1,559 research outputs found
Things to know about Bayesian networks
No full textAbstract
Bayesian networks help us model and understand the many variables that inform our decision-making processes. Anthony C. Constantinou and Norman Fenton explain how they work, how they are built and the pitfalls to avoid along the way</jats:p
Mechanisms of pelvic floor muscle function and the effect on the urethra during a cough
No full textBackground: Current measurement tools have difficulty identifying the automaticphysiologic processes maintaining continence, and many questions still remainabout pelvic floor muscle (PFM) function during automatic events.Objective: To perform a feasibility study to characterise the displacement, velocity,and acceleration of the PFM and the urethra during a cough.Design, setting, and participants: A volunteer convenience sample of 23 continentwomen and 9 women with stress urinary incontinence (SUI) from the generalcommunity of San Francisco Bay Area was studied.Measurements: Methods included perineal ultrasound imaging, motion trackingof the urogenital structures, and digital vaginal examination. Statistical analysisused one-tailed unpaired student t tests, and Welch’s correction was applied whenvariances were unequal.Results and limitations: The cough reflex activated the PFM of continent women tocompress the urogenital structures towards the pubic symphysis, which wasabsent in women with SUI. The maximum accelerations that acted on the PFMduring a cough were generally more similar than the velocities and displacements.The urethras of women with SUI were exposed to uncontrolled transverse accelerationand were displaced more than twice as far ( p = 0.0002), with almost twicethe velocity ( p = 0.0015) of the urethras of continent women. Caution regardingthe generalisability of this study is warranted due to the small number of women inthe SUI group and the significant difference in parity between groups.Conclusions: During a cough, normal PFM function produces timely compressionof the pelvic floor and additional external support to the urethra, reducing displacement,velocity, and acceleration. In women with SUI, who have weakerurethral attachments, this shortening contraction does not occur; consequently,the urethras of women with SUI move further and faster for a longer duratio
josuemtzmo/xarrayMannKendall: Mann Kendall significance test implemented in xarray.
No full textThis release contains an implementation of the Mann-Kendall significance test implemented in xarray. This currently supports 1D, 2D, and 3D datasets.
Additionally, this code was used to analyze the datasets of the manuscript:
> Martínez-Moreno, J., Hogg, A. McC., England, M. H., Constantinou, N. C., Kiss, A. E., and Morrison, A. K. Global changes in oceanic mesoscale currents over the satellite altimetry record. (submitted on Oct. 2020; preprint at doi:10.21203/rs.3.rs-88932/v1
josuemtzmo/EKE_SST_trends: EKE_SST_trends: Jupyter notebooks (Python) used to compute trends of Eddy kinetic energy and sea surface temperature
No full textThis repository contains the most recent code, figures and notebooks used to reproduce the manuscript:
Martínez-Moreno, J., Hogg, A. McC., England, M. H., Constantinou, N. C., Kiss, A. E., and Morrison, A. K. Global changes in oceanic mesoscale currents over the satellite altimetry record. (accepted on Feb. 2021; preprint at doi:10.21203/rs.3.rs-88932/v1)
The version of the toolboxes here correspond to the Github site:
https://github.com/josuemtzmo/EKE_SST_trend
High-power CMOS current driver with accurate transconductance for electrical impedance tomography
No full textCurrent drivers are fundamental circuits in bioimpedance measurements including electrical impedance tomography (EIT). In the case of EIT, the current driver is required to have a large output impedance to guarantee high current accuracy over a wide range of load impedance values. This paper presents an integrated current driver which meets these requirements and is capable of delivering large sinusoidal currents to the load. The current driver employs a differential architecture and negative feedback, the latter allowing the output current to be accurately set by the ratio of the input voltage to a resistor value. The circuit was fabricated in a 0.6- μm high-voltage CMOS process technology and its core occupies a silicon area of 0.64 mm (2) . It operates from a ± 9 V power supply and can deliver output currents up to 5 mA p-p. The accuracy of the maximum output current is within 0.41% up to 500 kHz, reducing to 0.47% at 1 MHz with a total harmonic distortion of 0.69%. The output impedance is 665 k Ω at 100 kHz and 372 k Ω at 500 kHz
Computational Investigation of Microreactor Configurations for Hydrogen Production from Formic Acid Decomposition Using a Pd/C Catalyst
