Regulatory control of fuel design and manufacturing

International Nuclear Information System (INIS)

1994-01-01

The regulatory control of the design and manufacturing of the nuclear fuel and of the control rods aims to ensure conformance to set requirements during normal operating conditions, anticipated operational transients and postulated accident conditions. The regulatory control of design, manufacturing, receiving inspections and the start of operation of the nuclear fuel are specified in the guide. The regulatory control procedure also applies to the control rods and the shield elements

Regulatory control of nuclear power plants

International Nuclear Information System (INIS)

2002-01-01

The purpose of this book is to support IAEA training courses and workshops in the field of regulatory control of nuclear power plants as well as to support the regulatory bodies of Member States in their own training activities. The target group is the professional staff members of nuclear safety regulatory bodies supervising nuclear power plants and having duties and responsibilities in the following regulatory fields: regulatory framework; regulatory organization; regulatory guidance; licensing and licensing documents; assessment of safety; and regulatory inspection and enforcement. Important topics such as regulatory competence and quality of regulatory work as well as emergency preparedness and public communication are also covered. The book also presents the key issues of nuclear safety such as 'defence-in-depth' and safety culture and explains how these should be taken into account in regulatory work, e.g. during safety assessment and regulatory inspection. The book also reflects how nuclear safety has been developed during the years on the basis of operating experience feedback and results of safety research by giving topical examples. The examples cover development of operating procedures and accident management to cope with complicated incidents and severe accidents to stress the importance of regulatory role in nuclear safety research. The main target group is new staff members of regulatory bodies, but the book also offers good examples for more experienced inspectors to be used as comparison and discussion basis in internal workshops organized by the regulatory bodies for refreshing and continuing training. The book was originally compiled on the basis of presentations provided during the two regulatory control training courses in 1997 and 1998. The textbook was reviewed at the beginning of the years 2000 and 2002 by IAEA staff members and consistency with the latest revisions of safety standards have been ensured. The textbook was completed in the

Classical dendritic cells are required for dietary antigen-mediated peripheral regulatory T cell and tolerance induction

Science.gov (United States)

Esterházy, Daria; Loschko, Jakob; London, Mariya; Jove, Veronica; Oliveira, Thiago Y.; Mucida, Daniel

2016-01-01

Oral tolerance prevents pathological inflammatory responses towards innocuous foreign antigens via peripheral regulatory T cells (pTreg cells). However, whether a particular subset of antigen-presenting cells (APCs) is required during dietary antigen exposure to instruct naïve CD4+ T cells to differentiate into pTreg cells has not been defined. Using myeloid lineage-specific APC depletion in mice, we found that monocyte-derived APCs are dispensable, while classical dendritic cells (cDCs) are critical for pTreg cell induction and oral tolerance. CD11b− cDCs from the gut-draining lymph nodes efficiently induced pTreg cells, and conversely, loss of IRF8-dependent CD11b− cDCs impaired their polarization, although oral tolerance remained intact. These data reveal the hierarchy of cDC subsets in pTreg cell induction and their redundancy during oral tolerance development. PMID:27019226

Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles

Science.gov (United States)

2007-11-01

Tolerant Overactuated Autonomous Vehicles Casavola, A.; Garone, E. (2007) Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous ...Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Tolerant Overactuated Autonomous Vehicles 3.2 - 2 RTO-MP-AVT-145 UNCLASSIFIED/UNLIMITED Control allocation problem (CAP) - Given a virtual input v(t

Fault tolerant controllers for sampled-data systems

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Stoustrup, Jakob

2004-01-01

A general compensator architecture for fault tolerant control (FTC) for sampled-data systems is proposed. The architecture is based on the YJBK parameterization of all stabilizing controllers, and uses the dual YJBK parameterization to quantify the performance of the fault tolerant system. The FTC...

Autonomous Congestion Control in Delay-Tolerant Networks

Science.gov (United States)

Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

2006-01-01

This presentation highlights communication congestion control in delay-tolerant networks (DTNs). Large-scale future space exploration will offer complex communication challenges that may be best addressed by establishing a network infrastructure. However, current internet techniques for congestion control are not well suited for operation of a network over interplanetary distances. An alternative, delay-tolerant technique for congestion control in a delay-tolerant network is presented. A simple DTN was constructed and an experimental congestion control mechanism was applied. The mechanism appeared to be effective and each router was able to make its bundle acceptance decisions autonomously. Future research will examine more complex topologies and alternative bundle acceptance rules that might enhance performance.

Fault Tolerant Control Using Gaussian Processes and Model Predictive Control

Directory of Open Access Journals (Sweden)

Yang Xiaoke

2015-03-01

Full Text Available Essential ingredients for fault-tolerant control are the ability to represent system behaviour following the occurrence of a fault, and the ability to exploit this representation for deciding control actions. Gaussian processes seem to be very promising candidates for the first of these, and model predictive control has a proven capability for the second. We therefore propose to use the two together to obtain fault-tolerant control functionality. Our proposal is illustrated by several reasonably realistic examples drawn from flight control.

Regulatory dendritic cells in autoimmunity: A comprehensive review.

Science.gov (United States)

Liu, Juan; Cao, Xuetao

2015-09-01

Dendritic cells (DCs) are professional antigen-presenting cells (APC) with significant phenotypic heterogeneity and functional plasticity. DCs play crucial roles in initiating effective adaptive immune responses for elimination of invading pathogens and also in inducing immune tolerance toward harmless components to maintain immune homeostasis. The regulatory capacity of DCs depends on their immature state and distinct subsets, yet not restricted to the immature state and one specialized subset. The tolerogenicity of DC is controlled by a complex network of environmental signals and cellular intrinsic mechanisms. Regulatory DCs play an important role in the maintenance of immunological tolerance via the induction of T cell unresponsiveness or apoptosis, and generation of regulatory T cells. DCs play essential roles in driving autoimmunity via promoting the activation of effector T cells such as T helper 1 and T helper 17 cells, and/or suppressing the generation of regulatory T cells. Besides, a breakdown of DCs-mediated tolerance due to abnormal environmental signals or breakdown of intrinsic regulatory mechanisms is closely linked with the pathogenesis of autoimmune diseases. Novel immunotherapy taking advantage of the tolerogenic potential of regulatory DCs is being developed for treatment of autoimmune diseases. In this review, we will describe the current understanding on the generation of regulatory DC and the role of regulatory DCs in promoting tolerogenic immune responses and suppressing autoimmune responses. The emerging roles of DCs dysfunction in the pathogenesis of autoimmune diseases and the potential application of regulatory DCs in the treatment of autoimmune diseases will also be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulatory Control of Radiation Sources. Safety Guide

International Nuclear Information System (INIS)

2009-01-01

This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

Fault tolerant control schemes using integral sliding modes

CERN Document Server

Hamayun, Mirza Tariq; Alwi, Halim

2016-01-01

The key attribute of a Fault Tolerant Control (FTC) system is its ability to maintain overall system stability and acceptable performance in the face of faults and failures within the feedback system. In this book Integral Sliding Mode (ISM) Control Allocation (CA) schemes for FTC are described, which have the potential to maintain close to nominal fault-free performance (for the entire system response), in the face of actuator faults and even complete failures of certain actuators. Broadly an ISM controller based around a model of the plant with the aim of creating a nonlinear fault tolerant feedback controller whose closed-loop performance is established during the design process. The second approach involves retro-fitting an ISM scheme to an existing feedback controller to introduce fault tolerance. This may be advantageous from an industrial perspective, because fault tolerance can be introduced without changing the existing control loops. A high fidelity benchmark model of a large transport aircraft is u...

Expression of cold and drought regulatory protein (CcCDR) of pigeonpea imparts enhanced tolerance to major abiotic stresses in transgenic rice plants.

Science.gov (United States)

Sunitha, Mellacheruvu; Srinath, Tamirisa; Reddy, Vudem Dashavantha; Rao, Khareedu Venkateswara

2017-06-01

Transgenic rice expressing pigeonpea Cc CDR conferred high-level tolerance to different abiotic stresses. The multiple stress tolerance observed in CcCDR -transgenic lines is attributed to the modulation of ABA-dependent and-independent signalling-pathway genes. Stable transgenic plants expressing Cajanus cajan cold and drought regulatory protein encoding gene (CcCDR), under the control of CaMV35S and rd29A promoters, have been generated in indica rice. Different transgenic lines of CcCDR, when subjected to drought, salt, and cold stresses, exhibited higher seed germination, seedling survival rates, shoot length, root length, and enhanced plant biomass when compared with the untransformed control plants. Furthermore, transgenic plants disclosed higher leaf chlorophyll content, proline, reducing sugars, SOD, and catalase activities, besides lower levels of MDA. Localization studies revealed that the CcCDR-GFP fusion protein was mainly present in the nucleus of transformed cells of rice. The CcCDR transgenics were found hypersensitive to abscisic acid (ABA) and showed reduced seed germination rates as compared to that of control plants. When the transgenic plants were exposed to drought and salt stresses at vegetative and reproductive stages, they revealed larger panicles and higher number of filled grains compared to the untransformed control plants. Under similar stress conditions, the expression levels of P5CS, bZIP, DREB, OsLEA3, and CIPK genes, involved in ABA-dependent and-independent signal transduction pathways, were found higher in the transgenic plants than the control plants. The overall results amply demonstrate that the transgenic rice expressing CcCDR bestows high-level tolerance to drought, salt, and cold stress conditions. Accordingly, the CcCDR might be deployed as a promising candidate gene for improving the multiple stress tolerance of diverse crop plants.

Novel neural networks-based fault tolerant control scheme with fault alarm.

Science.gov (United States)

Shen, Qikun; Jiang, Bin; Shi, Peng; Lim, Cheng-Chew

2014-11-01

In this paper, the problem of adaptive active fault-tolerant control for a class of nonlinear systems with unknown actuator fault is investigated. The actuator fault is assumed to have no traditional affine appearance of the system state variables and control input. The useful property of the basis function of the radial basis function neural network (NN), which will be used in the design of the fault tolerant controller, is explored. Based on the analysis of the design of normal and passive fault tolerant controllers, by using the implicit function theorem, a novel NN-based active fault-tolerant control scheme with fault alarm is proposed. Comparing with results in the literature, the fault-tolerant control scheme can minimize the time delay between fault occurrence and accommodation that is called the time delay due to fault diagnosis, and reduce the adverse effect on system performance. In addition, the FTC scheme has the advantages of a passive fault-tolerant control scheme as well as the traditional active fault-tolerant control scheme's properties. Furthermore, the fault-tolerant control scheme requires no additional fault detection and isolation model which is necessary in the traditional active fault-tolerant control scheme. Finally, simulation results are presented to demonstrate the efficiency of the developed techniques.

T-regulatory cells in chronic rejection versus stable grafts.

Science.gov (United States)

Al-Wedaie, Fatima; Farid, Eman; Tabbara, Khaled; El-Agroudy, Amgad E; Al-Ghareeb, Sumaya M

2015-04-01

Studying regulatory T cells in kidney allograft acceptance versus chronic rejection may help in the understanding of more mechanisms of immune tolerance and, in the future, may enable clinicians to induce immune tolerance and decrease the use of immunosuppressive drugs. The aim of the current study was to evaluate regulatory T cells in kidney transplant patients with stable graft versus transplant with biopsy-proven chronic rejection. The 3 groups that were studied included: kidney transplanted patients with no rejection episodes (n = 43); transplanted patients with biopsy-proven renal rejection (n = 27); and healthy age-matched nontransplanted individuals as controls (n = 42).The percentage of regulatory T cells (CD4+CD25+Foxp3+) in blood was determined by flow cytometry. The regulatory T cell percentage was significantly lower in chronic rejection patients than control or stable graft groups. No significant difference was observed in regulatory T cell percentage between the stable graft and control groups. In the stable graft group, patients on rapamycin had a significantly higher regulatory T cell percentage than patients on cyclosporine. No effect of donor type, infection, or duration after transplant was observed on regulatory T cell percentage. The results of the current study are consistent with previous studies addressing the function of regulatory T cells in inducing immunotolerance after kidney transplant. Considering the established role of regulatory T cells in graft maintenance and our observation of high regulatory T cell percentage in patients receiving rapamycin than cyclosporine, we recommend including rapamycin when possible in immunosuppressive protocols. The findings from the current study on the chronic rejection group support ongoing research of having treatment with regulatory T cells, which may constitute a novel, efficient antirejection therapy in the future.

What is Fault Tolerant Control

DEFF Research Database (Denmark)

Blanke, Mogens; Frei, C. W.; Kraus, K.

2000-01-01

Faults in automated processes will often cause undesired reactions and shut-down of a controlled plant, and the consequences could be damage to the plant, to personnel or the environment. Fault-tolerant control is the synonym for a set of recent techniques that were developed to increase plant...... availability and reduce the risk of safety hazards. Its aim is to prevent that simple faults develop into serious failure. Fault-tolerant control merges several disciplines to achieve this goal, including on-line fault diagnosis, automatic condition assessment and calculation of remedial actions when a fault...... is detected. The envelope of the possible remedial actions is wide. This paper introduces tools to analyze and explore structure and other fundamental properties of an automated system such that any redundancy in the process can be fully utilized to enhance safety and a availability....

Breaking Tolerance to Thyroid Antigens: Changing Concepts in Thyroid Autoimmunity

Science.gov (United States)

Rapoport, Basil

2014-01-01

Thyroid autoimmunity involves loss of tolerance to thyroid proteins in genetically susceptible individuals in association with environmental factors. In central tolerance, intrathymic autoantigen presentation deletes immature T cells with high affinity for autoantigen-derived peptides. Regulatory T cells provide an alternative mechanism to silence autoimmune T cells in the periphery. The TSH receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (Tg) have unusual properties (“immunogenicity”) that contribute to breaking tolerance, including size, abundance, membrane association, glycosylation, and polymorphisms. Insight into loss of tolerance to thyroid proteins comes from spontaneous and induced animal models: 1) intrathymic expression controls self-tolerance to the TSHR, not TPO or Tg; 2) regulatory T cells are not involved in TSHR self-tolerance and instead control the balance between Graves' disease and thyroiditis; 3) breaking TSHR tolerance involves contributions from major histocompatibility complex molecules (humans and induced mouse models), TSHR polymorphism(s) (humans), and alternative splicing (mice); 4) loss of tolerance to Tg before TPO indicates that greater Tg immunogenicity vs TPO dominates central tolerance expectations; 5) tolerance is induced by thyroid autoantigen administration before autoimmunity is established; 6) interferon-α therapy for hepatitis C infection enhances thyroid autoimmunity in patients with intact immunity; Graves' disease developing after T-cell depletion reflects reconstitution autoimmunity; and 7) most environmental factors (including excess iodine) “reveal,” but do not induce, thyroid autoimmunity. Micro-organisms likely exert their effects via bystander stimulation. Finally, no single mechanism explains the loss of tolerance to thyroid proteins. The goal of inducing self-tolerance to prevent autoimmune thyroid disease will require accurate prediction of at-risk individuals together with an antigen

Safety culture as a matter of regulatory control and regulatory effectiveness

International Nuclear Information System (INIS)

Camargo, C.T.M.; Furieri, E.B.; Arrieta, L.A.I.; Almeida, C.U.C.

2002-01-01

More than 15 years have passed since the term 'safety culture' was introduced by the International Nuclear Safety Advisory Group (INSAG), and although the concept now is widely accepted, practical applications and characteristics have been disseminated mainly for nuclear power plant operating organizations. There is still a lack of international guidance on the use of safety culture as a regulatory matter and on the application of the concept within regulatory organizations. This work explores the meaning of safety culture in two different fields: as an element of safety management systems it shall be a matter of regulatory control; as a complementary tool for quality management it should be used to enhance regulatory effectiveness. Brazilian recent experience on regulating nuclear power reactors provide some examples on how the concept of safety culture may influence regulatory strategies and regulatory management. (author)

Fault Tolerant Control Systems

DEFF Research Database (Denmark)

Bøgh, S. A.

This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...

Regulatory T cells: serious contenders in the promise for immunological tolerance in transplantation

Directory of Open Access Journals (Sweden)

Niloufar eSafinia

2015-08-01

Full Text Available Regulatory T cells (Tregs play an important role in immunoregulation and have been shown in animal models to promote transplantation tolerance and curb autoimmunity following their adoptive transfer. The safety and potential therapeutic efficacy of these cells has already been reported in Phase I trials of bone marrow transplantation and type I diabetes, the success of which has motivated the broadened application of these cells in solid organ transplantation. Despite major advances in the clinical translation of these cells, there are still key questions to be addressed to ensure that Tregs attest their reputation as ideal candidates for tolerance induction. In this review, we will discuss the unique traits of Tregs that have attracted such fame in the arena of tolerance induction. We will outline the protocols used for their ex vivo expansion and discuss the future directions of Treg cell therapy. In this regard, we will review the concept of Treg heterogeneity, the desire to isolate and expand a functionally superior Treg population and report on the effect of differing culture conditions. The relevance of Treg migratory capacity will also be discussed together with methods of in vivo visualization of the infused cells. Moreover, we will highlight key advances in the identification and expansion of antigen specific Tregs and discuss their significance for cell therapy application. We will also summarize the clinical parameters that are of importance, alongside cell manufacture, from the choice of immunosuppression regimens to the number of injections in order to direct the success of future efficacy trials of Treg cell therapy.Years of research in the field of tolerance have seen an accumulation of knowledge and expertise in the field of Treg biology. This perpetual progression has been the driving force behind the many successes to date and has put us now within touching distance of our ultimate success, immunological tolerance.

