300 research outputs found

    Fourth Amendment Accommodations: (UN)Compelling Public Needs, Balancing Acts, and the Fiction of Consent

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    The problems of public housing-including crime, drugs, and gun violence- have received an enormous amount of national attention. Much attention has also focused on warrantless searches and consent searches as solutions to these problems. This Note addresses the constitutionality of these proposals and asserts that if the Supreme Court\u27s current Fourth Amendment jurisprudence is taken to its logical extremes, warrantless searches in public housing can be found constitutional. The author argues, however, that such an interpretation fails to strike the proper balance between public need and privacy in the public housing context. The Note concludes by proposing alternative consent-based regimes that would pass constitutional muster

    Nonlinear optomechanical paddle nanocavities

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    Nonlinear optomechanical coupling is the basis for many potential future experiments in quantum optomechanics (e.g., quantum non-demolition measurements, preparation of non-classical states), which to date have been difficult to realize due to small non-linearity in typical optomechanical devices. Here we introduce an optomechanical system combining strong nonlinear optomechanical coupling, low mass and large optical mode spacing. This nanoscale "paddle nanocavity" supports mechanical resonances with hundreds of fg mass which couple nonlinearly to optical modes with a quadratic optomechanical coupling coefficient g(2)>2π×400g^{(2)} > 2\pi\times400 MHz/nm2^2, and a two phonon to single photon optomechanical coupling rate Δω0>2π×16\Delta \omega_0 > 2\pi\times 16 Hz. This coupling relies on strong phonon-photon interactions in a structure whose optical mode spectrum is highly non--degenerate. Nonlinear optomechanical readout of thermally driven motion in these devices should be observable for T >50> 50 mK, and measurement of phonon shot noise is achievable. This shows that strong nonlinear effects can be realized without relying on coupling between nearly degenerate optical modes, thus avoiding parasitic linear coupling present in two mode systems.Comment: 8 pages, 5 figure

    Early Ordovician (Tremadocian) brachiopods from the Eastern Alborz Mountains, Iran

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    Six linguliform and two rhynchonelliform brachiopods, including three new species Eurytreta ahmadii, Wahwahlingula kharbashi and Nanorthis bastamensis are described from Tremadocian strata (Paltodus deltifer deltifer conodont Biozone) in the Deh-Molla area southwest of Shahrud, Northern Iran. The fauna is dominated by micromorphic lingulides and acrotretides and shows distinct similarity to the contemporaneous micromorphic brachiopod association from Tremadocian chalcedonites of the Holy Cross Mountains, Poland. New data on the early ontogeny of the enigmatic lingulide Diencobolus show a very distinct pattern, including the presence of a metamorphic protegulum ornamented with flat-based pits and a single pair of larval setal bundles, which links this taxon to Paterula and suggests close phylogenetic relationships of both taxa to the Discinoidea

    Echocardiography to Supplement Stress Electrocardiography in Emergency Department Chest Pain Patients

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    Introduction: Chest pain (CP) patients in the Emergency Department (ED) present a diagnostic dilemma, with a low prevalence of coronary disease but grave consequences with misdiagnosis. A common diagnostic strategy involves ED cardiac monitoring while excluding myocardial necrosis, followed by stress testing. We sought to describe the use of stress echocardiography (echo) at our institution, to identify cardiac pathology compared with stress electrocardiography (ECG) alone.Methods: Retrospective cohort study of 57 urban ED Chest Pain Unit (CPU) patients from 2002-2005 with stress testing suggesting ischemia. Our main descriptive outcome was proportion and type of discordant findings between stress ECG testing and stress echo. The secondary outcome was whether stress echo results appeared to change management.Results: Thirty-four of 57 patients [59.7%, 95% confidence interval (CI) 46.9-72.4%] had stress echo results discordant with stress ECG results. The most common discordance was an abnormal stress ECG with a normal stress echo (n=17/57, 29.8%, CI 17.9-41.7%), followed by normal stress ECG but with reversible regional wall-motion abnormality on stress echo (n = 10/57, 17.5%, CI 7.7-27.4%). The remaining seven patients (12.3%, CI 3.8-20.8%) had non-diagnostic stress ECG due to sub-maximal effort. Stress echo showed reversible wall-motion abnormality in two, and five were normal. Twenty-five of the 34 patients (73.5%, CI 56.8-85.4%) with discordant results had a different diagnostic strategy than predicted from their stress ECG alone.Conclusion: The addition of echo to stress ECG testing in ED CPU patients altered diagnosis in 34/57 (59.7%, CI 46.9-72.4%) patients, and appeared to change management in 25/57 (43.9%, CI 31.8-57.6%) patients. [West J Emerg Med. 2010; 11(4):379-383.

