Galactic conformity measured in semi-analytic models

We study the correlation between the specific star formation rate of central galaxies and neighbour galaxies, also known as 'galactic conformity', out to 20 Mpc/h using three semi-analytic models (SAMs, one from L-GALAXIES and other two from GALFORM). The aim is to establish whether SAMs are able to show galactic conformity using different models and selection criteria. In all the models, when the selection of primary galaxies is based on an isolation criterion in real space, the mean fraction of quenched galaxies around quenched primary galaxies is higher than that around star-forming primary galaxies of the same stellar mass. The overall signal of conformity decreases when we remove satellites selected as primary galaxies, but the effect is much stronger in GALFORM models compared with the L-GALAXIES model. We find this difference is partially explained by the fact that in GALFORM once a galaxy becomes a satellite remains as such, whereas satellites can become centrals at a later time in L-GALAXIES. The signal of conformity decreases down to 60% in the L-GALAXIES model after removing central galaxies that were ejected from their host halo in the past. Galactic conformity is also influenced by primary galaxies at fixed stellar mass that reside in dark matter haloes of different masses. Finally, we explore a proxy of conformity between distinct haloes. In this case the conformity is weak beyond ~ 3 Mpc/h (<3% in L-GALAXIES, <1-2% in GALFORM models). Therefore, it seems difficult that conformity is directly related with a long-range effect.Comment: 15 pages, 7 figures. Accepted for publication in MNRA

Vortex ratchet reversal: The role of interstitial vortices

Triangular arrays of Ni nanotriangles embedded in superconducting Nb films exhibit unexpected dynamical vortex effects. Collective pinning with a vortex lattice configuration different from the expected fundamental triangular "Abrikosov state" is found. The vortex motion which prevails against the triangular periodic potential is produced by channelling effects between triangles. Interstitial vortices coexisting with pinned vortices in this asymmetric potential, lead to ratchet reversal, i.e. a DC output voltage which changes sign with the amplitude of an applied alternating drive current. In this landscape, ratchet reversal is always observed at all magnetic fields (all numbers of vortices) and at different temperatures. The ratchet reversal is unambiguously connected to the presence of two locations for the vortices: interstitial and above the artificial pinning sites.Comment: 21 pages, 4 figures, 1 Tabl

Efficacy of Controlled Memory and Shape Memory Nickel Titanium Instruments in Removing Filling Material from Severely Curved Root Canals: An Ex Vivo Study

Introduction: The aim of the present study was to compare the efficacy of four NiTi instruments with different properties (shape memory and control memory), in both rotary and reciprocating motions, during retreatment procedures. Methods and Materials: Mesial canals of thirty-two mandibular molars were instrumented, obturated, and then scanned with” Cone-beam Computed Tomography” (CBCT). Teeth were randomly divided into 4 groups (n=8) according to each system: “Shape Memory” (SM) instruments including Reciproc (R25 file) and ProTaper Next (X3 and X2 file), “Controlled Memory” (CM) instruments including WaveOne Gold (Primary file) and Hyflex (30.06 and 25.06 file). The specimens were rescanned after retreatment procedures. The volume of the residual material left inside the canals, the operating time and the fractured files were analyzed. ANOVA and student t-tests were used for statistical analysis. Results: There were no significant differences in the percentage of the residual filling material or requiring time amongst different groups of instruments (P&gt;0.05). However, CM instruments presented the highest frequency of fractured files [2 SM instruments (12.5%) and 7 CM instruments (43.75%)] with a significant difference (P=0.023). Conclusions: This ex vivo study showed that CM and SM instruments can remove filling materials from mandibular mesial root canals during retreatment procedures; nonetheless the CM instruments had a higher frequency of fractured files. No system was able to completely remove the filling materials. Therefore, additional procedures and techniques are needed to improve root canal cleanliness. Keywords: Endodontics; Retreatment; Root Canal Preparation; Tooth Roo

Repeated cocaine exposure decreases dopamine D2-like receptor modulation of Ca2+ homeostasis in rat nucleus accumbens neurons