Active Fault Tolerant Control for Ultrasonic Piezoelectric Motor

Science.gov (United States)

Boukhnifer, Moussa

2012-07-01

Ultrasonic piezoelectric motor technology is an important system component in integrated mechatronics devices working on extreme operating conditions. Due to these constraints, robustness and performance of the control interfaces should be taken into account in the motor design. In this paper, we apply a new architecture for a fault tolerant control using Youla parameterization for an ultrasonic piezoelectric motor. The distinguished feature of proposed controller architecture is that it shows structurally how the controller design for performance and robustness may be done separately which has the potential to overcome the conflict between performance and robustness in the traditional feedback framework. A fault tolerant control architecture includes two parts: one part for performance and the other part for robustness. The controller design works in such a way that the feedback control system will be solely controlled by the proportional plus double-integral PI2 performance controller for a nominal model without disturbances and H∞ robustification controller will only be activated in the presence of the uncertainties or an external disturbances. The simulation results demonstrate the effectiveness of the proposed fault tolerant control architecture.

Active Fault Tolerant Control of Livestock Stable Ventilation System

DEFF Research Database (Denmark)

Gholami, Mehdi

2011-01-01

Modern stables and greenhouses are equipped with different components for providing a comfortable climate for animals and plant. A component malfunction may result in loss of production. Therefore, it is desirable to design a control system, which is stable, and is able to provide an acceptable d...... are not included, while due to the physical limitation, the input signal can not have any value. In continuing, a passive fault tolerant controller (PFTC) based on state feedback is proposed to track a reference signal while the control inputs are bounded....... of fault. Designing a fault tolerant control scheme for the climate control system. In the first step, a conceptual multi-zone model for climate control of a live-stock building is derived. The model is a nonlinear hybrid model. Hybrid systems contain both discrete and continuous components. The parameters...... affine (PWA) components such as dead-zones, saturation, etc or contain piecewise nonlinear models which is the case for the climate control systems of the stables. Fault tolerant controller (FTC) is based on a switching scheme between a set of predefined passive fault tolerant controller (PFTC...

Regulatory controls for NORM contamination: Emerging issues and strategies

International Nuclear Information System (INIS)

Wennerberg, Linda

1992-01-01

Naturally occurring and accelerator-produced radioactive material (NORM) faces the increasing likelihood of federal or state regulatory control. Public concern and limited preliminary survey data fuel the debate over the necessity, approach, and jurisdiction of a NORM regulatory strategy. This debate requires the resolution of technical controversies and potentially competing state and federal agency interests. An additional facet of the debate is the impact of regulation upon traditionally non-nuclear industries, such as oil and gas production. Regulatory response has been initiated in several states, such as Louisiana's controls on equipment used in oil and gas production, to control specific industrial activities which generate NORM. A more comprehensive, generic federal strategy to control NORM contamination is also under review by the Environmental Protection Agency. This paper will detail the emerging technical issues, federal and state regulatory strategies under consideration, and evaluate the efficacy of selected regulatory approaches. (author)

Removal of regulatory controls for materials and sites

International Nuclear Information System (INIS)

2004-01-01

Issues with the removal of regulatory controls are very important on the agenda of the regulatory authorities dealing with radioactive waste management (RWM). These issues arise prominently in decommissioning and in site remediation, and decisions can be very wide ranging having potentially important economic impacts and reaching outside the RWM area. The RWMC Regulators Forum started to address these issues by holding a topical discussion at its meeting in March 2003. Ths present document collates the national regulatory positions in the area of removal of regulatory controls. A summary of the national positions is also provided. The document is up to date to April 2004. (authors)

Animal models of allergen-induced tolerance in asthma: are T-regulatory-1 cells (Tr-1) the solution for T-helper-2 cells (Th-2) in asthma?

Science.gov (United States)

Tournoy, K G; Hove, C; Grooten, J; Moerloose, K; Brusselle, G G; Joos, G F

2006-01-01

Non-specific anti-inflammatory medication is actually the treatment of choice for controlling the T-helper type 2 (Th-2) cell-driven airway inflammation in asthma. The induction of counterbalancing Th-1 cell clones, long considered a promising approach for immunotherapy, has failed to fulfil its promise because of potentially detrimental side-effects. This is therefore probably not a valid option for the treatment of asthma. With the increasing awareness that active immune mechanisms exist to control inflammatory responses, interest rises to investigate whether these can be exploited to control allergen-induced airway disease. The induction of antigen-specific T cells with suppressive characteristics (regulatory T cells) is therefore a potentially interesting approach. These regulatory T cells mediate tolerance in healthy, non-atopic individuals and have the potential of becoming an effective means of preventing allergen-induced airway inflammation and possibly of suppressing ongoing allergic immune responses. Here we review the available knowledge about allergen-induced suppressive immunity obtained from animal models taking into account the different developmental stages of allergic airway disease.

Fault Tolerant Control System Design Using Automated Methods from Risk Analysis

DEFF Research Database (Denmark)

Blanke, M.

Fault tolerant controls have the ability to be resilient to simple faults in control loop components.......Fault tolerant controls have the ability to be resilient to simple faults in control loop components....

Fault tolerant control of systems with saturations

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2013-01-01

This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture in connec......This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture...... in connection with faulty systems including input saturation gives an additional YJBK transfer function related to the input saturation. In the fault free case, this additional YJBK transfer function can be applied directly for optimizing the feedback loop around the input saturation. In the faulty case......, the design problem is a mixed design problem involved both parametric faults and input saturation....

Fault tolerant digital control systems for boiling water reactors

International Nuclear Information System (INIS)

Chakraborty, S.; Cash, N.R.

1986-01-01

In a Boiling Water Reactor nuclear power plant, the power generation control function is divided into several systems, each system controlling only a part of the total plant. Presently, each system is controlled by conventional analog or digital logic circuits with little interaction for coordinated control. The advent of microprocessors has allowed the development of distributed fault-tolerant digital controls. The objective is to replace these conventional controls with fault-tolerant digital controls connected together with digital communication links to form a fully integrated nuclear power plant control system

Evaluation of digital fault-tolerant architectures for nuclear power plant control systems

International Nuclear Information System (INIS)

Battle, R.E.

1990-01-01

Four fault tolerant architectures were evaluated for their potential reliability in service as control systems of nuclear power plants. The reliability analyses showed that human- and software-related common cause failures and single points of failure in the output modules are dominant contributors to system unreliability. The four architectures are triple-modular-redundant (TMR), both synchronous and asynchronous, and also dual synchronous and asynchronous. The evaluation includes a review of design features, an analysis of the importance of coverage, and reliability analyses of fault tolerant systems. An advantage of fault-tolerant controllers over those not fault tolerant, is that fault-tolerant controllers continue to function after the occurrence of most single hardware faults. However, most fault-tolerant controllers have single hardware components that will cause system failure, almost all controllers have single points of failure in software, and all are subject to common cause failures. Reliability analyses based on data from several industries that have fault-tolerant controllers were used to estimate the mean-time-between-failures of fault-tolerant controllers and to predict those failures modes that may be important in nuclear power plants. 7 refs., 4 tabs

Antigen-specific tolerance inhibits autoimmune uveitis in pre-sensitized animals by deletion and CD4+CD25+ T-regulatory cells.

Science.gov (United States)

Matta, Bharati; Jha, Purushottam; Bora, Puran S; Bora, Nalini S

2010-02-01

The objective of this study was to inhibit experimental autoimmune anterior uveitis (EAAU) by establishing antigen-specific immune tolerance in animals pre-sensitized with melanin-associated antigen (MAA). Intravenous administration of MAA on days 6, 7, 8 and 9 post-immunization induced tolerance and inhibited EAAU in all Lewis rats. The number of cells (total T cells, CD4(+) T cells and CD8(+) T cells) undergoing apoptosis dramatically increased in the popliteal lymph nodes (LNs) of the tolerized animals compared with non-tolerized animals. In addition, Fas ligand (FasL), TNF receptor 1 (TNFR1) and caspase-8 were upregulated in tolerized rats. Proliferation of total lymphocytes, CD4(+)T cells and CD8(+) T cells (harvested from the popliteal LNs) in response to antigenic stimulation was drastically reduced in the state of tolerance compared with the cells from non-tolerized animals. The level of interferon (IFN)-gamma and IL-2 decreased, whereas TGF-beta2 was elevated in the state of tolerance. Furthermore, the number of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) increased in the popliteal LNs of tolerized animals compared with non-tolerized animals. In conclusion, our results suggest that deletion of antigen-specific T cells by apoptosis and active suppression mediated by Tregs has an important role in the induction of antigen specific immune tolerance in animals with an established immune response against MAA.

The regulatory control of radioactive sources in Argentina

International Nuclear Information System (INIS)

Rojkind, Roberto Hector

1997-01-01

Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author)

Design of fault tolerant control system for steam generator using

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Ki; Seo, Mi Ro [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1998-12-31

A controller and sensor fault tolerant system for a steam generator is designed with fuzzy logic. A structure of the proposed fault tolerant redundant system is composed of a supervisor and two fuzzy weighting modulators. A supervisor alternatively checks a controller and a sensor induced performances to identify which part, a controller or a sensor, is faulty. In order to analyze controller induced performance both an error and a change in error of the system output are chosen as fuzzy variables. The fuzzy logic for a sensor induced performance uses two variables : a deviation between two sensor outputs and its frequency. Fuzzy weighting modulator generates an output signal compensated for faulty input signal. Simulations show that the proposed fault tolerant control scheme for a steam generator regulates well water level by suppressing fault effect of either controllers or sensors. Therefore through duplicating sensors and controllers with the proposed fault tolerant scheme, both a reliability of a steam generator control and sensor system and that of a power plant increase even more. 2 refs., 9 figs., 1 tab. (Author)

Pavlovian control of cross-tolerance between pentobarbital and ethanol.

Science.gov (United States)

Cappell, H; Roach, C; Poulos, C X

1981-01-01

Tolerance to several effects of a number of drugs has been shown to depend on Pavlovian conditioning processes. Experiment I extended the compensatory conditioning model (Siegel 1975) to tolerance to the hypothermic effect of pentobarbital (30 mg/kg). In Experiment I, rats that acquired hypothermic tolerance in one environment did not display tolerance when tested in an environment not previously associated with drug administration. In Experiment II, rats were made tolerant to the hypothermic effect of pentobarbital (30 mg/kg) and tested for cross-tolerance to ethanol (2.5 g/kg). Cross-tolerance was observed, but it was significantly reduced if the test was in an environment different from the one in which tolerance to pentobarbital was originally acquired. Thus, the compensatory conditioning model accounts for at least part of the tolerance and cross-tolerance to the thermic effects of alcohol and pentobarbital. The physiological processes in the CNS underlying tolerance and cross-tolerance for these drugs, therefore, are controlled by associative processes.

Passive Fault tolerant Control of an Inverted Double Pendulum

DEFF Research Database (Denmark)

Niemann, H.; Stoustrup, Jakob

2003-01-01

A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the Youla parameterization, which requires the nominal controller to be imp......A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the Youla parameterization, which requires the nominal controller...

Fault tolerant control of multivariable processes using auto-tuning PID controller.

Science.gov (United States)

Yu, Ding-Li; Chang, T K; Yu, Ding-Wen

2005-02-01

Fault tolerant control of dynamic processes is investigated in this paper using an auto-tuning PID controller. A fault tolerant control scheme is proposed composing an auto-tuning PID controller based on an adaptive neural network model. The model is trained online using the extended Kalman filter (EKF) algorithm to learn system post-fault dynamics. Based on this model, the PID controller adjusts its parameters to compensate the effects of the faults, so that the control performance is recovered from degradation. The auto-tuning algorithm for the PID controller is derived with the Lyapunov method and therefore, the model predicted tracking error is guaranteed to converge asymptotically. The method is applied to a simulated two-input two-output continuous stirred tank reactor (CSTR) with various faults, which demonstrate the applicability of the developed scheme to industrial processes.

Regulatory Control of Radiation Sources. Safety Guide (Arabic Edition)

International Nuclear Information System (INIS)

2012-01-01

This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

Regulatory T-Cell-Associated Cytokines in Systemic Lupus Erythematosus

Directory of Open Access Journals (Sweden)

Akiko Okamoto

2011-01-01

Full Text Available Systemic lupus erythematosus (SLE is an autoimmune disease characterized by autoantibody production, complement activation, and immune complex deposition, resulting in tissue and organ damage. An understanding of the mechanisms responsible for homeostatic control of inflammation, which involve both innate and adoptive immune responses, will enable the development of novel therapies for SLE. Regulatory T cells (Treg play critical roles in the induction of peripheral tolerance to self- and foreign antigens. Naturally occurring CD4+CD25+ Treg, which characteristically express the transcription factor forkhead box protein P3 (Foxp3, have been intensively studied because their deficiency abrogates self-tolerance and causes autoimmune disease. Moreover, regulatory cytokines such as interleukin-10 (IL-10 also play a central role in controlling inflammatory processes. This paper focuses on Tregs and Treg-associated cytokines which might regulate the pathogenesis of SLE and, hence, have clinical applications.

Industrial Cost-Benefit Assessment for Fault-tolerant Control Systems

DEFF Research Database (Denmark)

Thybo, C.; Blanke, M.

1998-01-01

Economic aspects are decisive for industrial acceptance of research concepts including the promising ideas in fault tolerant control. Fault tolerance is the ability of a system to detect, isolate and accommodate a fault, such that simple faults in a sub-system do not develop into failures....... The objective of this paper is to help, in the early product development state, to find the economical most suitable scheme. A salient result is that with increased customer awareness of total cost of ownership, new products can benefit significantly from applying fault tolerant control principles....

Regulatory accessibility and social influences on state self-control.

Science.gov (United States)

vanDellen, Michelle R; Hoyle, Rick H

2010-02-01

The current work examined how social factors influence self-control. Current conceptions of state self-control treat it largely as a function of regulatory capacity. The authors propose that state self-control might also be influenced by social factors because of regulatory accessibility. Studies 1 through 4 provide evidence that individuals' state self-control is influenced by the trait and state self-control of salient others such that thinking of others with good trait or state self-control leads to increases in state self-control and thinking of others with bad trait or state self-control leads to decreases in state self-control. Study 5 provides evidence that the salience of significant others influences both regulatory accessibility and state self-control. Combined, these studies suggest that the effects of social influences on state self-control occur through multiple mechanisms.

Concepts and Methods in Fault-tolerant Control

DEFF Research Database (Denmark)

Blanke, Mogens; Staroswiecly, M.; Wu, N.E.

2001-01-01

Faults in automated processes will often cause undesired reactions and shut-down of a controlled plant, and the consequences could be damage to technical parts of the plant, to personnel or the environment. Fault-tolerant control combines diagnosis with control methods to handle faults...

The Cellular and Molecular Mechanisms of Immuno-suppression by Human Type 1 Regulatory T cells

Directory of Open Access Journals (Sweden)

Silvia eGregori

2012-02-01

Full Text Available The immuno-regulatory mechanisms of IL-10-producing type 1 regulatory T (Tr1 cells have been widely studied over the years. However, several recent discoveries have shed new light on the cellular and molecular mechanisms that human Tr1 cells use to control immune responses and induce tolerance. In this review we outline the well-known and newly discovered regulatory properties of human Tr1 cells and provide an in-depth comparison of the known suppressor mechanisms of Tr1 cells with FOXP3+ Treg. We also highlight the role that Tr1 cells play in promoting and maintaining tolerance in autoimmunity, allergy, and transplantation.

The regulatory control of radioactive sources in Argentina

International Nuclear Information System (INIS)

Rojkind, R.H.

1998-01-01

Argentina has been conducting nuclear activities for more than forty years, and had established a Regulatory Authority as early as in 1956. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations were in force in Argentina before the accident in Goiania. The conclusions drawn from the Goiania accident encouraged the Argentine authorities to improve some regulatory procedures and helped to enhance the quality of the regulatory process. As a result, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain have improved. Lessons learned in Argentina from the accident in Goiania are presented as well as the main characteristics of an effective enforcement programme to prevent radiological accidents when radioactive sources are used for industrial, medical, research and teaching purposes. (author)

Low-income minority fathers' control strategies and children's regulatory skills

Science.gov (United States)

Malin, Jenessa L.; Cabrera, Natasha J.; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith

2015-01-01

The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24-months and children's regulatory skills at pre-kindergarten (pre-K). Using a sample of low-income minority families with 2-year-olds from the Early Head Start Evaluation Research Program (n = 71) we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24-months (e.g., regulatory behavior and regulatory language), and children's sustained attention and emotion regulation at pre-kindergarten. There were three main findings. First, fathers' overwhelmingly use commands (e.g., do that) to promote compliance in their 24-month old children. Second, children's vocabulary skills predict fathers' regulatory behaviors during a father-child interaction, whereas children's gender predicts fathers' regulatory language during an interaction. Third, controlling for maternal supportiveness, fathers' regulatory behaviors at 24-months predict children's sustained attention at pre-kindergarten whereas fathers' regulatory language at 24-months predicts children's emotion regulation at pre-kindergarten. Our findings highlight the importance of examining paternal contributions to children's regulatory skills. PMID:25798496

The regulatory control of radioactive sources in Argentina

Energy Technology Data Exchange (ETDEWEB)

Rojkind, Roberto Hector [Autoridade Regulatoria Nuclear, Buenos Aires (Argentina)

1997-12-31

Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author) 9 refs; e-mail: rrojkind at sede.arn.gov.br

Fault tolerant control for uncertain systems with parametric faults

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Poulsen, Niels Kjølstad

2006-01-01

A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...... is investigated. Conditions are given for closed-loop stability in case of false alarms or missing fault detection/isolation....

