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https://www.readbyqxmd.com/read/28098844/modeling-and-calibration-of-a-novel-one-mirror-galvanometric-laser-scanner
#1
Chengyi Yu, Xiaobo Chen, Juntong Xi
A laser stripe sensor has limited application when a point cloud of geometric samples on the surface of the object needs to be collected, so a galvanometric laser scanner is designed by using a one-mirror galvanometer element as its mechanical device to drive the laser stripe to sweep along the object. A novel mathematical model is derived for the proposed galvanometer laser scanner without any position assumptions and then a model-driven calibration procedure is proposed. Compared with available model-driven approaches, the influence of machining and assembly errors is considered in the proposed model...
January 15, 2017: Sensors
https://www.readbyqxmd.com/read/28098748/propagation-modeling-and-defending-of-a-mobile-sensor-worm-in-wireless-sensor-and-actuator-networks
#2
Tian Wang, Qun Wu, Sheng Wen, Yiqiao Cai, Hui Tian, Yonghong Chen, Baowei Wang
WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator's mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier...
January 13, 2017: Sensors
https://www.readbyqxmd.com/read/28098310/a-computational-model-predicts-genetic-nodes-that-allow-switching-between-species-specific-responses-in-a-conserved-signaling-network
#3
Adriana T Dawes, David Wu, Karley K Mahalak, Edward M Zitnik, Natalia Kravtsova, Haiwei Su, Helen M Chamberlin
Cell signaling networks regulate a variety of developmental and physiological processes, and changes in their response to external stimuli are often implicated in disease initiation and progression. To elucidate how different responses can arise from conserved signaling networks, we have developed a mathematical model of the well-characterized Caenorhabditis vulval development network involving EGF, Wnt and Notch signaling that recapitulates biologically observed behaviors. We experimentally block a specific element of the EGF pathway (MEK), and find different behaviors in vulval development in two Caenorhabditis species, C...
January 18, 2017: Integrative Biology: Quantitative Biosciences From Nano to Macro
https://www.readbyqxmd.com/read/28097669/mathematical-modeling-of-rotary-blood-pumps-in-a-pulsatile-in-vitro-flow-environment
#4
Tohid Pirbodaghi
Nowadays, sacrificing animals to develop medical devices and receive regulatory approval has become more common, which increases ethical concerns. Although in vivo tests are necessary for development and evaluation of new devices, nonetheless, with appropriate in vitro setups and mathematical models, a part of the validation process can be performed using these models to reduce the number of sacrificed animals. The main aim of this study is to present a mathematical model simulating the hydrodynamic function of a rotary blood pump (RBP) in a pulsatile in vitro flow environment...
January 18, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28097524/pubovisceralis-muscle-fiber-architecture-determination-comparison-between-biomechanical-modeling-and-diffusion-tensor-imaging
#5
Sofia Brandão, Marco Parente, Elisabete Silva, Thuane Da Roza, Teresa Mascarenhas, João Leitão, João Cunha, Renato Natal Jorge, Rita Gouveia Nunes
Biomechanical analysis of pelvic floor dysfunction requires knowledge of certain biomechanical parameters, such as muscle fiber direction, in order to adequately model function. Magnetic resonance (MR) diffusion tensor imaging (DTI) provides an estimate of overall muscle fiber directionality based on the mathematical description of water diffusivity. This work aimed at evaluating the concurrence between pubovisceralis muscle fiber representations obtained from DTI, and the maximum principal stress lines obtained through the finite element method...
January 17, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28095857/real-time-inverse-kinematics-for-the-upper-limb-a-model-based-algorithm-using-segment-orientations
#6
Bence J Borbély, Péter Szolgay
BACKGROUND: Model based analysis of human upper limb movements has key importance in understanding the motor control processes of our nervous system. Various simulation software packages have been developed over the years to perform model based analysis. These packages provide computationally intensive-and therefore off-line-solutions to calculate the anatomical joint angles from motion captured raw measurement data (also referred as inverse kinematics). In addition, recent developments in inertial motion sensing technology show that it may replace large, immobile and expensive optical systems with small, mobile and cheaper solutions in cases when a laboratory-free measurement setup is needed...
January 17, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28095851/analytical-method-for-calculation-of-deviations-from-intended-dosages-during-multi-infusion
#7
Maurits K Konings, Roland A Snijder, Joris H Radermacher, Annemoon M Timmerman
BACKGROUND: In this paper, a new method is presented that combines mechanical compliance effects with Poiseuille flow and push-out effects ("dead volume") in one single mathematical framework for calculating dosing errors in multi-infusion set-ups. In contrast to existing numerical methods, our method produces explicit expressions that illustrate the mathematical dependencies of the dosing errors on hardware parameters and pump flow rate settings. METHODS: Our new approach uses the Z-transform to model the contents of the catheter, and after implementation in Mathematica (Wolfram), explicit expressions are produced automatically...