The nucleus accumbens is a limbic structure in the forebrain which plays a critical role in cognitive function and addiction.  Dopamine modulates activity of medium spiny neurons in the nucleus accumbens.  Both dopamine D1-like and D2-like receptors (including D1R or D1,5R, and D2R or D2,3,4R, respectively) are thought to play critical roles in cocaine addiction.  Our previous studies demonstrated that repeated cocaine exposure (which alters dopamine transmission) decreases excitability of nucleus accumbens medium spiny neurons in cocaine-sensitized, withdrawn rats.  This decrease is characterized by a reduction in voltage-sensitive Na+ currents and high voltage-activated Ca2+ currents, along with increased voltage-gated K+ currents.  These changes are associated with enhanced activity in the D1R/cAMP/PKA/protein phosphatase 1 pathway and diminished calcineurin function.  Though D1R-mediated signaling is enhanced by repeated cocaine exposure, little is known whether and how the D2R is implicated in the cocaine-induced nucleus accumbens dysfunction.  Here, we performed a combined electrophysiological, biochemical, and neuroimaging study that reveals the cocaine-induced dysregulation of Ca2+ homeostasis with involvement of D2R.  Our novel findings reveal that D2R stimulation reduced Ca2+ influx preferentially via the L-type Ca2+ channels and evoked intracellular Ca2+ release, likely via inhibiting the cAMP/PKA cascade, in the nucleus accumbens medium spiny neurons of drug-free rats.  However, repeated cocaine exposure abolished the D2R effects on modulating Ca2+ homeostasis with enhanced PKA activity and led to a decrease in whole-cell Ca2+ influx.  These adaptations, which persisted for 21 days during cocaine abstinence, may contribute to the mechanism of cocaine withdrawal.Fil: Perez, Mariela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Ford, Kerstin A.. Rosalind Franklin University of Medicine and Science; Estados UnidosFil: Goussakov, Ivan. Rosalind Franklin University of Medicine and Science; Estados UnidosFil: Stutzmann, Grace E.. Rosalind Franklin University of Medicine and Science; Estados UnidosFil: Hu, Xiu-Ti. Rush University Medical Center; Estados Unido

Chemical characterization of a hypoglycemic extract from Cucurbita ficifolia bouche that induces liver glycogen accumulation in diabetic mice

Background: The aqueous extract of Cucurbita ficifolia (C. ficifolia) fruit has demonstrated hypoglycemic effect, which may be attributed to some components in the extract. However, the major secondary metabolites in this fruit have not yet been identified and little is known about its extra-pancreatic action, in particular, on liver carbohydrate metabolism. Therefore, in addition to the isolation and structural elucidation of the principal components in the aqueous extract of C. ficifolia, the aim of this study was to determine whether or not the hypoglycemic effect of the aqueous extract of Cucurbita ficifolia (C. ficifolia) fruit is due to accumulation of liver glycogen in diabetic mice.Materials and Methods: The aqueous extract from fruit of C. ficifolia was fractionated and its main secondary metabolites were purified and chemically characterized (NMR and GC-MS). Alloxan-induced diabetic mice received daily by gavage the aqueous extract (30 days). The liver glycogen content was quantified by spectroscopic method and by PAS stain; ALT and AST by spectrometric method; glycogen synthase, glycogen phosphorylase and GLUT2 by Western blot; the mRNA expression of GLUT2 and glucagon-receptor by RT-PCR; while serum insulin was quantified by ELISA method. A liver histological analysis was also performed by H&amp;E stain.Results: Chemical fingerprint showed five majoritarian compounds in the aqueous extract of C. ficifolia: p-coumaric acid, p-hydroxybenzoic acid, salicin, stigmast-7,2,2-dien-3-ol and stigmast-7-en-3-ol. The histological analysis showed accumulation of liver glycogen. Also, increased glycogen synthase and decreased glycogen phosphorylase were observed. Interestingly, the histological architecture evidenced a liver-protective effect due the extract.Conclusion: Five compounds were identified in C. ficifolia aqueous extract. The hypoglycemic effect of this extract may be partially explained by liver glycogen accumulation. The bioactive compound responsible for the hypoglycemic effect of this extract will be elucidated in subsequent studies.Keywords: Cucurbita ficifolia, Cucurbitaceae, liver glycogen, hypoglycemic plants, p-coumaric acid, salicin, p-hydroxybenzoic aci

Recombination reduction on lead halide perovskite solar cells based on low temperature synthesized hierarchical TiO2 nanorods