Controllability analysis of transcriptional regulatory networks reveals circular control patterns among transcription factors

DEFF Research Database (Denmark)

Österlund, Tobias; Bordel, Sergio; Nielsen, Jens

2015-01-01

% for the human network. The high controllability (low number of drivers needed to control the system) in yeast, mouse and human is due to the presence of internal loops in their regulatory networks where the TFs regulate each other in a circular fashion. We refer to these internal loops as circular control...... motifs (CCM). The E. coli transcriptional regulatory network, which does not have any CCMs, shows a hierarchical structure of the transcriptional regulatory network in contrast to the eukaryal networks. The presence of CCMs also has influence on the stability of these networks, as the presence of cycles...

Mine-hoist active fault tolerant control system and strategy

Energy Technology Data Exchange (ETDEWEB)

Wang, Z.; Wang, Y.; Meng, J.; Zhao, P.; Chang, Y. [China University of Mining and Technology, Xuzhou (China)] wzjsdstu@163.com

2005-06-01

Based on fault diagnosis and fault tolerant technologies, the mine-hoist active fault-tolerant control system (MAFCS) is presented with corresponding strategies, which includes the fault diagnosis module (FDM), the dynamic library (DL) and the fault-tolerant control model (FCM). When a fault is judged from some sensor by the FDM, FCM reconfigures the state of the MAFCS by calling the parameters from all sub libraries in DL, in order to ensure the reliability and safety of the mine hoist. The simulating result shows that MAFCS is of certain intelligence, which can adopt the corresponding control strategies according to different fault modes, even when there is quite a difference between the real data and the prior fault modes. 7 refs., 5 figs., 1 tab.

Guaranteed Cost Fault-Tolerant Control for Networked Control Systems with Sensor Faults

Directory of Open Access Journals (Sweden)

Qixin Zhu

2015-01-01

Full Text Available For the large scale and complicated structure of networked control systems, time-varying sensor faults could inevitably occur when the system works in a poor environment. Guaranteed cost fault-tolerant controller for the new networked control systems with time-varying sensor faults is designed in this paper. Based on time delay of the network transmission environment, the networked control systems with sensor faults are modeled as a discrete-time system with uncertain parameters. And the model of networked control systems is related to the boundary values of the sensor faults. Moreover, using Lyapunov stability theory and linear matrix inequalities (LMI approach, the guaranteed cost fault-tolerant controller is verified to render such networked control systems asymptotically stable. Finally, simulations are included to demonstrate the theoretical results.

Mast cell degranulation breaks peripheral tolerance.

Science.gov (United States)

de Vries, V C; Wasiuk, A; Bennett, K A; Benson, M J; Elgueta, R; Waldschmidt, T J; Noelle, R J

2009-10-01

Mast cells (MC) have been shown to mediate regulatory T-cell (T(reg))-dependent, peripheral allograft tolerance in both skin and cardiac transplants. Furthermore, T(reg) have been implicated in mitigating IgE-mediated MC degranulation, establishing a dynamic, reciprocal relationship between MC and T(reg) in controlling inflammation. In an allograft tolerance model, it is now shown that intragraft or systemic MC degranulation results in the transient loss of T(reg) suppressor activities with the acute, T-cell dependent rejection of established, tolerant allografts. Upon degranulation, MC mediators can be found in the skin, T(reg) rapidly leave the graft, MC accumulate in the regional lymph node and the T(reg) are impaired in the expression of suppressor molecules. Such a dramatic reversal of T(reg) function and tissue distribution by MC degranulation underscores how allergy may causes the transient breakdown of peripheral tolerance and episodes of acute T-cell inflammation.

Regulatory Accessibility and Social Influences on State Self-Control

OpenAIRE

vanDellen, Michelle R.; Hoyle, Rick H.

2009-01-01

The current work examined how social factors influence self-control. Current conceptions of state self-control treat it largely as a function of regulatory capacity. The authors propose that state self-control might also be influenced by social factors because of regulatory accessibility. Studies 1 through 4 provide evidence that individuals’ state self-control is influenced by the trait and state self-control of salient others such that thinking of others with good trait or state self-contro...

Differential sensitivity of regulatory and effector T cells to cell death: a prerequisite for transplant tolerance

Directory of Open Access Journals (Sweden)

Sylvaine eYou

2015-05-01

Full Text Available Despite significant progress achieved in transplantation, immunosuppressive therapies currently used to prevent graft rejection are still endowed with severe side effects impairing their efficiency over the long term. Thus, the development of graft-specific, non toxic innovative therapeutic strategies has become a major challenge, the goal being to selectively target alloreactive effector T cells while sparing CD4+Foxp3+ regulatory T cells (Tregs to promote operational tolerance. Various approaches, notably the one based on monoclonal antibodies or fusion proteins directed against the TCR/CD3 complex, TCR coreceptors, or costimulatory molecules, have been proposed to reduce the alloreactive T cell pool which is an essential prerequisite to create a therapeutic window allowing Tregs to induce and maintain allograft tolerance. In this minireview, we focus on the differential sensitivity of Tregs and effector T cells to the depleting and inhibitory effect of these immunotherapies, with a particular emphasis on CD3-specific antibodies that beyond their immunosuppressive effect, also express potent tolerogenic capacities.

Fault-tolerant Control of a Cyber-physical System

Science.gov (United States)

Roxana, Rusu-Both; Eva-Henrietta, Dulf

2017-10-01

Cyber-physical systems represent a new emerging field in automatic control. The fault system is a key component, because modern, large scale processes must meet high standards of performance, reliability and safety. Fault propagation in large scale chemical processes can lead to loss of production, energy, raw materials and even environmental hazard. The present paper develops a multi-agent fault-tolerant control architecture using robust fractional order controllers for a (13C) cryogenic separation column cascade. The JADE (Java Agent DEvelopment Framework) platform was used to implement the multi-agent fault tolerant control system while the operational model of the process was implemented in Matlab/SIMULINK environment. MACSimJX (Multiagent Control Using Simulink with Jade Extension) toolbox was used to link the control system and the process model. In order to verify the performance and to prove the feasibility of the proposed control architecture several fault simulation scenarios were performed.

Fault tolerancy in cooperative adaptive cruise control

NARCIS (Netherlands)

Nunen, E. van; Ploeg, J.; Medina, A.M.; Nijmeijer, H.

2013-01-01

Future mobility requires sound solutions in the field of fault tolerance in real-time applications amongst which Cooperative Adaptive Cruise Control (CACC). This control system cannot rely on the driver as a backup and is constantly active and therefore more prominent to the occurrences of faults

Internal Leakage Fault Detection and Tolerant Control of Single-Rod Hydraulic Actuators

Directory of Open Access Journals (Sweden)

Jianyong Yao

2014-01-01

Full Text Available The integration of internal leakage fault detection and tolerant control for single-rod hydraulic actuators is present in this paper. Fault detection is a potential technique to provide efficient condition monitoring and/or preventive maintenance, and fault tolerant control is a critical method to improve the safety and reliability of hydraulic servo systems. Based on quadratic Lyapunov functions, a performance-oriented fault detection method is proposed, which has a simple structure and is prone to implement in practice. The main feature is that, when a prescribed performance index is satisfied (even a slight fault has occurred, there is no fault alarmed; otherwise (i.e., a severe fault has occurred, the fault is detected and then a fault tolerant controller is activated. The proposed tolerant controller, which is based on the parameter adaptive methodology, is also prone to realize, and the learning mechanism is simple since only the internal leakage is considered in parameter adaptation and thus the persistent exciting (PE condition is easily satisfied. After the activation of the fault tolerant controller, the control performance is gradually recovered. Simulation results on a hydraulic servo system with both abrupt and incipient internal leakage fault demonstrate the effectiveness of the proposed fault detection and tolerant control method.

Regulatory control of the use of contractors by operating organizations. Peer discussions on regulatory practices

International Nuclear Information System (INIS)

2000-09-01

This report arises from the eighth series of peer discussions on regulatory practices entitled 'Regulatory control of the use of contractors by operating organizations'. Senior regulators from 19 Member States participated in two peer group discussions in March 2000 and May 2000. This report gives an account of the outcomes of these meetings and of practical suggestions put forward by senior regulators. These suggestions do not necessarily reflect the views of the governments of the nominating Member States, the organizations they belong to, or the International Atomic Energy Agency. The objective of this document is to share experience between regulatory bodies and provide practical suggestions for controlling the use of contractors and subcontractors by the operating organizations during all stages, especially operation, of a nuclear power plant, so as to ensure that the quality of work and services delivered is commensurate with the safety importance of the activities and that these are carried out in a manner that will not adversely affect the safe or reliable operation of the facility. These documented practical suggestions and experiences are the result of a series of peer discussions at the IAEA in 2000. It is considered that the manner in which control is exercised, and the various challenges connected to this control, are highly dependent upon the legislative framework, maturity of the nuclear programme, the size of the national nuclear industry and the culture in each country. The report is structured so that it covers the subject matter under the following main headings: Legal Provisions, Regulatory Strategy and Requirements; Regulatory Approaches for Controlling the Use of Contractors; Types of Contracts; Practical Suggestions

Low-income, minority fathers' control strategies and their children's regulatory skills.

Science.gov (United States)

Malin, Jenessa L; Cabrera, Natasha J; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith L

2014-01-01

The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24 months, and children's regulatory skills at prekindergarten (pre-K). Using a sample of low-income, minority families with 2-year-olds from the Early Head Start Research and Evaluation Project (n = 71), we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24 months (e.g., regulatory behavior and regulatory language), and children's sustained attention and emotion regulation at prekindergarten. There were three main findings. First, fathers overwhelmingly used commands (e.g., "Do that.") to promote compliance in their 24-month-old children. Second, children's vocabulary skills predicted fathers' regulatory behaviors during a father-child interaction whereas children's gender predicted fathers' regulatory language during an interaction. Third, controlling for maternal supportiveness, fathers' regulatory behaviors at 24 months predicted children's sustained attention at pre-K whereas fathers' regulatory language at 24 months predicted children's emotion regulation at pre-K. Our findings highlight the importance of examining paternal contributions to children's regulatory skills. © 2014 Michigan Association for Infant Mental Health.

Regulatory aspects of criticality control in Australia

International Nuclear Information System (INIS)

Zimin, Sergei

2003-01-01

With the creation of Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) the Australian approach to criticality safety was revisited. Consistency with international best practices is required by the Act that created ARPANSA and this was applied to practices in criticality safety adopted in other countries. This required extensive regulatory efforts both in auditing the major Australian Nuclear Operator, Australian Nuclear Science and Technology Organisation (ANSTO), and assessing the existing in Australia criticality safety practices and implementing the required changes using the new legislative power of ARPANSA. The adopted regulatory approach is formulated through both the issued by ARPANSA licenses for nuclear installations (including reactors, fuel stores and radioactive waste stores) and the string of new regulatory documents, including the Regulatory Assessment Principles and the Regulatory Assessment Guidelines for criticality safety. The main features of the adopted regulation include the requirements of independent peer-review, ongoing refresher training coupled with annual accreditation and the reliance on the safe design rather than on an administrative control. (author)

Towards Robust Predictive Fault–Tolerant Control for a Battery Assembly System

Directory of Open Access Journals (Sweden)

Seybold Lothar

2015-12-01

Full Text Available The paper deals with the modeling and fault-tolerant control of a real battery assembly system which is under implementation at the RAFI GmbH company (one of the leading electronic manufacturing service providers in Germany. To model and control the battery assembly system, a unified max-plus algebra and model predictive control framework is introduced. Subsequently, the control strategy is enhanced with fault-tolerance features that increase the overall performance of the production system being considered. In particular, it enables tolerating (up to some degree mobile robot, processing and transportation faults. The paper discusses also robustness issues, which are inevitable in real production systems. As a result, a novel robust predictive fault-tolerant strategy is developed that is applied to the battery assembly system. The last part of the paper shows illustrative examples, which clearly exhibit the performance of the proposed approach.

MATERNAL-FETAL TOLERANCE AS A MANIFESTATION OF REGULATORY CONTINUUM AND PLASTICITY OF THEIR IMMUNE SYSTEMS (in memory of I.P. Ashmarin

Directory of Open Access Journals (Sweden)

E. P. Kharchenko

2011-01-01

Full Text Available Abstract. Relations of immune tolerance between mother and fetus are considered in view of a common regulatory continuum which is formed under the influence of a growing fetus. To explain such an immune tolerance, a notion of immune system plasticity is introduced, as an analogue to the nervous system plasticity, which develops in response to a continuum of changes occurring in fetal and maternal organisms during the nine months of pregnancy. The immune system plasticity in females is supposed to be among possible factors causing collisions upon conception and in the course of pregnancy. (Med. Immunol., 2011, vol. 13, N 2-3, pp 121-132

Controlling the frontier: regulatory T-cells and intestinal homeostasis.

Science.gov (United States)

Bollrath, Julia; Powrie, Fiona M

2013-11-30

The intestine represents one of the most challenging sites for the immune system as immune cells must be able to mount an efficient response to invading pathogens while tolerating the large number and diverse array of resident commensal bacteria. Foxp3(+) regulatory T-cells (Tregs) play a non-redundant role at maintaining this balance. At the same time Treg cell differentiation and function can be modulated by the intestinal microbiota. In this review, we will discuss effector mechanisms of Treg cells in the intestine and how these cells can be influenced by the intestinal microbiota. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Concept for fault tolerant controllers

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Poulsen, Niels Kjølstad

2009-01-01

This paper describe a concept for fault tolerant controllers (FTC) based on the YJBK (after Youla, Jabr, Bongiorno and Kucera) parameterization. This controller architecture will allow to change the controller on-line in the case of faults in the system. In the described FTC concept, a safe mode...... controller is applied as the basic feedback controller. A controller for normal operation with high performance is obtained by including certain YJBK parameters (transfer functions) in the controller. This will allow a fast switch from normal operation to safe mode operation in case of critical faults...... in the system. The described FTC architecture allow the different feedback controllers to apply different sets of sensors and actuators....

Diagnosis and Fault-Tolerant Control for Thruster-Assisted Position Mooring System

DEFF Research Database (Denmark)

Nguyen, Trong Dong; Blanke, Mogens; Sørensen, Asgeir

2007-01-01

Development of fault-tolerant control systems is crucial to maintain safe operation of o®shore installations. The objective of this paper is to develop a fault- tolerant control for thruster-assisted position mooring (PM) system with faults occurring in the mooring lines. Faults in line......'s pretension or line breaks will degrade the performance of the positioning of the vessel. Faults will be detected and isolated through a fault diagnosis procedure. When faults are detected, they can be accommodated through the control action in which only parameter of the controlled plant has to be updated...... to cope with the faulty condition. Simulations will be carried out to verify the advantages of the fault-tolerant control strategy for the PM system....

Novel perspectives for the engineering of abiotic stress tolerance in plants.

Science.gov (United States)

Cabello, Julieta V; Lodeyro, Anabella F; Zurbriggen, Matias D

2014-04-01

Adverse environmental conditions pose serious limitations to agricultural production. Classical biotechnological approaches towards increasing abiotic stress tolerance focus on boosting plant endogenous defence mechanisms. However, overexpression of regulatory elements or effectors is usually accompanied by growth handicap and yield penalties due to crosstalk between developmental and stress-response networks. Herein we offer an overview on novel strategies with the potential to overcome these limitations based on the engineering of regulatory systems involved in the fine-tuning of the plant response to environmental hardships, including post-translational modifications, small RNAs, epigenetic control of gene expression and hormonal networks. The development and application of plant synthetic biology tools and approaches will add new functionalities and perspectives to genetic engineering programs for enhancing abiotic stress tolerance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Radiation practices and regulatory control

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.).

Radiation practices and regulatory control

International Nuclear Information System (INIS)

1997-01-01

The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.)

Sliding Mode Fault Tolerant Control with Adaptive Diagnosis for Aircraft Engines

Science.gov (United States)

Xiao, Lingfei; Du, Yanbin; Hu, Jixiang; Jiang, Bin

2018-03-01

In this paper, a novel sliding mode fault tolerant control method is presented for aircraft engine systems with uncertainties and disturbances on the basis of adaptive diagnostic observer. By taking both sensors faults and actuators faults into account, the general model of aircraft engine control systems which is subjected to uncertainties and disturbances, is considered. Then, the corresponding augmented dynamic model is established in order to facilitate the fault diagnosis and fault tolerant controller design. Next, a suitable detection observer is designed to detect the faults effectively. Through creating an adaptive diagnostic observer and based on sliding mode strategy, the sliding mode fault tolerant controller is constructed. Robust stabilization is discussed and the closed-loop system can be stabilized robustly. It is also proven that the adaptive diagnostic observer output errors and the estimations of faults converge to a set exponentially, and the converge rate greater than some value which can be adjusted by choosing designable parameters properly. The simulation on a twin-shaft aircraft engine verifies the applicability of the proposed fault tolerant control method.

Thymic versus induced regulatory T cells – who regulates the regulators?

