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Epigenetics of B Cells and Antibody Responses

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197903 Year: Pages: 121 DOI: 10.3389/978-2-88919-790-3 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2017-02-03 17:04:57
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Epigenetics is the study of changes in gene activity that are heritable but not caused by changes in the DNA sequence. By modulating gene activities, epigenetic changes regulate cell functions. They include DNA methylation, histone posttranslational modifications and gene silencing by the action of non-coding RNAs, particularly microRNAs. It is now clear that epigenetic changes regulate B cell development. By acting in concert with networks of transcription factors, they modulate the activation of B cell lineage specific gene programs and repress inappropriate gene transcription in particular B cell differentiation states. A hallmark of B cell development in the bone marrow is the assembly of the B cell receptor (BCR) for antigen through rearrangement of immunoglobulin heavy (IgH) and light (IgL) chain V(D)J genes, as mediated by RAG1/RAG2 recombinases. Ig V(D)J rearrangement critically times the progression from pro-B cell to pre-B cell and, finally, mature B cell. Such progression is modulated by epigenetic marks, such as DNA methylation and histone posttranslational modifications, that increase chromatin accessibility and target RAG/RAG2 to V, D and J DNA. It is also dependent on the expression of multiple microRNAs. Mice deficient in Ago2, which is essential for microRNA biogenesis and function, have B cell development blocked at the pro-B cell stage. In agreement with this, B cell specific ablation of microRNA by B cell-specific knockout of Dicer virtually blocks B cell differentiation at the pro-B to pre-B cell transition. After mature B cells encounter antigen, changes of the epigenetic landscape are induced by the same stimuli that drive the antibody response; such epigenetic changes underpin the maturation of the antibody response itself. They instruct those B cell differentiation processes, somatic hypermutation (SHM), class switch DNA recombination (CSR) and plasma cell differentiation, that are central to the maturation of the antibody response as well as differentiation of memory B cells. Inducible histone modifications, together with DNA methylation and microRNAs modulate the transcriptome, particularly the expression of activation-induced cytidine deaminase (AID), central to SHM and CSR, and B lymphocyte-induced maturation protein-1 (Blimp-1), which is central to plasma cell differentiation. Combinatorial histone modifications also function as histone codes in the targeting of the CSR and, possibly, the SHM machinery to the Ig locus by recruiting specific adaptors (histone code readers) that can in turn target and/or stabilize CSR/SHM factors. Epigenetic alterations in memory B cells contribute to their functionally distinction from their naive counterparts. Memory B cells inherit epigenetic information from their precursors and acquire new epigenetic marks, which make these resting B cells poised to promptly respond to antigen. The cross/feedback regulation of different epigenetic modifications/elements further increases the complexity of the B cell epigenome, which interacts with the genetic information for precise modulation of gene expression. It is increasingly evident that epigenetic dysregulation in B cells, including aberrant expression of microRNAs, can result in aberrant antibody responses to microbial pathogens, emergence of pathogenic autoantibodies or B cell neoplastic transformation. Epigenetic marks are potential targets for new therapeutics in autoimmunity and B cell malignancy.

Smart Sensors for Structural Health Monitoring

Authors: --- ---
ISBN: 9783039217588 9783039217595 Year: Pages: 342 DOI: 10.3390/books978-3-03921-759-5 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-12-09 11:49:16
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Smart sensors are technologies designed to facilitate the monitoring operations. For instance, power consumption can be minimized through on-board processing and smart interrogation algorithms, and state detection enhanced through collaboration between sensor nodes. Applied to structural health monitoring, smart sensors are key enablers of sparse and dense sensor networks capable of monitoring full-scale structures and components. They are also critical in empowering operators with decision making capabilities. The objective of this Special Issue is to generate discussions on the latest advances in research on smart sensing technologies for structural health monitoring applications, with a focus on decision-enabling systems. This Special Issue covers a wide range of related topics such as innovative sensors and sensing technologies for crack, displacement, and sudden event monitoring, sensor optimization, and novel sensor data processing algorithms for damage and defect detection, operational modal analysis, and system identification of a wide variety of structures (bridges, transmission line towers, high-speed trains, masonry light houses, etc.).