No full textThe need to replace fossil fuels with sustainable alternatives has been a critical issue in recent years. Hydrogen fuel is a promising alternative to fossil fuels because of its wide availability and high energy density. For the very first time, novel microreactor configurations for the formic acid decomposition have been studied using computational modeling methodologies. The decomposition of formic acid using a commercial 5 wt % Pd/C catalyst, under mild conditions, has been assessed in packed bed, coated wall, and membrane microreactors. Computational fluid dynamics (CFD) was utilized to develop the comprehensive heterogeneous microreactor models. The CFD modeling study begins with the development of a packed bed microreactor to validate the experimental work, subsequently followed by the theoretical development of novel microreactor configurations to perform further studies. Previous work using CFD modeling had predicted that the deactivation of the Pd/C catalyst was due to the production of the poisoning species CO during the reaction. The novel membrane microreactor facilitates the continuous removal of CO during the reaction, therefore prolonging the lifetime of the catalyst and enhancing the formic acid conversion by approximately 40% when compared to the other microreactor configurations. For all microreactors studied, the formic acid conversion increases as the temperature increases, and the liquid flow rate decreases. Further studies revealed that all microreactor configurations had negligible internal and external pore diffusion resistances. The detailed models developed in this work have provided an interesting insight into the intensification of the formic acid decomposition reaction over a Pd/C catalyst
In Vivo Metabolic Analysis of Pseudomonas Aeruginosa Live Bacteria Using High Resolution Magic Angle Spinning NMR Spectroscopy
No full textPseudomonas aeruginosa (PA) is a human opportunistic pathogen responsible for chronic and acute infections, and is a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Bacterical cell walls have a very complicated structure, consisting of integrated macromolecules such as carbohydrates, lipids, and proteins. This structure is highly heterogeneous among individual bacterial cells, due to constant biosynthesis, assembly, disassembly, and turnover. To understand the bacterical cell wall structures destructive methods have been used to analyze the individual components. These in vitro results may not faithfully reflect the native
structural and conformational information. Recently, cell NMR spectroscopy has gained recent popularity. 1H High Resolution Magic Angle Spinning (HRMAS) NMR can determine bacterial structure in detail. Here, 1H HRMAS NMR was applied to Pseudomonas aeruginosa to determine the metabolites in living cells
josuemtzmo/EKE_SST_trends: EKE_SST_trends: Jupyter notebooks (Python) used to compute trends of Eddy kinetic energy and sea surface temperature
No full textThis repository contains the code, figures, and LaTeX files used for the manuscript:
Martínez-Moreno, J., Hogg, A. McC., England, M. H., Constantinou, N. C., Kiss, A. E., and Morrison, A. K. Global changes in oceanic mesoscale currents over the satellite altimetry record. (submitted on Oct. 2020; preprint at doi:10.21203/rs.3.rs-88932/v1)
The version of the toolboxes here correspond to the github site:
https://github.com/josuemtzmo/EKE_SST_trend
Essentials of science – Development, evaluation and transfer into school practice of a competence oriented science course.
No full textStiller C, Stockey A, Hahn S, Wilde M. Essentials of science – Development, evaluation and transfer into school practice of a competence oriented science course. In: Constantinou CP, Papadouris N, Hadjigeorgiou A, eds. Proceedings of the 13. European Science Education Reserach Association (ESERA) Conference. Part 10. Nicosia, Cyprus: European Science Education Research Association; 2014: 1846-1853
The possible role of Ziziphus lotus as an ecosystem engineer in semiarid landscapes
No full textPositive interactions between nurse plants and their facilitated species are most notable in dry/high-elevation habitats. Plants that modify limiting resources or constraining variables creating an even stronger positive impact on the community are considered ecosystem engineers. Ziziphus lotus, a dominant deep-rooted shrub of arid/semi-arid Mediterranean habitats, can create fertile islets; most likely acting as a nurse plant. To further investigate its role as an ecosystem engineer, we assessed for Thymbra capitata the density of 1377 individuals and the night time-dehydration of 66 individuals, growing around 11 Z.lotus plants for three successive zones (0–5m, 5–10m and 10–15m) and for wetter and drier habitats created by topography in Cyprus. We discovered that T. capitata significantly increases in density (by c. 2.5 times) and can improve its night-time rehydration in mid-summer (by c. 60 times) when growing up to 5m around Z.lotus compared to thymes growing 10–15m away. Density and stem moisture for thymes growing near Z.lotus do not seem to be significantly affected by topography. Hence, Z.lotus may have properties to be classified as an ecosystem engineer and the potential to boost semiarid ecosystem productivity in the battle against desertification under global climatic change
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