112 research outputs found

    The Right to Counsel During Custodial Interrogation: Equivocal References to an Attorney-Determining What Statements or Conduct Should Constitute an Accused\u27s Invocation of the Right to Counsel

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    The fifth amendment to the United States Constitution guarantees to all persons the privilege against compelled self-incrimination. In Miranda v. Arizona, the United States Supreme Court interpreted the fifth amendment to require a specified set of procedural safeguards that law enforcement officers must follow to protect adequately each individual\u27s fifth amendment rights. The Miranda safeguards require that prior to an accused\u27s custodial interrogation, government officials must inform the accused that he has the right to remain silent; that any of his statements maybe used against him in a subsequent criminal action; that he has the right to confer with counsel; and that if he cannot afford to hire counsel, the court will appoint an attorney to represent him. The government may not use a confession obtained in violation of these Miranda safeguards to prove the guilt of a defendant. An accused\u27s right to counsel at pretrial criminal proceedings protects that individual from providing a compelled or involuntary confession. The right to counsel ensures that the government affords assistance to an accused in dealing with the criminal process and also protects an accused from inadvertent self-incrimination. An accused\u27s right to have an attorney present during any questioning is absolute. Courts must exclude any statement given by an accused during custodial interrogation unless the interrogating officers advise the accused, prior to questioning, of his right to have counsel present during questioning, and the accused voluntarily, knowingly, and intelligently waives this right. Furthermore,Miranda holds that if an accused indicates in any manner and at any stage of the process that he wishes to consult with an attorney before speaking there can be no questioning. Thus, even if an accused initially waives his right and agrees to speak with law enforcement officials, he may cease the questioning at any time by invoking his right to counsel. When an accused invokes his constitutional right to counsel, he also effectively exercises his right to remain silent, thus requiring the interrogation to cease until the government affords him the opportunity to confer with an attorney. This Note focuses on determining when an accused has invoked his right to counsel. Because Miranda\u27s in any manner language does not indicate what degree of clarity is required for a defendant to invoke his right to counsel, the judiciary has struggled to create a standard to determine when an accused\u27s equivocal reference to an attorney constitutes an invocation of the right to counsel. The Supreme Court has not addressed specifically the is-sue of whether an equivocal reference to an attorney is an invocation of the right to counsel.\u27 Recently, in Smith v. Illinois the Supreme Court explicitly declined to resolve the issue of equivocal references to an attorney.15 Thus, the conflicting standards for determining the consequences of an ambiguous reference to counsel remain among the various courts

    A Current Mode Detector Array for Gamma-Ray Asymmetry Measurements

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    We have built a CsI(Tl) gamma-ray detector array for the NPDGamma experiment to search for a small parity-violating directional asymmetry in the angular distribution of 2.2 MeV gamma-rays from the capture of polarized cold neutrons by protons with a sensitivity of several ppb. The weak pion-nucleon coupling constant can be determined from this asymmetry. The small size of the asymmetry requires a high cold neutron flux, control of systematic errors at the ppb level, and the use of current mode gamma-ray detection with vacuum photo diodes and low-noise solid-state preamplifiers. The average detector photoelectron yield was determined to be 1300 photoelectrons per MeV. The RMS width seen in the measurement is therefore dominated by the fluctuations in the number of gamma rays absorbed in the detector (counting statistics) rather than the intrinsic detector noise. The detectors were tested for noise performance, sensitivity to magnetic fields, pedestal stability and cosmic background. False asymmetries due to gain changes and electronic pickup in the detector system were measured to be consistent with zero to an accuracy of 10−910^{-9} in a few hours. We report on the design, operating criteria, and the results of measurements performed to test the detector array.Comment: 33 pages, 20 figures, 2 table

    A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

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    TRIUMF experiment E497 is a study of parity violation in pp scattering at an energy where the leading term in the analyzing power is expected to vanish, thus measuring a unique combination of weak-interaction flavour conserving terms. It is desired to reach a level of sensitivity of 2x10^-8 in both statistical and systematic errors. The leading systematic errors depend on transverse polarization components and, at least, the first moment of transverse polarization. A novel polarimeter that measures profiles of both transverse components of polarization as a function of position is described.Comment: 19 pages LaTeX, 10 PostScript figures. To appear in Nuclear Instruments and Methods in Physics Research, Section

    Precision Measurement of PArity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

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    The NPDGamma experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the Îł\gamma emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon (πNN\pi NN) coupling constant {\it fπ1^1_{\pi}}Comment: Proceedings of the PANIC'05 Conference, Santa Fe, NM, USA, October 24-28, 2005, 3 pages, 2 figure

    Parity Violation in Proton-Proton Scattering

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    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at 230 MeV and near 1.3 GeV. These experiments are intended to provide stringent constraints on the set of six effective weak meson-nucleon coupling constants, which characterize the weak interaction between hadrons in the energy domain where meson exchange models provide an appropriate description. The 221 MeV is unique in that it selects a single transition amplitude (3P2-1D2) and consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The TRIUMF 221 MeV proton-proton parity violation experiment is described in some detail. A preliminary result for the longitudinal analyzing power is Az = (1.1 +/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are commented on. The anomaly at 6 GeV/c requires that a new multi-GeV proton-proton parity violation experiment be performed.Comment: 13 Pages LaTeX, 5 PostScript figures, uses espcrc1.sty. Invited talk at QULEN97, International Conference on Quark Lepton Nuclear Physics -- Nonperturbative QCD Hadron Physics & Electroweak Nuclear Processes --, Osaka, Japan May 20--23, 199

    Breakup Density in Spectator Fragmentation

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    Proton-proton correlations and correlations of protons, deuterons and tritons with alpha particles from spectator decays following 197Au + 197Au collisions at 1000 MeV per nucleon have been measured with two highly efficient detector hodoscopes. The constructed correlation functions, interpreted within the approximation of a simultaneous volume decay, indicate a moderate expansion and low breakup densities, similar to assumptions made in statistical multifragmentation models. PACS numbers: 25.70.Pq, 21.65.+f, 25.70.Mn, 25.75.GzComment: 11 pages, LaTeX with 3 included figures; Also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.htm

    Isospin Effects in Nuclear Multifragmentation

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    We develop an improved Statistical Multifragmentation Model that provides the capability to calculate calorimetric and isotopic observables with precision. With this new model we examine the influence of nuclear isospin on the fragment elemental and isotopic distributions. We show that the proposed improvements on the model are essential for studying isospin effects in nuclear multifragmentation. In particular, these calculations show that accurate comparisons to experimental data require that the nuclear masses, free energies and secondary decay must be handled with higher precision than many current models accord.Comment: 46 pages, 16 figure

    TRY plant trait database – enhanced coverage and open access

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    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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