Directory of Open Access Journals (Sweden)

Giovanni Antonio Maria Povoleri

2013-06-01

Full Text Available Physiological health must balance immunological responsiveness against foreign pathogens with tolerance towards self-components and commensals. Disruption of this balance causes autoimmune diseases/chronic inflammation, in case of excessive immune responses, and persistent infection/immunodeficiency if regulatory components are overactive. This homeostasis occurs at two different levels: at a resting state to prevent autoimmune disease, as autoreactive effector T-cells (Teffs are only partially deleted in the thymus, and during inflammation to prevent excessive tissue injury, contract the immune response and enable tissue repair. Adaptive immune cells with regulatory function (regulatory T-cells are essential to control Teffs. Two sets of regulatory T cell are required to achieve the desired control: those emerging de novo from embryonic/neonatal thymus (thymic or tTregs, whose function is to control autoreactive Teffs to prevent autoimmune diseases, and those induced in the periphery (peripheral or pTregs to acquire regulatory phenotype in response to pathogens/inflammation. The differentiation mechanisms of these cells determine their commitment to lineage and plasticity towards other phenotypes. tTregs, expressing high levels of IL-2 receptor alpha chain (CD25, and the transcription factor Foxp3, are the most important, since mutations or deletions in these genes cause fatal autoimmune diseases in both mice and men. In the periphery, instead, Foxp3+ pTregs can be induced from naïve precursors in response to environmental signals. Here, we discuss molecular signatures and induction processes, mechanisms and sites of action, lineage stability and differentiating characteristics of both Foxp3+ and Foxp3- populations of regulatory T cells, derived from the thymus or induced peripherally. We relate these predicates to programs of cell-based therapy for the treatment of autoimmune diseases and induction of tolerance to transplants.

Fault Tolerant Wind Farm Control

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Stoustrup, Jakob

2013-01-01

In the recent years the wind turbine industry has focused on optimizing the cost of energy. One of the important factors in this is to increase reliability of the wind turbines. Advanced fault detection, isolation and accommodation are important tools in this process. Clearly most faults are deal...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

Adaptive Observer-Based Fault-Tolerant Control Design for Uncertain Systems

Directory of Open Access Journals (Sweden)

Huaming Qian

2015-01-01

Full Text Available This study focuses on the design of the robust fault-tolerant control (FTC system based on adaptive observer for uncertain linear time invariant (LTI systems. In order to improve robustness, rapidity, and accuracy of traditional fault estimation algorithm, an adaptive fault estimation algorithm (AFEA using an augmented observer is presented. By utilizing a new fault estimator model, an improved AFEA based on linear matrix inequality (LMI technique is proposed to increase the performance. Furthermore, an observer-based state feedback fault-tolerant control strategy is designed, which guarantees the stability and performance of the faulty system. Moreover, the adaptive observer and the fault-tolerant controller are designed separately, whose performance can be considered, respectively. Finally, simulation results of an aircraft application are presented to illustrate the effectiveness of the proposed design methods.

Real-time fault diagnosis and fault-tolerant control

OpenAIRE

Gao, Zhiwei; Ding, Steven X.; Cecati, Carlo

2015-01-01

This "Special Section on Real-Time Fault Diagnosis and Fault-Tolerant Control" of the IEEE Transactions on Industrial Electronics is motivated to provide a forum for academic and industrial communities to report recent theoretic/application results in real-time monitoring, diagnosis, and fault-tolerant design, and exchange the ideas about the emerging research direction in this field. Twenty-three papers were eventually selected through a strict peer-reviewed procedure, which represent the mo...

Regulatory dendritic cell therapy: from rodents to clinical application

OpenAIRE

Raïch-Regué, Dalia; Glancy, Megan; Thomson, Angus W.

2013-01-01

Dendritic cells (DC) are highly-specialized, bone marrow-derived antigen-presenting cells that induce or regulate innate and adaptive immunity. Regulatory or “tolerogenic” DC play a crucial role in maintaining self tolerance in the healthy steady-state. These regulatory innate immune cells subvert naïve or memory T cell responses by various mechanisms. Regulatory DC (DCreg) also exhibit the ability to induce or restore T cell tolerance in many animal models of autoimmune disease or transplant...

Regulatory control of radiation sources in Slovakia

International Nuclear Information System (INIS)

Auxtova, L.

2001-01-01

In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

Industrial Cost-Benefit Assessment for Fault-tolerant Control Systems

DEFF Research Database (Denmark)

Thybo, Claus; Blanke, Mogens

1998-01-01

Economic aspects are decisive for industrial acceptance of research concepts including the promising ideas in fault tolerant control. Fault tolerance is the ability of a system to detect, isolate and accommodate a fault, such that simple faults in a sub-system do not develop into failures...... at a system level. In a design phase for an industrial system, possibilities span from fail safe design where any single point failure is accommodated by hardware, over fault-tolerant design where selected faults are handled without extra hardware, to fault-ignorant design where no extra precaution is taken...

Data-driven design of fault diagnosis and fault-tolerant control systems

CERN Document Server

Ding, Steven X

2014-01-01

Data-driven Design of Fault Diagnosis and Fault-tolerant Control Systems presents basic statistical process monitoring, fault diagnosis, and control methods, and introduces advanced data-driven schemes for the design of fault diagnosis and fault-tolerant control systems catering to the needs of dynamic industrial processes. With ever increasing demands for reliability, availability and safety in technical processes and assets, process monitoring and fault-tolerance have become important issues surrounding the design of automatic control systems. This text shows the reader how, thanks to the rapid development of information technology, key techniques of data-driven and statistical process monitoring and control can now become widely used in industrial practice to address these issues. To allow for self-contained study and facilitate implementation in real applications, important mathematical and control theoretical knowledge and tools are included in this book. Major schemes are presented in algorithm form and...

Advanced I&C for Fault-Tolerant Supervisory Control of Small Modular Reactors

Energy Technology Data Exchange (ETDEWEB)

Cole, Daniel G. [Univ. of Pittsburgh, PA (United States)

2018-01-30

In this research, we have developed a supervisory control approach to enable automated control of SMRs. By design the supervisory control system has an hierarchical, interconnected, adaptive control architecture. A considerable advantage to this architecture is that it allows subsystems to communicate at different/finer granularity, facilitates monitoring of process at the modular and plant levels, and enables supervisory control. We have investigated the deployment of automation, monitoring, and data collection technologies to enable operation of multiple SMRs. Each unit's controller collects and transfers information from local loops and optimize that unit’s parameters. Information is passed from the each SMR unit controller to the supervisory controller, which supervises the actions of SMR units and manage plant processes. The information processed at the supervisory level will provide operators the necessary information needed for reactor, unit, and plant operation. In conjunction with the supervisory effort, we have investigated techniques for fault-tolerant networks, over which information is transmitted between local loops and the supervisory controller to maintain a safe level of operational normalcy in the presence of anomalies. The fault-tolerance of the supervisory control architecture, the network that supports it, and the impact of fault-tolerance on multi-unit SMR plant control has been a second focus of this research. To this end, we have investigated the deployment of advanced automation, monitoring, and data collection and communications technologies to enable operation of multiple SMRs. We have created a fault-tolerant multi-unit SMR supervisory controller that collects and transfers information from local loops, supervise their actions, and adaptively optimize the controller parameters. The goal of this research has been to develop the methodologies and procedures for fault-tolerant supervisory control of small modular reactors. To achieve

Regulatory control of radiation sources in the Philippines

International Nuclear Information System (INIS)

Daroy, Rosita R.

1995-01-01

This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

Transplantation Tolerance Induction: Cell Therapies and Their Mechanisms

OpenAIRE

Scalea, Joseph R.; Tomita, Yusuke; Lindholm, Christopher R.; Burlingham, William

2016-01-01

Cell based therapies have been studied extensively in the context of transplantation tolerance induction. The most successful protocols have relied on transfusion of bone marrow prior to the transplantation of a renal allograft. However, it is not clear that stem cells found in bone marrow are required in order to render a transplant candidate immunologically tolerant. Accordingly, mesenchymal stem cells, regulatory myeloid cells, T regulatory cells, and other cell types, are being tested as ...

Plant-based oral tolerance to hemophilia therapy employs a complex immune regulatory response including LAP+CD4+ T cells.

Science.gov (United States)

Wang, Xiaomei; Su, Jin; Sherman, Alexandra; Rogers, Geoffrey L; Liao, Gongxian; Hoffman, Brad E; Leong, Kam W; Terhorst, Cox; Daniell, Henry; Herzog, Roland W

2015-04-09

Coagulation factor replacement therapy for the X-linked bleeding disorder hemophilia is severely complicated by antibody ("inhibitor") formation. We previously found that oral delivery to hemophilic mice of cholera toxin B subunit-coagulation factor fusion proteins expressed in chloroplasts of transgenic plants suppressed inhibitor formation directed against factors VIII and IX and anaphylaxis against factor IX (FIX). This observation and the relatively high concentration of antigen in the chloroplasts prompted us to evaluate the underlying tolerance mechanisms. The combination of oral delivery of bioencapsulated FIX and intravenous replacement therapy induced a complex, interleukin-10 (IL-10)-dependent, antigen-specific systemic immune suppression of pathogenic antibody formation (immunoglobulin [Ig] 1/inhibitors, IgE) in hemophilia B mice. Tolerance induction was also successful in preimmune mice but required prolonged oral delivery once replacement therapy was resumed. Orally delivered antigen, initially targeted to epithelial cells, was taken up by dendritic cells throughout the small intestine and additionally by F4/80(+) cells in the duodenum. Consistent with the immunomodulatory responses, frequencies of tolerogenic CD103(+) and plasmacytoid dendritic cells were increased. Ultimately, latency-associated peptide expressing CD4(+) regulatory T cells (CD4(+)CD25(-)LAP(+) cells with upregulated IL-10 and transforming growth factor-β (TGF-β) expression) as well as conventional CD4(+)CD25(+) regulatory T cells systemically suppressed anti-FIX responses. © 2015 by The American Society of Hematology.

Regulatory control of maintenance activities in Argentine nuclear power plants

International Nuclear Information System (INIS)

Calvo, J.C.; Caruso, G.

2000-01-01

The main maintenance objective is to assure that the safety features of structures, components and systems of nuclear power plants are kept as designed. Therefore, there is a direct relationship between safety and maintenance. Owing to the above mentioned, maintenance activities are considered a relevant regulatory issue for the Argentine Nuclear Regulatory Authority (ARN). This paper describes the regulatory control to maintenance activities of Argentine nuclear power plants. It also addresses essential elements for maintenance control, routine inspections, special inspections during planned outages, audits and license conditions and requirements. (author)

Regulatory control of radiation sources in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Daroy, Rosita R

1996-12-31

This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI`s regulatory functions are presented. (author). Paper presented during the IAEA Regional (RCA) Workshop on System of Notification, Registration, Licensing, and Control of Radiation Sources and Installations, Jakarta, Indonesia, 24-28 April 1995. 6 refs., 2 figs., 12 tabs.

Criteria of exemption of regulatory control for radioactive material

International Nuclear Information System (INIS)

Marco A. Medrano Lopez

1991-01-01

Being based on the information contained in the 10 CFR Part 20, of the section 20.301 until the 20.306 where the mechanisms by means of which can prepare the waste of low level are indicated. While the Nuclear Regulatory Commission (NRC) it amended in the year of 1985 the Act of Politics on Low level Wastes, in particular the section 10 of the amendment of the Act, relative to the concept BRC treats those groups of radioactive waste in that their activity contents are so low that they could be exempt of the regulatory control, either liberating them toward the environment or to exempt people or organizations of the regulatory control

Dual Nature of Translational Control by Regulatory BC RNAs ▿

Science.gov (United States)

Eom, Taesun; Berardi, Valerio; Zhong, Jun; Risuleo, Gianfranco; Tiedge, Henri

2011-01-01

In higher eukaryotes, increasing evidence suggests, gene expression is to a large degree controlled by RNA. Regulatory RNAs have been implicated in the management of neuronal function and plasticity in mammalian brains. However, much of the molecular-mechanistic framework that enables neuronal regulatory RNAs to control gene expression remains poorly understood. Here, we establish molecular mechanisms that underlie the regulatory capacity of neuronal BC RNAs in the translational control of gene expression. We report that regulatory BC RNAs employ a two-pronged approach in translational control. One of two distinct repression mechanisms is mediated by C-loop motifs in BC RNA 3′ stem-loop domains. These C-loops bind to eIF4B and prevent the factor's interaction with 18S rRNA of the small ribosomal subunit. In the second mechanism, the central A-rich domains of BC RNAs target eIF4A, specifically inhibiting its RNA helicase activity. Thus, BC RNAs repress translation initiation in a bimodal mechanistic approach. As BC RNA functionality has evolved independently in rodent and primate lineages, our data suggest that BC RNA translational control was necessitated and implemented during mammalian phylogenetic development of complex neural systems. PMID:21930783

Induced Foxp3+ T cells colonising tolerated allografts exhibit the hypomethylation pattern typical of mature regulatory T cells.

Directory of Open Access Journals (Sweden)

Robert eHilbrands

2016-04-01

Full Text Available Regulatory T cells expressing the transcription factor Foxp3 require acquisition of a specific hypomethylation pattern to ensure optimal functional commitment, limited lineage plasticity and long-term maintenance of tolerance. A better understanding of the molecular mechanisms involved in the generation of these epigenetic changes in vivo will contribute to the clinical exploitation of Foxp3+Treg. Here we show that both in vitro and in vivo generated antigen specific Foxp3+Treg can acquire Treg-specific epigenetic characteristics and prevent skin graft rejection in an animal model.

Aircraft Attitude Distributed Fault-tolerant Control Based on Dynamic Actuator

Directory of Open Access Journals (Sweden)

Zhou Hong-Cheng

2014-09-01

Full Text Available For attitude control system, based on decentralized fault-tolerant control framework, actuators damage and stuck fault detection and identification unit are designed for the flight control system. And observer-based auxiliary system unit is also designed. The auxiliary system implies control surface damage faults and disturbances information. Firstly, we give the attitude control system under actuator stuck, lose of effectiveness, and control surface damages faults. Secondly, a multi-observer is designed for actuator fault detection and identification using a decision-making mechanism to determine current actuator failure modes. Then, an adaptive sliding mode observer is designed for implicit control surface damages and interference information. The reconfigurable controller can achieve fault tolerant using the information of adaptive sliding mode observer. Finally, the simulation results show the effectiveness of the proposed method.

LOW-INCOME, MINORITY FATHERS’ CONTROL STRATEGIES AND THEIR CHILDREN'S REGULATORY SKILLS

OpenAIRE

Malin, Jenessa L.; Cabrera, Natasha J.; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith Lee

2014-01-01

The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24-months and children's regulatory skills at pre-kindergarten (pre-K). Using a sample of low-income minority families with 2-year-olds from the Early Head Start Evaluation Research Program (n = 71) we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24-months (e.g., regulatory behavior and regulatory language), an...

Evaluation of digital fault-tolerant architectures for nuclear power plant control systems

International Nuclear Information System (INIS)

Battle, R.E.

1990-01-01

This paper reports on four fault-tolerant architectures that were evaluated for their potential reliability in service as control systems of nuclear power plants. The reliability analyses showed that human- and software-related common cause failures and single points of failure in the output modules are dominant contributors to system unreliability. The four architectures are triple-modular-redundant, both synchronous and asynchronous, and also dual synchronous and asynchronous. The evaluation includes a review of design features, an analysis of the importance of coverage, and reliability analyses of fault-tolerant systems. Reliability analyses based on data from several industries that have fault-tolerant controllers were used to estimate the mean-time-between-failures of fault-tolerant controllers and to predict those failure modes that may be important in nuclear power plants

SIFT - Design and analysis of a fault-tolerant computer for aircraft control. [Software Implemented Fault Tolerant systems

Science.gov (United States)

Wensley, J. H.; Lamport, L.; Goldberg, J.; Green, M. W.; Levitt, K. N.; Melliar-Smith, P. M.; Shostak, R. E.; Weinstock, C. B.

1978-01-01

SIFT (Software Implemented Fault Tolerance) is an ultrareliable computer for critical aircraft control applications that achieves fault tolerance by the replication of tasks among processing units. The main processing units are off-the-shelf minicomputers, with standard microcomputers serving as the interface to the I/O system. Fault isolation is achieved by using a specially designed redundant bus system to interconnect the processing units. Error detection and analysis and system reconfiguration are performed by software. Iterative tasks are redundantly executed, and the results of each iteration are voted upon before being used. Thus, any single failure in a processing unit or bus can be tolerated with triplication of tasks, and subsequent failures can be tolerated after reconfiguration. Independent execution by separate processors means that the processors need only be loosely synchronized, and a novel fault-tolerant synchronization method is described.

Regulatory aspects of low doses control in Albania

International Nuclear Information System (INIS)

Dollani, K.; Kushe, R.

1997-01-01

In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

Regulatory T cells, maternal-foetal immune tolerance and recurrent miscarriage: new therapeutic challenging opportunities.

Science.gov (United States)

Alijotas-Reig, Jaume; Melnychuk, Taisiia; Gris, Josep Maria

2015-03-15

Because maternal alloreactive lymphocytes are not depleted during pregnancy, local and/or systemic mechanisms have to play a key role in altering the maternal immune response. Peripheral T regulatory cells (pTregs) at the maternal-foetal interface are necessary in situ to prevent early abortion, but only those pTregs that have been previously exposed to paternal alloantigens. It has been showed that pregnancy selectively stimulates the accumulation of maternal Foxp3(+)CD4(+)CD25(+) (Foxp3Tregs) cells with foetal specificity. Interestingly, after delivery, foetal-specific pTregs persist at elevated levels, maintain tolerance to pre-existing foetal antigen, and rapidly re-accumulate during subsequent pregnancy. pTreg up-regulation could be hypothesized as a possible future therapeutic strategy in humans. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Regulatory Control of Radioactive Sources in Spain

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, M.; Martin, J.L., E-mail: mrm@csn.es [Nuclear Safety Council, Madrid (Spain)

2011-07-15

The arrangements for the regulatory control of the safety and security of sealed radioactive sources in Spain are described. Emphasis is given to the situations which are most likely to result in the loss of control of sources and on the procedures introduced to reduce the likelihood of losses in these cases. Finally, the strategy for locating sources which have been lost from control (orphan sources) is described. (author)

Transplantation Tolerance Induction: Cell Therapies and their Mechanisms

Directory of Open Access Journals (Sweden)

Joseph R Scalea

2016-03-01

Full Text Available Cell based therapies have been studied extensively in the context of transplantation tolerance induction. The most successful protocols have relied on transfusion of bone marrow prior to the transplantation of a renal allograft. However, it is not clear that stem cells found in bone marrow are required in order to render a transplant candidate immunologically tolerant. Accordingly, mesenchymal stem cells, regulatory myeloid cells, T regulatory cells, and other cell types, are being tested as possible routes to tolerance induction, in the absence of donor derived stem cells. Early data with each of these cell types have been encouraging. However, the induction regimen capable of achieving consistent tolerance, whilst avoiding unwanted sided effects, and which is scalable to the human patient, has yet to be identified. Here we present the status of investigations of various tolerogenic cell types and the mechanistic rationale for their use in in tolerance induction protocols.