Keywords

optical crack growth sensor --- digital sampling moiré --- 2D crack growth --- calibration --- concrete crack --- feature extraction --- mapping construction --- fuzzy classification --- rotary ultrasonic array --- bending stiffness --- damage identification --- environmental noise --- bridge --- test vehicle --- structural impact monitoring --- sensors distribution optimization --- NSGA-II --- energy analysis of wavelet band --- principal component analysis --- transmission tower --- settlement --- wind force --- acceleration --- modal frequencies --- sudden event monitoring --- wireless smart sensors --- demand-based nodes --- event-triggered sensing --- data fusion --- patch antenna --- sensor --- structural health monitoring --- crack identification --- resonant frequency --- damage identification --- sensor optimization --- Virtual Distortion Method (VDM) --- Particle Swarm Optimization (PSO) algorithm --- sensitivity --- structural health monitoring --- piezoelectric wafer active sensors --- active sensing --- passive sensing --- damage detection --- acoustic emission --- uniaxial stress measurement --- structural steel members --- amplitude spectrum --- phase spectrum --- shear-wave birefringence --- acoustoelastic effect --- damage detection --- smartphones --- steel frame --- shaking table tests --- wavelet packet decomposition --- low-velocity impacts --- strain wave --- impactor stiffness --- data processing --- feature selection --- impact identification --- crack --- strain --- distributed dense sensor network --- structural health monitoring --- fibre bundle --- reflective optical sensor --- tip clearance --- turbine --- aero engine --- principal component analysis --- space window --- time window --- damage detection --- length effect --- stress detection --- electromagnetic oscillation --- steel strand --- concrete structures --- SHM --- stretching method --- model updating --- displacement sensor --- helical antenna --- resonant frequency --- perturbation theory --- normal mode --- wheel minor defect --- high-speed train --- online wayside detection --- Bayesian blind source separation --- FBG sensor array

Climate Variability and Climate Change Impacts on Land Surface, Hydrological Processes and Water Management

Authors: --- ---
ISBN: 9783039215072 9783039215089 Year: Pages: 460 DOI: 10.3390/books978-3-03921-508-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Environmental Sciences
Added to DOAB on : 2019-12-09 11:49:15
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During the last several decades, Earth´s climate has undergone significant changes due to anthropogenic global warming, and feedbacks to the water cycle. Therefore, persistent efforts are required to improve our understanding of hydrological processes and to engage in efficient water management strategies that explicitly consider changing environmental conditions. The twenty-four contributions in this book have broadly addressed topics across four major research areas: (1) Climate and land-use change impacts on hydrological processes, (2) hydrological trends and causality analysis faced in hydrology, (3) hydrological model simulations and predictions, and (4) reviews on water prices and climate extremes. The broad spectrum of international contributions to the Special Issue indicates that climate change impacts on water resources analysis attracts global attention. We hope that the collection of articles presented here can provide scientists, policymakers and stakeholders alike with insights that support sustainable decision-making in the face of climate change and increasingly scarce environmental resources.

Keywords

hydrological drought --- Three Gorges Dam --- GRACE --- compound extremes --- climate change --- multivariate distribution --- quantile regression --- indicator --- PUB --- rainfall-runoff experiments --- distributed hydrological model --- Hydro-Informatic Modelling System (HIMS) --- freshwater availability --- runoff --- simulated rainfall --- plot scale --- litter layer --- topsoil --- karst --- Yellow River Delta --- estuarine wetlands --- spatiotemporal change analysis --- remote sensing --- intra-annual climate change --- variation in percentage of flood-season precipitation --- natural streamflow variation --- contribution and sensitivity analysis --- Yellow River --- highland agricultural field area --- diffuse pollutant discharge --- multiple regression model --- climate change --- jackknife validation --- water security --- water pricing --- sustainable water management --- trends and patterns --- economics --- precipitation --- air temperature --- river discharge --- Mann-Kendall test --- Selenga river basin --- Lake Baikal basin --- Mongolia --- snowfall to precipitation ratio --- WRF model --- arid region --- Xinjiang --- water resources management --- climate change --- LULCC --- Budyko equation --- streamflow --- drought --- climate variability --- land surface change --- runoff --- Budyko framework --- elasticity coefficient --- Weihe River Basin --- flood --- streamflow --- CMIP5 --- climate change --- HEC-RAS --- trend analysis --- precipitation --- temperature --- eco-region --- Ethiopia --- Three Gorges Project --- dam --- runoff changes --- flood control --- Yangtze River --- benefits --- evapotranspiration --- Pan evaporation --- TFPW-MK --- Haihe River Basin --- hydrological simulation --- quantitative analysis --- SWAT model --- land use/cover change --- climate change --- scenario simulation --- Climate variability --- Large-scale climate indices --- Reservoir inflow forecasting --- Ensemble empirical mode decomposition --- Time series model --- Artificial intelligence model --- grid-based --- HRU-based --- SHM --- SWAT --- large scale basin --- climate change --- human activities --- power operations --- cascade joint operation chart --- inter-basin water transfer project --- climate change --- MATOPIBA agricultural frontier --- water security --- hydroclimatic analysis --- water conflicts --- average annual runoff --- runoff map --- hydrological model --- GIS --- DPR Korea --- streamflow reduction --- climate change --- coal mining --- SWCM --- coal mining concentrated watershed --- the Loess Plateau --- hydrology --- land cover --- land use and climate change --- water resources management --- macro scale modeling --- climate variability --- climate change --- land use change --- hydrological processes --- trends --- water management --- model --- predictions

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