Intensive research on the electron transport material (ETM) has been pursued to improve the efficiency of perovskite solar cells (PSCs) and decrease their cost. More importantly, the role of the ETM layer is not yet fully understood, and research on new device architectures is still needed. Here, we report the use of three-dimensional (3D) TiO2 with a hierarchical architecture based on rutile nanorods (NR) as photoanode material for PSCs. The proposed hierarchical nanorod (HNR) films were synthesized by a two-step low temperature (180 °C) hydrothermal method, and consist of TiO2 nanorod trunks with optimal lengths of 540 nm and TiO2 nanobranches with lengths of 45 nm. Different device configurations were fabricated with TiO2 structures (compact layer, NR and HNR) and CH3NH3PbI3, using different synthetic routes, as the active material. PSCs based on HNR-CH3NH3PbI3 achieved the highest power conversion efficiency compared to PSCs with other TiO2 structures. This result can be ascribed mainly to lower charge recombination as determined by impedance spectroscopy. Furthermore, we have observed that the CH3NH3PbI3 perovskite deposited by the two-step route shows higher efficiency, surface coverage and infiltration within the structure of 3D HNR than the one-step CH3NH3PbI3−xClx perovskite.This work was supported by the Universitat Jaume I (project 12I361.01/1), the Spanish MINECO (project MAT2013-47192- C3-1-R), CONACYT-México (project CB-2010/153270) and UNAM (PAPIIT-IN1030

