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In this paper, we present a statistical model of an indirect path generated in an ultra-wideband (UWB) human tracking scenario. When performing moving target detection, an indirect path signal can generate ghost targets that may cause a false alarm. For this purpose, we performed radar measurements in an indoor environment and established a statistical model of an indirect path based on the measurement data. The proposed model takes the form of a modified Saleh--Valenzuela model, which is used in a UWB channel model. An application example of the proposed model for mitigating false alarms is also presented. [ABSTRACT FROM AUTHOR]

Purpose: Anorexia is a common symptom in terminal cancer patients. Some data have suggested a role of visfatin in regulating feeding behavior. We studied the relationship of a serum visfatin level and anorexia in cancer patients provided with hospice care. Methods: After informed consent was obtained, 69 cancer patients over 20 years old at a hospice center were enrolled in the study from July 2009 to July 2010. We characterized patients by age, sex, body mass index, primary cancer site, and Eastern Cooperative Oncology Group (ECOG) performance status, etc. Also, blood tests were performed to measure the level of hemoglobin, white blood cell (WBC), C-reactive protein (CRP), total cholesterol, albumin, lymphocyte count, glucose, blood urea nitrogen (BUN), creatinine, tumor necrosis factor-alpha (TNF-α), interukin-6, leptin and visfatin. Results: The mean age of subjects was 65.5 years old, According to univariate analysis, pulse, ECOG performance scale, opioid use and visfatin level were different between the anorexia and non-anorexic group (P<0.05). The median visfatin level was higher in the anorexia group than the good appetite group (P=0.0323). Serum visfatin concentrations were not related with either body mass index or serum leptin or total cholesterol levels, but it was negatively correlated with serum albumin levels (P=0.0198) and lymphocyte counts (P=0.0013). Conclusion: This study did not identify a novel link between visfatin levels and anorexia in cancer patients at a hospice. [ABSTRACT FROM AUTHOR]

Accurate detection of direct path signal is essential for ranging to the full capabilities of ultra-wideband (UWB) signals. However, the possibility of a large error can be a challenging problem for accurate ranging and positioning. Three different kinds of potential errors encountered in correlation-based time-of-arrival (TOA) estimation are introduced, and an approximate analysis of them is posed. Upper and lower bounding technique is applied to the variance of one of them, namely an early false alarm error. Probability of occurrence of the other two kinds of error is found using the channel statistics, and the mean square of them is evaluated by simulation method. Discussion of the effect of multiple-access schemes on the accuracy of UWB TOA estimation is initiated. [ABSTRACT FROM PUBLISHER]

Signal digitization is a commonly overlooked part of ion mobility-mass spectrometry (IMS-MS) workflows, yet it greatly affects signal-to-noise ratio and MS resolution measurements. Here, we report on the integration of a 2 GS/s, 14-bit ADC with structures for lossless ion manipulations (SLIM-IMS-MS) and compare the performance to a commonly used 8-bit ADC. The 14-bit ADC provided a reduction in the digitized noise by a factor of ~6, owing largely to the use of smaller bit sizes. The low baseline allowed threshold voltage levels to be set very close to the MCP baseline voltage, allowing for as much signal to be acquired as possible without overloading or excessive digitization of MCP baseline noise. Analyses of Agilent tuning mixture ions and a mixture of heavy labeled phosphopeptides showed that the 14-bit ADC provided a ~1.5-2× signal-to-noise (S/N) increase for high intensity ions, such as the Agilent tuning mixture ions and the 2+ and 3+ charge states of many phosphopeptide constituents. However, signal enhancements were as much as 10-fold for low intensity ions, and the 14-bit ADC enabled discernible signal intensities otherwise lost using an 8-bit digitizer. Additionally, the 14-bit ADC required ~14-fold fewer mass spectra to be averaged to produce a mass spectrum with a similar S/N as the 8-bit ADC, demonstrating ~10× higher measurement throughput. The high resolution, low baseline, and fast speed of the new 14-bit ADC enables high performance digitization of MS, IMS-MS, and SLIM-IMS-MS spectra and provides a much better picture of analyte profiles in complex mixtures. [ABSTRACT FROM AUTHOR]

Background: The molecular, biochemical, and genetic mechanisms that regulate the complex metabolic network of soybean seed development determine the ultimate balance of protein, lipid, and carbohydrate stored in the mature seed. Many of the genes and metabolites that participate in seed metabolism are unknown or poorly defined; even more remains to be understood about the regulation of their metabolic networks. A global omics analysis can provide insights into the regulation of seed metabolism, even without a priori assumptions about the structure of these networks. Results: With the future goal of predictive biology in mind, we have combined metabolomics, transcriptomics, and metabolic flux technologies to reveal the global developmental and metabolic networks that determine the structure and composition of the mature soybean seed. We have coupled this global approach with interactive bioinformatics and statistical analyses to gain insights into the biochemical programs that determine soybean seed composition. For this purpose, we used Plant/Eukaryotic and Microbial Metabolomics Systems Resource (PMR, http://www.metnetdb.org/pmr, a platform that incorporates metabolomics data to develop hypotheses concerning the organization and regulation of metabolic networks, and MetNet systems biology tools http://www.metnetdb. org for plant omics data, a framework to enable interactive visualization of metabolic and regulatory networks. Conclusions: This combination of high-throughput experimental data and bioinformatics analyses has revealed sets of specific genes, genetic perturbations and mechanisms, and metabolic changes that are associated with the developmental variation in soybean seed composition. Researchers can explore these metabolomics and transcriptomics data interactively at PMR. [ABSTRACT FROM AUTHOR]

In this work we report on the photoluminescence (PL) characteristics of porous silicon (PS) prepared by electrochemical anodization of a p-type Si wafer using chemically metal-dissolved hydrofluoric solutions. Various solid metals, oxidative (Al, Fe, Sn, Ni, Cr) and reductive (Cu), were used for this work. The effects of metals on the PL properties in as-grown, illuminated, and aged states have been studied. It is found that for the as-grown state the PL intensity is reduced by the addition of metal. In particular, the Cu-doped PS reveals a PL intensity lower by one order of magnitude as compared to that of normal PS. The improvement of stability in the PL intensity under illumination was only observed for the Cu-doped PS sample, which is more stable by a factor of 2 as compared to that of normal PS. On the other hand, the improved stability of the PL intensity in the aged state was observed for metal-doped PS samples other than for the Cu-doped sample. From the results, it is suggested that reductive metals are more effective in reducing the PL degradation caused by illumination while oxidative metals are more effective in reducing the PL degradation caused by ageing. [ABSTRACT FROM AUTHOR]