2,100 research outputs found

    \u3cem\u3eUnited States v. The William\u3c/em\u3e and The Phenomena of Jury Nullification in Early 19th Century America

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    In September 1808, Judge John Davis upheld the constitutionality of the Embargo Act of 1807 under the Constitution’s Article I, Section 8, Clause 3 Interstate Commerce power. Judge Davis’s original opinion curiously lacks any reference to Marbury v. Madison. Judge Davis defends judicial review and rejects the notion of jury nullification. While Judge Davis upheld the embargo’s constitutionality, a subsequent jury trial on the facts resulted in the return of The William to its rightful owners. This case reflects the attempts by early American judges to carve out the power of judicial review and maintain the appearance of an impartial judiciary

    The Symmetries of Nature

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    The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of symmetries during the last century has produced many breakthroughs in our understanding of the substructure of matter. In this talk, a number of these advances are discussed, and the important role that George Sudarshan played in their development is emphasize

    La siempre cambiante contextualización de la naturaleza de la ciencia : documentos recientes sobre la reforma de la educación científica en los Estados Unidos y su impacto en el logro de la alfabetización científica

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    Diversos autores han manifestado una gran preocupación por la marginalización de la naturaleza de la ciencia (NDC) en los Next Generation Science Standards (NGSS). Sin embargo, un análisis conceptual cuidadoso de cómo se trata la NDC en los NGSS, en comparación con los documentos de reforma curricular previos en los Estados Unidos, revela una situación compleja de cómo se contextualiza la NDC y de las suposiciones correspondientes a cómo esta se enseña y aprende mejor. Una perspectiva histórica de cómo surge la NDC como un componente educativo importante se provee antes de discutir el rol de la NDC en los NGSS y en documentos de reforma previos.Many have expressed concerns over the marginalization of nature of science (NOS) in the Next Generation Science Standards (NGSS). However, a careful conceptual analysis of how the NGSS addresses NOS relative to previous U.S. reform documents reveals a complex situation related to how NOS is contextualized and apparent assumptions about how NOS is best taught and learned. A historical perspective of the emergence of NOS as an important educational outcome is provided before discussing the role of NOS in the NGSS and in previous reform documents

    An investigation into the feasibility of myoglobin-based single-electron transistors

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    Myoglobin single-electron transistors were investigated using nanometer- gap platinum electrodes fabricated by electromigration at cryogenic temperatures. Apomyoglobin (myoglobin without heme group) was used as a reference. The results suggest single electron transport is mediated by resonant tunneling with the electronic and vibrational levels of the heme group in a single protein. They also represent a proof-of-principle that proteins with redox centers across nanometer-gap electrodes can be utilized to fabricate single-electron transistors. The protein orientation and conformation may significantly affect the conductance of these devices. Future improvements in device reproducibility and yield will require control of these factors

    Ferrimagnetism of dilute Ising antiferromagnets

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    It is shown that nearest-neighbor antiferromagnetic interactions of identical Ising spins on imbalanced bipartite lattice and imbalanced bipartite hierarchical fractal result in ferrimagnetic order instead of antiferromagnetic one. On some crystal lattices dilute Ising antiferromagnets may also become ferrimagnets due to the imbalanced nature of the magnetic percolation cluster when it coexists with the percolation cluster of vacancies. As evidenced by the existing experiments on FepZn1pF2Fe_pZn_{1-p}F_2, such ferrimagnetism is inherent property of bcc lattice so thermodynamics of these compounds at low pp can be similar to that of antiferromagnet on imbalanced hierarchical fractal.Comment: 6 pages, 4 figure

    Nonlocal mixing of supercurrents in Josephson ballistic point contact

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    We study coherent current states in the mesoscopic superconducting weak link simultaneously subjected to the order parameter phase difference on the contact and to the tangential to the junction interface superfluid velocity in the banks. The Josephson current-phase relation controlled by the external transport current is obtained. At phase difference close to pi the nonlocal nature of the Josephson phase-dependent current results in the appearance of two vortexlike states in the vicinity of the contact.Comment: 4 pages, 6 figures; to be published in Phys. Rev. B; e-mail: [email protected]