January 17, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28095721/a-lateral-dynamics-of-a-wheelchair-identification-and-analysis-of-tire-parameters
#8
L C A Silva, F C Corrêa, J J Eckert, F M Santiciolli, F G Dedini
In vehicle dynamics studies, the tire behaviour plays an important role in planar motion of the vehicle. Therefore, a correct representation of tire is a necessity. This paper describes a mathematical model for wheelchair tire based on the Magic Formula model. This model is widely used to represent forces and moments between the tire and the ground; however some experimental parameters must be determined. The purpose of this work is to identify the tire parameters for the wheelchair tire model, implementing them in a dynamic model of the wheelchair...
February 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28095405/defining-the-risk-of-zika-and-chikungunya-virus-transmission-in-human-population-centers-of-the-eastern-united-states
#9
Carrie A Manore, Richard S Ostfeld, Folashade B Agusto, Holly Gaff, Shannon L LaDeau
The recent spread of mosquito-transmitted viruses and associated disease to the Americas motivates a new, data-driven evaluation of risk in temperate population centers. Temperate regions are generally expected to pose low risk for significant mosquito-borne disease; however, the spread of the Asian tiger mosquito (Aedes albopictus) across densely populated urban areas has established a new landscape of risk. We use a model informed by field data to assess the conditions likely to facilitate local transmission of chikungunya and Zika viruses from an infected traveler to Ae...
January 17, 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28095307/pre-exposure-prophylaxis-and-antiretroviral-treatment-interventions-with-drug-resistance
#10
REVIEW
Komi Afassinou, Faraimunashe Chirove, Keshlan S Govinder
We introduce a model for HIV/AIDS which can be utilized to assess the impact of combining pre-exposure prophylaxis (PrEP) and antiretroviral drugs (ARVs) use interventions (incorporating drug resistance). Mathematical and numerical analyses are carried out to investigate the effects of the combined controls in the presence of PrEP drug resistance. Our results predict a significant decrease in the number of new HIV infections when PrEP and ARVs are concurrently implemented at high levels. The results also reveal that PrEP drug resistance has the potential to slow down or reverse the effects of PrEP, especially at low efficacy levels...
January 14, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28094856/percent-depth-doses-and-x-ray-beam-characterizations-of-a-fluoroscopic-system-incorporating-copper-filtration
#11
Kevin A Wunderle, Andrew R Godley, Zhilei Liu Shen, Joseph T Rakowski, Frank F Dong
PURPOSE: In this investigation, we sought to characterize X-ray beam qualities and quantify percent depth dose (PDD) curves for fluoroscopic X-ray beams incorporating added copper (Cu) filtration, such as those commonly used in fluoroscopically guided interventions (FGI). The intended application of this research is for dosimetry in soft tissue from FGI procedures using these data. METHODS: All measurements in this study were acquired on a Siemens (Erlangen, Germany) Artis zeego fluoroscope...
January 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28094342/optimizing-isothiocyanate-formation-during-enzymatic-glucosinolate-breakdown-by-adjusting-ph-value-temperature-and-dilution-in-brassica-vegetables-and-arabidopsis-thaliana
#12
Franziska S Hanschen, Rebecca Klopsch, Teresa Oliviero, Monika Schreiner, Ruud Verkerk, Matthijs Dekker
Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and epithionitriles. Domestic processing conditions, such as changes in pH value, temperature or dilution, might also affect isothiocyanate formation. Therefore, the influences of these three factors were evaluated in accessions of Brassica rapa, Brassica oleracea, and Arabidopsis thaliana...
January 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28093557/hebbian-plasticity-requires-compensatory-processes-on-multiple-timescales
#13
REVIEW
Friedemann Zenke, Wulfram Gerstner
We review a body of theoretical and experimental research on Hebbian and homeostatic plasticity, starting from a puzzling observation: while homeostasis of synapses found in experiments is a slow compensatory process, most mathematical models of synaptic plasticity use rapid compensatory processes (RCPs). Even worse, with the slow homeostatic plasticity reported in experiments, simulations of existing plasticity models cannot maintain network stability unless further control mechanisms are implemented. To solve this paradox, we suggest that in addition to slow forms of homeostatic plasticity there are RCPs which stabilize synaptic plasticity on short timescales...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093460/a-double-edged-sword-does-highly-active-antiretroviral-therapy-contribute-to-syphilis-incidence-by-impairing-immunity-to-treponema-pallidum
#14
REVIEW
Michael L Rekart, Wilfred Ndifon, Robert C Brunham, Jonathan Dushoff, Sang Woo Park, Sanjana Rawat, Caroline E Cameron
BACKGROUND AND HYPOTHESIS: Recently, the world has experienced a rapidly escalating outbreak of infectious syphilis primarily affecting men who have sex with men (MSM); many are taking highly active antiretroviral therapy (HAART) for HIV-1 infection. The prevailing hypothesis is that HAART availability and effectiveness have led to the perception among both individuals who are HIV-1 infected and those who are uninfected that HIV-1 transmission has become much less likely, and the effects of HIV-1 infection less deadly...
January 16, 2017: Sexually Transmitted Infections
https://www.readbyqxmd.com/read/28093213/characterization-of-the-efficiency-and-uncertainty-of-skimmed-milk-flocculation-for-the-simultaneous-concentration-and-quantification-of-water-borne-viruses-bacteria-and-protozoa
#15
Eloy Gonzales-Gustavson, Yexenia Cardenas-Youngs, Miquel Calvo, Marcelle Figueira Marques da Silva, Ayalkibet Hundesa, Inmaculada Amorós, Yolanda Moreno, Laura Moreno-Mesonero, Rosa Rosell, Lliliane Ganges, Rosa Araujo, Rosina Girones
In this study, the use of skimmed milk flocculation (SMF) to simultaneously concentrate viruses, bacteria and protozoa was evaluated. We selected strains of faecal indicator bacteria and pathogens, such as Escherichia coli and Helicobacter pylori. The viruses selected were adenovirus (HAdV 35), rotavirus (RoV SA-11), the bacteriophage MS2 and bovine viral diarrhoea virus (BVDV). The protozoa tested were Acanthamoeba, Giardia and Cryptosporidium. The mean recoveries with q(RT)PCR were 66% (HAdV 35), 24% (MS2), 28% (RoV SA-11), 15% (BVDV), 60% (E...
January 13, 2017: Journal of Microbiological Methods
https://www.readbyqxmd.com/read/28092963/mathematical-modeling-of-continuous-and-intermittent-androgen-suppression-for-the-treatment-of-advanced-prostate-cancer
#16
Alacia M Voth, John G Alford, Edward W Swim
Prostate cancer is one of the most prevalent types of cancer among men. It is stimulated by the androgens, or male sexual hormones, which circulate in the blood and diffuse into the tissue where they stimulate the prostate tumor to grow. One of the most important treatments for advanced prostate cancer has become androgen deprivation therapy (ADT). In this paper we present three different models of ADT for prostate cancer: continuous androgen suppression (CAS), intermittent androgen suppression (IAS), and periodic androgen suppression...
June 1, 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/28092962/effects-of-selection-and-mutation-on-epidemiology-of-x-linked-genetic-diseases
#17
Francesca Verrilli, Hamed Kebriaei, Luigi Glielmo, Martin Corless, Carmen Del Vecchio
The epidemiology of X-linked recessive diseases, a class of genetic disorders, is modeled with a discrete-time, structured, non linear mathematical system. The model accounts for both de novo mutations (i.e., affected sibling born to unaffected parents) and selection (i.e., distinct fitness rates depending on individual's health conditions). Assuming that the population is constant over generations and relying on Lyapunov theory we found the domain of attraction of model's equilibrium point and studied the convergence properties of the degenerate equilibrium where only affected individuals survive...
June 1, 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/28092960/mathematical-analysis-and-dynamic-active-subspaces-for-a-long-term-model-of-hiv
#18
Tyson Loudon, Stephen Pankavich
a long-term model of HIV infection dynamics [8] was developed to describe the entire time course of the disease. It consists of a large system of ODEs with many parameters, and is expensive to simulate. In the current paper, this model is analyzed by determining all infection-free steady states and studying the local stability properties of the unique biologically-relevant equilibrium. Active subspace methods are then used to perform a global sensitivity analysis and study the dependence of an infected individual's T-cell count on the parameter space...
June 1, 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/28092959/mixed-vaccination-strategy-for-the-control-of-tuberculosis-a-case-study-in-china
#19
Siyu Liu, Yong Li, Yingjie Bi, Qingdao Huang
This study first presents a mathematical model of TB transmission considering BCG vaccination compartment to investigate the transmission dynamics nowadays. Based on data reported by the National Bureau of Statistics of China, the basic reproduction number is estimated approximately as R0=1.1892. To reach the new End TB goal raised by WHO in 2015, considering the health system in China, we design a mixed vaccination strategy. Theoretical analysis indicates that the infectious population asymptotically tends to zero with the new vaccination strategy which is the combination of constant vaccination and pulse vaccination...
June 1, 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/28092957/germinal-center-dynamics-during-acute-and-chronic-infection
#20
Samantha Erwin, Stanca M Ciupe
The ability of the immune system to clear pathogens is limited during chronic virus infections where potent long-lived plasma and memory B-cells are produced only after germinal center B-cells undergo many rounds of somatic hypermutations. In this paper, we investigate the mechanisms of germinal center B-cell formation by developing mathematical models for the dynamics of B-cell somatic hypermutations. We use the models to determine how B-cell selection and competition for T follicular helper cells and antigen influences the size and composition of germinal centers in acute and chronic infections...
June 1, 2017: Mathematical Biosciences and Engineering: MBE
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