Vibrational properties of CdGa2S4 at high pressure

[EN] Raman scattering measurements have been performed in cadmium digallium sulphide (CdGa2S4) with defect chalcopyrite structure up to 25 GPa in order to study its pressure-induced phase transitions. These measurements have been complemented and compared with latticedynamics ab initio calculations including the TO-LO splitting at high pressures in order to provide a better assignment of experimental Raman modes. In addition, experimental and theoretical Gruneisen parameters have been reported in order to calculate the molar heat capacity and thermal expansion coefficient of CdGa2S4. Our measurements provide evidence that CdGa2S4 undergoes an irreversible phase transition above 15 GPa to a Raman-inactive phase, likely with a disordered rock salt structure. Moreover, the Raman spectrum observed on downstroke from 25 GPa to 2 GPa has been attributed to a new phase, tentatively identified as a disordered zinc blende structure, that undergoes a reversible phase transition to the Raman-inactive phase above 10 GPa. Published under license by AIP Publishing.The authors thank the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) under Grant Nos. MAT2016-75586-C4-2/3-P and MAT2015-71070-REDC (MALTA Consolider) and the Generalitat Valenciana under Project No. PROMETEO/2018/123-EFIMAT. E. P.-G., A. M., and P. R.-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster.Gallego-Parra, S.; Gomis, O.; Vilaplana Cerda, RI.; Ortiz, H.; Perez-Gonzalez, E.; Luna Molina, R.; Rodríguez-Hernández, P.... (2019). Vibrational properties of CdGa2S4 at high pressure. Journal of Applied Physics. 125(11):1-12. https://doi.org/10.1063/1.5080503S11212511Gomis, O., Santamaría-Pérez, D., Vilaplana, R., Luna, R., Sans, J. A., Manjón, F. J., … Ursaki, V. V. (2014). Structural and elastic properties of defect chalcopyrite HgGa2S4 under high pressure. Journal of Alloys and Compounds, 583, 70-78. doi:10.1016/j.jallcom.2013.08.123Cohen, M. L. (1985). Calculation of bulk moduli of diamond and zinc-blende solids. Physical Review B, 32(12), 7988-7991. doi:10.1103/physrevb.32.7988Kim, J. W., & Kim, Y. J. (2007). Optical Properties of Eu Doped M-Ga2S4 (M:Zn, Ca, Sr) Phosphors for White Light Emitting Diodes. Journal of Nanoscience and Nanotechnology, 7(11), 4065-4068. doi:10.1166/jnn.2007.066Yu, R., Noh, H. M., Moon, B. K., Choi, B. C., Jeong, J. H., Jang, K., … Jang, J. K. (2013). Photoluminescence properties of a new red-emitting Mn-activated ZnGa2S4 phosphor. Materials Research Bulletin, 48(6), 2154-2158. doi:10.1016/j.materresbull.2013.02.017Liang, F., Kang, L., Lin, Z., Wu, Y., & Chen, C. (2017). Analysis and prediction of mid-IR nonlinear optical metal sulfides with diamond-like structures. Coordination Chemistry Reviews, 333, 57-70. doi:10.1016/j.ccr.2016.11.012Sahariya, J., Kumar, P., & Soni, A. (2017). Structural and optical investigations of ZnGa2X4 (X = S, Se) compounds for solar photovoltaic applications. Materials Chemistry and Physics, 199, 257-264. doi:10.1016/j.matchemphys.2017.07.003Syrbu, N. N., Tiron, A. V., Parvan, V. I., Zalamai, V. V., & Tiginyanu, I. M. (2015). Interference of birefractive waves in CdGa2S4 crystals. Physica B: Condensed Matter, 463, 88-92. doi:10.1016/j.physb.2015.02.007Vilaplana, R., Gomis, O., Manjón, F. J., Ortiz, H. M., Pérez-González, E., López-Solano, J., … Tiginyanu, I. M. (2013). Lattice Dynamics Study of HgGa2Se4at High Pressures. The Journal of Physical Chemistry C, 117(30), 15773-15781. doi:10.1021/jp402493rGrzechnik, A., Ursaki, V. V., Syassen, K., Loa, I., Tiginyanu, I. M., & Hanfland, M. (2001). Pressure-Induced Phase Transitions in Cadmium Thiogallate CdGa2Se4. Journal of Solid State Chemistry, 160(1), 205-211. doi:10.1006/jssc.2001.9224Gomis, O., Vilaplana, R., Manjón, F. J., Ruiz-Fuertes, J., Pérez-González, E., López-Solano, J., … Tiginyanu, I. M. (2015). HgGa2 Se4 under high pressure: An optical absorption study. physica status solidi (b), 252(9), 2043-2051. doi:10.1002/pssb.201451714Rahnamaye Aliabad, H. A., Basirat, S., & Ahmad, I. (2017). Structural, electronical and thermoelectric properties of CdGa2S4 compound under high pressures by mBJ approach. Journal of Materials Science: Materials in Electronics, 28(21), 16476-16483. doi:10.1007/s10854-017-7559-1Ursaki, V. V., Burlakov, I. I., Tiginyanu, I. M., Raptis, Y. S., Anastassakis, E., & Anedda, A. (1999). Phase transitions in defect chalcopyrite compounds under hydrostatic pressure. Physical Review B, 59(1), 257-268. doi:10.1103/physrevb.59.257Klotz, S., Chervin, J.