Controlled dephasing of a quantum dot in the Kondo regime

Kondo correlation in a spin polarized quantum dot (QD) results from the dynamical formation of a spin singlet between the dot's net spin and a Kondo cloud of electrons in the leads, leading to enhanced coherent transport through the QD. We demonstrate here significant dephasing of such transport by coupling the QD and its leads to potential fluctuations in a near by 'potential detector'. The qualitative dephasing is similar to that of a QD in the Coulomb Blockade regime in spite of the fact that the mechanism of transport is quite different. A much stronger than expected suppression of coherent transport is measured, suggesting that dephasing is induced mostly in the 'Kondo cloud' of electrons within the leads and not in the QD.Comment: to be published in PR

Caries Prevalence In Maine Based On College Of Dental Medicine (UNE) Findings

Poster presentation outlining a retrospective study conducted in order to better understand the needs of Maine residents and provide the appropriate oral health care in the future. Background and Overview: Dental caries is a progressive, irreversible microbial disease affecting the hard tissues of the tooth. It is the most prevalent chronic disease affecting the human race. Once it occurs, its manifestations persist throughout life even when the lesion is treated. It usually begins soon after the teeth erupt into the oral cavity, thus, it is a post eruptive disease. It affects people of both genders, all races, all ages, and all socio- economic groups. Currently there is limited research regarding the prevalence of caries in the state of Maine, particularly for the adult population. The presence of caries is a major oral health indicator and further research is needed in this area in order to provide better oral health care, especially in the rural areas. Much of the literature focuses on caries prevalence in children, particularly from a study called the New England Children’s Amalgam Trial. A five year follow-up of this study revealed high risk children continuing to develop new caries even after semiannual dental care. This finding is alarming and it makes one wonder how the adult population is fairing with caries development as well. In order to bridge this gap in the literature and determine a more accurate picture of caries prevalence within the state of Maine, this ongoing retrospective study is designed to analyze and record caries prevalence among the patient population at the UNE Dental Clinic using past patient dental records. The DMFT and DMFS indices are epidemiological tools used to measure and classify caries. These two tools were the focus of the data analysis throughout this study. This initial investigation into the caries prevalence of Maine is only the foundation for future research and more definitive conclusions on the state of Maine’s adult oral health.https://dune.une.edu/cdm_studpost/1002/thumbnail.jp

Estimating Heterogeneous Intra-class Correlation Coefficients in Dyadic Ecological Momentary Assessment

A method is described for estimating and testing predictors for influence on the variance of momentary behaviors in dyadic ecological momentary assessment data. Results show that the method allows intraclass correlations of momentary observations from two members of the same couple to vary by observation-level, individual-level and couple-level predictors

Getting What You Pay For: Children’s Use of Market Norms to Regulate Exchanges

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152678/1/cdev13088.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152678/2/cdev13088_am.pd

Issues in the reporting of epidemiological studies: a survey of recent practice.

OBJECTIVES: To review current practice in the analysis and reporting of epidemiological research and to identify limitations. DESIGN: Examination of articles published in January 2001 that investigated associations between risk factors/exposure variables and disease events/measures in individuals. SETTING: Eligible English language journals including all major epidemiological journals, all major general medical journals, and the two leading journals in cardiovascular disease and cancer. MAIN OUTCOME MEASURE: Each article was evaluated with a standard proforma. RESULTS: We found 73 articles in observational epidemiology; most were either cohort or case-control studies. Most studies looked at cancer and cardiovascular disease, even after we excluded specialty journals. Quantitative exposure variables predominated, which were mostly analysed as ordered categories but with little consistency or explanation regarding choice of categories. Sample selection, participant refusal, and data quality received insufficient attention in many articles. Statistical analyses commonly used odds ratios (38 articles) and hazard/rate ratios (23), with some inconsistent use of terminology. Confidence intervals were reported in most studies (68), though use of P values was less common (38). Few articles explained their choice of confounding variables; many performed subgroup analyses claiming an effect modifier, though interaction tests were rare. Several investigated multiple associations between exposure and outcome, increasing the likelihood of false positive claims. There was evidence of publication bias. CONCLUSIONS: This survey raises concerns regarding inadequacies in the analysis and reporting of epidemiological publications in mainstream journals

Ion-beam modification of fullerene

The response of thin films of fullerene (C60) to energetic ion impact is investigated. The diagnostics employed include Fourier-transform infrared and Raman spectroscopies, cross-sectional transmission electron microscopy, and atomic force microscopy. By combining the information obtained from these diagnostics with that from the dependence of the conductivity on ion dose, it is concluded that each C60 molecule completely disintegrates when hit by an energetic ion. The cross section for the destruction is about 6×10-13 cm2 for irradiation with 620-keV Xe ions. The disintegration occurs when C atoms are knocked out of the molecule either directly by the impinging ion or by an energetic knock-on C atom within the damage cascade. This process is quite different from the Coulomb-explosion mechanism previously proposed in the literature. For very low ion doses

Enhanced transport in transistor by tuning transition-metal oxide electronic states interfaced with diamond

High electron affinity transition-metal oxides (TMOs) have gained a central role in two-dimensional (2D) electronics by enabling unprecedented surface charge doping efficiency in numerous exotic 2D solid-state semiconductors. Among them, diamond-based 2D electronics are entering a new era by using TMOs as surface acceptors instead of previous molecular-like unstable acceptors. Similarly, surface-doped diamond with TMOs has recently yielded record sheet hole concentrations (2 × 1014 cm−2) and launched the quest for its implementation in microelectronic devices. Regrettably, field-effect transistor operation based on this surface doping has been so far disappointing due to fundamental material obstacles such as (i) carrier scattering induced by nonhomogeneous morphology of TMO surface acceptor layer, (ii) stoichiometry changes caused by typical transistor fabrication process, and (iii) carrier transport loss due to electronic band energy misalignment. This work proposes and demonstrates a general strategy that synergistically surmounts these three barriers by developing an atomic layer deposition of a hydrogenated MoO3 layer as a novel efficient surface charge acceptor for transistors. It shows high surface uniformity, enhanced immunity to harsh fabrication conditions, and benefits from tunable electronic gap states for improving carrier transfer at interfaces. These breakthroughs permit crucial integration of TMO surface doping into transistor fabrication flows and allow outperforming electronic devices to be reached