Learning on a Budget via Teacher Imitation

Deep Reinforcement Learning (RL) techniques can benefit greatly from leveraging prior experience, which can be either self-generated or acquired from other entities. Action advising is a framework that provides a flexible way to transfer such knowledge in the form of actions between teacher-student peers. However, due to the realistic concerns, the number of these interactions is limited with a budget; therefore, it is crucial to perform these in the most appropriate moments. There have been several promising studies recently that address this problem setting especially from the student's perspective. Despite their success, they have some shortcomings when it comes to the practical applicability and integrity as an overall solution to the learning from advice challenge. In this paper, we extend the idea of advice reusing via teacher imitation to construct a unified approach that addresses both advice collection and advice utilisation problems. We also propose a method to automatically tune the relevant hyperparameters of these components on-the-fly to make it able to adapt to any task with minimal human intervention. The experiments we performed in 5 different Atari games verify that our algorithm either surpasses or performs on-par with its top competitors while being far simpler to be employed. Furthermore, its individual components are also found to be providing significant advantages alone

A new time-frequency analysis technique for neuroelectric signals

Cataloged from PDF version of article.In the presence of external stimuli, the functioning brain emits neuroelectrical signals which can be recorded as the Event Related Potential (ERP) signals. To understand the brain cognitive functions, ERP signals have been the subject matter of many applications in the field of cognitive psychophysiology. Due to the non–stationary nature of the ERP signals, commonly used time or frequency analysis techniques fail to capture the time–frequency domain localized nature of the ERP signal components. In this study, the newly developed Time–Frequency Component Analyzer (TFCA) approach is adapted to the ERP signal analysis. The results obtained on the actual ERP signals show that the TFCA does not have a precedent in resolution and extraction of uncontaminated individual ERP signal components. Furthermore, unlike the existing ERP analysis techniques, the TFCA based analysis technique can reliably measures the subject dependent variations in the ERP signals, which iiiopens up new possibilities in the clinical studies. Thus, TFCA serves as an ideal tool for studying the intricate machinery of the human brain.Tüfekçi, D. İlhanM.S

Polarized Proton Beams from Laser-induced Plasmas

We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the PIC simulation code VLPL to make theoretical predictions about the behavior of proton spins in laser-induced plasmas. Simulations of spin-polarized targets show that the polarization is conserved during the acceleration process. For the experimental realization, a polarized HCl gas-jet target is under construction using the fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and simultaneously circular polarized light of the fifth harmonic to photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their degree of polarization is measured with a Lamb-shift polarimeter. The final experiments, aiming at the first observation of a polarized particle beam from laser-generated plasmas, will be carried out at the 10 PW laser system SULF at SIOM/Shanghai.Comment: 7 pages, 7 figure

Investigation of mitophagy biomarkers in corneal epithelium of keratoconus patients

Purpose: The pathological mechanisms of keratoconus (KC) have not been elucidated yet. Mitophagy is an important mechanism that eliminates damaged mitochondria under oxidative stress, and it could be one of the leading pathological causes of KC. This study aimed to find out the role of mitophagy in the keratoconic corneal epithelium. Methods: The corneal epithelia were collected from the 103 progressive KC patients and the 46 control subjects. The real-time quantitative PCR was performed for PTEN-putative kinase-1 (PINK1), PARKIN, p62, and BNIP3 gene expressions in 31 KC and 9 control subjects. Western blot analyses were performed to investigate the protein expressions of PINK1, PARKIN, LC3B, ATG5, and BECLIN in the remaining 109 corneal epithelium samples from 72 patients and 37 control subjects. Results: mRNA and protein expressions of PINK1 decreased significantly in the corneal epithelium of KC patients compared to the control subjects. No significant change was found in mRNA levels of PARKIN, p62, and BNIP3 in KC patients. The protein expression of PARKIN, LC3B, ATG5, and Beclin did not significantly differ between KC patients and control subjects. Gene expression levels of mitophagy biomarkers were not affected by the KC grade. Conclusions: PINK1/PARKIN-dependent mitophagy is affected in the keratoconic corneal epithelium. We found significant decreases in both mRNA and protein expressions of PINK1 in the keratoconic corneal epithelium. However, we did not observe any other significant change in mitophagy markers. Mitochondrial stress-related mitophagy pathways could be interrupted by the decreased levels of PINK1 in the keratoconic corneal epithelium, but solely PINK1 dysregulation is not likely to induce KC pathogenesis

Diseño y Evaluación de un programa informático para la educación musical de maestros no especialistas. El caso de EMOLAB.