-C., Munsch, P., & Le Marchand, G. (2009). Hydrostatic limits of 11 pressure transmitting media. Journal of Physics D: Applied Physics, 42(7), 075413. doi:10.1088/0022-3727/42/7/075413Blöchl, P. E. (1994). Projector augmented-wave method. Physical Review B, 50(24), 17953-17979. doi:10.1103/physrevb.50.17953Kresse, G., & Furthmüller, J. (1996). Efficient iterative schemes forab initiototal-energy calculations using a plane-wave basis set. Physical Review B, 54(16), 11169-11186. doi:10.1103/physrevb.54.11169Baroni, S., de Gironcoli, S., Dal Corso, A., & Giannozzi, P. (2001). Phonons and related crystal properties from density-functional perturbation theory. Reviews of Modern Physics, 73(2), 515-562. doi:10.1103/revmodphys.73.515Perdew, J. P., Ruzsinszky, A., Csonka, G. I., Vydrov, O. A., Scuseria, G. E., Constantin, L. A., … Burke, K. (2008). Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces. Physical Review Letters, 100(13). doi:10.1103/physrevlett.100.136406Sans, J. Á., Santamaría-Pérez, D., Popescu, C., Gomis, O., Manjón, F. J., Vilaplana, R., … Tiginyanu, I. M. (2014). Structural and Vibrational Properties of CdAl2S4under High Pressure: Experimental and Theoretical Approach. The Journal of Physical Chemistry C, 118(28), 15363-15374. doi:10.1021/jp5037926Lottici, P. P., & Razzetti, C. (1984). Raman scattering in mixed defect chalcopyrite crystals. Journal of Molecular Structure, 115, 133-136. doi:10.1016/0022-2860(84)80032-0Kerimova, T. G., Abdullaev, N. A., Mamedova, I. A., Badalova, Z. I., Guliev, R. A., Paucar, R., … Mamedov, N. T. (2013). Optical phonons in CdGa2S4x Se4(1 − x) alloys. Semiconductors, 47(6), 761-766. doi:10.1134/s1063782613060110Tiginyanu, I. M., Lottici, P. P., Razzetti, C., & Gennari, S. (1993). Effects of the Cations on the Raman Spectra of Sulphur Defect Chalcopyrites. Japanese Journal of Applied Physics, 32(S3), 561. doi:10.7567/jjaps.32s3.561Kerimova, T. G., Mamedova, I. A., Abdullayev, N. A., Asadullayeva, S. Q., & Badalova, Z. I. (2014). Raman scattering in ZnGa2Se4 single crystals. Semiconductors, 48(7), 868-871. doi:10.1134/s1063782614070112Razzetti, C., & Lottici, P. P. (1993). Raman Scattering in Defective AIIB2IIIX4VICompounds and Alloys. Japanese Journal of Applied Physics, 32(S3), 431. doi:10.7567/jjaps.32s3.431Syrbu, N. N., Nemerenco, L. L., & Cojocaru, O. (2002). Vibrational and Polariton Spectra of CdGa2S4 and CdAl2S4 Crystals. Crystal Research and Technology, 37(1), 101-110. doi:10.1002/1521-4079(200202)37:13.0.co;2-dGomis, O., Vilaplana, R., Manjón, F. J., Santamaría-Pérez, D., Errandonea, D., Pérez-González, E., … Ursaki, V. V. (2013). High-pressure study of the structural and elastic properties of defect-chalcopyrite HgGa2Se4. Journal of Applied Physics, 113(7), 073510. doi:10.1063/1.4792495Gomis, O., Ortiz, H. M., Sans, J. A., Manjón, F. J., Santamaría-Pérez, D., Rodríguez-Hernández, P., & Muñoz, A. (2016). InBO3 and ScBO3 at high pressures: An ab initio study of elastic and thermodynamic properties. Journal of Physics and Chemistry of Solids, 98, 198-208. doi:10.1016/j.jpcs.2016.07.002K. R. Allakhverdiev, Frontiers of High Pressure Research II: Application of High Pressure to Low-Dimensional Novel Electronic Materials (Springer, 2001), p. 99.Lottici, P. P., & Razzetti, C. (1983). A comparison of the raman spectra of ZnGa2Se4 and other gallium defect chalcopyrites. Solid State Communications, 46(9), 681-684. doi:10.1016/0038-1098(83)90506-9Sanjuán, M. L., & Morón, M. C. (2002). Raman study of Zn1−xMnxGa2Se4 diluted magnetic semiconductors: disorder and resonance effects. Physica B: Condensed Matter, 316-317, 565-567. doi:10.1016/s0921-4526(02)00574-4Radautsan, S. I., Tiginyanu, I. M., Ursakii, V. V., Fomin, V. M., & Pokatilov, E. P. (1990). The Peculiarities of the Temperature Broadening of Raman Light Scattering Lines in Zn(Cd)Ga2Se4 Single Crystals. physica status solidi (b), 162(1), K63-K66. doi:10.1002/pssb.2221620143Bernard, J. E., & Zunger, A. (1988). Ordered-vacancy-compound semiconductors: PseudocubicCdIn2Se4. Physical Review B, 37(12), 6835-6856. doi:10.1103/physrevb.37.6835Manjón, F. J., Gomis, O., Vilaplana, R., Sans, J. A., & Ortiz, H. M. (2013). Order-disorder processes in adamantine ternary ordered-vacancy compounds. physica status solidi (b), 250(8), 1496-1504. doi:10.1002/pssb.201248596Mitani, T., Naitou, T., Matsuishi, K., Onari, S., Allakhverdiev, K., Gashimzade, F., & Kerimova, T. (2003). Raman scattering in CdGa2Se4 under pressure. physica status solidi (b), 235(2), 321-325. doi:10.1002/pssb.200301579Meenakshi, S., Vijyakumar, V., Godwal, B. K., Eifler, A., Orgzall, I., Tkachev, S., & Hochheimer, H. D. (2006). High pressure X-ray diffraction study of CdAl2Se4 and Raman study of AAl2Se4 (A=Hg, Zn) and CdAl2X4 (X=Se, S). Journal of Physics and Chemistry of Solids, 67(8), 1660-1667. doi:10.1016/j.jpcs.2006.02.015Manjón, F. J., Marí, B., Serrano, J., & Romero, A. H. (2005). Silent Raman modes in zinc oxide and related