486 research outputs found

    Anisotropic magnetic field responses of ferroelectric polarization in a trigonal multiferroic CuFe1-xAlxO2 (x=0.015)

    Full text link
    We have investigated magnetic field dependences of a ferroelectric incommensurate-helimagnetic order in a trigonal magneto-electric (ME) multiferroic CuFe1-xAlxO2 with x=0.015, which exhibits the ferroelectric phase as a ground state, by means of neutron diffraction, magnetization and dielectric polarization measurements under magnetic fields applied along various directions. From the present results, we have established the H-T magnetic phase diagrams for the three principal directions of magnetic fields; (i) parallel to the c axis, (ii) parallel to the helical axis, and (iii) perpendicular to the c and the helical axes. While the previous dielectric polarization (P) measurements on CuFe1-xGaxO2 with x=0.035 have demonstrated that the magnetic field dependence of the `magnetic domain structure' results in distinct magnetic field responses of P [S. Seki et al., Phys. Rev. Lett., 103 237601 (2009)], the present study have revealed that the anisotropic magnetic field dependence of the ferroelectric helimagnetic order `in each magnetic domain' can be also a source of a variety of magnetic field responses of P in CuFe1-xAxO2 systems (A=Al, Ga).Comment: 11 pages, 9 figures, accepted for publication in Phys. Rev.

    Challenge of monitoring cohesive movement in homing fish using fine-scale 3D positioning

    Get PDF
    Rockfish, which are well known for their site fidelity and homing ability, live sympatrically with many conspecifics. Conspecifics may be external drivers influencing rockfish movement, and rockfish may move cohesively while travelling. We tested whether rockfish formed a group when returning to their original habitat after artificial displacement and examined the routes they travelled to return home. A fine-scale multi-individual simultaneous positioning method was used to observe the movement trajectories of tagged fish. Our results showed that tagged fish, released in groups, returned to their original habitat (5 of 8 fish) but generally did not travel with other individuals. There was one exception in which 2 individuals moved together for ~100 s immediately after release. These 2 fish had no designated leader, alternating as leader and follower. Our hypothesis was partially corroborated by these rockfish possibly travelling cohesively. The returning fish tended to travel along the sea bottom and the coastline, independent of current; thus, they likely used visual cues, rather than olfactory or social cues, to return home

    Half-magnetization plateaux in Cr spinels

    Full text link
    Magnetization plateaux, visible as anomalies in magnetic susceptibility at low temperatures, are one of the hallmarks of frustrated magnetism. An extremely robust half-magnetization plateau is observed in the spinel oxides CdCr2O4 and HgCr2O4, where it is accompanied by a substantial lattice distortion. We give an overview of the present state experiment for CdCr2O4 and HgCr2O4, and show how such a half-magnetization plateau arises quite naturally in a simple model of these systems, once coupling to the lattice is taken into account.Comment: 8 pages latex using IOP macros, from review talk given at RHMF 2006 (Sendai

    Prediction and failure of anti-angiogenesis escape

    Get PDF
    Many clinical trials have demonstrated the benefit of anti-angiogenesis therapy in the treatment of gynecologic cancer. However, these benefits have often been in terms of progression-free rather than overall survival and in some cases, the magnitude of benefit demonstrated in the pivotal phase 3 trials has been disappointing when compared with the percentage of patients who responded in earlier phase 2 trials. Two potential explanations for this are the current inability to stratify patients according to chance of benefit and the development of resistance mechanisms within the tumor. In this article, we review the prediction of response and the proposed resistance and escape mechanisms involved in anti-angiogenesis therapy, including the up-regulation of alternative proangiogenic pathways, vascular co-option, and resistance to hypoxia. These insights may offer a personalized strategy for anti-angiogenesis therapy and help us to consider the best selection of other therapies that should be combined with anti-angiogenesis therapy to improve the outcome of patients with gynecologic cancer

    Magnetization plateaux of S = 1/2 two-dimensional frustrated antiferromagnet Cs2_2CuBr4_4

