Magnetic-Field Dependence of Tunnel Couplings in Carbon Nanotube Quantum Dots

By means of sequential and cotunneling spectroscopy, we study the tunnel couplings between metallic leads and individual levels in a carbon nanotube quantum dot. The levels are ordered in shells consisting of two doublets with strong- and weak-tunnel couplings, leading to gate-dependent level renormalization. By comparison to a one- and two-shell model, this is shown to be a consequence of disorder-induced valley mixing in the nanotube. Moreover, a parallel magnetic field is shown to reduce this mixing and thus suppress the effects of tunnel renormalization.Comment: 5 pages, 3 figures; revised version as publishe

Spin-orbit interaction and asymmetry effects on Kondo ridges at finite magnetic field

We study electron transport through a serial double quantum dot with Rashba spin-orbit interaction (SOI) and Zeeman field of amplitude B in presence of local Coulomb repulsion. The linear conductance as a function of a gate voltage Vg equally shifting the levels on both dots shows two B=0 Kondo ridges which are robust against SOI as time-reversal symmetry is preserved. Resulting from the crossing of a spin-up and a spin-down level at vanishing SOI two additional Kondo plateaus appear at finite B. They are not protected by symmetry and rapidly vanish if the SOI is turned on. Left-right asymmetric level-lead couplings and detuned on-site energies lead to a simultaneous breaking of left-right and bonding-anti-bonding state symmetry. In this case the finite-B Kondo ridges in the Vg-B plane are bent with respect to the Vg-axis. For the Kondo ridge to develop different level renormalizations must be compensated by adjusting B.Comment: 8 pages, 5 figures, revised version as publishe

Comparison of Biomarkers in Blood and Saliva in Healthy Adults

Researchers measure biomarkers as a reflection of patient health status or intervention outcomes. While blood is generally regarded as the best body fluid for evaluation of systemic processes, substitution of saliva samples for blood would be less invasive and more convenient. The concentration of specific biomarkers may differ between blood and saliva. The objective of this study was to compare multiple biomarkers (27 cytokines) in plasma samples, passive drool saliva samples, and filter paper saliva samples in 50 healthy adults. Demographic data and three samples were obtained from each subject: saliva collected on filter paper over 1 minute, saliva collected by passive drool over 30 seconds, and venous blood (3 mL) collected by venipuncture. Cytokines were assayed using Bio-Rad multiplex suspension array technology. Descriptive statistics and pairwise correlations were used for data analysis. The sample was 52% male and 74% white. Mean age was 26 (range = 19–63 years, sd = 9.7). The most consistent and highest correlations were between the passive drool and filter paper saliva samples, although relationships were dependent on the specific biomarker. Correlations were not robust enough to support substitution of one collection method for another. There was little correlation between the plasma and passive drool saliva samples. Caution should be used in substituting saliva for blood, and relationships differ by biomarker

Interplay of Coulomb interaction and spin-orbit effects in multi-level quantum dots

We study electron transport through a multi-level quantum dot with Rashba spin-orbit interaction in the presence of local Coulomb repulsion. Motivated by recent experiments, we compute the level splitting induced by the spin-orbit interaction at finite Zeeman fields $B$, which provides a measure of the renormalized spin-orbit energy. This level splitting is responsible for the suppression of the Kondo ridges at finite $B$ characteristic for the multi-level structure. In addition, the dependence of renormalized $g$-factors on the relative orientation of the applied $B$ field and the spin-orbit direction following two different protocols used in experiments is investigated.Comment: 11 pages, 13 figure

Hepatitis C screening practices in primary care

An estimated 2.7-4 million people in the United States have been infected with the hepatitis C virus (HCV), of those, about 3.2 million have current HCV infections. However, 45-85% of people infected do not know they have HCV. Chronic HCV infection can lead to cirrhosis, liver failure, and hepatocellular carcinoma. The purpose of this project was to increase HCV screening rates in a primary care clinic among the birth cohort

A Hybrid Approach to General Information Extraction

Information Extraction (IE) is the process of analyzing documents and identifying desired pieces of information within them. Many IE systems have been developed over the last couple of decades, but there is still room for improvement as IE remains an open problem for researchers. This work discusses the development of a hybrid IE system that attempts to combine the strengths of rule-based and statistical IE systems while avoiding their unique pitfalls in order to achieve high performance for any type of information on any type of document. Test results show that this system operates competitively in cases where target information belongs to a highly-structured data type and when critical contextual information is in close proximity to the target

Going With the Flow: Movement of Large Wood in a Flashy Urban Headstream

By Jayla Brown, Biological Sciences - Animal Biology; Peter Grap, University of Cincinnati Advisor: Michael Booth Presentation ID: 142 Abstract: Pieces of large wood in streams create crucial habitat features, slowing water velocity and encouraging the development of deeper, more connected pools. These stream characteristics create better habitats for aquatic life inhabiting the ecosystem. If wood moves frequently, these structural benefits cannot develop. The purpose of this project was to analyze the movement of large woody debris in Cooper Creek-a stream running through Bechtold Park in Sycamore Township, Ohio. Through this project we hoped to discover how stability and structural characteristics of wood impact their mobility. The large woody debris in the stream was mapped to the nearest meter, characterized with categories pertaining to size, alignment, stability, and individually marked using passive integrated transponders for identification purposes. After each storm event, we relocated each individual piece of wood and characterized any movements or changes. Streamflow was measured using an electromagnetic flow meter and continuously recording water level loggers to track the magnitude of storm related flows. By tracking the movements- or lack thereof - of pieces of wood, we were able to associate characteristics with the tendency to move. Pieces secured by other pieces of a larger jam or wedged behind standing trees were stable, while pieces freely sitting in the stream or within the water surface moved. There was not a relationship between structure and movement. We couldn\u27t evaluate a relationship between discharge of storm events and movement due to the limited number of storm events. This project will provide helpful insight for improving habitat in urban headwater streams.&nbsp

Evaluating and monitoring analgesia and sedation in the intensive care unit

Management of analgesia and sedation in the intensive care unit requires evaluation and monitoring of key parameters in order to detect and quantify pain and agitation, and to quantify sedation. The routine use of subjective scales for pain, agitation, and sedation promotes more effective management, including patient-focused titration of medications to specific end-points. The need for frequent measurement reflects the dynamic nature of pain, agitation, and sedation, which change constantly in critically ill patients. Further, close monitoring promotes repeated evaluation of response to therapy, thus helping to avoid over-sedation and to eliminate pain and agitation. Pain assessment tools include self-report (often using a numeric pain scale) for communicative patients and pain scales that incorporate observed behaviors and physiologic measures for noncommunicative patients. Some of these tools have undergone validity testing but more work is needed. Sedation-agitation scales can be used to identify and quantify agitation, and to grade the depth of sedation. Some scales incorporate a step-wise assessment of response to increasingly noxious stimuli and a brief assessment of cognition to define levels of consciousness; these tools can often be quickly performed and easily recalled. Many of the sedation-agitation scales have been extensively tested for inter-rater reliability and validated against a variety of parameters. Objective measurement of indicators of consciousness and brain function, such as with processed electroencephalography signals, holds considerable promise, but has not achieved widespread implementation. Further clarification of the roles of these tools, particularly within the context of patient safety, is needed, as is further technology development to eliminate artifacts and investigation to demonstrate added value