Method for forming heterogeneous single garnet based crystals for passive Q-switched lasers and microlasers

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing a garnet-based activator region and a garnet-based Q-switch. Disclosed methods include hydrothermal growth techniques for the growth of differing epitaxial layers on a host. A YAG host material can be doped in one region with a suitable activator ion for lasing and can be formed with another region that is doped with a saturable absorber to form the Q-switch. Regions can be formed with controlled thickness in conjunction. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity to provide short pulses of high power emissions using high frequency pulse modes

Heterogeneous single vanadate based crystals for Q-switched lasers and microlasers and method for forming same

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing a vanadate-based activator region and a vanadate-based Q-switch. Disclosed methods include hydrothermal growth techniques for the growth of differing layers on a host. A YVO4 host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is doped with a saturable absorber. Regions can be formed with controlled thickness. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity to provide short pulses of high power emissions using high frequency pulse modes

Neutrinos with Lorentz-violating operators of arbitrary dimension

The behavior of fermions in the presence of Lorentz and CPT violation is studied. Allowing for operators of any mass dimension, we classify all Lorentz-violating terms in the quadratic Lagrange density for free fermions. The result is adapted to obtain the effective hamiltonian describing the propagation and mixing of three flavors of left-handed neutrinos in the presence of Lorentz violation involving operators of arbitrary mass dimension. A characterization of the neutrino coefficients for Lorentz violation is provided via a decomposition using spin-weighted spherical harmonics. The restriction of the general theory to various special cases is discussed, including among others the renormalizable limit, the massless scenario, flavor-blind and oscillation-free models, the diagonalizable case, and several isotropic limits. The formalism is combined with existing data on neutrino oscillations and kinematics to extract a variety of measures of coefficients for Lorentz and CPT violation. For oscillations, we use results from the short-baseline experiments LSND and MiniBooNE to obtain explicit sensitivities to effects from flavor-mixing Lorentz-violating operators up to mass dimension 10, and we present methods to analyze data from long-baseline experiments. For propagation, we use time-of-flight measurements from the supernova SN1987A and from a variety of experiments including MINOS and OPERA to constrain oscillation-free Lorentz-violating operators up to mass dimension 10, and we discuss constraints from threshold effects in meson decays and Cherenkov emission.Comment: 35 pages two-column REVTe

Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy including senscence, necrosis, and autophagy, but not apoptosis

In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer

Insights into ultrafast demagnetization in pseudo-gap half metals

Interest in femtosecond demagnetization experiments was sparked by Bigot's discovery in 1995. These experiments unveil the elementary mechanisms coupling the electrons' temperature to their spin order. Even though first quantitative models describing ultrafast demagnetization have just been published within the past year, new calculations also suggest alternative mechanisms. Simultaneously, the application of fast demagnetization experiments has been demonstrated to provide key insight into technologically important systems such as high spin polarization metals, and consequently there is broad interest in further understanding the physics of these phenomena. To gain new and relevant insights, we perform ultrafast optical pump-probe experiments to characterize the demagnetization processes of highly spin-polarized magnetic thin films on a femtosecond time scale. Previous studies have suggested shifting the Fermi energy into the center of the gap by tuning the number of electrons and thereby to study its influence on spin-flip processes. Here we show that choosing isoelectronic Heusler compounds (Co2MnSi, Co2MnGe and Co2FeAl) allows us to vary the degree of spin polarization between 60% and 86%. We explain this behavior by considering the robustness of the gap against structural disorder. Moreover, we observe that Co-Fe-based pseudo gap materials, such as partially ordered Co-Fe-Ge alloys and also the well-known Co-Fe-B alloys, can reach similar values of the spin polarization. By using the unique features of these metals we vary the number of possible spin-flip channels, which allows us to pinpoint and control the half metals electronic structure and its influence onto the elementary mechanisms of ultrafast demagnetization.Comment: 17 pages, 4 figures, plus Supplementary Informatio

Hydrothermal Growth of Heterogeneous Single Crystals for Solid State Laser Applications

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing regions that are based upon the same host material but differ from one another according to some material feature such that they can perform various functions related to lasing. Disclosed methods include hydrothermal growth techniques for the growth of differing epitaxial layers on a host. A host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is undoped and can act as an endcap, a waveguide cladding layer, or a substrate to provide strength and/or contact to a heat sink. Regions can be formed with controlled thickness in conjunction. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity

Pathways to school readiness: Executive functioning predicts academic and social-emotional aspects of school readiness.

The current study specified the extent to which hot and cool aspects of executive functioning predicted academic and social-emotional indicators of school readiness. It was unique in focusing on positive aspects of social-emotional readiness, rather than problem behaviors. One hundred four 3- to 5-year-old children completed tasks measuring executive functioning, social-emotional readiness, academic readiness, and vocabulary. As expected, age predicted executive functioning components and social-emotional readiness. Moreover, working memory and inhibitory control directly predicted academic readiness, whereas delay of gratification predicted social-emotional readiness. Working memory and inhibitory control predicted delay of gratification, consistent with the notion that simpler executive functions may set the stage for more complex executive functions. Interestingly, social-emotional readiness predicted academic readiness. These findings confirm that hot and cool aspects of executive functioning are related to social-emotional and academic school readiness

Stepping Up The Pressure: Arousal Can Be Associated With A Reduction In Male Aggression

The attentional myopia model of behavioral control [Mann and Ward, 2007] was tested in an experiment investigating the relationship between physiological arousal and aggression. Drawing on previous work linking arousal and narrowed attentional focus, the model predicts that arousal will lead to behavior that is relatively disinhibited in situations in which promoting pressures to aggress are highly salient. In situations in which inhibitory pressures are more salient, the model predicts behavior that is relatively restrained. In the experiment, 81 male undergraduates delivered noise-blasts against a provoking confederate while experiencing either high or low levels of physiological arousal and, at the same time, being exposed to cues that served either to promote or inhibit aggression. In addition to supporting the predictions of the model, this experiment provided some of the first evidence for enhanced control of aggression under conditions of heightened physiological arousal. Implications for interventions designed to reduce aggression are discussed. Aggr. Behav. 34:584–592, 2008. © 2008 Wiley-Liss, Inc

The lattice stiffening transition in UO2 single crystals

The effective Debye temperatures (θDE) of the surface region of UO2 single crystals, prepared by the hydrothermal synthesis technique, were obtained from temperature-dependent x-ray photoemission in the temperature range of 300 K–623 K. A lattice stiffening transition, characterized by different regions of different effective Debye temperature, 500 ± 59 K below 475 K and 165 ± 21 K above 475 K is identified. A comparison of the temperature dependence of the effective UO2 Debye temperature, with the changes in the lattice expansion coefficient for UO2, support strong lattice-phonon interaction arising from the Jahn–Teller distortion