    Full text link
    The field induced magnetic phase transitions of Cs2_2CuBr4_4 were investigated by means of magnetization process and neutron scattering experiments. This system undergoes magnetic phase transition at Ne\'{e}l temperature TN=1.4T_\mathrm{N}=1.4 K at zero field, and exhibits the magnetization plateau at approximately one third of the saturation magnetization for the field directions HbH\parallel b and HcH\parallel c. In the present study, additional symptom of the two-third magnetization plateau was found in the field derivative of the magnetization process. The magnetic structure was found to be incommensurate with the ordering vector Q=(0,0.575,0)\boldsymbol{Q}=(0, 0.575, 0) at zero field. With increasing magnetic field parallel to the c-axis, the ordering vector increases continuously and is locked at Q=(0,0.662,0)\boldsymbol{Q}=(0, 0.662, 0) in the plateau field range 13.1T<H<14.4T13.1 \mathrm{T} < H < 14.4 \mathrm{T}. This indicates that the collinear \textit{up-up-down} spin structure is stabilized by quantum fluctuation at the magnetization plateau.Comment: 6 pages, 4 Postscript figures, uses iopams.sty and IOPART.CL

    Clusterin is a potential molecular predictor for ovarian cancer patient's survival: targeting Clusterin improves response to paclitaxel

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Clusterin is a cytoprotective chaperone protein involved in numerous physiological processes, carcinogenesis, tumor growth and tissue remodelling. The purpose of this study was to investigate whether clusterin (CLU), an antiapoptotic molecule, could be a potential predictor molecule for ovarian cancer and whether or not targeting this molecule can improve survival of ovarian cancer patients.</p> <p>Methods</p> <p>Clusterin expression was compared between ten primary and their recurrent tumors from same patients immunohistochemically. We analyzed prognostic significance of CLU expression in another 47 ovarian cancer tissue samples by immunohistochemistry. We used small interference RNA to knock down CLU in the chemo-resistant ovarian cancer cell lines. KF-TX and SKOV-3-TX, paclitaxel-resistant ovarian cancer cells, were established from parental KF and SKOV-3 chemo-sensitive cell lines, respectively. Either siRNA or second generation antisense oligodeoxynucleotide against CLU (OGX-011), which is currently evaluated in clinical phase II trials in other cancer s, was used to modulate sensitivity to paclitaxel (TX) in ovarian cancer cells <it>in vitro</it>. Cellular viability assay, FACS analysis and annexin V staining were used to evaluate the comparative effect of CLU knocking down in ovarian cancer cells.</p> <p>Results</p> <p>Immunohistochemical analysis of CLU expression in primary ovarian cancer tissue specimens and their recurrent counterparts from same patients demonstrated higher expression of CLU in the recurrent resistant tumors compared with their primary tumors. High expression of CLU by immunohistochemistry among 47 surgical tissue specimens of early-stage (stage I/II) ovarian cancer, who underwent complete cytoreduction as a primary surgery, significantly related to poor survival, while none of other clinicopathological factors analyzed were related to survival in this patient cohort. Secretory CLU (s-CLU; 60 KDa) expression was upregulated in TX-resistant ovarian cancer cells compared to parental cells. Transfection of siRNA or OGX-011 clearly reduced CLU expression. Cell viability assay, FACS analysis and annexin V staining demonstrated that targeting CLU expression by siRNA or OGX-011 sensitized ovarian cancer cells to TX.</p> <p>Conclusion</p> <p>We conclude that CLU could be a potential molecular target to predict survival while targeting this s-CLU may improve survival of patients with ovarian cancer.</p

    An English-to-Turkish interlingual MT system

    Get PDF
    This paper describes the integration of a Turkish generation system with the KANT knowledge-based machine translation system to produce a prototype English-Turkish interlingua-based machine translation system. These two independently constructed systems were successfully integrated within a period of two months, through development of a module which maps KANT interlingua expressions to Turkish syntactic structures. The combined system is able to translate completely and correctly 44 of 52 benchmark sentences in the domain of broadcast news captions. This study is the first known application of knowledge-based machine translation from English to Turkish, and our initial results show promise for future development. © Springer-Verlag Berlin Heidelberg 1998

    Geological structure of an arsenic-contaminated aquifer at Sonargaon, Bangladesh

    Get PDF
    ArticleJOURNAL OF GEOLOGY. 116(3):288-302(2008)journal articl
    corecore