Regulatory control, nuclear safety regulation and waste management in Spain

International Nuclear Information System (INIS)

Martin, A.

2000-01-01

This article presents the challenges that faces the spanish regulatory authority. The deregulation of electricity industry imposes severe changes in nuclear power economics and forces nuclear power to compete with other sources of electricity. A pressure is perceived for regulatory effectiveness primarily since the cost of regulation is a component of the cost of the product. This effectiveness gain in regulatory control will be reached through systematic strategic analysis, formulation and implementation. The regulatory aspects of plant life extension and of waste management are examined

Regulatory dendritic cells for promotion of liver transplant operational tolerance: Rationale for a clinical trial and accompanying mechanistic studies.

Science.gov (United States)

Thomson, Angus W; Humar, Abhinav; Lakkis, Fadi G; Metes, Diana M

2018-05-01

Dendritic cells (DC) are rare, bone marrow (BM)-derived innate immune cells that critically maintain self-tolerance in the healthy steady-state. Regulatory DC (DCreg) with capacity to suppress allograft rejection and promote transplant tolerance in pre-clinical models can readily be generated from BM precursors or circulating blood monocytes. These DCreg enhance allograft survival via various mechanisms, including promotion of regulatory T cells. In non-human primates receiving minimal immunosuppressive drug therapy (IS), infusion of DCreg of donor origin, one week before transplant, safely prolongs renal allograft survival and selectively attenuates anti-donor CD8 + memory T cell responses in the early post-transplant period. Based on these observations, and in view of the critical need to reduce patient dependence on non-specific IS agents that predispose to cardiometabolic side effects and renal insufficiency, we will conduct a first-in-human safety and preliminary efficacy study of donor-derived DCreg infusion to achieve early (18 months post-transplant) complete IS withdrawal in low-risk, living donor liver transplant recipients receiving standard-of-care IS (mycophenolate mofetil, tacrolimus and steroids). We will test the hypothesis that, although donor-derived DCreg are short-lived, they will induce robust donor-specific T cell hyporesponsiveness. We will examine immunological mechanisms by sequential analysis of blood and tissue samples, incorporating cutting-edge technologies. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Regulatory control of radiation sources and radioactive materials in the Czech Republic

International Nuclear Information System (INIS)

Drabova, D.; Prouza, Z.

2001-01-01

The paper describes legal and regulatory provisions for radiation protection and safe use of sources of ionizing radiation in the Czech Republic with special emphasis on aspects of bringing activities under regulatory control and releasing them from it. It covers the development of a new legal framework, the work of the regulatory body, an overview of sources in use and provisions to achieve effective regulatory control of facilities and releases of radioactive material into the environment. Also, it describes reported unusual events with a proposed scheme for their classification and evaluation. (author)

Active fault-tolerant control strategy of large civil aircraft under elevator failures

Directory of Open Access Journals (Sweden)

Wang Xingjian

2015-12-01

Full Text Available Aircraft longitudinal control is the most important actuation system and its failures would lead to catastrophic accident of aircraft. This paper proposes an active fault-tolerant control (AFTC strategy for civil aircraft with different numbers of faulty elevators. In order to improve the fault-tolerant flight control system performance and effective utilization of the control surface, trimmable horizontal stabilizer (THS is considered to generate the extra pitch moment. A suitable switching mechanism with performance improvement coefficient is proposed to determine when it is worthwhile to utilize THS. Furthermore, AFTC strategy is detailed by using model following technique and the proposed THS switching mechanism. The basic fault-tolerant controller is designed to guarantee longitudinal control system stability and acceptable performance degradation under partial elevators failure. The proposed AFTC is applied to Boeing 747-200 numerical model and simulation results validate the effectiveness of the proposed AFTC approach.

Design of passive fault-tolerant controllers of a quadrotor based on sliding mode theory

Directory of Open Access Journals (Sweden)

Merheb Abdel-Razzak

2015-09-01

Full Text Available Abstract In this paper, sliding mode control is used to develop two passive fault tolerant controllers for an AscTec Pelican UAV quadrotor. In the first approach, a regular sliding mode controller (SMC augmented with an integrator uses the robustness property of variable structure control to tolerate partial actuator faults. The second approach is a cascaded sliding mode controller with an inner and outer SMC loops. In this configuration, faults are tolerated in the fast inner loop controlling the velocity system. Tuning the controllers to find the optimal values of the sliding mode controller gains is made using the ecological systems algorithm (ESA, a biologically inspired stochastic search algorithm based on the natural equilibrium of animal species. The controllers are tested using SIMULINK in the presence of two different types of actuator faults, partial loss of motor power affecting all the motors at once, and partial loss of motor speed. Results of the quadrotor following a continuous path demonstrated the effectiveness of the controllers, which are able to tolerate a significant number of actuator faults despite the lack of hardware redundancy in the quadrotor system. Tuning the controller using a faulty system improves further its ability to afford more severe faults. Simulation results show that passive schemes reserve their important role in fault tolerant control and are complementary to active techniques

The role of Foxp3+ regulatory T cells in liver transplant tolerance.

Science.gov (United States)

Li, W; Carper, K; Zheng, X X; Kuhr, C S; Reyes, J D; Liang, Y; Perkins, D L; Thomson, A W; Perkins, J D

2006-12-01

The liver has long been considered a tolerogenic organ that favors the induction of peripheral tolerance. The mechanisms underlying liver tolerogenicity remain largely undefined. In this study, we characterized Foxp3-expressing CD4+ CD25+ regulatory T cells (Treg) in liver allograft recipients and examined the role of Treg in inherent liver tolerogenicity by employing the mouse spontaneous liver transplant tolerance model. Orthotopic liver transplantation was performed from C57BL/10 (H2b) to C3H/HeJ (H2k) mice. The percentage of CD4+ CD25+ Treg was expanded in the liver grafts and recipient spleens from day 5 up to day 100 posttransplantation, associated with high intracellular Foxp3 and CTLA4 expression. Immunohistochemistry further demonstrated significant numbers of Foxp3+ cells in the liver grafts and recipient spleens and increased transforming growth factor beta expression in the recipient spleens throughout the time courses. Adoptive transfer of spleen cells from the long-term liver allograft survivors significantly prolonged donor heart graft survival. Depletion of recipient CD4+ CD25+ Treg using anti-CD25 monoclonal antibody (250 microg/d) induced acute liver allograft rejection, associated with elevated anti-donor T-cell proliferative responses, CTL and natural killer activities, enhanced interleukin (IL)-2, interferon-gamma, IL-10, and decreased IL-4 production, and decreased T-cell apoptotic activity in anti-CD25-treated recipients. Moreover, CTLA4 blockade by anti-CTLA4 monoclonal antibody administration exacerbated liver graft rejection when combined with anti-CD25 monoclonal antibody. Thus, Foxp3+ CD4+ CD25+ Treg appear to underpin spontaneous acceptance of major histocompatability complex- mismatched liver allografts in mice. CTLA4, IL-4, and apoptosis of alloreactive T cells appear to contribute to the function of Treg and regulation of graft outcome.

Diagnosis and Fault-tolerant Control

DEFF Research Database (Denmark)

Blanke, Mogens; Kinnaert, Michel; Lunze, Jan

the applicability of the presented methods. The theoretical results are illustrated by two running examples which are used throughout the book. The book addresses engineering students, engineers in industry and researchers who wish to get a survey over the variety of approaches to process diagnosis and fault......The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process...

Fault Tolerant Autonomous Lateral Control for Heavy Vehicles

OpenAIRE

Talbot, Craig Matthew; Papadimitriou, Iakovos; Tomizuka, Masayoshi

2004-01-01

This report summarizes the research results of TO4233, "Fault Tolerant Autonomous Lateral Control for Heavy Vehicles". This project represents a continuing effort of PATH's research on Automated Highway Systems (AHS) and more specifically in the area of heavy vehicles. Research on the lateral control of heavy vehicles for AHS has been going on at PATH since 1993. MOU129, "Steering and Braking Control of Heavy Duty Vehicles" was the first project and it was followed by MOU242, "Lateral Control...

Passive Fault Tolerant Control of Piecewise Affine Systems Based on H Infinity Synthesis

DEFF Research Database (Denmark)

Gholami, Mehdi; Cocquempot, vincent; Schiøler, Henrik

2011-01-01

In this paper we design a passive fault tolerant controller against actuator faults for discretetime piecewise affine (PWA) systems. By using dissipativity theory and H analysis, fault tolerant state feedback controller design is expressed as a set of Linear Matrix Inequalities (LMIs). In the cur...

Regulatory Framework for Controlling the Research Reactor Decommissioning Project

International Nuclear Information System (INIS)

Melani, Ai; Chang, Soon Heung

2009-01-01

Decommissioning is one of important stages in construction and operation of research reactors. Currently, there are three research reactors operating in Indonesia. These reactors are operated by the National Nuclear Energy Agency (BATAN). The age of the three research reactors varies from 22 to 45 years since the reactors reached their first criticality. Regulatory control of the three reactors is conducted by the Nuclear Energy Regulatory Agency (BAPETEN). Controlling the reactors is carried out based on the Act No. 10/1997 on Nuclear Energy, Government Regulations and BAPETEN Chairman Decrees concerning the nuclear safety, security and safeguards. Nevertheless, BAPETEN still lack of the regulation, especially for controlling the decommissioning project. Therefore, in the near future BAPETEN has to prepare the regulations for decommissioning, particularly to anticipate the decommissioning of the oldest research reactors, which probably will be done in the next ten years. In this papers author give a list of regulations should be prepared by BAPETEN for the decommissioning stage of research reactor in Indonesia based on the international regulatory practice

Fault tolerance and reliability in integrated ship control

DEFF Research Database (Denmark)

Nielsen, Jens Frederik Dalsgaard; Izadi-Zamanabadi, Roozbeh; Schiøler, Henrik

2002-01-01

Various strategies for achieving fault tolerance in large scale control systems are discussed. The positive and negative impacts of distribution through network communication are presented. The ATOMOS framework for standardized reliable marine automation is presented along with the corresponding...

A Ship Propulsion System Model for Fault-tolerant Control

DEFF Research Database (Denmark)

Izadi-Zamanabadi, Roozbeh; Blanke, M.

This report presents a propulsion system model for a low speed marine vehicle, which can be used as a test benchmark for Fault-Tolerant Control purposes. The benchmark serves the purpose of offering realistic and challenging problems relevant in both FDI and (autonomous) supervisory control area...

An early response regulatory cluster induced by low temperature and hydrogen peroxide in seedlings of chilling-tolerant japonica rice

Directory of Open Access Journals (Sweden)

Jia Yulin

2007-06-01

Full Text Available Abstract Background Plants respond to low temperature through an intricately coordinated transcriptional network. The CBF/DREB-regulated network of genes has been shown to play a prominent role in freeze-tolerance of Arabidopsis through the process of cold acclimation (CA. Recent evidence also showed that the CBF/DREB regulon is not unique to CA but evolutionarily conserved between chilling-insensitive (temperate and chilling-sensitive (warm-season plants. In this study, the wide contrast in chilling sensitivity between indica and japonica rice was used as model to identify other regulatory clusters by integrative analysis of promoter architecture (ab initio and gene expression profiles. Results Transcriptome analysis in chilling tolerant japonica rice identified a subset of 121 'early response' genes that were upregulated during the initial 24 hours at 10°C. Among this group were four transcription factors including ROS-bZIP1 and another larger sub-group with a common feature of having as1/ocs-like elements in their promoters. Cold-induction of ROS-bZIP1 preceded the induction of as1/ocs-like element-containing genes and they were also induced by exogenous H2O2 at ambient temperature. Coordinated expression patterns and similar promoter architectures among the 'early response' genes suggest that they belong to a potential regulon (ROS-bZIP – as1/ocs regulatory module that responds to elevated levels of ROS during chilling stress. Cultivar-specific expression signatures of the candidate genes indicate a positive correlation between the activity of the putative regulon and genotypic variation in chilling tolerance. Conclusion A hypothetical model of an ROS-mediated regulon (ROS-bZIP – as1/ocs triggered by chilling stress was assembled in rice. Based on the current results, it appears that this regulon is independent of ABA and CBF/DREB, and that its activation has an important contribution in configuring the rapid responses of rice seedlings

Moving through the stressed genome: Emerging regulatory roles for transposons in plant stress tolerance

Directory of Open Access Journals (Sweden)

Negi Pooja

2016-10-01

Full Text Available The recognition of a positive correlation between organism genome size with its transposable element (TE content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock’s original ’Controlling Element’ hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences which project TEs as distributed genomic control modules. According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution and function, and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement.

Authority Defied : Need for Cognitive Closure Influences Regulatory Control When Resisting Authority

NARCIS (Netherlands)

Damen, Tom G. E.; van Leeuwen, Matthijs L.; Dijksterhuis, Ap; van Baaren, Rick B.

The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the

Authority Defied: Need for Cognitive Closure Influences Regulatory Control When Resisting Authority

NARCIS (Netherlands)

Damen, T.G.E.; Leeuwen, M.L. van; Dijksterhuis, A.J.; Baaren, R.B. van

2014-01-01

The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the

The regulatory roles of B cell subsets in transplantation.

Science.gov (United States)

Chu, Zhulang; Zou, Weilong; Xu, Yanan; Sun, Qiquan; Zhao, Yong

2018-02-01

B cells mediate allograft rejection through antigen presentation, and production of cytokines and antibodies. More and more immunosuppressive agents specifically targeting B cells and plasma cells have been applied in clinical transplantation. However, recent studies have indicated the regulatory roles of B cells. Therefore, it is vital to clarify the different effects of B cell subsets in organ transplantation so that we can completely understand the diverse functions of B cells in transplantation. Areas covered: This review focuses on the regulatory roles of B cells in transplantation. B cell subsets with immune modulation and factors mediating immunosuppressive functions of regulatory B (Breg) cells were analyzed. Therapies targeting B cells and the application of B cells for transplant tolerance induction were discussed. Expert commentary: Besides involving rejection, B cells could also play regulatory roles in transplantation. Breg cells and the related markers may be used to predict the immune tolerant state in transplant recipients. New therapeutic strategies targeting B cells should be explored to promote tolerance induction with less impact on the host's protective immunity in organ transplanted patients.

A fault-tolerant strategy based on SMC for current-controlled converters

Science.gov (United States)

Azer, Peter M.; Marei, Mostafa I.; Sattar, Ahmed A.

2018-05-01

The sliding mode control (SMC) is used to control variable structure systems such as power electronics converters. This paper presents a fault-tolerant strategy based on the SMC for current-controlled AC-DC converters. The proposed SMC is based on three sliding surfaces for the three legs of the AC-DC converter. Two sliding surfaces are assigned to control the phase currents since the input three-phase currents are balanced. Hence, the third sliding surface is considered as an extra degree of freedom which is utilised to control the neutral voltage. This action is utilised to enhance the performance of the converter during open-switch faults. The proposed fault-tolerant strategy is based on allocating the sliding surface of the faulty leg to control the neutral voltage. Consequently, the current waveform is improved. The behaviour of the current-controlled converter during different types of open-switch faults is analysed. Double switch faults include three cases: two upper switch fault; upper and lower switch fault at different legs; and two switches of the same leg. The dynamic performance of the proposed system is evaluated during healthy and open-switch fault operations. Simulation results exhibit the various merits of the proposed SMC-based fault-tolerant strategy.

Fault-Tolerant Control Strategy for Steering Failures in Wheeled Planetary Rovers

Directory of Open Access Journals (Sweden)

Alexandre Carvalho Leite

2012-01-01

Full Text Available Fault-tolerant control design of wheeled planetary rovers is described. This paper covers all steps of the design process, from modeling/simulation to experimentation. A simplified contact model is used with a multibody simulation model and tuned to fit the experimental data. The nominal mode controller is designed to be stable and has its parameters optimized to improve tracking performance and cope with physical boundaries and actuator saturations. This controller was implemented in the real rover and validated experimentally. An impact analysis defines the repertory of faults to be handled. Failures in steering joints are chosen as fault modes; they combined six fault modes and a total of 63 possible configurations of these faults. The fault-tolerant controller is designed as a two-step procedure to provide alternative steering and reuse the nominal controller in a way that resembles a crab-like driving mode. Three fault modes are injected (one, two, and three failed steering joints in the real rover to evaluate the response of the nonreconfigured and reconfigured control systems in face of these faults. The experimental results justify our proposed fault-tolerant controller very satisfactorily. Additional concluding comments and an outlook summarize the lessons learned during the whole design process and foresee the next steps of the research.

Anti-regulatory T cells

DEFF Research Database (Denmark)

Andersen, Mads Hald

2017-01-01

responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells—termed anti-regulatory T cells (anti-Tregs)—that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune...... reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells......Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host...

