598 research outputs found

    Investigating the regional variation in rules and best management practices for forestry in New Zealand

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    Under the Resource Management Act 1991 (NZ), the interpretation and implementation of environmental policy is primarily the responsibility of local government. The management of forestry operations may be influenced by statutory rules published in regional and district plans, and recommended best management practices (BMPs) published in guidelines. There are concerns that inconsistency between jurisdictions’ rules have a negative impact on the forestry industry’s financial and environmental outcomes. This research investigated and quantified the variation in Permitted Activity rules and BMPs, for culvert installation and earthworks, between New Zealand’s 16 Regional Councils. Significant variation in these regional rules and BMPs existed in both the level of control (i.e., the number of rules and BMPs per council), and the nature of control (i.e., the proportion of rules or BMPs utilised). Further, the rules and BMPs of one council are seldom the same as another. This variation is apparent on both a national scale and when considering only neighbouring pairs of councils

    Interaction between counter-propagating quantum Hall edge channels in the 3D topological insulator BiSbTeSe2_2

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    The quantum Hall effect is studied in the topological insulator BiSbTeSe2_2. By employing top- and back-gate electric fields at high magnetic field, the Landau levels of the Dirac cones in the top and bottom topological surface states can be tuned independently. When one surface is tuned to the electron-doped side of the Dirac cone and the other surface to the hole-doped side, the quantum Hall edge channels are counter-propagating. The opposite edge mode direction, combined with the opposite helicities of top and bottom surfaces, allows for scattering between these counter-propagating edge modes. The total Hall conductance is integer valued only when the scattering is strong. For weaker interaction, a non-integer quantum Hall effect is expected and measured

    Season of infectious mononucleosis as a risk factor for multiple sclerosis : a UK primary care case-control study

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    This study is based in part on data from the Full Feature General Practice Research Database obtained under licence from the UK Medicines and Healthcare Products Regulatory Agency. However, the interpretation and conclusions contained in this study are those of the authors alone. Access to the GPRD database was funded through the Medical Research Council’s licence agreement with MHRA. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. We acknowledge the data management support of the Grampian Data Safe Haven (DaSH) and the associated financial support of NHS Research Scotland through NHS Grampian investment in the Grampian DaSH.Peer reviewedPostprintPostprintPostprin

    Attenuation of neural responses in primary visual cortex during the attentional blink

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    Information-processing bottlenecks are characteristic of many cognitive and neural systems. One such bottleneck is revealed by tasks in which rapidly successive stimulus events must be reported. Here, observers missed the second of two visual targets if it occurred within 700 ms of the first [an "attentional blink" (AB)], even though this second target could be reported accurately when the first item was ignored. Isolating neural responses to such rapid events has proven difficult because current magnetic resonance imaging methods rely on relatively sluggish changes in the brain's physiological response to sensory inputs. Here, we overcame this limitation by presenting successive visual targets at different spatial locations, thereby exploiting the retinotopic organization of early cortical visual areas to distinguish neural activity associated with successive target events. We show that neural activity in primary visual cortex is significantly modulated during the AB, and that this activity mirrors behavioral measures of target identification accuracy. The findings suggest that the neural signature of perceptual suppression during processing of rapidly successive stimuli is evident at the earliest stages of cortical sensory processing

    NPSHR (NPSH3) IMPROVEMENT OF A LOW PRESSURE SAFETY INJECTION PUMP

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    Case StudiesThis case study discusses the rerate of a set of vertically-mounted singlestage end-suction centrifugal pumps used for low pressure safety injection (LPSI) in a nuclear power plant. The original LPSI pumps were supplied early 1970’s and for safety purposes it was decided to overhaul these pumps to improve NPSHR (i.e. NPSH3). The rerate consisted of replacing the existing impeller with a new design yielding close to identical head performance characteristic, yet better NPSHR. Aim was to improve NPSHR by (minimally) 0.5 m (1.64 ft) at rated capacity of 682 m3 /h (3003 USGPM) and 1470 r/min running speed, and demonstrate by test the actual improvement in NPSHR

    4π4\pi periodic Andreev bound states in a Dirac semimetal

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    Electrons in a Dirac semimetals possess linear dispersion in all three spatial dimensions, and form part of a developing platform of novel quantum materials. Bi1x_{1-x}Sbx_x supports a three-dimensional Dirac cone at the Sb-induced band inversion point. Nanoscale phase-sensitive junction technology is used to induce superconductivity in this Dirac semimetal. Radio frequency irradiation experiments reveal a significant contribution of 4π\pi-periodic Andreev bound states to the supercurrent in Nb-Bi0.97_{0.97}Sb0.03_{0.03}-Nb Josephson junctions. The conditions for a substantial 4π4\pi contribution to the supercurrent are favourable because of the Dirac cone's topological protection against backscattering, providing very broad transmission resonances. The large g-factor of the Zeeman effect from a magnetic field applied in the plane of the junction, allows tuning of the Josephson junctions from 0 to π\pi regimes.Comment: Supplementary information is include

    Genetic diversity trends in twentieth century crop cultivars: a meta analysis

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    In recent years, an increasing number of papers has been published on the genetic diversity trends in crop cultivars released in the last century using a variety of molecular techniques. No clear general trends in diversity have emerged from these studies. Meta analytical techniques, using a study weight adapted for use with diversity indices, were applied to analyze these studies. In the meta analysis, 44 published papers were used, addressing diversity trends in released crop varieties in the twentieth century for eight different field crops, wheat being the most represented. The meta analysis demonstrated that overall in the long run no substantial reduction in the regional diversity of crop varieties released by plant breeders has taken place. A significant reduction of 6% in diversity in the 1960s as compared with the diversity in the 1950s was observed. Indications are that after the 1960s and 1970s breeders have been able to again increase the diversity in released varieties. Thus, a gradual narrowing of the genetic base of the varieties released by breeders could not be observed. Separate analyses for wheat and the group of other field crops and separate analyses on the basis of regions all showed similar trends in diversity
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