Este trabajo expone el diseño, desarrollo y evaluación de un software como apoyo docente en una materia de formación musical básica para futuros maestros generalistas. La evaluación del programa fue realizada por estudiantes de primer año del Grado de Maestro en Educación Primaria. Cumplimentaron un cuestionario que recogió sus opiniones (versatilidad, eficacia, facilidad de uso, calidad del entorno gráfico, adecuación, interés, facilitación del aprendizaje, feedback, funcionalidad) y percepciones sobre aspectos más generales (control, orientación, afectividad, consulta, verificación, seguimiento). Los resultados sugieren que el alumnado percibe EMOLab como herramienta de gran ayuda en el desarrollo de sus habilidades musicales

Microscopic nonequilibrium theory of double-barrier Josephson junctions

We study nonequilibrium charge transport in a double-barrier Josephson junction, including nonstationary phenomena, using the time-dependent quasiclassical Keldysh Green's function formalism. We supplement the kinetic equations by appropriate time-dependent boundary conditions and solve the time-dependent problem in a number of regimes. From the solutions, current-voltage characteristics are derived. It is understood why the quasiparticle current can show excess current as well as deficit current and how the subgap conductance behaves as function of junction parameters. A time-dependent nonequilibrium contribution to the distribution function is found to cause a non-zero averaged supercurrent even in the presence of an applied voltage. Energy relaxation due to inelastic scattering in the interlayer has a prominent role in determining the transport properties of double-barrier junctions. Actual inelastic scattering parameters are derived from experiments. It is shown as an application of the microscopic model, how the nature of the intrinsic shunt in double-barrier junctions can be explained in terms of energy relaxation and the opening of Andreev channels.Comment: Accepted for Phys. Rev.

Ion source and LEBT of KAHVELab proton beamline

The KAHVE Laboratory, at Bo\u{g}azi\c{c}i University, Istanbul, Turkey is home to an educational proton linac project. The proton beam will originate from a 20 keV H+ source and will be delivered to a two module Radio Frequency Quadrupole (RFQ) operating at 800 MHz via a low energy beam transport (LEBT) line. Currently, the design phase being over, commissioning and stability tests are ongoing for the proton beamline which is already produced and installed except the RFQ which is being manufactured. This work summarizes the design, production and test phases of the ion source and LEBT line components

A characterization of the molecular phenotype and inflammatory response of schizophrenia patient-derived microglia-like cells

Different lines of evidence support a causal role for microglia in the pathogenesis of schizophrenia. However, how schizophrenia patient-derived microglia are affected at the phenotypic and functional level is still largely unknown. We used a recently described model to induce patient-derived microglia-like cells and used this to analyze changes in the molecular phenotype and function of myeloid cells in schizophrenia. We isolated monocytes from twenty recent-onset schizophrenia patients and twenty non-psychiatric controls. We cultured the cells towards an induced microglia-like phenotype (iMG), analyzed the phenotype of the cells by RNA sequencing and mass cytometry, and their response to LPS. Mass cytometry showed a high heterogeneity of iMG in cells derived from patients as well as controls. The prevalence of two iMG clusters was significantly higher in schizophrenia patients (adjusted p-value <0.001). These subsets are characterized by expression of ApoE, Ccr2, CD18, CD44, and CD95, as well as IRF8, P2Y(12), Cx3cr1 and HLA-DR. In addition, we found that patient derived iMG show an enhanced response to LPS, with increased secretion of TNF-alpha. Further studies are needed to replicate these findings, to determine whether similar subclusters are present in schizophrenia patients in vivo, and to address how these subclusters are related to the increased response to LPS, as well as other microglial functions

Activation-Induced Cytidine Deaminase (AID) Deficiency Causes the Autosomal Recessive Form of the Hyper-IgM Syndrome (HIGM2)

AbstractThe activation-induced cytidine deaminase (AID) gene, specifically expressed in germinal center B cells in mice, is a member of the cytidine deaminase family. We herein report mutations in the human counterpart of AID in patients with the autosomal recessive form of hyper-IgM syndrome (HIGM2). Three major abnormalities characterize AID deficiency: (1) the absence of immunoglobulin class switch recombination, (2) the lack of immunoglobulin somatic hypermutations, and (3) lymph node hyperplasia caused by the presence of giant germinal centers. The phenotype observed in HIGM2 patients (and in AID−/− mice) demonstrates the absolute requirement for AID in several crucial steps of B cell terminal differentiation necessary for efficient antibody responses