Fractal gene regulatory networks for robust locomotion control of modular robots

DEFF Research Database (Denmark)

Zahadat, Payam; Christensen, David Johan; Schultz, Ulrik Pagh

2010-01-01

Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed and the ......Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed...

Reliable, fault tolerant control systems for nuclear generating stations

International Nuclear Information System (INIS)

McNeil, T.O.; Olmstead, R.A.; Schafer, S.

1990-01-01

Two operational features of CANDU Nuclear Power Stations provide for high plant availability. First, the plant re-fuels on-line, thereby eliminating the need for periodic and lengthy refuelling 'outages'. Second, the all plants are controlled by real-time computer systems. Later plants are also protected using real-time computer systems. In the past twenty years, the control systems now operating in 21 plants have achieved an availability of 99.8%, making significant contributions to high CANDU plant capacity factors. This paper describes some of the features that ensure the high degree of system fault tolerance and hence high plant availability. The emphasis will be placed on the fault tolerant features of the computer systems included in the latest reactor design - the CANDU 3 (450MWe). (author)

Active Disturbance Rejection Approach for Robust Fault-Tolerant Control via Observer Assisted Sliding Mode Control

Directory of Open Access Journals (Sweden)

John Cortés-Romero

2013-01-01

Full Text Available This work proposes an active disturbance rejection approach for the establishment of a sliding mode control strategy in fault-tolerant operations. The core of the proposed active disturbance rejection assistance is a Generalized Proportional Integral (GPI observer which is in charge of the active estimation of lumped nonlinear endogenous and exogenous disturbance inputs related to the creation of local sliding regimes with limited control authority. Possibilities are explored for the GPI observer assisted sliding mode control in fault-tolerant schemes. Convincing improvements are presented with respect to classical sliding mode control strategies. As a collateral advantage, the observer-based control architecture offers the possibility of chattering reduction given that a significant part of the control signal is of the continuous type. The case study considers a classical DC motor control affected by actuator faults, parametric failures, and perturbations. Experimental results and comparisons with other established sliding mode controller design methodologies, which validate the proposed approach, are provided.

A Fault Tolerant Direct Control Allocation Scheme with Integral Sliding Modes

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Hamayun Mirza Tariq

2015-03-01

Full Text Available In this paper, integral sliding mode control ideas are combined with direct control allocation in order to create a fault tolerant control scheme. Traditional integral sliding mode control can directly handle actuator faults; however, it cannot do so with actuator failures. Therefore, a mechanism needs to be adopted to distribute the control effort amongst the remaining functioning actuators in cases of faults or failures, so that an acceptable level of closed-loop performance can be retained. This paper considers the possibility of introducing fault tolerance even if fault or failure information is not provided to the control strategy. To demonstrate the efficacy of the proposed scheme, a high fidelity nonlinear model of a large civil aircraft is considered in the simulations in the presence of wind, gusts and sensor noise.

Wind turbine fault detection and fault tolerant control

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Johnson, Kathryn

2013-01-01

In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes...

Thioredoxin priming prolongs lung allograft survival by promoting immune tolerance.

Directory of Open Access Journals (Sweden)

Hanbo Hu

Full Text Available Tolerance to allograft antigen is the major challenge and final goal of transplant medicine. Our previous study demonstrated that thioredoxin-1 (Trx priming of donor lung significantly protected allogeneic lung graft. To determine whether Trx priming of donor lung inhibits allograft rejection, extends allograft survival and induces immune tolerance, orthotopic left lung transplantation was performed from Lewis to Sprague-Dawley rats without immunosuppression. Donor lungs were primed with Trx at 4°C for 4 hr prior to transplantation. After up to 37 days post-transplantation, allograft lung morphology, recipient T cell and humoral alloantigen-specific immune responses were examined. We found that Trx-primed lungs exhibited much reduced acute rejection and associated lung injuries resulting in loss of graft functional area at 5-37 days post-transplant in contrast to the control groups. CD4+ T cells from the recipients with Trx-primed grafts responded to the stimulation of dendritic cells (DCs of donor origin, in contrast to DCs from the third party, with significantly reduced proliferation. Consistent with above findings, we observed that CD4+Foxp3+ regulatory T cells in spleen cells from the recipients with Trx-primed grafts were significantly increased compared to controls, and CD4+ T cells from the recipients with Trx-primed grafts produced much higher levels of immunosuppressive cytokine, IL-10 when stimulated with allogeneic donor DCs. In addition, humoral immune tolerance was also induced as there was no significant increase levels of serum antibodies against donor antigens in Trx-lung recipients when re-challenged with allogeneic donor antigens. Our results demonstrate that one-time Trx-priming of donor lung grafts prior to transplantation significantly prolongs the survival of the grafts through inducing or promoting cellular and humoral alloantigen-specific immune tolerance, which might be associated with the induction of

The enigmatic role of mast cells in dominant tolerance.

Science.gov (United States)

de Vries, Victor C; Pino-Lagos, Karina; Elgueta, Raul; Noelle, Randolph J

2009-08-01

The role of regulatory T cells (Treg) in peripheral tolerance has been studied extensively in transplantation research. Recently, mast cells have been shown to play an indispensable role in allograft tolerance. The purpose of this review is to inform the reader on the current standings of the role of mast cells in dominant tolerance with an emphasis on the interaction of mast cells with Treg. Mast cells are required to sustain peripheral tolerance via Treg. Treg can stabilize mast cells degranulation by contact-dependent mechanisms through the interaction of OX40 and its ligand OX40L, and by production of soluble factors, such as interleukin-10 and transforming growth factor-beta. Conversely, the activation and subsequent degranulation of mast cells break peripheral tolerance. Both mast cells and Treg are needed to create a local immunosuppressive environment in the transplant. Treg are not only necessary to suppress effector T-cell responses but also to stabilize mast cells. Mast cells in return could contribute to the immunosuppressive state by release of transforming growth factor-beta, interleukin-10 and specific proteases. However, the molecular basis for mast cells control of Treg suppression in organ transplantation is still unresolved.

Perspectives on Regulatory T Cell Therapies.

Science.gov (United States)

Probst-Kepper, Michael; Kröger, Andrea; Garritsen, Henk S P; Buer, Jan

2009-01-01

Adoptive transfer in animal models clearly indicate an essential role of CD4+ CD25+ FOXP3+ regulatory T (T(reg)) cells in prevention and treatment of autoimmune and graft-versus-host disease. Thus, T(reg) cell therapies and development of drugs that specifically enhance T(reg) cell function and development represent promising tools to establish dominant tolerance. So far, lack of specific markers to differentiate human T(reg) cells from activated CD4+ CD25+ effector T cells, which also express FOXP3 at different levels, hampered such an approach. Recent identification of the orphan receptor glycoprotein-A repetitions predominant (GARP or LRRC32) as T(reg) cell-specific key molecule that dominantly controls FOXP3 via a positive feedback loop opens up new perspectives for molecular and cellular therapies. This brief review focuses on the role of GARP as a safeguard of a complex regulatory network of human T(reg) cells and its implications for regulatory T cell therapies in autoimmunity and graft-versus-host disease.

Regulatory control for safe usage of radiation sources in India

International Nuclear Information System (INIS)

Ghosh, P.K.; Sonawane, A.U.

1998-01-01

The widespread applications of radioactive materials and radiation generating equipment in the field of industry, medicine agriculture and research in India necessitated the establishment of an efficient regulatory framework and consequently the Atomic Energy Regulatory Board (AERB) was constituted to exercise regulatory control over the safe usage of the radioactive materials and the radiation generating equipment. The Atomic Energy Act, 1962 and the Radiation Protection Rules, 1971 promulgated under the Act forms the basis of radiation safety in India and Chairman, AERB is the Competent Authority to enforce the regulatory provisions of the Radiation Protection Rules, 1971, for safe use of radiation source in the country. AERB has published a number of documents such as Radiation Surveillance Procedures, Standards, Codes, Guides and Manuals for safe use and handling of radioactive materials and radiation generating equipment. Apart from nuclear fuel cycle documents, these publications pertain to industrial radiography, medical application of radiation, transport of radioactive material, industrial gamma irradiators, X-ray units etc. AERB safety related publications are based on international standards e.g. BSS, IAEA, ICRP, ISO etc. This paper outlines the methodology of regulatory control exercised by AERB for safe use of the radioactive materials and the radiation generating equipment in the country. (author)

Genetic control of mammalian T-cell proliferation with synthetic RNA regulatory systems

OpenAIRE

Chen, Yvonne Y.; Jensen, Michael C.; Smolke, Christina D.

2010-01-01

RNA molecules perform diverse regulatory functions in natural biological systems, and numerous synthetic RNA-based control devices that integrate sensing and gene-regulatory functions have been demonstrated, predominantly in bacteria and yeast. Despite potential advantages of RNA-based genetic control strategies in clinical applications, there has been limited success in extending engineered RNA devices to mammalian gene-expression control and no example of their application to functional res...

Induction of Foxp3-expressing regulatory T-cells by donor blood transfusion is required for tolerance to rat liver allografts.

Directory of Open Access Journals (Sweden)

Yuta Abe

Full Text Available BACKGROUND: Donor-specific blood transfusion (DST prior to solid organ transplantation has been shown to induce long-term allograft survival in the absence of immunosuppressive therapy. Although the mechanisms underlying DST-induced allograft tolerance are not well defined, there is evidence to suggest DST induces one or more populations of antigen-specific regulatory cells that suppress allograft rejection. However, neither the identity nor the regulatory properties of these tolerogenic lymphocytes have been reported. Therefore, the objective of this study was to define the kinetics, phenotype and suppressive function of the regulatory cells induced by DST alone or in combination with liver allograft transplantation (LTx. METHODOLOGY/PRINCIPAL FINDINGS: Tolerance to Dark Agouti (DA; RT1(a rat liver allografts was induced by injection (iv of 1 ml of heparinized DA blood to naïve Lewis (LEW; RT1(l rats once per week for 4 weeks prior to LTx. We found that preoperative DST alone generates CD4(+ T-cells that when transferred into naïve LEW recipients are capable of suppressing DA liver allograft rejection and promoting long-term survival of the graft and recipient. However, these DST-generated T-cells did not express the regulatory T-cell (Treg transcription factor Foxp3 nor did they suppress alloantigen (DA-induced activation of LEW T-cells in vitro suggesting that these lymphocytes are not fully functional regulatory Tregs. We did observe that DST+LTx (but not DST alone induced the time-dependent formation of CD4(+Foxp3(+ Tregs that potently suppressed alloantigen-induced activation of naïve LEW T-cells in vitro and liver allograft rejection in vivo. Finally, we present data demonstrating that virtually all of the Foxp3-expressing Tregs reside within the CD4(+CD45RC(- population whereas in which approximately 50% of these Tregs express CD25. CONCLUSIONS/SIGNIFICANCE: We conclude that preoperative DST, in the absence of liver allograft

Data Driven Fault Tolerant Control : A Subspace Approach

NARCIS (Netherlands)

Dong, J.

2009-01-01

The main stream research on fault detection and fault tolerant control has been focused on model based methods. As far as a model is concerned, changes therein due to faults have to be extracted from measured data. Generally speaking, existing approaches process measured inputs and outputs either by

Regulatory BC1 RNA in Cognitive Control

Science.gov (United States)

Iacoangeli, Anna; Dosunmu, Aderemi; Eom, Taesun; Stefanov, Dimitre G.; Tiedge, Henri

2017-01-01

Dendritic regulatory BC1 RNA is a non-protein-coding (npc) RNA that operates in the translational control of gene expression. The absence of BC1 RNA in BC1 knockout (KO) animals causes translational dysregulation that entails neuronal phenotypic alterations including prolonged epileptiform discharges, audiogenic seizure activity in vivo, and…

A modal H∞-norm-based performance requirement for damage-tolerant active controller design

Science.gov (United States)

Genari, Helói F. G.; Mechbal, Nazih; Coffignal, Gérard; Nóbrega, Eurípedes G. O.

2017-04-01

Damage-tolerant active control (DTAC) is a recent research area that encompasses control design methodologies resulting from the application of fault-tolerant control methods to vibration control of structures subject to damage. The possibility of damage occurrence is not usually considered in the active vibration control design requirements. Damage changes the structure dynamics, which may produce unexpected modal behavior of the closed-loop system, usually not anticipated by the controller design approaches. A modal H∞ norm and a respective robust controller design framework were recently introduced, and this method is here extended to face a new DTAC strategy implementation. Considering that damage affects each vibration mode differently, this paper adopts the modal H∞ norm to include damage as a design requirement. The basic idea is to create an appropriate energy distribution over the frequency range of interest and respective vibration modes, guaranteeing robustness, damage tolerance, and adequate overall performance, taking into account that it is common to have previous knowledge of the structure regions where damage may occur during its operational life. For this purpose, a structural health monitoring technique is applied to evaluate modal modifications caused by damage. This information is used to create modal weighing matrices, conducting to the modal H∞ controller design. Finite element models are adopted for a case study structure, including different damage severities, in order to validate the proposed control strategy. Results show the effectiveness of the proposed methodology with respect to damage tolerance.

Drought Response in Wheat: Key Genes and Regulatory Mechanisms Controlling Root System Architecture and Transpiration Efficiency

Directory of Open Access Journals (Sweden)

Manoj Kulkarni

2017-12-01

Full Text Available Abiotic stresses such as, drought, heat, salinity, and flooding threaten global food security. Crop genetic improvement with increased resilience to abiotic stresses is a critical component of crop breeding strategies. Wheat is an important cereal crop and a staple food source globally. Enhanced drought tolerance in wheat is critical for sustainable food production and global food security. Recent advances in drought tolerance research have uncovered many key genes and transcription regulators governing morpho-physiological traits. Genes controlling root architecture and stomatal development play an important role in soil moisture extraction and its retention, and therefore have been targets of molecular breeding strategies for improving drought tolerance. In this systematic review, we have summarized evidence of beneficial contributions of root and stomatal traits to plant adaptation to drought stress. Specifically, we discuss a few key genes such as, DRO1 in rice and ERECTA in Arabidopsis and rice that were identified to be the enhancers of drought tolerance via regulation of root traits and transpiration efficiency. Additionally, we highlight several transcription factor families, such as, ERF (ethylene response factors, DREB (dehydration responsive element binding, ZFP (zinc finger proteins, WRKY, and MYB that were identified to be both positive and negative regulators of drought responses in wheat, rice, maize, and/or Arabidopsis. The overall aim of this review is to provide an overview of candidate genes that have been identified as regulators of drought response in plants. The lack of a reference genome sequence for wheat and non-transgenic approaches for manipulation of gene functions in wheat in the past had impeded high-resolution interrogation of functional elements, including genes and QTLs, and their application in cultivar improvement. The recent developments in wheat genomics and reverse genetics, including the availability of a

Drought response in wheat: key genes and regulatory mechanisms controlling root system architecture and transpiration efficiency

Science.gov (United States)

Kulkarni, Manoj; Soolanayakanahally, Raju; Ogawa, Satoshi; Uga, Yusaku; Selvaraj, Michael G.; Kagale, Sateesh

2017-12-01

Abiotic stresses such as drought, heat, salinity and flooding threaten global food security. Crop genetic improvement with increased resilience to abiotic stresses is a critical component of crop breeding strategies. Wheat is an important cereal crop and a staple food source globally. Enhanced drought tolerance in wheat is critical for sustainable food production and global food security. Recent advances in drought tolerance research have uncovered many key genes and transcription regulators governing morpho-physiological traits. Genes controlling root architecture and stomatal development play an important role in soil moisture extraction and its retention, and therefore have been targets of molecular breeding strategies for improving drought tolerance. In this systematic review, we have summarized evidence of beneficial contributions of root and stomatal traits to plant adaptation to drought stress. Specifically, we discuss a few key genes such as DRO1 in rice and ERECTA in Arabidopsis and rice that were identified to be the enhancers of drought tolerance via regulation of root traits and transpiration efficiency. Additionally, we highlight several transcription factor families, such as ERF (ethylene response factors), DREB (dehydration responsive element binding), ZFP (zinc finger proteins), WRKY and MYB that were identified to be both positive and negative regulators of drought responses in wheat, rice, maize and/or Arabidopsis. The overall aim of this review was to provide an overview of candidate genes that have been tested as regulators of drought response in plants. The lack of a reference genome sequence for wheat and nontransgenic approaches for manipulation of gene functions in the past had impeded high-resolution interrogation of functional elements, including genes and QTLs, and their application in cultivar improvement. The recent developments in wheat genomics and reverse genetics, including the availability of a gold-standard reference genome

Development and Evaluation of Fault-Tolerant Flight Control Systems

Science.gov (United States)

Song, Yong D.; Gupta, Kajal (Technical Monitor)

2004-01-01

The research is concerned with developing a new approach to enhancing fault tolerance of flight control systems. The original motivation for fault-tolerant control comes from the need for safe operation of control elements (e.g. actuators) in the event of hardware failures in high reliability systems. One such example is modem space vehicle subjected to actuator/sensor impairments. A major task in flight control is to revise the control policy to balance impairment detectability and to achieve sufficient robustness. This involves careful selection of types and parameters of the controllers and the impairment detecting filters used. It also involves a decision, upon the identification of some failures, on whether and how a control reconfiguration should take place in order to maintain a certain system performance level. In this project new flight dynamic model under uncertain flight conditions is considered, in which the effects of both ramp and jump faults are reflected. Stabilization algorithms based on neural network and adaptive method are derived. The control algorithms are shown to be effective in dealing with uncertain dynamics due to external disturbances and unpredictable faults. The overall strategy is easy to set up and the computation involved is much less as compared with other strategies. Computer simulation software is developed. A serious of simulation studies have been conducted with varying flight conditions.

