Transport Through Andreev Bound States in a Graphene Quantum Dot

Andreev reflection-where an electron in a normal metal backscatters off a superconductor into a hole-forms the basis of low energy transport through superconducting junctions. Andreev reflection in confined regions gives rise to discrete Andreev bound states (ABS), which can carry a supercurrent and have recently been proposed as the basis of qubits [1-3]. Although signatures of Andreev reflection and bound states in conductance have been widely reported [4], it has been difficult to directly probe individual ABS. Here, we report transport measurements of sharp, gate-tunable ABS formed in a superconductor-quantum dot (QD)-normal system, which incorporates graphene. The QD exists in the graphene under the superconducting contact, due to a work-function mismatch [5, 6]. The ABS form when the discrete QD levels are proximity coupled to the superconducting contact. Due to the low density of states of graphene and the sensitivity of the QD levels to an applied gate voltage, the ABS spectra are narrow, can be tuned to zero energy via gate voltage, and show a striking pattern in transport measurements.Comment: 25 Pages, included SO

Use of zinc deposited in deciduous teeth as a retrospective measurement of dietary zinc exposure during early development

Purpose: We proposed that zinc (Zn) deposition in deciduous teeth would be a timed record of exposure to this essential micronutrient over very early life. We tested this hypothesis by gathering information on the maternal and child's diet during pregnancy and early infancy and measuring mineral deposition in the dentine at points during deciduous tooth development.Methods: We developed a short food frequency questionnaire (S-FFQ) to record consumption of food containing Zn during pregnancy and over the first year of life of the child in an Indonesian population. Zn, Sr and Ca were measured by laser ablation ICP-MS in a series of points across the developmental timeline in deciduous teeth extracted from 18 children undergoing the process as part of dental treatment whose mothers completed the SFFQ. Mothers and children were classified into either high Zn or low Zn groups according to calculated daily Zn intake.Results: The Zn/Sr ratio in dentine deposited over late pregnancy and 0–3 months post-partum was higher (p < 0.001, 2-way ANOVA; p < 0.05 by Holm-Sidak post hoc test) in the teeth of children of mothers classified as high Zn consumers (n = 10) than in children of mothers classified as low Zn consumers (n = 8).Conclusion: The S-FFQ was validated internally as adequately accurate to measure zinc intake retrospectively during pregnancy and post-partum (∼7 years prior) by virtue of the correlation with measurements of zinc in deciduous teeth. The ratio of Zn/Sr in deciduous teeth appears to be a biomarker of exposure to zinc nutrition during early development and offers promise for use as a record of prior exposure along a timeline for research studies and, potentially, to identify individuals at heightened risk of detrimental impacts of poor early life zinc nutrition on health in later life and to implement preventative interventions

Use of zinc deposited in deciduous teeth as a retrospective measurement of dietary zinc exposure during early development

Purpose: We proposed that zinc (Zn) deposition in deciduous teeth would be a timed record of exposure to this essential micronutrient over very early life. We tested this hypothesis by gathering information on the maternal and child's diet during pregnancy and early infancy and measuring mineral deposition in the dentine at points during deciduous tooth development.Methods: We developed a short food frequency questionnaire (S-FFQ) to record consumption of food containing Zn during pregnancy and over the first year of life of the child in an Indonesian population. Zn, Sr and Ca were measured by laser ablation ICP-MS in a series of points across the developmental timeline in deciduous teeth extracted from 18 children undergoing the process as part of dental treatment whose mothers completed the SFFQ. Mothers and children were classified into either high Zn or low Zn groups according to calculated daily Zn intake.Results: The Zn/Sr ratio in dentine deposited over late pregnancy and 0–3 months post-partum was higher (p < 0.001, 2-way ANOVA; p < 0.05 by Holm-Sidak post hoc test) in the teeth of children of mothers classified as high Zn consumers (n = 10) than in children of mothers classified as low Zn consumers (n = 8).Conclusion: The S-FFQ was validated internally as adequately accurate to measure zinc intake retrospectively during pregnancy and post-partum (∼7 years prior) by virtue of the correlation with measurements of zinc in deciduous teeth. The ratio of Zn/Sr in deciduous teeth appears to be a biomarker of exposure to zinc nutrition during early development and offers promise for use as a record of prior exposure along a timeline for research studies and, potentially, to identify individuals at heightened risk of detrimental impacts of poor early life zinc nutrition on health in later life and to implement preventative interventions

Self-energy-part resummed quark and gluon propagators in a spin-polarized quark matter and generalized Boltzmann equations

