4,753 research outputs found
Placing Rights And Liberties In Pawn Until The Defeat Of Hitlerism”: Canadian Intelligence Gathering In The Second World War
Abstract:
A monograph regarding the history of Canada’s intelligence gathering apparatus has not been published, leaving a gap in modern historiography. In an attempt to partially fill this academic void, this essay examines RCMP intelligence Bulletins drafted during World War Two that have been declassified under the Access to Information Act. Analysis of the Bulletins clearly indicates the Canadian intelligence gathering apparatus underwent a massive expansion of scope during the war. The RCMP began investigating people and organizations based upon their race, religion, political affiliation or nationalist beliefs. Disregard of human rights and privacy during the period was so widespread, even the police remarked upon the depth of their new powers inside the Bulletins. Some people, such as the future Prime Minister Diefenbaker, worked to enshrine human rights in the Canadian constitution thereafter, attempting to prevent the police from acquiring such powers ever again. Due to parallel tactics used during World War Two and the modern day, an effective Supreme Court challenge could be mounted against tactics used in Canada’s war on terror based upon historical and constitutional grounds
Ichnology of an Intertidal Carbonate Sand Flat: Pigeon Creek, San Salvador Island, Bahamas
Reprinted from: James L. Carew (ed.), May 30–June 3, 1996, Proceedings of the 8th Symposium on the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Bahamian Field Station
Use of Bioadvantaged Materials for Use in Bituminous Modification
AbstractHistorically, the use of “green” materials around the world has been limited due to their higher production costs when compared to petrochemical derived materials. However, due to the recent volatility and increasing price of petroleum derivatives, there is a growing demand for the use of environmentally friendly materials. One of the most commonly used materials for bitumen modification are poly(styrene-block-butadiene-block-styrene) (SBS) type polymers. Recently, Iowa State University Chemical Engineering Department was able to synthetize thermoplastic elastomers using acrylated epoxidized soybean oil (AESO), a bioadvantaged replacement of butadiene, and styrene with the use of controlled radical polymerization techniques. Initial rheological tests conducted on the bitumen-polymer blends have shown that the biopolymers improve the complex shear modulus of the bitumen to a similar and even greater extent as the commercially available SBS polymers
The Role of the Radial Orbit Instability in Dark Matter Halo Formation and Structure
For a decade, N-body simulations have revealed a nearly universal dark matter
density profile, which appears to be robust to changes in the overall density
of the universe and the underlying power spectrum. Despite its universality,
the physical origin of this profile has not yet been well understood.
Semi--analytic models by Barnes et al. (2005) have suggested that the density
structure of dark matter halos is determined by the onset of the radial orbit
instability (ROI). We have tested this hypothesis using N-body simulations of
collapsing dark matter halos with a variety of initial conditions. For
dynamically cold initial conditions, the resulting halo structures are triaxial
in shape, due to the mild aspect of the instability. We examine how variations
in initial velocity dispersion affect the onset of the instability, and find
that an isotropic velocity dispersion can suppress the ROI entirely, while a
purely radial dispersion does not. The quantity sigma^2/vc^2 is a criterion for
instability, where regions with sigma^2/vc^2 <~1 become triaxial due to the ROI
or other perturbations. We also find that the radial orbit instability sets a
scale length at which the velocity dispersion changes rapidly from isotropic to
radially anisotropic. This scale length is proportional to the radius at which
the density profile changes shape, as is the case in the semi--analytic models;
however, the coefficient of proportionality is different by a factor of ~2.5.
We conclude that the radial orbit instability is likely to be a key physical
mechanism responsible for the nearly universal profiles of simulated dark
matter halos.Comment: 13 pages, 12 figures, accepted to Ap
High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents
We report a precise determination of the 19Ne half-life to be s. This result disagrees with the most recent precision
measurements and is important for placing bounds on predicted right-handed
interactions that are absent in the current Standard Model. We are able to
identify and disentangle two competing systematic effects that influence the
accuracy of such measurements. Our findings prompt a reassessment of results
from previous high-precision lifetime measurements that used similar equipment
and methods.Comment: 5 pages and 5 figures. Paper accepted for publication in Phys. Rev.