The IAEA Regional Training Course on Regulatory Control of Radiation Sources

International Nuclear Information System (INIS)

2000-01-01

Materials of the IAEA Regional Training Course contains 8 presented lectures. Authors deals with regulatory control of radiation sources. The next materials of the IAEA were presented: Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. (IAEA-TECDOC-1067); Safety assessment plants for authorization and inspection of radiation sources (IAEA-TECDOC-1113); Regulatory authority information system RAIS, Version 2.0, Instruction manual

Scientific rationale for the Finnish Allergy Programme 2008-2018: emphasis on prevention and endorsing tolerance.

Science.gov (United States)

von Hertzen, L C; Savolainen, J; Hannuksela, M; Klaukka, T; Lauerma, A; Mäkelä, M J; Pekkanen, J; Pietinalho, A; Vaarala, O; Valovirta, E; Vartiainen, E; Haahtela, T

2009-05-01

In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both

The regulatory control of ionizing radiation sources in Lithuania

International Nuclear Information System (INIS)

Mastauskas, A.; Ziliukas, J.; Morkunas, G.

1998-01-01

The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

Distributed Fault-Tolerant Control of Networked Uncertain Euler-Lagrange Systems Under Actuator Faults.

Science.gov (United States)

Chen, Gang; Song, Yongduan; Lewis, Frank L

2016-05-03

This paper investigates the distributed fault-tolerant control problem of networked Euler-Lagrange systems with actuator and communication link faults. An adaptive fault-tolerant cooperative control scheme is proposed to achieve the coordinated tracking control of networked uncertain Lagrange systems on a general directed communication topology, which contains a spanning tree with the root node being the active target system. The proposed algorithm is capable of compensating for the actuator bias fault, the partial loss of effectiveness actuation fault, the communication link fault, the model uncertainty, and the external disturbance simultaneously. The control scheme does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online, which largely reduces the online computation and expedites the responsiveness of the controller. To validate the effectiveness of the proposed method, a test-bed of multiple robot-arm cooperative control system is developed for real-time verification. Experiments on the networked robot-arms are conduced and the results confirm the benefits and the effectiveness of the proposed distributed fault-tolerant control algorithms.

Fault tolerant homopolar magnetic bearings with flux invariant control

International Nuclear Information System (INIS)

Na, Uhn Joo

2006-01-01

The theory for a novel fault-tolerant 4-active-pole homopolar magnetic bearing is developed. If any one coil of the four coils in the bearing actuator fail, the remaining three coil currents change via an optimal distribution matrix such that the same opposing pole, C-core type, control fluxes as those of the un-failed bearing are produced. The homopolar magnetic bearing thus provides unaltered magnetic forces without any loss of the bearing load capacity even if any one coil suddenly fails. Numerical examples are provided to illustrate the novel fault-tolerant, 4-active pole homopolar magnetic bearings

A Design Method for Fault Reconfiguration and Fault-Tolerant Control of a Servo Motor

Directory of Open Access Journals (Sweden)

Jing He

2013-01-01

Full Text Available A design scheme that integrates fault reconfiguration and fault-tolerant position control is proposed for a nonlinear servo system with friction. Analysis of the non-linear friction torque and fault in the system is used to guide design of a sliding mode position controller. A sliding mode observer is designed to achieve fault reconfiguration based on the equivalence principle. Thus, active fault-tolerant position control of the system can be realized. A real-time simulation experiment is performed on a hardware-in-loop simulation platform. The results show that the system reconfigures well for both incipient and abrupt faults. Under the fault-tolerant control mechanism, the output signal for the system position can rapidly track given values without being influenced by faults.

Generation of American elm trees with tolerance to Dutch elm disease through controlled crosses and selection

Science.gov (United States)

James M. Slavicek; Kathleen S. Knight

2012-01-01

The goal of our research and development efforts is to generate new and/or improved selections of the American elm (Ulmus americana L.) with tolerance/resistance to Dutch elm disease (DED). The approaches we are taking for this effort include: 1) controlled breeding using known DED -tolerant selections, 2) controlled breeding using DED-tolerant...

Regulatory control analysis and design for sewer systems

DEFF Research Database (Denmark)

Mollerup, Ane Loft; Mikkelsen, Peter Steen; Thornberg, Dines

2015-01-01

A systematic methodology for regulatory control analysis and design is adapted for sewer system operation and evaluated. The main challenge with adapting the methodology is the handling of the stochastic and transient nature of the rainfall disturbances, inherent to sewer system operation...

Oral Tolerance: Therapeutic Implications for Autoimmune Diseases

Directory of Open Access Journals (Sweden)

Ana M. C. Faria

2006-01-01

Full Text Available Oral tolerance is classically defined as the suppression of immune responses to antigens (Ag that have been administered previously by the oral route. Multiple mechanisms of tolerance are induced by oral Ag. Low doses favor active suppression, whereas higher doses favor clonal anergy/deletion. Oral Ag induces Th2 (IL-4/IL-10 and Th3 (TGF-β regulatory T cells (Tregs plus CD4+CD25+ regulatory cells and LAP+T cells. Induction of oral tolerance is enhanced by IL-4, IL-10, anti-IL-12, TGF-β, cholera toxin B subunit (CTB, Flt-3 ligand, anti-CD40 ligand and continuous feeding of Ag. In addition to oral tolerance, nasal tolerance has also been shown to be effective in suppressing inflammatory conditions with the advantage of a lower dose requirement. Oral and nasal tolerance suppress several animal models of autoimmune diseases including experimental allergic encephalomyelitis (EAE, uveitis, thyroiditis, myasthenia, arthritis and diabetes in the nonobese diabetic (NOD mouse, plus non-autoimmune diseases such as asthma, atherosclerosis, colitis and stroke. Oral tolerance has been tested in human autoimmune diseases including MS, arthritis, uveitis and diabetes and in allergy, contact sensitivity to DNCB, nickel allergy. Positive results have been observed in phase II trials and new trials for arthritis, MS and diabetes are underway. Mucosal tolerance is an attractive approach for treatment of autoimmune and inflammatory diseases because of lack of toxicity, ease of administration over time and Ag-specific mechanism of action. The successful application of oral tolerance for the treatment of human diseases will depend on dose, developing immune markers to assess immunologic effects, route (nasal versus oral, formulation, mucosal adjuvants, combination therapy and early therapy.

Stochastic Model Predictive Fault Tolerant Control Based on Conditional Value at Risk for Wind Energy Conversion System

Directory of Open Access Journals (Sweden)

Yun-Tao Shi

2018-01-01

Full Text Available Wind energy has been drawing considerable attention in recent years. However, due to the random nature of wind and high failure rate of wind energy conversion systems (WECSs, how to implement fault-tolerant WECS control is becoming a significant issue. This paper addresses the fault-tolerant control problem of a WECS with a probable actuator fault. A new stochastic model predictive control (SMPC fault-tolerant controller with the Conditional Value at Risk (CVaR objective function is proposed in this paper. First, the Markov jump linear model is used to describe the WECS dynamics, which are affected by many stochastic factors, like the wind. The Markov jump linear model can precisely model the random WECS properties. Second, the scenario-based SMPC is used as the controller to address the control problem of the WECS. With this controller, all the possible realizations of the disturbance in prediction horizon are enumerated by scenario trees so that an uncertain SMPC problem can be transformed into a deterministic model predictive control (MPC problem. Finally, the CVaR object function is adopted to improve the fault-tolerant control performance of the SMPC controller. CVaR can provide a balance between the performance and random failure risks of the system. The Min-Max performance index is introduced to compare the fault-tolerant control performance with the proposed controller. The comparison results show that the proposed method has better fault-tolerant control performance.

Tolerance of Volume Control Noninvasive Ventilation in Subjects With Amyotrophic Lateral Sclerosis.

Science.gov (United States)

Martínez, Daniel; Sancho, Jesús; Servera, Emilio; Marín, Julio

2015-12-01

Noninvasive ventilation (NIV) tolerance has been identified as an independent predictor of survival in amyotrophic lateral sclerosis (ALS). Volume control continuous mandatory ventilation (VC-CMV) NIV has been associated with poor tolerance. The aim of this study was to determine the tolerance of subjects with ALS to VC-CMV NIV. This was a prospective study involving subjects with ALS who were treated with VC-CMV NIV. Respiratory and functional parameters were recorded when the subjects began ventilatory support. NIV tolerance was evaluated after 3 months. Eighty-seven subjects with ALS were included. After 3 months, 80 subjects (92%) remained tolerant of NIV. Tolerant subjects presented greater survival (median 22.0 months, 95% CI 14.78-29.21) than intolerant subjects (median 6.0 months, 95% CI 0.86-11.13) (P = .03). The variables that best predicted NIV tolerance were mechanically assisted cough peak flow (P = .01) and percentage of time spent with SpO2 NIV (P = .03) CONCLUSIONS: VC-CMV NIV provides high rates of NIV tolerance in subjects with ALS. Mechanically assisted cough peak flow and percentage of time spent with SpO2 NIV are the 2 factors associated with tolerance of VC-CMV NIV in subjects with ALS. Copyright © 2015 by Daedalus Enterprises.

Continuous improvement of the regulatory framework for the control of medical exposure

International Nuclear Information System (INIS)

Larcher, Ana M.; Ortiz Lopez, Pedro; Arias, Cesar; Marechal, Maria H.; Hernandez Alvarez, Ramon; Ferrer Garcia, Natividad; Castaneda Mucino, Antonia; Faller, Blanca

2008-01-01

One of the key elements to guide the improvement of the regulatory control is the availability of a self-assessment tool for regulatory performance. Although there is general guidance on self-assessment for regulators and users (IAEA), there is a need for more specific advice on how to address challenges and difficulties faced by regulatory bodies, when regulating radiation protection of patients. Examples of these challenges are the need for regulatory initiatives, in cooperation with health and education authorities, professional bodies and equipment suppliers, and to put in place necessary elements that are beyond responsibility of individual user of radiation, to enable them compliance with safety standards. Purpose: Within the programme of the Ibero American Forum of Nuclear and Radiation Safety Regulatory Organizations, a project to develop such a self-assessment tool for the regulatory control of medical exposure has been designed. Method: National experiences in transposing and enforcing the international radiation safety standards, as to how the requirements are included in national regulations are reviewed. Further, difficulties to the implementation of safety requirements are analyzed and a self-assessment approach and possible regulatory solutions a are presented. Results and discussion: In this study the following documents are being produced: 1) transposition of international requirements into national regulations in the six countries of the Forum, 2) difficulties to implement and enforce the requirements, 3) guidance on self-assessment of regulatory framework for medical exposure, 4) suggested contribution to the revision of international radiation safety standards. (author)

Regulatory Mechanisms Controlling Maturation of Serotonin Neuron Identity and Function.

Science.gov (United States)

Spencer, William C; Deneris, Evan S

2017-01-01

The brain serotonin (5-hydroxytryptamine; 5-HT) system has been extensively studied for its role in normal physiology and behavior, as well as, neuropsychiatric disorders. The broad influence of 5-HT on brain function, is in part due to the vast connectivity pattern of 5-HT-producing neurons throughout the CNS. 5-HT neurons are born and terminally specified midway through embryogenesis, then enter a protracted period of maturation, where they functionally integrate into CNS circuitry and then are maintained throughout life. The transcriptional regulatory networks controlling progenitor cell generation and terminal specification of 5-HT neurons are relatively well-understood, yet the factors controlling 5-HT neuron maturation are only recently coming to light. In this review, we first provide an update on the regulatory network controlling 5-HT neuron development, then delve deeper into the properties and regulatory strategies governing 5-HT neuron maturation. In particular, we discuss the role of the 5-HT neuron terminal selector transcription factor (TF) Pet-1 as a key regulator of 5-HT neuron maturation. Pet-1 was originally shown to positively regulate genes needed for 5-HT synthesis, reuptake and vesicular transport, hence 5-HT neuron-type transmitter identity. It has now been shown to regulate, both positively and negatively, many other categories of genes in 5-HT neurons including ion channels, GPCRs, transporters, neuropeptides, and other transcription factors. Its function as a terminal selector results in the maturation of 5-HT neuron excitability, firing characteristics, and synaptic modulation by several neurotransmitters. Furthermore, there is a temporal requirement for Pet-1 in the control of postmitotic gene expression trajectories thus indicating a direct role in 5-HT neuron maturation. Proper regulation of the maturation of cellular identity is critical for normal neuronal functioning and perturbations in the gene regulatory networks controlling

Licensing and regulatory control of nuclear power plants in Canada

International Nuclear Information System (INIS)

Atchison, R.J.

1975-01-01

The paper discusses the safety philosophy adopted in Canada, the safety criteria and regulatory requirements necessary for the application of this philosophy to reactor design and operation, and finally the means by which compliance with Board requirements is effected. It is emphasized that the effectiveness of regulatory control depends not only on the underlying philosophy but also on the detailed way in which it is applied. (orig./HP) [de

Active Fault-Tolerant Control for Wind Turbine with Simultaneous Actuator and Sensor Faults

Directory of Open Access Journals (Sweden)

Lei Wang

2017-01-01

Full Text Available The purpose of this paper is to show a novel fault-tolerant tracking control (FTC strategy with robust fault estimation and compensating for simultaneous actuator sensor faults. Based on the framework of fault-tolerant control, developing an FTC design method for wind turbines is a challenge and, thus, they can tolerate simultaneous pitch actuator and pitch sensor faults having bounded first time derivatives. The paper’s key contribution is proposing a descriptor sliding mode method, in which for establishing a novel augmented descriptor system, with which we can estimate the state of system and reconstruct fault by designing descriptor sliding mode observer, the paper introduces an auxiliary descriptor state vector composed by a system state vector, actuator fault vector, and sensor fault vector. By the optimized method of LMI, the conditions for stability that estimated error dynamics are set up to promote the determination of the parameters designed. With this estimation, and designing a fault-tolerant controller, the system’s stability can be maintained. The effectiveness of the design strategy is verified by implementing the controller in the National Renewable Energy Laboratory’s 5-MW nonlinear, high-fidelity wind turbine model (FAST and simulating it in MATLAB/Simulink.

Identification and Characterization of 5′ Untranslated Regions (5′UTRs in Zymomonas mobilis as Regulatory Biological Parts

Directory of Open Access Journals (Sweden)

Seung Hee Cho

2017-12-01

Full Text Available Regulatory RNA regions within a transcript, particularly in the 5′ untranslated region (5′UTR, have been shown in a variety of organisms to control the expression levels of these mRNAs in response to various metabolites or environmental conditions. Considering the unique tolerance of Zymomonas mobilis to ethanol and the growing interest in engineering microbial strains with enhanced tolerance to industrial inhibitors, we searched natural cis-regulatory regions in this microorganism using transcriptomic data and bioinformatics analysis. Potential regulatory 5′UTRs were identified and filtered based on length, gene function, relative gene counts, and conservation in other organisms. An in vivo fluorescence-based screening system was developed to confirm the responsiveness of 36 5′UTR candidates to ethanol, acetate, and xylose stresses. UTR_ZMO0347 (5′UTR of gene ZMO0347 encoding the RNA binding protein Hfq was found to down-regulate downstream gene expression under ethanol stress. Genomic deletion of UTR_ZMO0347 led to a general decrease of hfq expression at the transcript level and increased sensitivity for observed changes in Hfq expression at the protein level. The role of UTR_ZMO0347 and other 5′UTRs gives us insight into the regulatory network of Z. mobilis in response to stress and unlocks new strategies for engineering robust industrial strains as well as for harvesting novel responsive regulatory biological parts for controllable gene expression platforms in this organism.

Evaporator unit as a benchmark for plug and play and fault tolerant control

DEFF Research Database (Denmark)

Izadi-Zamanabadi, Roozbeh; Vinther, Kasper; Mojallali, Hamed

2012-01-01

This paper presents a challenging industrial benchmark for implementation of control strategies under realistic working conditions. The developed control strategies should perform in a plug & play manner, i.e. adapt to varying working conditions, optimize their performance, and provide fault...... tolerance. A fault tolerant strategy is needed to deal with a faulty sensor measurement of the evaporation pressure. The design and algorithmic challenges in the control of an evaporator include: unknown model parameters, large parameter variations, varying loads, and external discrete phenomena...... such as compressor switch on/o or abrupt change in compressor speed....

Regulating the path from legacy recognition, through recovery to release from regulatory control.

Science.gov (United States)

Sneve, Malgorzata Karpow; Smith, Graham

2015-04-01

Past development of processes and technologies using radioactive material led to construction of many facilities worldwide. Some of these facilities were built and operated before the regulatory infrastructure was in place to ensure adequate control of radioactive material during operation and decommissioning. In other cases, controls were in place but did not meet modern standards, leading to what is now considered to have been inadequate control. Accidents and other events have occurred resulting in loss of control of radioactive material and unplanned releases to the environment. The legacy from these circumstances is that many countries have areas or facilities at which abnormal radiation conditions exist at levels that give rise to concerns about environmental and human health of potential interest to regulatory authorities. Regulation of these legacy situations is complex. This paper examines the regulatory challenges associated with such legacy management and brings forward suggestions for finding the path from: legacy recognition; implementation, as necessary, of urgent mitigation measures; development of a longer-term management strategy, through to release from regulatory control. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fault Tolerant Position-mooring Control for Offshore Vessels

DEFF Research Database (Denmark)

Blanke, Mogens; Nguyen, Trong Dong

2018-01-01

Fault-tolerance is crucial to maintain safety in offshore operations. The objective of this paper is to show how systematic analysis and design of fault-tolerance is conducted for a complex automation system, exemplified by thruster assisted Position-mooring. Using redundancy as required....... Functional faults that are only detectable, are rendered isolable through an active isolation approach. Once functional faults are isolated, they are handled by fault accommodation techniques to meet overall control objectives specified by class requirements. The paper illustrates the generic methodology...... by a system to handle faults in mooring lines, sensors or thrusters. Simulations and model basin experiments are carried out to validate the concept for scenarios with single or multiple faults. The results demonstrate that enhanced availability and safety are obtainable with this design approach. While...