nitrides. Journal of Applied Physics, 97(5), 053516. doi:10.1063/1.1856222H. Bilz and W. Kress, Phonon Dispersion Relations in Insulators (Springer, 1979), p. 110.Cheng, Y. C., Jin, C. Q., Gao, F., Wu, X. L., Zhong, W., Li, S. H., & Chu, P. K. (2009). Raman scattering study of zinc blende and wurtzite ZnS. Journal of Applied Physics, 106(12), 123505. doi:10.1063/1.3270401(2017). Theoretical Analysis of Elastic, Mechanical and Phonon Properties of Wurtzite Zinc Sulfide under Pressure. Crystals, 7(6), 161. doi:10.3390/cryst7060161González, J., Fernández, B. J., Besson, J. M., Gauthier, M., & Polian, A. (1992). High-pressure behavior of Raman modes inCuGaS2. Physical Review B, 46(23), 15092-15101. doi:10.1103/physrevb.46.15092Talwar, D. N., Vandevyver, M., Kunc, K., & Zigone, M. (1981). Lattice dynamics of zinc chalcogenides under compression: Phonon dispersion, mode Grüneisen, and thermal expansion. Physical Review B, 24(2), 741-753. doi:10.1103/physrevb.24.741Griesinger, A., Spindler, K., & Hahne, E. (1999). Measurements and theoretical modelling of the effective thermal conductivity of zeolites. International Journal of Heat and Mass Transfer, 42(23), 4363-4374. doi:10.1016/s0017-9310(99)00096-4Hofmeister, A. M., & Mao, H. -k. (2002). Redefinition of the mode Gruneisen parameter for polyatomic substances and thermodynamic implications. Proceedings of the National Academy of Sciences, 99(2), 559-564. doi:10.1073/pnas.241631698Miller, S. A., Gorai, P., Ortiz, B. R., Goyal, A., Gao, D., Barnett, S. A., … Toberer, E. S. (2017). Capturing Anharmonicity in a Lattice Thermal Conductivity Model for High-Throughput Predictions. Chemistry of Materials, 29(6), 2494-2501. doi:10.1021/acs.chemmater.6b04179Zeier, W. G., Zevalkink, A., Gibbs, Z. M., Hautier, G., Kanatzidis, M. G., & Snyder, G. J. (2016). Thinking Like a Chemist: Intuition in Thermoelectric Materials. Angewandte Chemie International Edition, 55(24), 6826-6841. doi:10.1002/anie.201508381Barron, T. H. . (1957). Grüneisen parameters for the equation of state of solids. Annals of Physics, 1(1), 77-90. doi:10.1016/0003-4916(57)90006-4Arora, A. K. (1990). Grüneisen parameter of soft phonons and high pressure phase transitions in semiconductors. Journal of Physics and Chemistry of Solids, 51(4), 373-375. doi:10.1016/0022-3697(90)90122-vGrüneisen, E. (1912). Theorie des festen Zustandes einatomiger Elemente. Annalen der Physik, 344(12), 257-306. doi:10.1002/andp.19123441202Mishra, K. K., Bevara, S., Ravindran, T. R., Patwe, S. J., Gupta, M. K., Mittal, R., … Tyagi, A. K. (2018). High pressure behavior of complex phosphate K2Ce[PO4]2: Grüneisen parameter and anharmonicity properties. Journal of Solid State Chemistry, 258, 845-853. doi:10.1016/j.jssc.2017.12.022Manjon, F. J., Tiginyanu, I., & Ursaki, V. (Eds.). (2014). Pressure-Induced Phase Transitions in AB2X4 Chalcogenide Compounds. Springer Series in Materials Science. doi:10.1007/978-3-642-40367-5Allakhverdiev, K., Gashimzade, F., Kerimova, T., Mitani, T., Naitou, T., Matsuishi, K., & Onari, S. (2003). Raman scattering under pressure in ZnGa2Se4. Journal of Physics and Chemistry of Solids, 64(9-10), 1597-1601. doi:10.1016/s0022-3697(03)00077-5Parlak, C., & Eryiğit, R. (2006). Ab initiovolume-dependent elastic and lattice dynamical properties of chalcopyriteCuGaSe2. Physical Review B, 73(24). doi:10.1103/physrevb.73.245217Kern, G., Kresse, G., & Hafner, J. (1999). Ab initiocalculation of the lattice dynamics and phase diagram of boron nitride. Physical Review B, 59(13), 8551-8559. doi:10.1103/physrevb.59.8551B. A. Weinstein and R. Zallen, Light Scattering in Solids IV (Springer, 1984), p. 463.Schwer, H., & Krämer, V. (1990). The crystal structures of CdAl2S4, HgAl2S4, and HgGa2S4. Zeitschrift für Kristallographie, 190(1-2), 103-110. doi:10.1524/zkri.1990.190.1-2.103Mamedov, K. K., Aliev, M. M., Kerimov, I. G., & Kh. Nani, R. (1972). Heat capacity of AIIB2IIIC4VI-type ternary semiconducting compounds at low temperatures. Physica Status Solidi (a), 9(2), K149-K152. doi:10.1002/pssa.2210090255Quintero, M., Morocoima, M., Guerrero, E., & Ruiz, J. (1994). Temperature variation of lattice parameters and thermal expansion coefficients of the compound MnGa2Se4. Physica Status Solidi (a), 146(2), 587-593. doi:10.1002/pssa.2211460203Ravindran, T. R., Arora, A. K., & Mary, T. A. (2000). High Pressure Behavior ofZrW2O8: Grüneisen Parameter and Thermal Properties. Physical Review Letters, 84(17), 3879-3882. doi:10.1103/physrevlett.84.3879Morocoima, M., Quintero, M., Guerrero, E., Tovar, R., & Conflant, P. (1997). Temperature variation of lattice parameters and thermal expansion coefficients of the compound ZnGa2Se4. Journal of Physics and Chemistry of Solids, 58(3), 503-507. doi:10.1016/s0022-3697(96)00048-

