Ironies of History and the Dissidence of Memory

Located at the heart of Ankara, Turkey’s national capital, Middle East Technical University (METU) is among the largest public universities in Turkey, with an international reputation in education and research excellence. Its history, however, offers a compelling story concerning the ironies of history and the urgency of dissident memory to inform contemporary social justice struggles across the globe. This dissident memory is rooted in political struggles and revolutionary dreams of a passionate generation of university students for social justice and freedom

Thermoluminescence study of Mn doped lithium tetraborate powder and pellet samples synthesized by solution combustion synthesis

In this paper, the thermoluminescence (TL) dosimetric characteristics under beta-ray, x-ray and gamma-ray excitations of powder and pellet Mn-doped lithium tetraborates (LTB) which were produced by solution combustion synthesis technique were investigated, and the results were compared with that of TLD-100 chips. The chemical composition and morphologies of the obtained LTB and Mn-doped LTB (LTB:Mn) were confirmed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and scanning electron microscopy (SEM) with EDX. LTB:Mn was studied using luminescence spectroscopy. In addition, the effects of sintering and annealing temperatures and times on the thermoluminescence (TL) properties of LTB:Mn were investigated. The glow curves of powder samples as well as pellet samples exposed to different beta doses exhibited a low temperature peak at about 100 °C followed by an intense principal high temperature peak at about 260 °C. The kinetic parameters (E, b, s) associated with the prominent glow peaks were estimated using Tm-Tstop, initial rise (IR) and computerized glow curve deconvolution (CGCD) methods. The TL response of integral TL output increased linearly with increasing the dose in the range of 0.1-10 Gy and was followed by a superlinearity up to 100 Gy both for powder and pellet samples using beta-rays. Powder and pellet LTB:Mn were irradiated to a known dose by a linear accelerator with 6 and 18 MV photon beams, 6-15 MeV electron beams and a traceable 137Cs beam to investigate energy response. Further, TL sensitivity, fading properties and recycling effects related with beta exposure of LTB:Mn phosphor were evaluated and its relative energy response was also compared with that of TLD-100 chips. The comparison of the results showed that the obtained phosphors have good TL dose response with adequate sensitivity and linearity for the measurement of medical doses

Laboratory tests with Lepidoptera to assess non-target effects of Bt maize pollen: analysis of current studies and recommendations for a standardised design

Background and approach Common standards for laboratory studies of non-target organisms are recognised as prerequisite to assist the risk assessments regarding the evaluation of environmental effects of transgenic crops. Here, we provide specific recommendations significant for experimental procedures of laboratory studies to test potential adverse effects of Bt maize on larvae of non-target Lepidoptera. We searched and analysed both ecotoxicological test protocols for pesticides in the EU as well as the non-target tests with Lepidoptera applied in unpublished industry studies submitted officially by agro-companies for the GMO authorisation in Europe. Results The classical ecotoxicology protocols applied for testing pesticides could serve as general guidelines, but do not completely fit the specific and differing requirements for assessing non-target effects of transgenic crops. The analysis of the non-target studies submitted for the application of the cultivation of Bt maize in Europe revealed critical limitations, thus corroborating the urgent need for common quality criteria. Based on our evaluations, we identified several issues requiring harmonisation or standardisation of the experimental conditions and approach, e.g., the application of Bt maize pollen, synthetic toxins, the provided diet for larvae, experimental controls, magnitude and duration of exposure to Bt, relevant variables to be recorded, and sufficient statistical power. Conclusions Our recommendations should stimulate the development of precise guidance for the authorities, and support the operationalisation of the required laboratory tests for the evaluation of non-target effects of Bt maize pollen on non-target Lepidoptera, also contributing to standards of other ecotoxicity tests with Lepidoptera larvae, e.g., for pesticides.This article has been prepared as an outcome of the BfN research project “Basisdaten zur Effektbewertung verschiedener Bt-Toxine auf Schmetterlingslarven” (FKZ 3515890100)

Ultrasound Findings in a Case of Myeloid Sarcoma of the Breast

Myeloid sarcoma is a rare, solid extramedullary tumor originating from immature granulocytic cells or monocytes. Breast involvement without an aleukemic or myeloproliferative disorder is very infrequent. A 21-year-old female patient was admitted with bilateral palpable breast masses for four months. The patient had given birth approximately one year ago. The ultrasonographic examination revealed multiple, oval shaped—some of them with microlubulated margins—hypoechoic, solid masses of which, the largest mass measured 4.5 . 2.5 cm, evaluated as BI-RADS 4. The histopthological examination suggested hematolymphoid neoplasm. In the differential diagnosis of solid breast lesions, myeloid sarcoma should be kept in mind even without hematological findings. Early diagnosis of this tumor is important for the effectiveness of the medical treatment

A Hybrid 3D/2D Field Response Calculation for Liquid Argon Detectors with PCB Based Anode Plane

Liquid Argon Time Projection Chamber (LArTPC) technology is commonly utilized in neutrino detector designs. It enables detailed reconstruction of neutrino events with high spatial precision and low energy threshold. Its field response (FR) model describes the time-dependent electric currents induced in the anode-plane electrodes when ionization electrons drift nearby. An accurate and precise FR is a crucial input to LArTPC detector simulations and charge reconstruction. Established LArTPC designs have been based on parallel wire planes. It allows accurate and computationally economic two-dimensional (2D) FR models utilizing the translational symmetry along the direction of the wires. Recently, novel LArTPC designs utilize electrodes formed on printed circuit board (PCB) in the shape of strips with through holes. The translational symmetry is no longer a good approximation near the electrodes and a new FR calculation that employs regions with three dimensions (3D) has been developed. Extending the 2D models to 3D would be computationally expensive. Fortuitously, the nature of strips with through holes allows for a computationally economic approach based on the finite-difference method (FDM). In this paper, we present a new software package "pochoir" that calculates LArTPC field response for these new strip-based anode designs. This package combines 3D calculations in the volume near the electrodes with 2D far-field solutions to achieve fast and precise field response computation. We apply the resulting FR to simulate and reconstruct samples of cosmic-ray muons and $^{39}$Ar decays from a Vertical Drift (VD) detector prototype operated at CERN. We find the difference between real and simulated data within 5 %. Current state-of-the-art LArTPC software requires a 2D FR which we provide by averaging over one dimension and estimate that variations lost in this average are smaller than 7 %.Comment: 16 pages, 12 figure

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum