promoted proliferation in an NF-ĪŗB independent manner. We established stable 32D.R cell lines that overexpressed PKCĪ¶. Overexpression of PKCĪ¶ increased the intensity and duration of CSF-1 induced Erk activity and rendered cells more responsive to CSF-1 mediated proliferation. In contrast to 32D.R cells, PKCĪ¶ inhibition in BMMs had only a modest effect on proliferation. Moreover, PKCĪ¶ -specific and pan-PKC inhibitors induced a paradoxical increase in MEK-Erk phosphorylation suggesting that PKCs targeted a common negative regulatory step upstream of MEK. Our results demonstrated that CSF-1 dependent Erk activation and proliferation are regulated differentially in progenitors and differentiated cells
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