    Extraction of the Spin Glass Correlation Length

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    The peak of the spin glass relaxation rate, S(t)=d{-M_{TRM}(t,t_w)}/H/{d ln t}, is directly related to the typical value of the free energy barrier which can be explored over experimental time scales. A change in magnetic field H generates an energy E_z={N_s}{X_fc}{H^2} by which the barrier heights are reduced, where X_{fc} is the field cooled susceptibility per spin, and N_s is the number of correlated spins. The shift of the peak of S(t) gives E_z, generating the correlation length, Ksi(t,T), for Cu:Mn 6at.% and CdCr_{1.7}In_{0.3}S_4. Fits to power law dynamics, Ksi(t,T)\propto {t}^{\alpha(T)} and activated dynamics Ksi(t,T) \propto {ln t}^{1/psi} compare well with simulation fits, but possess too small a prefactor for activated dynamics.Comment: 4 pages, 4 figures. Department of Physics, University of California, Riverside, California, and Service de Physique de l'Etat Condense, CEA Saclay, Gif sur Yvette, France. To appear in Phys. Rev. Lett. January 4, 199

    HIV infection is associated with elevated biomarkers of immune activation in Ugandan adults with pneumonia.

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    IntroductionPneumonia is an important cause of morbidity and mortality in persons living with human immunodeficiency virus (HIV) infection. How immune activation differs among HIV-infected and HIV-uninfected adults with pneumonia is unknown.MethodsThe Inflammation, Aging, Microbes, and Obstructive Lung Disease (I AM OLD) Cohort is a prospective cohort of adults with pneumonia in Uganda. In this cross-sectional analysis, plasma was collected at pneumonia presentation to measure the following 12 biomarkers: interleukin 6 (IL-6), soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1 and sTNFR-2), high sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer, soluble CD27 (sCD27), interferon gamma-inducible protein 10 (IP-10), soluble CD14 (sCD14), soluble CD163 (sCD163), hyaluronan, and intestinal fatty acid binding protein. We asked whether biomarker levels differed between HIV-infected and HIV-uninfected participants, and whether higher levels of these biomarkers were associated with mortality.ResultsOne hundred seventy-three participants were enrolled. Fifty-three percent were HIV-infected. Eight plasma biomarkers-sTNFR-1, sTNFR-2, hsCRP, D-dimer, sCD27, IP-10, sCD14, and hyaluronan-were higher among participants with HIV infection, after adjustment for pneumonia severity. Higher levels of 8 biomarkers-IL-6, sTNFR-1, sTNFR-2, hsCRP, IP-10, sCD14, sCD163, and hyaluronan-were associated with increased 2-month mortality.ConclusionsAs in other clinical contexts, HIV infection is associated with a greater degree of immune activation among Ugandan adults with pneumonia. Some of these are also associated with short-term mortality. Further study is needed to explore whether these biomarkers might predict poor long-term outcomes-such as the development of obstructive lung disease-in patients with HIV who have recovered from pneumonia

    Ordering in a spin glass under applied magnetic field

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    Torque, torque relaxation, and magnetization measurements on a AuFe spin glass sample are reported. The experiments carried out up to 7 T show a transverse irreversibility line in the (H,T) plane up to high applied fields, and a distinct strong longitudinal irreversibility line at lower fields. The data demonstrate for that this type of sample, a Heisenberg spin glass with moderately strong anisotropy, the spin glass ordered state survives under high applied fields in contrast to predictions of certain "droplet" type scaling models. The overall phase diagram closely ressembles those of mean field or chiral models, which both have replica symmetry breaking transitions.Comment: 4 pages, 3 figures, accepted for PR
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