    Study Clinical Symptoms and Para-Clinical Findings in Poisoning Patient with Aluminum Phosphide in Patients Referred to Imam Khomeini Hospital in Ardabil (Northwest of Iran)

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    Background: Aluminum phosphide is used in different area in Iran. According to that the herbal form of these pills are used increasingly, comparison and evaluation of these patients in terms of clinical and laboratory symptoms are important. We studied on clinical and Para-clinical findings in patients who had taken aluminum phosphide and its herbal form in this study.Methods: This is a descriptive and analytic study which carried out during 2006-2012. In this study, laboratory variables, white blood cell count, hematocrit, blood glucose, sodium, potassium and bicarbonate, arterial blood gas also clinical finding after taking aluminum phosphide pills, and vital signs of poisoned patients were extracted.Results: In this study 386 poisoned patients were evaluated. We divided poisoned patients in two groups, case and herbal. 35% had been taking original Aluminum phosphide (case group) and 65% herbal form (herbal group). In totally 18.7% of poisoned patients were male. The average age of patients in herbal group was 23.22 ±8.20 years and in case group was 24.78±7.04 years. In both groups, nausea and vomiting were the most prevalent clinical signs. Experiments in a separate group showed significant different in blood pressure upper (P<0.001), Po2 level lower (P<0.001), pH lower (P<0.001) and bicarbonate lower (P<0.001) but there was no significant difference in respiratory rate, temperature, hemoglobin level and hematocrit. Also was observed that 70.4% of patients in case group died but all patients in herbal group survived (P<0.001).Conclusion: The results of this study indicated that arterial blood gas of patients is a useful tool for differentiating oral poisoning with original and herbal rice pill. Hence, in patients with clinical toxicity of rice tablet can be used to differentiate these two tablets

    Nearly perfect resonant absorption and coherent thermal emission by hBN-based photonic crystals

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    In this paper, we numerically demonstrate mid-IR nearly perfect resonant absorption and coherent thermal emission for both polarizations and wide angular region using multilayer designs of unpatterned films of hexagonal boron nitride (hBN). In these optimized structures, the films of hBN are transferred onto a Ge spacer layer on top of a one-dimensional photonic crystal (1D PC) composed of alternating layers of KBr and Ge. According to the perfect agreements between our analytical and numerical results, we discover that the mentioned optical characteristic of the hBN-based 1D PCs is due to a strong coupling between localized photonic modes supported by the PC and the phononic modes of hBN films. These coupled modes are referred as Tamm phonons. Moreover, our findings prove that the resonant absorptions can be red- or blue-shifted by changing the thickness of hBN and the spacer layer. The obtained results in this paper are beneficial for designing coherent thermal sources, light absorbers, and sensors operating within 6.2 μm to 7.3 μm in a wide angular range and both polarizations. The planar and lithography free nature of this multilayer design is a prominent factor that makes it a large scale compatible design. © 2017 Optical Society of America

    Ultra-broadband Asymmetric Light Transmission and Absorption Through The Use of Metal Free Multilayer Capped Dielectric Microsphere Resonator

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    In this paper, we propose a simple design with an excellent performance to obtain high contrast in transmission asymmetry based on dielectric microspheres. Initially, we scrutinize the impact of the sphere radius on forward and backward transmissions. Afterward, by introducing a capping layer on top of the sphere, transmission response for the backward illuminated light will be blocked. In the next step, in order to replace the reflecting metal cap with a metal free absorbing design, we adopt a modeling approach based on the transfer matrix method (TMM) to explore an ideal material to achieve metal free perfect absorption in a multilayer configuration of material-insulator-material-insulator (MIMI). As a result of our investigations, it is found that Titanium Nitride (TiN) is an excellent alternative to replace metal in a MIMI multilayer stack. Setting this stack as the top capping coating, we obtain a high contrast between forward and backward light transmission where in an ultra-broadband range of 400 nm-1000 nm, forward transmission is above 0.85 while its backward response stays below 0.2. Moreover, due to the existence of multilayer stack, a high asymmetry is also observed for absorption profiles. This design has a relatively simple and large scale compatible fabrication route. © 2017 The Author(s)

    Hybrid plasmon-phonon polariton bands in graphene-hexagonal boron nitride metamaterials [Invited]

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    We theoretically investigate mid-infrared electromagnetic wave propagation in multilayered graphene-hexagonal boron nitride (hBN) metamaterials. Hexagonal boron nitride is a natural hyperbolic material that supports highly dispersive phonon polariton modes in two Reststrahlen bands with different types of hyperbolicity. Due to the hybridization of surface plasmon polaritons of graphene and hyperbolic phonon polaritons of hBN, each isolated unit cell of the graphene-hBN metamaterial supports hybrid plasmon-phonon polaritons (HPPs). Through the investigation of band structure of the metamaterial we find that, due to the coupling between the HPPs supported by each unit cell, the graphene-hBN metamaterial can support HPP bands. The dispersion of these bands can be noticeably modified for different thicknesses of hBN layers, leading to the appearance of bands with considerably flat dispersions. Moreover, analysis of light transmission through the metamaterial reveals that this system is capable of supporting high-k propagating HPPs. This characteristic makes graphene-hBN metamaterials very promising candidates for the modification of the spontaneous emission of a quantum emitter, hyperlensing, negative refraction, and waveguiding. © 2017 Optical Society of America
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