A CSI-Based Indoor Positioning System Using Single UWB Ranging Correction.

A fingerprint-based localization system is an economic way to solve an indoor positioning problem. However, the traditional off-line fingerprint collection stage is a time-consuming and laborious process which limits the use of fingerprint-based localization systems. In this paper, based on ubiquitous Wireless Fidelity (Wi-Fi) equipment and a low-cost Ultra-Wideband (UWB) ranging system (with only one UWB anchor), a ready-to-use indoor localization system is proposed to realize long-term and high-accuracy indoor positioning. More specifically, in this system, it is divided into two stages: (1) an initial stage, and (2) a positioning stage. In the initial stage, an Inertial Measure Unit (IMU) is used to calculate the position using Pedestrian Dead Reckon (PDR) algorithm within a preset number of steps, and the location-related fingerprints are collected to train a Convolutional Neural Network (CNN) regression model; simultaneously, in order to make the UWB ranging system adapt to the Non-Line-of-Sight (NLoS) environment, the increments of acceleration and angular velocity in IMU and the increments of single UWB ranging measures are correlated to pre-train a Supported Vector Regression (SVR). After reaching the threshold of time or step number, the system is changed into a positioning stage, and the CNN predicts the position calibrated by corrected UWB ranging. At last, a series of practical experiments are conducted in the real environment; the experiment results show that, due to the corrected UWB ranging measures calibrating the CNN parameters in every positioning period, this system has stable localization results in a comparative long-term range. Additionally, it has the advantages of stability, low cost, anti-noise, etc.

Effects of bed compression on protein separation on gel filtration chromatography at bench and pilot scale.

BACKGROUND: Poorly packed chromatography columns are known to reduce drastically the column efficiency and produce broader peaks. Controlled bed compression has been suggested to be a useful approach for solving this problem. Here the relationship between column efficiency and resolution of protein separation are examined when preparative chromatography media were compressed using mechanical and hydrodynamic methods. Sepharose CL-6B, an agarose based size exclusion media was examined at bench and pilot scale. The asymmetry and height equivalent of a theoretical plate (HETP) was determined by using 2% v/v acetone, whereas the void volume and intraparticle porosity (ϵ p) were estimated by using blue dextran. A protein mixture of ovalbumin (chicken), bovine serum albumin (BSA) and γ'- globulin (bovine) with molecular weights of 44, 67 and 158 kDa, respectively, were used as a 'model' separation challenge. RESULTS: Mechanical compression achieved a reduction in plate height for the column with a concomitant improvement in asymmetry. Furthermore, the theoretical plate height decreased significantly with mechanical compression resulting in a 40% improvement in purity compared with uncompressed columns at the most extreme conditions of compression used. CONCLUSION: The results suggest that the mechanical bed compression of Sepharose CL-6B can be used to improve the resolution of protein separation. © 2017 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Perinatal transmission in infants of mothers with chronic hepatitis B in California.

AIM: To evaluate maternal hepatitis B virus (HBV) DNA as risk for perinatal HBV infection among infants of HBV-infected women in California. METHODS: Retrospective analysis among infants born to hepatitis B surface antigen (HBsAg)-positive mothers who received post vaccination serologic testing (PVST) between 2005 and 2011 in California. Demographic information was collected from the California Department of Public Health Perinatal Hepatitis B Program databaseand matched to birth certificate records. HBV DNA level and hepatitis B e antigen (HBeAg) status were obtained from three large commercial laboratories in California and provider records if available and matched to mother infant pairs. Univariate analysis compared infected and uninfected infants. Multivariate analysis was restricted to infected infants and controls with complete maternal HBV DNA results using a predefined high HBV DNA level of > 2 × 107 IU/mL, a 5:1 ratio of cases to controls and a two-sided confidence level of 95%. RESULTS: A total of 17687 infants were born to HBsAg positive mothers in California between Jan 1 2005 and Dec 31, 2011. Among 11473 infants with PVST, only 125 (1.1%) were found to be HBV infected. Among these infected infants, lapses in Advisory Committee on Immunization Practices recommended post exposure prophylaxis (PEP) occurred in only 9 infants. However, PEP errors were not significantly different between infected and uninfected infants. Among the 347 uninfected and infected infants who had maternal HBeAg and HBV DNA level, case-control analysis found HBeAg positivity (70.4% vs 28.9%, OR = 46.76, 95%CI: 6.05-361.32, P < 0.001) and a maternal HBV DNA level ≥ 2 × 107 IU/mL (92.6% vs 18.5%, OR = 54.5, 95%CI: 12.22-247.55, P < 0.001) were associated with perinatal HBV infection. In multivariate logistic regression, maternal HBV DNA level ≥ 2 × 107 IU/mL was the only significant independent predictor of perinatal HBV infection. CONCLUSION: In California, transmission is low and most infected infants receive appropriate PEP and vaccination. Maternal HBV DNA ≥ 2 × 107 IU/mL is associated with high risk of perinatal infection.