Let
Circumstances and consequences of falls among people with chronic stroke
Falls are common after stroke; however, circumstances and consequences are relatively unknown. Our objectives were to identify the differences between fallers and non-fallers among people with chronic stroke, identify the circumstances of fall events, and examine the consequences of the falls. This is a secondary data analysis; all participants included sustained a stroke. Variables included demographics, stroke characteristics, and comorbidities. Falls were collected via self-report, and circumstances and consequences were derived from participant description of the event and categorized as appropriate. Among 160 participants, 53 (33%) reported a fall during the 1 yr period. Circumstances of falls were categorized as intrinsic or extrinsic. Location and circumstance of the fall were included: 70% occurred at home and 40% were associated with impaired physical or mental state (e.g., inattention to tying shoes). Additionally, 21% of falls were associated with activities of daily living and mobility and 34% with slips or trips. The majority who fell sustained an injury (72%). Injuries ranged from bruising to fractures, and 55% of those with an injury sought medical care (32% to emergency department). Poststroke falls are associated with an alarming rate of injury and healthcare utilization. Targeting mental and physical states may be key to fall prevention
Point-of-care HCV RNA screening by finger-prick is technically feasible but uptake is reduced by concomitant offer of HIV testing
Development, Validation, and Assessment of an Ischemic Stroke or Transient Ischemic Attack-Specific Prediction Tool for Obstructive Sleep Apnea
BACKGROUND:
Screening instruments for obstructive sleep apnea (OSA), as used routinely to guide clinicians regarding patient referral for polysomnography (PSG), rely heavily on symptomatology. We sought to develop and validate a cerebrovascular disease-specific OSA prediction model less reliant on symptomatology, and to compare its performance with commonly used screening instruments within a population with ischemic stroke or transient ischemic attack (TIA).
METHODS:
Using data on demographic factors, anthropometric measurements, medical history, stroke severity, sleep questionnaires, and PSG from 2 independently derived, multisite, randomized trials that enrolled patients with stroke or TIA, we developed and validated a model to predict the presence of OSA (i.e., Apnea-Hypopnea Index ≥5 events per hour). Model performance was compared with that of the Berlin Questionnaire, Epworth Sleepiness Scale (ESS), the Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender instrument, and the Sleep Apnea Clinical Score.
RESULTS:
The new SLEEP Inventory (Sex, Left heart failure, ESS, Enlarged neck, weight [in Pounds], Insulin resistance/diabetes, and National Institutes of Health Stroke Scale) performed modestly better than other instruments in identifying patients with OSA, showing reasonable discrimination in the development (c-statistic .732) and validation (c-statistic .731) study populations, and having the highest negative predictive value of all in struments.
CONCLUSIONS:
Clinicians should be aware of these limitations in OSA screening instruments when making decisions about referral for PSG. The high negative predictive value of the SLEEP INventory may be useful in determining and prioritizing patients with stroke or TIA least in need of overnight PSG
Air-Combat Strategy Using Approximate Dynamic Programming
Unmanned Aircraft Systems (UAS) have the potential to perform many
of the dangerous missions currently own by manned aircraft. Yet, the
complexity of some tasks, such as air combat, have precluded UAS from
successfully carrying out these missions autonomously. This paper presents
a formulation of a level flight, fixed velocity, one-on-one air combat maneuvering problem and an approximate dynamic programming (ADP) approach for computing an efficient approximation of the optimal policy. In the version of the problem formulation considered, the aircraft learning the
optimal policy is given a slight performance advantage. This ADP approach
provides a fast response to a rapidly changing tactical situation, long planning horizons, and good performance without explicit coding of air combat tactics. The method's success is due to extensive feature development, reward shaping and trajectory sampling. An accompanying fast and e ffective rollout-based policy extraction method is used to accomplish on-line implementation. Simulation results are provided that demonstrate the robustness of the method against an opponent beginning from both off ensive and defensive situations. Flight results are also presented using micro-UAS own at MIT's Real-time indoor Autonomous Vehicle test ENvironment
(RAVEN).Defense University Research Instrumentation Program (U.S.) (grant number FA9550-07-1-0321)United States. Air Force Office of Scientific Research (AFOSR # FA9550-08-1-0086)American Society for Engineering Education (National Defense Science and Engineering Graduate Fellowship
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