We construct perturbative frameworks for studying nonequilibrium spin-polarized quark matter. We employ the closed-time-path formalism and use the gradient approximation in the derivative expansion. After constructing self-energy-part resummed quark and gluon propagators, we formulate two kind of mutually equivalent perturbative frameworks: The first one is formulated on the basis of the initial-particle distribution function, and the second one is formulated on the basis of `` physical''-particle distribution function. In the course of construction of the second framework, the generalized Boltzmann equations and their relatives {\em directly} come out, which describe the evolution of the system. The frameworks are relevant to the study of a magnetic character of quark matters, e.g., possible quark stars.Comment: 57 page

Utopian Archives, Decolonial Affordances: Introduction to Special Issue

Colonial archives constituted a technology that enabled the collection, storage, ordering, retrieval and exchange of knowledge as an instrument of colonial governance. It is not surprising that when such archives were inherited by independent nation-states they were not given the authority previously granted them and have often been neglected. What, then, is the future of colonial archives in postcolonial nations? How should we rethink these archives in relation to decolonial futures? This essay introduces a collection of articles that explore the repertoires of action latent in archives and how colonial archives are being reconfigured to imagine decolonial futures

Crohn's disease activity index and Vienna classification - Is it worthwhile to calculate before surgery?

Background: Crohn's disease (CD) patients with increased disease activity may reveal an increased risk for perioperative complications. The `Crohn's disease activity index' (CDAI) and the `Vienna classification' (VC) were developed for standardized disease activity estimations. The significance of these scores to predict extent, type and early outcome of surgery in CD patients was analyzed. Methods: In 179 surgically treated CD patients, the CDAI and VC were assessed from a prospective database. Relations of the scores with CD risk factors, type, number, location and complications of surgery were analyzed. Results: VC behavior and location subtypes were associated with distinct types of surgery (i.e. `strictureplasty' in `stricturing disease', `colon surgery' in `colon involvement'), but not with surgery type and extent or outcome. Surgery extent (i.e. with 5 vs. 3 `surgical sites' 425 +/- 25 vs. 223.3 +/- 25) and complications (357.1 +/- 36.9 (with) vs. 244.4 +/- 13 (without)) were associated with elevated CDAI levels; however, nicotine abuse remained the only significant risk factor for perioperative complications after multiple logistic regression. Conclusion: The significance of VC or CDAI for predicting the extent of surgery or complications is limited. None of the tested variables except preoperative nicotine abuse influenced the likelihood for perioperative complications. Copyright (c) 2006 S. Karger AG, Base

Fort Lewis electric energy baseline and efficiency resource assessment

In support of the US DOE Federal Energy Management Program, the Pacific Northwest Laboratory is developing a fuel-neutral approach for identifying, evaluating, and acquiring all cost-effective energy projects at federal installations. Fort Lewis, a US Army installation near Tacoma, Washington, was selected as the pilot site for developing this approach. This site was chosen in conjunction with the interests of the Bonneville Power Administration to develop programs for its federal sector customers and the Army Forces Command to develop an in-house program to upgrade the energy efficiency of its installations. This report documents the electricity assessment portion of the approach, providing an estimate of the electricity use baseline and efficiency improvement potential for major sectors and end uses at the Fort. Although the assessment did not identify all possible efficiency improvement opportunities, it is estimated that electricity use can be reduced by at least 20% cost-effectively at the $0.045/kWh marginal cost of electricity in the Pacific Northwest. 12 refs., 3 figs., 7 tabs

Fort Lewis electric energy baseline and efficiency resource assessment

The mission of the US Department of Energy (DOE) Federal Energy Management Program (FEMP) is to lead the improvement of energy efficiency and fuel flexibility within the federal sector. Through Pacific Northwest Laboratory, FEMP is developing a fuel-neutral approach for identifying, evaluating, and acquiring all cost-effective energy projects at federal installations. In this report, we describe PNL's assessment of the electric energy efficiency resource potential at Fort Lewis (near Tacoma, WA). Through this assessment, we developed an estimate of the electricity use baseline and efficiency improvement potential for major sectors and end uses at the Fort. Developing the baseline was essential to segment the end uses that are targets for broad-based efficiency improvement programs and to provide TPU with the basis for its proposal to Bonneville. An estimate of the efficiency resource is presented to reflect the available quantity of resource for three electricity price ranges. The baseline and efficiency resource estimates did not identify all possible areas of opportunity, but instead identified the majority of the resource; areas of additional opportunity are noted, to encourage further effort. 2 figs., 2 tabs