578 research outputs found

    Carlisle Indian Industrial School

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    The Carlisle Indian School (1879–1918) was an audacious educational experiment. Capt. Richard Henry Pratt, the school’s founder and first superintendent, persuaded the federal government that training Native children to accept the white man’s ways and values would be more efficient than fighting deadly battles. The result was that the last Indian war would be waged against Native children in the classroom.More than 10,500 children from virtually every Native nation in the United States were taken from their homes and transported to Pennsylvania. Carlisle provided a blueprint for the federal Indian school system that was established across the United States and served as a model for many residential schools in Canada. The Carlisle experiment initiated patterns of dislocation and rupture far deeper and more profound and enduring than its initiators ever grasped.Carlisle Indian Industrial School offers varied perspectives on the school by interweaving the voices of students’ descendants, poets, and activists with cutting-edge research by Native and non-Native scholars. These contributions reveal the continuing impact and vitality of historical and collective memory, as well as the complex and enduring legacies of a school that still touches the lives of many Native Americans

    No Effect of Steady Rotation on Solid 4^4He in a Torsional Oscillator

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    We have measured the response of a torsional oscillator containing polycrystalline hcp solid 4^{4}He to applied steady rotation in an attempt to verify the observations of several other groups that were initially interpreted as evidence for macroscopic quantum effects. The geometry of the cell was that of a simple annulus, with a fill line of relatively narrow diameter in the centre of the torsion rod. Varying the angular velocity of rotation up to 2\,rad\,s1^{-1} showed that there were no step-like features in the resonant frequency or dissipation of the oscillator and no history dependence, even though we achieved the sensitivity required to detect the various effects seen in earlier experiments on other rotating cryostats. All small changes during rotation were consistent with those occurring with an empty cell. We thus observed no effects on the samples of solid 4^4He attributable to steady rotation.Comment: 8 pages, 3 figures, accepted in J. Low Temp. Phy

    Cluster spacecraft observations of a ULF wave enhanced by Space Plasma Exploration by Active Radar (SPEAR)

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    Space Plasma Exploration by Active Radar (SPEAR) is a high-latitude ionospheric heating facility capable of exciting ULF waves on local magnetic field lines. We examine an interval from 1 February 2006 when SPEAR was transmitting a 1 Hz modulation signal with a 10 min on-off cycle. Ground magnetometer data indicated that SPEAR modulated currents in the local ionosphere at 1 Hz, and enhanced a natural field line resonance with a 10 min period. During this interval the Cluster spacecraft passed over the heater site. Signatures of the SPEAR-enhanced field line resonance were present in the magnetic field data measured by the magnetometer on-board Cluster-2. These are the first joint ground- and space-based detections of field line tagging by SPEAR

    Fine-scale electric fields and Joule heating from observations of the Aurora

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    Optical measurements from three selected wavelengths have been combined with modelling of emissions from an auroral event to estimate the magnitude and direction of small-scale electric fields on either side of an auroral arc. The temporal resolution of the estimates is 0.1 seconds, which is much higher resolution than measurements from SuperDARN in the same region, with which we compare our estimates. Additionally, we have used the SCANDI instrument to measure the neutral wind during the event in order to calculate the height integrated Joule heating. Joule heating obtained from the small scale electric fields gives larger values (17 ± 11 and 6 ± 9 mWm−2 on average on each side of the arc) than the Joule heating obtained from more conventionally used SuperDARN data (5 mWm−2). This result is significant, because Joule heating will cause changes in the thermosphere from thermal expansion and thermal conductivity, and may also affect the acceleration of the neutral wind. Our result indicates that high spatial and temporal resolution electric fields may play an important role in the dynamics of the magnetosphere-ionosphere-thermosphere system

    The interaction between transpolar arcs and cusp spots

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    Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a "wedge" of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high-latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting--i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare

    Understanding insider threat attacks using natural language processing: Automatically mapping organic narrative reports to existing insider threat frameworks

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    Traditionally cyber security has focused on defending against external threats, over the last decade we have seen an increasing awareness of the threat posed by internal actors. Current approaches to reducing this risk have been based upon technical controls, psychologically understanding the insider’s decision-making processes or sociological approaches ensuring constructive workplace behaviour. However, it is clear that these controls are not enough to mitigate this threat with a 2019 report suggesting that 34% of breaches involved internal actors. There are a number of Insider threat frameworks that bridge the gap between these views, creating a holistic view of insider threat. These models can be difficult to contextualise within an organisation and hence developing actionable insight is challenging. An important task in understanding an insider attack is to gather a 360-degree understanding of the incident across multiple business areas: e.g. co-workers, HR, IT, etc. can be key to understanding the attack. We propose a new approach to gathering organic narratives of an insider threat incident that then uses a computational approach to map these narratives to an existing insider threat framework. Leveraging Natural Language Processing (NLP) we exploit a large collection of insider threat reporting to create an understanding of insider threat. This understanding is then applied to a set of reports of a single attack to generate a computational representation of the attack. This representation is then successfully mapped to an existing, manual insider threat framework

    Anomalous damping of a low frequency vibrating wire in superfluid He-3-B due to vortex shielding

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    We have investigated the behaviour of a large vibrating wire resonator in the B-phase of superfluid He-3 at zero pressure and at temperatures below 200 mu K. The vibrating wire has a low resonant frequency of around 60 Hz. At low velocities the motion of the wire is impeded by its intrinsic (vacuum) damping and by the scattering of thermal quasiparticle excitations. At higher velocities we would normally expect the motion to be further damped by the creation of quasiparticles from pair-breaking. However, for a range of temperatures, as we increase the driving force we observe a sudden decrease in the damping of the wire. This results from a reduction in the thermal damping arising from the presence of quantum vortex lines generated by the wire. These vortex lines Andreev-reflect low energy excitations and thus partially shield the wire from incident thermal quasiparticles

    Stability of flow and the transition to turbulence around a quartz tuning fork in superfluid He-4 at very low temperatures

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    We have studied the transition between pure potential flow and turbulent flow around a quartz tuning fork resonator in superfluid He-4 at millikelvin temperatures. Turbulent flow is identified by an additional drag force on the fork prongs due to the creation of quantized vortices. When driven at a constant driving force amplitude, the transition to turbulence causes an abrupt decrease in the velocity amplitude of the prongs. For a range of driving forces, continuous switching is observed between the two flow states. We have made a statistical study of the switching characteristics and of the lifetimes of the unstable states. We find a characteristic velocity nu(star) which separates quasistable turbulent flow at higher velocities and quasistable potential flow at lower velocities. We show that the potential-to-turbulent flow transition is driven by random processes involving remanent vortices pinned to the prongs

    Boundary spanning as identity work in university business engagement roles

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    The study explores how boundary-spanning is carried out to further community engagement in 15 universities of differing sizes/ages across the United Kingdom. Fifteen interviewees participated in a series of four semi-structured interviews, aged between 35–50 and with a first degree (with almost half with an MSc). One third were women. All managed their own teams and felt these were their base in negotiating difficult internal territory.. Here, boundary spanning is found to be synonymous with identity work, carried out to enable individuals to adapt to different internal and external conditions and requirements through processes of interaction and learning. It also suggests the strategic construction of identities to address perceived threats and insecurities - and the impacts of change, dominant organisational discourse and senior management on this process. Their job titles were not useful as identity badges to signal meaning, due to these being outside ‘what universities are for’
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