Rocking ratchet induced by pure magnetic potentials with broken reflection symmetry

A ratchet effect (the rectification of an ac injected current) which is purely magnetic in origin has been observed in a superconducting-magnetic nanostructure hybrid. The hybrid consists of a superconducting Nb film in contact with an array of nanoscale magnetic triangles, circular rings or elliptical rings. The arrays were placed into well-defined remanent magnetic states by application of different magnetic field cycles. The stray fields from these remanent states provide a magnetic landscape which influences the motion of superconducting vortices. We examined both randomly varying landscapes from demagnetized samples, and ordered landscapes from samples at remanence after saturation in which the magnetic rings form parallel onion states containing two domain walls. The ratchet effect is absent if the rings are in the demagnetized state or if the vortices propagate parallel to the magnetic reflection symmetry axis (perpendicular to the magnetic domain walls) in the ordered onion state. On the other hand, when the vortices move perpendicular to the magnetic reflection symmetry axis in the ordered onion state (parallel to the domain walls) a clear ratchet effect is observed. This behavior differs qualitatively from that observed in samples containing arrays of triangular Ni nanostructures, which show a ratchet of structural origin.Comment: 16 pages, 6 figures and 1 tabl

Bridging the GUI gap with reactive values and relations

There are at present two ways to write GUIs for functional code. One is to use standard GUI toolkits, with all the benefits they bring in terms of feature completeness, choice of platform, conformance to platform-specific look-and-feel, long-term viability, etc. However, such GUI APIs mandate an imperative programming style for the GUI and related parts of the application. Alternatively, we can use a functional GUI toolkit. The GUI can then be written in a functional style, but at the cost of foregoing many advantages of standard toolkits that often will be of critical importance. This paper introduces a light-weight framework structured around the notions of reactive values and reactive relations . It allows standard toolkits to be used from functional code written in a functional style. We thus bridge the gap between the two worlds, bringing the advantages of both to the developer. Our framework is available on Hackage and has been been validated through the development of non-trivial applications in a commercial context, and with different standard GUI toolkits