Controllability and controller-observer design for a class of linear time-varying systems

“The final publication is available at Springer via http://dx.doi.org/10.1007/s10852-012-9212-6"In this paper a class of linear time-varying control systems is considered. The time variation consists of a scalar time-varying coefficient multiplying the state matrix of an otherwise time-invariant system. Under very weak assumptions of this coefficient, we show that the controllability can be assessed by an algebraic rank condition, Kalman canonical decomposition is possible, and we give a method for designing a linear state-feedback controller and Luenberger observer

Investigation of Multiple Recognitions Used for EFL Writing in Authentic Contexts

Recognition technologies had been prevailing and widely used for EFL learning. We investigated the different recognitions used for EFL writing based on image-to-text, translated speech-to-text, and location-to-text recognitions – ITR, TSTR, and LTR. A quasi-experiment was implemented for 12 weeks in a vocational high school with experimental and control groups in two stages. Pre-test, posttests 1 and 2, questionnaires, and interviews were conducted and analyzed. Experimental learners, who wrote writing based on ITR and TSTR, outperformed control learners who wrote that based on TSTR only. Also, the experimental learners, who wore writing based on ITR, TSTR, and LTR, outperformed the control learners who wrote that based on ITR and TSTR. Particularly, LTR was beneficial for identifying controlling ideas and addressing the writing topics. ITR was beneficial for brainstorming and generating more ideas. TSTR was beneficial for yielding and transferring writing contents into words. The multiple recognitions were beneficial for most EFL writers, especially for low-ability language writers. Most writers were interested in describing based on authentic context learning. However, they complained about the low accuracy of LTR and TSTR and the difficulty of ITR texts when writing. Accordingly, the LTR database with various categories of places, the generation of ITR based on the language abilities of learners, and the higher accuracy of TSTR should be strictly considered when applying multiple recognitions for EFL writing

A comparison of gantry-mounted x-ray-based real-time target tracking methods.

PURPOSE: Most modern radiotherapy machines are built with a 2D kV imaging system. Combining this imaging system with a 2D-3D inference method would allow for a ready-made option for real-time 3D tumor tracking. This work investigates and compares the accuracy of four existing 2D-3D inference methods using both motion traces inferred from external surrogates and measured internally from implanted beacons. METHOD: Tumor motion data from 160 fractions (46 thoracic/abdominal patients) of Synchrony traces (inferred traces), and 28 fractions (7 lung patients) of Calypso traces (internal traces) from the LIGHT SABR trial (NCT02514512) were used in this study. The motion traces were used as the ground truth. The ground truth trajectories were used in silico to generate 2D positions projected on the kV detector. These 2D traces were then passed to the 2D-3D inference methods: interdimensional correlation, Gaussian probability density function (PDF), arbitrary-shape PDF, and the Kalman filter. The inferred 3D positions were compared with the ground truth to determine tracking errors. The relationships between tracking error and motion magnitude, interdimensional correlation, and breathing periodicity index (BPI) were also investigated. RESULTS: Larger tracking errors were observed from the Calypso traces, with RMS and 95th percentile 3D errors of 0.84-1.25 mm and 1.72-2.64 mm, compared to 0.45-0.68 mm and 0.74-1.13 mm from the Synchrony traces. The Gaussian PDF method was found to be the most accurate, followed by the Kalman filter, the interdimensional correlation method, and the arbitrary-shape PDF method. Tracking error was found to strongly and positively correlate with motion magnitude for both the Synchrony and Calypso traces and for all four methods. Interdimensional correlation and BPI were found to negatively correlate with tracking error only for the Synchrony traces. The Synchrony traces exhibited higher interdimensional correlation than the Calypso traces especially in the anterior-posterior direction. CONCLUSION: Inferred traces often exhibit higher interdimensional correlation, which are not true representation of thoracic/abdominal motion and may underestimate kV-based tracking errors. The use of internal traces acquired from systems such as Calypso is advised for future kV-based tracking studies. The Gaussian PDF method is the most accurate 2D-3D inference method for tracking thoracic/abdominal targets. Motion magnitude has significant impact on 2D-3D inference error, and should be considered when estimating kV-based tracking error

Evaluation of Naloxone Administration in the Non-Anesthesia Setting at a Comprehensive Cancer Center

Mary Lou Warren (left), Susy Varghese (center), Kristy Nguyen (right) pictured.https://openworks.mdanderson.org/aprn-week-22/1019/thumbnail.jp

Increased MicroRNA-34b and -34c Predominantly Expressed in Stromal Tissues Is Associated with Poor Prognosis in Human Colon Cancer

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Neural tissue engineering with structured hydrogels in CNS models and therapies

The development of techniques to create and use multiphase microstructured hydrogels (granular hydrogels or microgels) has enabled the generation of cultures with more biologically relevant architecture and use of structured hydrogels is especially pertinent to the development of new types of central nervous system (CNS) culture models and therapies. We review material choice and the customisation of hydrogel structure, as well as the use of hydrogels in developmental models. Combining the use of structured hydrogel techniques with developmentally relevant tissue culture approaches will enable the generation of more relevant models and treatments to repair damaged CNS tissue architecture