Timely HIV diagnosis and HIV/TB comanagement among California patients in 2008.

OBJECTIVE: National guidelines highlight the roles of early HIV diagnosis and effective comanagement for HIV and tuberculosis (TB) to prevent mortality and morbidity from HIV-related TB. We assessed HIV diagnosis timing and HIV/TB comanagement for California HIV/TB patients. METHODS: We reviewed and analyzed public health charts for California HIV/TB patients reported during 2008. HIV diagnoses fewer than three months before TB diagnosis were considered new HIV diagnoses. We determined the proportion of patients with new HIV diagnoses, risk factors for new HIV diagnoses, and proportion of patients receiving recommended CD4 cell count measurements, supervised TB therapy, and antiretroviral therapy (ART). RESULTS: Of 130 HIV/TB patients, 51% had new HIV diagnoses. Foreign-born patients were more likely than U.S.-born patients to have new HIV diagnoses. Supervised TB therapy and CD4 cell count measurements followed national recommendations for 91% and 74% of patients, respectively. At least 73% of patients started ART before completing TB therapy. Compared with patients who had previous HIV diagnoses, patients with new HIV diagnoses started ART later and had lower CD4 cell counts and higher viral loads at TB diagnosis. CONCLUSIONS: Although most HIV/TB patients received the recommended treatment, half had new HIV diagnoses. Compared with patients who had previous HIV diagnoses, patients with new HIV diagnoses had greater immunosuppression at TB diagnosis. A new diagnosis indicates that HIV could have been diagnosed earlier and ART or treatment for latent TB infection could have been initiated to prevent TB development.

HIV status determination among tuberculosis patients from California during 2008.

CONTEXT: Human immunodeficiency virus (HIV) infection complicates care and contributes to poor outcomes among tuberculosis (TB) patients. The Centers for Disease Control and Prevention recommends that providers test all TB patients for HIV. OBJECTIVE: We assessed completeness of HIV status determination among TB patients and identified key gaps in adherence. DESIGN: We conducted a retrospective review of public health charts to determine the HIV status for all TB patients reported in California during 2008. We then used logistic regression to determine the factors associated with a known (positive or negative) HIV status. A random sample of TB patients was selected for secondary review to characterize the timing of HIV status determination and the providers who had opportunity to test for HIV. SETTING: California TB programs. PARTICIPANTS: All TB patients reported from California in 2008. MAIN OUTCOME MEASURES: Proportion of patients with a known HIV status, adjusted odds ratios for having a known HIV status, proportion of patients with a known HIV status before TB diagnosis, and proportion of patients diagnosed with TB by different provider types. RESULTS: Only 1752 (66%) of 2667 TB patients had a known HIV status. Having a known HIV status was strongly associated with those aged between 15 and 44 years and being managed with any public provider involvement. Of 292 patients in the random sample, 12 patients (4%) had a known HIV status before TB diagnosis. Among the remaining 280 patients, 187 patients (67%) were diagnosed with TB by a private provider. CONCLUSIONS: The HIV status determination of TB patients was selective and not routine as recommended. Private providers can play a key role in testing for HIV at TB diagnosis. California TB programs should ensure that all TB patients have an HIV status by promulgating national recommendations, educating private providers on the benefits of testing TB patients for HIV, and monitoring completeness of HIV status determination.