Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and controls

Summary: This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information. Introduction: Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture. Methods: In a nested case-control analysis, we studied 368 women (mean age 76.2 ± 3.2years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS. Results: Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.56-0.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.60-0.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD. Conclusions: Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alon

The average mixing matrix signature

Laplacian-based descriptors, such as the Heat Kernel Signature and the Wave Kernel Signature, allow one to embed the vertices of a graph onto a vectorial space, and have been successfully used to find the optimal matching between a pair of input graphs. While the HKS uses a heat di↵usion process to probe the local structure of a graph, the WKS attempts to do the same through wave propagation. In this paper, we propose an alternative structural descriptor that is based on continuoustime quantum walks. More specifically, we characterise the structure of a graph using its average mixing matrix. The average mixing matrix is a doubly-stochastic matrix that encodes the time-averaged behaviour of a continuous-time quantum walk on the graph. We propose to use the rows of the average mixing matrix for increasing stopping times to develop a novel signature, the Average Mixing Matrix Signature (AMMS). We perform an extensive range of experiments and we show that the proposed signature is robust under structural perturbations of the original graphs and it outperforms both the HKS and WKS when used as a node descriptor in a graph matching task

Association of 1,5-Anhydroglucitol and 2-h Postprandial Blood Glucose in Type 2 Diabetic Patients

OBJECTIVE—To assess the association of 1,5-anhydroglucitol (1,5-AG) with 2-h postprandial glucose values in type 2 diabetic patients followed over 12 months in an outpatient setting

Comparison of serum lipoprotein(a) distribution and its correlates among black and white populations.

BACKGROUND. Epidemiological data on serum lipoprotein(a) (Lp(a)), a presumably strong risk factor for coronary artery disease in White populations, has mostly been derived, in Black populations, from small samples. This study compares the distribution and the determinants of serum Lp(a) in Blacks and in Whites using large representative samples and the same methods in both populations. METHODS. The distribution and the correlates of serum Lp(a) were investigated in population-based samples of 701 Blacks in the Seychelles and 634 Whites in Switzerland, aged 25-64 years. Serum Lp(a) was quantified using a commercial immunoradiometric assay. RESULTS. The distribution of serum Lp(a) was similarly skewed in both ethnic groups, but median Lp(a) concentration was about twofold higher in Blacks (210 mg/l) compared to Whites (100 mg/l). The proportions of individuals with elevated serum Lp(a) (> 300 mg/l) was about 50% higher in Blacks (37.5%) than in Whites (25.2%). In both ethnic groups, serum Lp(a) was found to correlate with total cholesterol, LDL-cholesterol and apoprotein B but not with HDL-cholesterol, alcohol intake, smoking, and body mass index. The variance in serum Lp(a) concentration explained by any combination of these factors was smaller than 5.3% in the two populations. CONCLUSIONS. The measured factors did not explain the higher levels of serum Lp(a) found in Blacks compared to Whites. These findings are consistent with the hypothesis that genetic factors account for much of the variation of serum Lp(a) in both populations

Degradation mechanism analysis in temperature stress tests on III-V ultra-high concentrator solar cells using a 3D distributed model

A temperature stress test was carried out on GaAs single-junction solar cells to analyze the degradation suffered when working at ultra-high concentrations. The acceleration of the degradation was realized at two different temperatures: 130 °C and 150 °C. In both cases, the degradation trend was the same, and only gradual failures were observed. A fit of the dark I–V curve at 25 °C with a 3D distributed model before and after the test was done. The fit with the 3D distributed model revealed degradation at the perimeter because the recombination current in the depletion region of the perimeter increased by about fourfold after the temperature stress test. Therefore, this test did not cause any morphological change in the devices, and although the devices were isolated with silicone, the perimeter region was revealed as the most fragile component of the solar cell. Consequently, the current flowing beneath the busbar favors the progression of defects in the device in the perimeter region

A nested alignment graph kernel through the dynamic time warping framework

In this paper, we propose a novel nested alignment graph kernel drawing on depth-based complexity traces and the dynamic time warping framework. Specifically, for a pair of graphs, we commence by computing the depth-based complexity traces rooted at the centroid vertices. The resulting kernel for the graphs is defined by measuring the global alignment kernel, which is developed through the dynamic time warping framework, between the complexity traces. We show that the proposed kernel simultaneously considers the local and global graph characteristics in terms of the complexity traces, but also provides richer statistic measures by incorporating the whole spectrum of alignment costs between these traces. Our experiments demonstrate the effectiveness and efficiency of the proposed kernel

Entropic graph embedding via multivariate degree distributions

Although there are many existing alternative methods for using structural characterizations of undirected graphs for embedding, clustering and classification problems, there is relatively little literature aimed at dealing with such problems for directed graphs. In this paper we present a novel method for characterizing graph structure that can be used to embed directed graphs into a feature space. The method commences from a characterization based on the distribution of the von Neumann entropy of a directed graph with the in and out-degree configurations associated with directed edges. We start from a recently developed expression for the von Neumann entropy of a directed graph, which depends on vertex in-degree and out-degree statistics, and thus obtain a multivariate edge-based distribution of entropy. We show how this distribution can be encoded as a multi-dimensional histogram, which captures the structure of a directed graph and reflects its complexity. By performing principal components analysis on a sample of histograms, we embed populations of directed graphs into a low dimensional space. Finally, we undertake experiments on both artificial and real-world data to demonstrate that our directed graph embedding method is effective in distinguishing different types of directed graphs

Coherent radar reflections from an electron-beam induced particle cascade

Experiment T-576 ran at SLAC in 2018, in development of a new radar-based detection scheme for ultra-high energy neutrinos. In this experiment, the electron beam (N∼109e− at ∼10 GeV) was directed into a plastic target to simulate a 1019 eV neutrino-induced shower in ice. This shower was interrogated with radio frequency (RF) radiation, in an attempt to measure a radar-like reflection from the ionization produced in the target during the particle shower. This technique could be employed to detect the rare interactions of ultra-high-energy neutrinos in dense material, such as polar ice sheets, extending the extant energy range of detected neutrinos up to EeV and beyond. In this proceeding, we detail the experiment and present results from the analysis and the observation of a signal consistent with a radar signal

First LIGO search for gravitational wave bursts from cosmic (super)strings

We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR