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Neural Nets and Fuzzy Logic
Published in Abraham Kandel, Gideon Langholz, Lotfi A. Zadeh, Hybrid Architectures for Intelligent Systems, 2020
A fuzzy efferent neural net (FEN) is composed of at least two of the following types of layers of neurons (see Figure 7): Organizing (Planning or Coordinating) Layer. This layer is composed of FDNs whose purpose is to recruit neurons to perform a task in response to a fuzzy classification, e.g., as required in fuzzy control. The complexity of this processing will be reflected in the number of Organizing Layers. Some of them are related to the Planning of Actions (e.g., Associative Areas in the brain), whereas some others are related to the Coordination of Chosen Actions (e.g., Cerebellum).Effector Layer. This layer is composed of fuzzy neurons controlling the effector devices performing the Label or Symbolic/Analog Conversion for the final output of the system. The effector neurons control, for example, muscle, glands, motors, etc.
Machine Learning in Metabolic Engineering
Published in Shampa Sen, Leonid Datta, Sayak Mitra, Machine Learning and IoT, 2018
Enzyme activity is generally manipulated by certain effectors (inhibitors or activators) that bind to the enzyme, thus influencing its job as a catalyst. The response coefficient describes the influence exerted by such an effector (ei) on the flux of the metabolite (Jk): RXiJk=eiJkdJkdei Another coefficient—the elasticity coefficient—expresses the relationship between metabolite concentration (Xj) and rate of the reaction (νi), both of which are system variables: εXji=Xjνi∂νi∂Xj Going back to the analogy of a metabolic pathway with a factory layout, we get to know what changes need to be made at which points in the factory layout and by how much, after performing metabolic control analysis. Hereafter, the biochemical engineer performs genetic engineering or other techniques to effectively change the factory processes.
Systems Biology
Published in Lawrence S. Chan, William C. Tang, Engineering-Medicine, 2019
Lawrence S. Chan, William C. Tang
Despite its unfathomable complexity, however, there is one central organizing principle unifying all physiological activities: homeostasis (Stanfield 2017). Homeostasis is the ability to maintain a relatively constant internal environment even when the external environment changes. The internal environments that are regulated and maintained include temperature, volume, and composition. How homeostasis is maintained by checking and balancing ALL physiological aspects of the entire body requires organ systems integration. Disruption of homeostasis is the basis for disease and even death. In engineering terms, the aspects of the body that are being regulated are called “variables”. The most common variables are body temperature, blood glucose concentration, pH level of blood, etc. The control method is called “negative feedback”. When the regulated variable decreases below the “homeostatic level”, the system responds to make it increase, and vice versa. The desired value of the variable, or “homeostatic level”, is called “set point”. Examples of set points are: body temperature set at 37°C; blood glucose concentration set at 100 mg·dL−1; and blood pH set at 7.4. “Error signal” is the information needed for the negative feedback, and is the difference between the value of the set point and the value of the regulated variable. The “hardware” needed for the negative-feedback control are “sensors” that measure the current value of the variable, “integrating centers” that process the error signal and execute control, and “effectors” that actuate and change the regulated variable. The sensors are the receptors in the body such as thermoreceptors to sense the temperature they are exposed to, photoreceptors to sense light, baroreceptors to sense pressure, etc. They are specialized cells that transduce one form of energy into chemical or electrochemical energy, which serve as the signals for the integrating centers. The integrating centers then orchestrate appropriate responses. Many of these integrating centers are found in the brain and some in the spinal cord. The effectors are muscles and glands that carry out the commands from the integrating centers.
Involvement of Pseudomonas aeruginosa in the occurrence of community and hospital acquired diarrhea, and its virulence diversity among the stool and the environmental samples
Published in International Journal of Environmental Health Research, 2022
Parisa Fakhkhari, Elahe Tajeddin, Masoumeh Azimirad, Siavosh Salmanzadeh-Ahrabi, Ahya Abdi-Ali, Bahram Nikmanesh, Babak Eshrati, Mohammad Mehdi Gouya, Parviz Owlia, Mohammad Reza Zali, Masoud Alebouyeh
Although P. aeruginosa is an agent linked to the gastrointestinal infections, it generally causes diseases in exraintestinal sites. P. aeruginosa exploits some virulence factors to establish its infection in the lung (Ballok and O’Toole 2013). P. aeruginosa exotoxins have several functions, including Adenosine diphosphate (ADP)-ribosyltransferase (such as Exotoxin A), cytotoxic (such as pyocyanin), and proteolytic (such as elastase that degrades host defenses) activities (Shi et al. 2012). This bacterium encodes a type III secretions system, a system that can inject toxic effector proteins into the cytoplasm of eukaryotic cells. Currently, four effector proteins are defined in P. aeruginosa: ExoU, ExoS, ExoT, and ExoY. These effector proteins modulate host cell functions, change cytoskeletal organization, and signal transduction. While most of P. aeruginosa strains carry exoT and exoY genes, exoS and exoU show diversity among the isolates.
Review on the current treatment status of vein of Galen malformations and future directions in research and treatment
Published in Expert Review of Medical Devices, 2021
Panagiotis Primikiris, Georgios Hadjigeorgiou, Maria Tsamopoulou, Alessandra Biondi, Christina Iosif
In the same study, a significant enrichment in transmitted EPHB4 mutations (P= 1.68 × 10−6) was observed in probands. Among the Ephrin family, EPHB4 is a transmembrane receptor, which is highly expressed in venous endothelial cells during development [138,139]. It specifically binds to EphrinB2 [140], a transmembrane protein expressed in arterial endothelial cells [141]. This signaling system, in concert with Notch signaling, plays an important role in arterial-venous differentiation and the coordinated activation of the two proteins is important for establishing the venous and arterial endothelial identity and corresponding vessel formation [118,125,138,142]. To summarize, the membrane-tethered ligand, EphrinB2, binds to its receptor, EPHB4, which interacts with its downstream effector RASA1. A dysregulation of downstream genes can result from mutations in this signaling axis that cause excessive PI3K/mTORC1 pathway activity [143].
Design and fluid flow simulation of modified laparoscopic forceps
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Md. Abdul Raheem Junaidi, Ram Chandra Murthy Kalluri, Y. V. Daseswara Rao, Alla Gopala Krishna Gokhale, Aakrit Patel
Maryland forceps is a crucial instrument in laparoscopic surgeries. Many patents are proposed based on different components design and its usage from the 1990s (Smith 1992; Moran et al. 2008; Fan et al. 2015; Lee et al. 2016). In 1992, Smith (1992) invented disposable Maryland dissectors used in Minimally Invasive Surgery (MIS). Later, two other designs were proposed in 2015 (Fan et al. 2015) and 2008 (Moran et al. 2008). Figure 3 shows a disposable laparoscopic surgical instrument having end effectors manipulated by the handle. The handle is made of lightweight plastic or stainless steel, the inner tube is made of aluminum, and the outer tube is made of plastic, end effector and claws are made of cast bronze, aluminum alloy is used for clevis. Plastic shrink is wrapped over the tube and handle to prevent electric shock. Insulation is also ferruled on the handle to ensure insulation from handle to the tube. The tube and push rod imparts axial translation to the end effector. When the handle is closed inward, the end effector moves to the right and vice-versa. These forceps are unipolar or bipolar and use ultrasonic frequency electrical supply to dissect the unhealthy tissue. Figure 3 shows another form of Maryland forceps used in surgeries wherein the end effectors are pulled and pushed in order to manipulate the tissue.