Towards a Theory of “Use” in the Autonomous Things

The way users perceive and use information system artefacts has been mainly studied from the notion of behavioural believes, cognitive efforts, and deliberate use (e.g., clicking or scrolling) by human actors to produce certain outcomes. The autonomous things, however, do not require deliberate cognitive processes and physical actions to operate. Hence, the existing notions of logical and deliberate use by human actors to produce certain outcomes warrant a revisit. Consequently, drawing on the theories of consciousness and technology adoption, we proposed the notions of conscious use in the context of autonomous things. We argue that unlike the manually operated technologies and systems, the “use” of an autonomous artefact is a state of a user’s consciousness rather than a logical, deliberate cognitive, or somatic activity. A fully autonomous artefact is consciously perceived by users anticipating their needs (through sensory information and situational awareness) without requiring any cognitive efforts, instructions, and physical contact to produce the desired outcomes

Modeling a DFIG-Based Wind Turbine Focusing on DFIG and Aerodynamic Models

The present study is an attempt to develop and implement mathematical models of variable speed wind turbines using Doubly-Fed Induction Generator (DFIG) including aerodynamic model and DFIG through newly developed Matlab/Simulink .The so called models are developed in order to investigate dynamic behavior of power networks as well as to design and evaluate the behavior of each wind turbine under normal and disturbance conditions. In the study, aerodynamic (rotor) model is based on torque coefficient Cq look up table which is according to BEM method. DFIG model is developed in two sub models including generator and power converters. In generator model, electrical dynamic equations of wound rotor induction generator are provided in two different models (fifth-order model and third-order model) by choosing synchronous rotating reference frame.  As the simulation result revealed, the stator power is limited at rated value at high wind speed but wind turbine is operated at optimum power efficiency at lower wind speed to gain optimal power output, indicating a good agreement with the real behavior of the system

Modeling a DFIG-Based Wind Turbine Focusing on DFIG and Aerodynamic Models

The present study is an attempt to develop and implement mathematical models of variable speed wind turbines using Doubly-Fed Induction Generator (DFIG) including aerodynamic model and DFIG through newly developed Matlab/Simulink .The so called models are developed in order to investigate dynamic behavior of power networks as well as to design and evaluate the behavior of each wind turbine under normal and disturbance conditions. In the study, aerodynamic (rotor) model is based on torque coefficient Cq look up table which is according to BEM method. DFIG model is developed in two sub models including generator and power converters. In generator model, electrical dynamic equations of wound rotor induction generator are provided in two different models (fifth-order model and third-order model) by choosing synchronous rotating reference frame.  As the simulation result revealed, the stator power is limited at rated value at high wind speed but wind turbine is operated at optimum power efficiency at lower wind speed to gain optimal power output, indicating a good agreement with the real behavior of the system

Acceptance-Promoting Practice Framework for Online Collaborative Learning and EdTech in Formal Education: a Thematic Analysis of Literature

This exploratory quantitative study seeks to identify (a) the e-learning practices that can improve the acceptance of online collaborative learning (OCL) and the associated EdTech in formal learning contexts and (b) the characteristics or features of such EdTech. A systematic review was conducted combined with a thematic analysis of literature (i.e., 42 journal articles relevant to OCL that was published from 2001 to 2020 from Scopus database), the findings of which not only attained all research objectives with the proposed the acceptance-promoting practice framework for OCL and EdTech (APPFOE) in formal education (see Figure 7), but also identified the challenges that OCL learners generally confront. The proposed APPFOE reveals a number of practices in three main themes (viz., teacher presence, OCL EdTech, and learners’ control over learning) that can handle those challenges and promote the acceptance of OCL and the associated EdTech in light of the extended unified theory of acceptance and use of technology model. The implications for positive social change include the potential to guide educators in their class interactions, aid policymakers with their alignment of resources, assist EdTech professionals and entrepreneurs in their product development, and contribute to the growing body of academic knowledge in some respects, hence lay out the basis for some future research

Beta Amyloid Peptides: Extracellular and Intracellular Mechanisms of Clearance in Alzheimer’s Disease

Alzheimer’s disease (AD) is a neurodegenerative disease and the most common form of dementia, characterized by the overproduction and accumulation of different amyloid-β peptide peptides (Aβ) within different areas in the brain conducting to memory loss and dementia. The Aβ cascade hypothesis of AD was originally proposed by Selkoe in 1991 by the theory that accumulation of Aβ42 is the initial trigger for neurodegeneration. The Aβ cascade hypothesis assumes that changes in the production or accumulation of Aβ are responsible for AD pathology. Different Aβ clearance mechanisms are also affected by AD pathology. Studies from the past years have revealed that the blocking of Aβ production is not effective for reducing the brain Aβ levels. However, the relevance of Aβ clearance in AD, especially in late-onset sporadic AD (LOAD), has been heightened, and the study of the Aβ clearance mechanisms has elucidated new possible therapeutic targets. This chapter summarizes recent data underlying the idea of the reduced Aβ clearance and subsequent Aβ spread in AD. We discuss the Aβ clearance mechanisms altered in AD, and the Aβ clearance through autophagy in more detail, a more recent mechanism proposed, and the new strategies to eliminate Aβ42 inducing autophagy

