8,411 research outputs found
An FPGA-based infant monitoring system
We have designed an automated visual surveillance system for monitoring sleeping infants. The low-level image
processing is implemented on an embedded Xilinx’s Virtex
II XC2v6000 FPGA and quantifies the level of scene activity using a specially designed background subtraction algorithm. We present our algorithm and show how we have
optimised it for this platform
A Magnetic Bead-Based Sensor for the Quantification of Multiple Prostate Cancer Biomarkers.
Novel biomarker assays and upgraded analytical tools are urgently needed to accurately discriminate benign prostatic hypertrophy (BPH) from prostate cancer (CaP). To address this unmet clinical need, we report a piezeoelectric/magnetic bead-based assay to quantitate prostate specific antigen (PSA; free and total), prostatic acid phosphatase, carbonic anhydrase 1 (CA1), osteonectin, IL-6 soluble receptor (IL-6sr), and spondin-2. We used the sensor to measure these seven proteins in serum samples from 120 benign prostate hypertrophy patients and 100 Gleason score 6 and 7 CaP using serum samples previously collected and banked. The results were analyzed with receiver operator characteristic curve analysis. There were significant differences between BPH and CaP patients in the PSA, CA1, and spondin-2 assays. The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6). Some of these data seem to contradict previous reports and highlight the importance of sample selection and proper assay building in the development of biomarker measurement schemes. This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair
Predictability of Critical Transitions
Critical transitions in multistable systems have been discussed as models for
a variety of phenomena ranging from the extinctions of species to
socio-economic changes and climate transitions between ice-ages and warm-ages.
From bifurcation theory we can expect certain critical transitions to be
preceded by a decreased recovery from external perturbations. The consequences
of this critical slowing down have been observed as an increase in variance and
autocorrelation prior to the transition. However especially in the presence of
noise it is not clear, whether these changes in observation variables are
statistically relevant such that they could be used as indicators for critical
transitions. In this contribution we investigate the predictability of critical
transitions in conceptual models. We study the quadratic integrate-and-fire
model and the van der Pol model, under the influence of external noise. We
focus especially on the statistical analysis of the success of predictions and
the overall predictability of the system. The performance of different
indicator variables turns out to be dependent on the specific model under study
and the conditions of accessing it. Furthermore, we study the influence of the
magnitude of transitions on the predictive performance
Real-time kinetics and high-resolution melt curves in single-molecule digital LAMP to differentiate and study specific and non-specific amplification
Isothermal amplification assays, such as loop-mediated isothermal amplification (LAMP), show great utility for the development of rapid diagnostics for infectious diseases because they have high sensitivity, pathogen-specificity and potential for implementation at the point of care. However, elimination of non-specific amplification remains a key challenge for the optimization of LAMP assays. Here, using chlamydia DNA as a clinically relevant target and high-throughput sequencing as an analytical tool, we investigate a potential mechanism of non-specific amplification. We then develop a real-time digital LAMP (dLAMP) with high-resolution melting temperature (HRM) analysis and use this single-molecule approach to analyze approximately 1.2 million amplification events. We show that single-molecule HRM provides insight into specific and non-specific amplification in LAMP that are difficult to deduce from bulk measurements. We use real-time dLAMP with HRM to evaluate differences between polymerase enzymes, the impact of assay parameters (e.g. time, rate or florescence intensity), and the effect background human DNA. By differentiating true and false positives, HRM enables determination of the optimal assay and analysis parameters that leads to the lowest limit of detection (LOD) in a digital isothermal amplification assay
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