125 research outputs found
Investigation of local breakdown of the Quantum Hall effect in graphene probed with invasive metal contacts:
No full textWe investigate the local breakdown of the Quantum Hall Effect (QHE) effect in a graphene device caused by the constraints of the Hall bar geometry and finite size of the sample. First to account for principal features of the data we use a multi-carrier model that simulates the transverse and longitudinal resistance of doped samples in low magnetic fields. This model however can not reproduce the reduction of Hall voltage measured in the vicinity of the current leads. Therefore we introduce a second model which describes the effect of distribution of electric field in the device, giving a reasonable scenario that can explain our experimental data and deviations from the case of perfect geometry. We conclude that the existence of Hot Spots in two corners of the sample leads to the local break down of the QHE around this points.M.S.Includes bibliographical references (p. 65-68)by Fabian Duer
Editor\u27s Introduction
No full textThe author reflects on the issues presented at the Conflict Resolution Quarterly (CRQ) which includes the work of organizational ombudsman, court mediators, mediation trainers, and peace accords. She focuses on the role of mediators and their impact on future court regarding self-selection bias and mediation programs. She presents the details based on the researches by Landon Hancock, Joshua Weiss, and Glen Duerr in regards with mediation for conflict management and justice administration
Ulcerative colitis–risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study
No full textRichard Duerr and colleagues present a genome-wide association study of ulcerative colitis. They identify new risk loci on chromosomes 1p36 and 12q15
Book Review: Cultural Contestation in Ethnic Conflict
No full textReviews the book, Cultural contestation in ethnic conflict by Marc Howard Ross (2007). In his attempt to bring greater definitional use to the term culture, the author takes a broad approach with chapters on Northern Ireland, Catalonia, Israel, France, South Africa, and the American South. Abroad approach may serve to facilitate an understanding of what culture is and how it moves. Despite his impressive attempt to grapple with multiple identities, as the French headscarves case illuminates, it does not fully explain why Breuillyan sense of power is the dominant force within a state. Sport, however, is merely a tool within Ross’s psychocultural framework that he applies to the arguments throughout the book with the purpose of bridging incompatible identities and addressing basic threats. Conflict mitigation, with requisite attention to psychocultural narratives, may be advanced in this manner. Emphasis on psychological explanations for solving conflict, both timid and fissiparous, has become increasingly en vogue in recent times. This trend has occurred for good reason given the attention paid to symbolism, political entrepreneurs, and historical grievances and threats of group extinction. The author should be applauded for melding numerous and diverse cases into one succinct account
Experimental and finite element studies of pin plate behavior
No full textCurrent procedures commonly in use for the design of pinned connections are based on limited research and investigation results which have been reported in the literature over the years. The structural specifications, such as AISC and AASHTO, provide empirical design formulas and/or proportion requirements for pin plates which are valid for basic rectangular link plates, but are of questionable suitability when applied to the many non-rectangular shapes encountered in practice, e.g., asymmetrical lifting eyes. This thesis presents the results of a three-phase investigation of the behavior of pin plates under static loading. The first phase presents a summary of major theoretical and experimental work conducted by previous investigators. Methods of calculating elastic stresses and ultimate loads are presented, and comparisons of the various formulas are made. The second phase reports the results of new pin plate tests conducted by the author. Asymmetrical shapes, large pin-to-hole clearances, and high strength steels are all addressed in these tests. In the third phase, the finite element computer program ANSYS is used to analyze two of the specimens from the test program. Correlations to test measurements and previous work are used to verify the accuracy of the model. The findings of the three phases are brought together in the final chapters. Particular attention is paid to the present and proposed methods of pin plate design contained in the AISC Specification. Conclusions are drawn where appropriate, and recommendations for additional research are presented in the last chapter.Civil and Environmental Engineering, Department o
Evolution equations for multi-time wavefunctions
No full textMulti-time wavefunctions are of particular interest in relativistic quantum mechanics. A multitime wavefunction has separate time-variables for each particle; this makes it a manifestly Lorentz-invariant object. The time-evolution equations are systems of Schroedinger equations; one for each particle's time variable and each with a certain Hamiltonian. We derive conditions under which these systems of equations have a common solution. Also, we derive three main results about concrete multi-time models. First we show that a model proposed by Duerr and Tumulka in 2001 is inconsistent. The second result is a consistent model for a constant number of particles with a cutoff pair potential. The third result is a consistent theory for a simple quantum field theoretic model with creation and annihilation of particles. Existence and uniqueness of solutions is proven for both models.M.S.Includes bibliographical referencesIncludes vitaby Sören Philipp Petra
Exploiting knowledge of immune selection in HIV-1 to detect HIV-specific CD8 T-cell responses
No full textSince HLA-restricted cytotoxic T-cell responses select specific polymorphisms in HIV-1 sequences and HLA diversity is relatively static in human populations, we investigated the use of peptide epitopes based on sites of HLA-associated adaptation in HIV-1 sequences to stimulate and detect T-cell responses ex vivo. These "HLA-optimised" peptides captured more HIV-1 Nef-specific responses compared with overlapping peptides of a single consensus sequence, in interferon-γ enzyme linked immunospot assays. Sites of immune selection can reveal more immunogenic epitopes in HLA-diverse populations and offer insights into the nature of HLA-epitope targeting, which could be applied in vaccine design
Infect Dis Obstet Gynecol
No full textSpecific morphotypic profiles of normal and abnormal vaginal flora, including bacterial vaginosis (BV), were characterized. A prospective study of 350 women yielded concurrent Gram-stain data and clinical assessment (n = 3455 visits). Microbiological profiles were constructed by Gram stain. Eight profile definitions were based on dichotomizing the levels of Lactobacillus, Gardnerella, and curved, Gram-negative bacillus (Mobiluncus) morphotypes. Of these, two were rare, and the other six demonstrated a graded association with the clinical components of BV. The proposed profiles from the Gram stain reflect the morphotypic categories describing vaginal flora that may enable clearer elucidation of gynecologic and obstetric outcomes in various populations.2004772
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