New Triazoloquinoxaline Ligand and its Polymeric 1D Silver(I) complex Synthesis, Structure, and Antimicrobial activity

The organic ligand 4-Benzyl-1-(N,N-dimethylamino)-[1,2,4]triazolo[4,3a]quinoxaline 1 (L) and its polymeric silver(I) complex, [Ag2L(NO3)2]n (2), have been synthesized and characterized. The organic ligand 1 crystallizes in the triclinic space group P¯1. The unit cell contains two parallel-stacked molecules. The complex [Ag2L(NO3)2]n (2) crystallizes in the monoclinic space group P21/n. The structure contains two different silver(I) ions. Ag(2) is coordinated by three oxygens (involving two nitrate groups) and to a nitrogen of the triazole ring of 1. These ligands form a strongly distorted tetrahedral, nearly planar coordination sphere. Ag(1) has an approximately tetrahedral geometry. It is bonded to one oxygen of a nitrate anion and a nitrogen of two different L; this aspect giving rise to an infinite chain structure. A final bond to Ag(1) involves the carbon of a phenyl group. It is more weakly bonded to the phenyl carbons on either side of this, so that the Ag(1)-phenyl bonding has aspects of an Ag-allyl bond. Ag(1) and Ag(2) participate in bonding to a common nitrate anion and alternate, the two distinct modes of bridging between them lead to a zig-zag chain structure. In addition to spectroscopic studies, the biological activities of the ligand and of the complex were scanned over a wide range of Gram positive and Gram negative flesh- and bone-eating bacteria. The results are discussed in comparison with well-known antibiotics

Posttranscriptional Upregulation of IDH1 by HuR Establishes a Powerful Survival Phenotype in Pancreatic Cancer Cells.

Cancer aggressiveness may result from the selective pressure of a harsh nutrient-deprived microenvironment. Here we illustrate how such conditions promote chemotherapy resistance in pancreatic ductal adenocarcinoma (PDAC). Glucose or glutamine withdrawal resulted in a 5- to 10-fold protective effect with chemotherapy treatment. PDAC xenografts were less sensitive to gemcitabine in hypoglycemic mice compared with hyperglycemic mice. Consistent with this observation, patients receiving adjuvant gemcitabine (n = 107) with elevated serum glucose levels (HgbA1C \u3e 6.5%) exhibited improved survival. We identified enhanced antioxidant defense as a driver of chemoresistance in this setting. ROS levels were doubled in vitro by either nutrient withdrawal or gemcitabine treatment, but depriving PDAC cells of nutrients before gemcitabine treatment attenuated this effect. Mechanistic investigations based on RNAi or CRISPR approaches implicated the RNA binding protein HuR in preserving survival under nutrient withdrawal, with or without gemcitabine. Notably, RNA deep sequencing and functional analyses in HuR-deficient PDAC cell lines identified isocitrate dehydrogenase 1 (IDH1) as the sole antioxidant enzyme under HuR regulation. HuR-deficient PDAC cells lacked the ability to engraft successfully in immunocompromised mice, but IDH1 overexpression in these cells was sufficient to fully restore chemoresistance under low nutrient conditions. Overall, our findings highlight the HuR–IDH1 regulatory axis as a critical, actionable therapeutic target in pancreatic cancer

High temperature fusion reactor design

Fusion energy may have unique advantages over other systems as a source for high temperature process heat. A conceptual design of a blanket for a 7 m tokamak reactor has been developed that is capable of producing 1100/sup 0/C process heat at a pressure of approximately 10 atmospheres. The design is based on the use of a falling bed of MgO spheres as the high temperature heat transfer system. By preheating the spheres with energy taken from the low temperature tritium breeding part of the blanket, 1086 MW of energy can be generated at 1100/sup 0/C from a system that produces 3000 MW of total energy while sustaining a tritium breeding ratio of 1.07. The tritium breeding is accomplished using Li/sub 2/O modules both in front of (6 cm thick) and behind (50 cm thick) the high temperature ducts. Steam is used as the first wall and front tritium breeding module coolant while helium is used in the rear tritium breeding region. The system produces 600 MW of net electricity for use on the grid

Alternate-fuel reactor studies

A number of studies related to improvements and/or greater understanding of alternate-fueled reactors is presented. These studies cover the areas of non-Maxwellian distributions, materials and lifetime analysis, a /sup 3/He-breeding blanket, tritium-rich startup effects, high field magnet support, and reactor operation spanning the range from full D-T operation to operation with no tritium breeding