Natural Orifice Surgery (NOS) Using StomaphyX™ for Repair of Gastric Leaks after Bariatric Revisions

Gastric leaks represent serious complications of bariatric surgery. With the increasing popularity and performance of bariatric procedures, the incidence of leaks and associated complications are expected to increase. Minimally invasive natural orifice surgery represents a novel and promising approach to gastric leak management, especially for morbidly obese patients who are at much higher risk from open or laparoscopic surgical procedures. The present article reports two cases of the safe and successful use of the EndoGastric Solutions StomaphyX™ device to alter the flow of gastric contents and repair gastric leaks resulting from bariatric revision surgery. Both patients were at a high risk and could not undergo another open or laparoscopic surgery to correct the leaks that were not healing. The StomaphyX procedures lasted approximately 30 min, were performed without any complications, and resulted in the resolution of the gastric leaks in both patients

A covalently crosslinked bioink for multi-materials drop-on-demand 3D bioprinting of three-dimensional cell cultures

In vitro three-dimensional (3D) cell models have been accepted to better recapitulate aspects of in vivo organ environment than 2D cell culture. Currently, the production of these complex in vitro 3D cell models with multiple cell types and microenvironments remains challenging and prone to human error. Here we report a versatile bioink comprised of a 4-arm PEG based polymer with distal maleimide derivatives as the main ink component and a bis-thiol species as the activator that crosslinks the polymer to form the hydrogel in less than a second. The rapid gelation makes the polymer system compatible with 3D bioprinting. The ink is combined with a drop-on-demand 3D bioprinting platform consisting of eight independently addressable nozzles and high-throughput printing logic for creating complex 3D cell culture models. The combination of multiple nozzles and fast printing logic enables the rapid preparation of many complex 3D structures comprising multiple hydrogel environments in the one structure in a standard 96-well plate format. The platform compatibility for biological applications was validated using pancreatic ductal adenocarcinoma cancer (PDAC) cells with their phenotypic responses controlled by tuning the hydrogel microenvironment

Forward osmosis–membrane distillation hybrid system for desalination using mixed trivalent draw solution

© 2020 Elsevier B.V. Finding suitable draw solutions is still a major problem when developing FO technologies. This study represents the first time a mixed trivalent draw solution containing of EDTA–2Na and Na3PO4 was systemically studied for FO performance. The objective here was to achieve simultaneously low reverse salt flux and high water flux. The FO results showed that the mixed trivalent draw solution-based 0.3 M EDTA–2Na and 0.55 M Na3PO4 underwent higher water flux (Jw = 9.17 L/m2⋅h) than that of pure 0.85 M EDTA-2Na (Jw = 7.02 L/m2⋅h) due to its lower viscosity. Additionally, the specific reverse salt flux caused by mixing 0.3 M EDTA–2Na with 0.55 M Na3PO4 draw solution was only 0.053 g/L using DI water as the feed solution. Donnan equilibrium force and formed complexation of [EDTANa]3-, [HPO4Na]- with the FO membrane are believed to constitute the main mechanism for minimizing salt leakage from the mixed draw solution. Moreover, the FO desalination process utilizing the mixed trivalent draw solution achieved water fluxes of 6.12 L/m2⋅h with brackish water (TDS = 5000 mg/L) and 3.10 L/m2⋅h with seawater (TDS = 35,000 mg/L) as the feed solution. Lastly, diluted mixed trivalent draw solution following the FO process was effectively separated using the MD process with salt rejection >99.99% at a mild feed temperature of 55 °C

Relationship Between Obesity and Diabetes in a US Adult Population: Findings from the National Health and Nutrition Examination Survey, 1999–2006

# The Author(s) 2010. This article is published with open access at Springerlink.com Background Obesity is one of the most important modifiable risk factors for the prevention of type 2 diabetes. The aim of this study was to examine the prevalence of diabetes with increasing severity of obesity and the distribution of HbA1c levels in diabetics participating in the latest National Health and Nutrition Examination Survey (NHANES). Methods Data from a representative sample of adults with diabetes participating in the NHANES between 1999 and 2006 were reviewed. The prevalence of diabetes and levels of fasting glucose, insulin, c-peptide, and HbA1c were examined across different weight classes with normal weight, overweight, and obesity classes 1, 2, and 3 were defined as body mass index (BMI) of <25.0, 25.0–29.9, 30.0–34.9, 35.0–39.9, and equal to 40.0, respectively. The distribution of HbA1c levels among adults with diabetes was also examined. Results There were 2,894 adults with diabetes (13.6%) among the 21,205 surveyed participants. Among the adults with diabetes, the mean age was 59 years, the mean fasting glucose was 155±2 mg/dl, and the mean HbA1c was 7.2%; 80.3 % of diabetics were considered overweight (BMI≥25) and 49.1 % of diabetics were considered obese (BMI≥30). Presented as a poster presentation at the American Society fo