Fault-tolerant control for current sensors of doubly fed induction generators based on an improved fault detection method

DEFF Research Database (Denmark)

Li, Hui; Yang, Chao; Hu, Yaogang

2014-01-01

Fault-tolerant control of current sensors is studied in this paper to improve the reliability of a doubly fed induction generator (DFIG). A fault-tolerant control system of current sensors is presented for the DFIG, which consists of a new current observer and an improved current sensor fault...... detection algorithm, and fault-tolerant control system are investigated by simulation. The results indicate that the outputs of the observer and the sensor are highly coherent. The fault detection algorithm can efficiently detect both soft and hard faults in current sensors, and the fault-tolerant control...

Regulatory control of low level radiation exposure in Tanzania

International Nuclear Information System (INIS)

Nyanda, A.M.; Muhogora, W.E.

1997-01-01

In Tanzania, the radiation protection law was issued in 1983. Under this law, the National Radiation Commission is responsible for safe uses of ionizing radiation. The regulatory control of the resulting doses from the uses of radiation sources in medicine, industry, research and teaching is presented. The system of control reflects the existing interactions between the National Radiation Commission and users through the established radiation protection infrastructure. From the national dose registry data, it is found that the highest annual individual doses over 10 years ago, came from less than 5% of total monitored workers and were in the range 10 - 15 mSv y -1 . The experienced radiation levels in uncontrolled areas of potential workplaces is less than 1 μSv h -1 . The possibility for associating such low dose levels to the effectiveness of the existing regulatory dose control framework is discussed. Despite of this achievement, the need to improve further the radiation protection and safety programs is found necessary. (author)

Fault Tolerant Control for Civil Structures Based on LMI Approach

Directory of Open Access Journals (Sweden)

Chunxu Qu

2013-01-01

Full Text Available The control system may lose the performance to suppress the structural vibration due to the faults in sensors or actuators. This paper designs the filter to perform the fault detection and isolation (FDI and then reforms the control strategy to achieve the fault tolerant control (FTC. The dynamic equation of the structure with active mass damper (AMD is first formulated. Then, an estimated system is built to transform the FDI filter design problem to the static gain optimization problem. The gain is designed to minimize the gap between the estimated system and the practical system, which can be calculated by linear matrix inequality (LMI approach. The FDI filter is finally used to isolate the sensor faults and reform the FTC strategy. The efficiency of FDI and FTC is validated by the numerical simulation of a three-story structure with AMD system with the consideration of sensor faults. The results show that the proposed FDI filter can detect the sensor faults and FTC controller can effectively tolerate the faults and suppress the structural vibration.

Authority defied: need for cognitive closure influences regulatory control when resisting authority.

Science.gov (United States)

Damen, Tom G E; van Leeuwen, Matthijs L; Dijksterhuis, Ap; van Baaren, Rick B

2014-08-01

The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the influence attempt of an authority figure (Study 2; N = 50). Results showed that resisting the influence attempt from a high-authority figure was more depleting for participants higher in NCC compared to individuals lower in NCC. However, when they were given instructions and time to prepare the act of resistance, individuals high in NCC actually showed an increase in regulatory control. Authority is usually viewed as a general principle of influence; however, the present studies suggest that there are individual differences that influence how people may experience interactions with authorities. © 2013 Wiley Periodicals, Inc.

Design of passive fault-tolerant flight controller against actuator failures

Directory of Open Access Journals (Sweden)

Xiang Yu

2015-02-01

Full Text Available The problem of designing passive fault-tolerant flight controller is addressed when the normal and faulty cases are prescribed. First of all, the considered fault and fault-free cases are formed by polytopes. As considering that the safety of a post-fault system is directly related to the maximum values of physical variables in the system, peak-to-peak gain is selected to represent the relationships among the amplitudes of actuator outputs, system outputs, and reference commands. Based on the parameter dependent Lyapunov and slack methods, the passive fault-tolerant flight controllers in the absence/presence of system uncertainty for actuator failure cases are designed, respectively. Case studies of an airplane under actuator failures are carried out to validate the effectiveness of the proposed approach.

Continuous Improvement of the Regulatory Framework for the Control of Medical Exposure

International Nuclear Information System (INIS)

Larcher, A.M.; Ortiz lopez, Pedro; Arias, Cesar; Marechal, Maria H.; Hernandez Alvarez, Ramon; Ferrer Garcia, Natividad; Castaneda Mucino, Antonia; Faller, Blanca

2011-01-01

Background: One of the key elements to guide the improvement of the regulatory control is the availability of a self-assessment tool for regulatory performance. Although there is general guidance on self-assessment for regulators and users (IAEA), there is a need for specific advice on how to address challenges and difficulties faced by regulatory bodies, when regulating radiation protection of patients. Examples of these challenges are the need of regulatory initiatives, in cooperation with health and education authorities, professional bodies and equipment suppliers, and to put in place necessary elements that are beyond responsibility of individual users of radiation, to enable them compliance with safety standards. Purpose: within the programme of the Ibero American Forum of Nuclear and Radiation Safety Regulatory Organizations, a project to develop such a self assessment tool for the regulatory control of medical exposure has been designed. Method: national experiences in transposing and enforcing the international radiation safety standards, as to how the requirements are included in national regulations are reviewed. Further, difficulties to the implementation of safety requirements are included in national regulations are analyzed and a self assessment approach and possible regulatory solutions are presented. Results and discussion: in tis study the following documents are being produced: 1) Transposition of international requirements into national regulations in the six countries of the Forum, 2) difficulties to implement and enforce the requirements, 3) guidance on self assessment of regulatory framework for medical exposure, 4) suggested contribution to the revision of international radiation safety standards. (authors)

An improved fault-tolerant control scheme for PWM inverter-fed induction motor-based EVs.

Science.gov (United States)

Tabbache, Bekheïra; Benbouzid, Mohamed; Kheloui, Abdelaziz; Bourgeot, Jean-Matthieu; Mamoune, Abdeslam

2013-11-01

This paper proposes an improved fault-tolerant control scheme for PWM inverter-fed induction motor-based electric vehicles. The proposed strategy deals with power switch (IGBTs) failures mitigation within a reconfigurable induction motor control. To increase the vehicle powertrain reliability regarding IGBT open-circuit failures, 4-wire and 4-leg PWM inverter topologies are investigated and their performances discussed in a vehicle context. The proposed fault-tolerant topologies require only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, mitigating the IGBTs failures by specific inverter control. Indeed, the two topologies exploit the induction motor neutral accessibility for fault-tolerant purposes. The 4-wire topology uses then classical hysteresis controllers to account for the IGBT failures. The 4-leg topology, meanwhile, uses a specific 3D space vector PWM to handle vehicle requirements in terms of size (DC bus capacitors) and cost (IGBTs number). Experiments on an induction motor drive and simulations on an electric vehicle are carried-out using a European urban driving cycle to show that the proposed fault-tolerant control approach is effective and provides a simple configuration with high performance in terms of speed and torque responses. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Adaptive robust fault-tolerant control for linear MIMO systems with unmatched uncertainties

Science.gov (United States)

Zhang, Kangkang; Jiang, Bin; Yan, Xing-Gang; Mao, Zehui

2017-10-01

In this paper, two novel fault-tolerant control design approaches are proposed for linear MIMO systems with actuator additive faults, multiplicative faults and unmatched uncertainties. For time-varying multiplicative and additive faults, new adaptive laws and additive compensation functions are proposed. A set of conditions is developed such that the unmatched uncertainties are compensated by actuators in control. On the other hand, for unmatched uncertainties with their projection in unmatched space being not zero, based on a (vector) relative degree condition, additive functions are designed to compensate for the uncertainties from output channels in the presence of actuator faults. The developed fault-tolerant control schemes are applied to two aircraft systems to demonstrate the efficiency of the proposed approaches.

Adolescent threat-related interpretive bias and its modification: the moderating role of regulatory control

NARCIS (Netherlands)

Salemink, E.; Wiers, R.W.

2012-01-01

Dual process models describe psychopathology as the consequence of an imbalance between a fast, impulsive system and a regulatory control system and have recently been applied to anxiety disorders. The aim of the current study was to specifically examine the role of a regulatory control system in

Fault Tolerant Flight Control Using Sliding Modes and Subspace Identification-Based Predictive Control

KAUST Repository

Siddiqui, Bilal A.; El-Ferik, Sami; Abdelkader, Mohamed

2016-01-01

In this work, a cascade structure of a time-scale separated integral sliding mode and model predictive control is proposed as a viable alternative for fault-tolerant control. A multi-variable sliding mode control law is designed as the inner loop of the flight control system. Subspace identification is carried out on the aircraft in closed loop. The identified plant is then used for model predictive controllers in the outer loop. The overall control law demonstrates improved robustness to measurement noise, modeling uncertainties, multiple faults and severe wind turbulence and gusts. In addition, the flight control system employs filters and dead-zone nonlinear elements to reduce chattering and improve handling quality. Simulation results demonstrate the efficiency of the proposed controller using conventional fighter aircraft without control redundancy.

Fault Tolerant Flight Control Using Sliding Modes and Subspace Identification-Based Predictive Control

KAUST Repository

Siddiqui, Bilal A.

2016-07-26

In this work, a cascade structure of a time-scale separated integral sliding mode and model predictive control is proposed as a viable alternative for fault-tolerant control. A multi-variable sliding mode control law is designed as the inner loop of the flight control system. Subspace identification is carried out on the aircraft in closed loop. The identified plant is then used for model predictive controllers in the outer loop. The overall control law demonstrates improved robustness to measurement noise, modeling uncertainties, multiple faults and severe wind turbulence and gusts. In addition, the flight control system employs filters and dead-zone nonlinear elements to reduce chattering and improve handling quality. Simulation results demonstrate the efficiency of the proposed controller using conventional fighter aircraft without control redundancy.

Engineering antigen-specific immunological tolerance.

Energy Technology Data Exchange (ETDEWEB)

Kontos, Stephan; Grimm, Alizee J.; Hubbell, Jeffrey A.

2015-05-01

Unwanted immunity develops in response to many protein drugs, in autoimmunity, in allergy, and in transplantation. Approaches to induce immunological tolerance aim to either prevent these responses or reverse them after they have already taken place. We present here recent developments in approaches, based on engineered peptides, proteins and biomaterials, that harness mechanisms of peripheral tolerance both prophylactically and therapeutically to induce antigenspecific immunological tolerance. These mechanisms are based on responses of B and T lymphocytes to other cells in their immune environment that result in cellular deletion or ignorance to particular antigens, or in development of active immune regulatory responses. Several of these approaches are moving toward clinical development, and some are already in early stages of clinical testing.

Data-Reconciliation Based Fault-Tolerant Model Predictive Control for a Biomass Boiler

Directory of Open Access Journals (Sweden)

Palash Sarkar

2017-02-01

Full Text Available This paper presents a novel, effective method to handle critical sensor faults affecting a control system devised to operate a biomass boiler. In particular, the proposed method consists of integrating a data reconciliation algorithm in a model predictive control loop, so as to annihilate the effects of faults occurring in the sensor of the flue gas oxygen concentration, by feeding the controller with the reconciled measurements. Indeed, the oxygen content in flue gas is a key variable in control of biomass boilers due its close connections with both combustion efficiency and polluting emissions. The main benefit of including the data reconciliation algorithm in the loop, as a fault tolerant component, with respect to applying standard fault tolerant methods, is that controller reconfiguration is not required anymore, since the original controller operates on the restored, reliable data. The integrated data reconciliation–model predictive control (MPC strategy has been validated by running simulations on a specific type of biomass boiler—the KPA Unicon BioGrate boiler.

Fault diagnosis and fault-tolerant finite control set-model predictive control of a multiphase voltage-source inverter supplying BLDC motor.

Science.gov (United States)

Salehifar, Mehdi; Moreno-Equilaz, Manuel

2016-01-01

Due to its fault tolerance, a multiphase brushless direct current (BLDC) motor can meet high reliability demand for application in electric vehicles. The voltage-source inverter (VSI) supplying the motor is subjected to open circuit faults. Therefore, it is necessary to design a fault-tolerant (FT) control algorithm with an embedded fault diagnosis (FD) block. In this paper, finite control set-model predictive control (FCS-MPC) is developed to implement the fault-tolerant control algorithm of a five-phase BLDC motor. The developed control method is fast, simple, and flexible. A FD method based on available information from the control block is proposed; this method is simple, robust to common transients in motor and able to localize multiple open circuit faults. The proposed FD and FT control algorithm are embedded in a five-phase BLDC motor drive. In order to validate the theory presented, simulation and experimental results are conducted on a five-phase two-level VSI supplying a five-phase BLDC motor. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

75 FR 17571 - Pendimethalin; Pesticide Tolerances

Science.gov (United States)

2010-04-07

... Enforcement Methodology Adequate enforcement methodology, using liquid chromatography/mass spectrometry... Order Reviews This final rule establishes tolerances under section 408(d) of FFDCA in response to a... actions from review under Executive Order 12866, entitled Regulatory Planning and Review (58 FR 51735...

JUNGBRUNNEN1 Confers Drought Tolerance Downstream of the HD-Zip I Transcription Factor AtHB13

Directory of Open Access Journals (Sweden)

Saghar Ebrahimian-Motlagh

2017-12-01

Full Text Available Low water availability is the major environmental factor limiting growth and productivity of plants and crops and is therefore considered of high importance for agriculture affected by climate change. Identifying regulatory components controlling the response and tolerance to drought stress is thus of major importance. The NAC transcription factor (TF JUNGBRUNNEN1 (JUB1 from Arabidopsis thaliana extends leaf longevity under non-stress growth conditions, lowers cellular hydrogen peroxide (H2O2 level, and enhances tolerance against heat stress and salinity. Here, we additionally find that JUB1 strongly increases tolerance to drought stress in Arabidopsis when expressed from both, a constitutive (CaMV 35S and an abiotic stress-induced (RD29A promoter. Employing a yeast one-hybrid screen we identified HD-Zip class I TF AtHB13 as an upstream regulator of JUB1. AtHB13 has previously been reported to act as a positive regulator of drought tolerance. AtHB13 and JUB1 thereby establish a joint drought stress control module.

Competent authority regulatory control of the transport of radioactive material

International Nuclear Information System (INIS)

1987-04-01

The purpose of this guide is to assist competent authorities in regulating the transport of radioactive materials and to assist users of transport regulations in their interactions with competent authorities. The guide should assist specifically those countries which are establishing their regulatory framework and further assist countries with established procedures to harmonize their application and implementation of the IAEA Regulations. This guide specifically covers various aspects of the competent authority implementation of the IAEA Regulations for the Safe Transport of Radioactive Material. In addition, physical protection and safeguards control of the transport of nuclear materials as well as third party liability aspects are briefly discussed. This is because they have to be taken into account in overall transport regulatory activities, especially when establishing the regulatory framework

Criteria of exemption of regulatory control for radioactive material; Criterios de exencion del control regulatorio para material radiactivo

Energy Technology Data Exchange (ETDEWEB)

Medrano Lopez, Marco A [Gerencia de Seguridad Radiologica, Instituto Nacional de Investigaciones Nucleares, Salazar (Mexico)

1991-07-01

Being based on the information contained in the 10 CFR Part 20, of the section 20.301 until the 20.306 where the mechanisms by means of which can prepare the waste of low level are indicated. While the Nuclear Regulatory Commission (NRC) it amended in the year of 1985 the Act of Politics on Low level Wastes, in particular the section 10 of the amendment of the Act, relative to the concept BRC treats those groups of radioactive waste in that their activity contents are so low that they could be exempt of the regulatory control, either liberating them toward the environment or to exempt people or organizations of the regulatory control.

Regulatory systems for the control of land remediation processes

Energy Technology Data Exchange (ETDEWEB)

Lowe, J.; Vijgen, J.; Summersgill, M.

2003-07-01

One of the recurring themes in looking at land remediation over the last decade has been identifying and overcoming barriers to the use of innovative, sustainable technologies, whilst still ensuring that there are no adverse environmental impacts from their use. In parallel with this, the regeneration of brownfield sites has increasingly needed effective and economic solutions that leave the site without the stigma of being associated with contamination and waste disposal. Regulatory controls are often identified as one of the main barriers to both of these objectives. Previously, the focus of attention in the study of regulatory controls relating to land contamination has largely been on regimes that trigger the need for clean-up. These may be pollution control legislation or land-use planning controls. However, the focus of this paper will be on the controls on the selection and implementation of the remediation technologies and processes themselves. It will look in particular at the European-wide controls on waste management, pollution prevention and environmental impact assessment. The UK work is being carried out by a working group involving: landowners; developers; public sector regeneration agencies; house-builders; industry; insurers; technology providers; professional advisers; local government authorities; and national government regulators and policy-makers. This multi-stakeholder approach has facilitated the identification of practical, legal, financial and administrative issues to assist in developing new solutions. (orig.)

National Program Initiative to Prevent Illicit Trafficking for Radioactive Materials Out of Regulatory Control at the Border

International Nuclear Information System (INIS)

Suharyanta, S.

2016-01-01

The existing function of regulatory authority in a country which use a lot of radioactive sources is important key. The regulatory body has to in a position independence from other operators and nuclear research centre activities, so that their justification on Regulatory objective of safety and security can be achieved. The essential function of regulatory authority has to be represented such as development regulations, perform review and assessment, inspection and enforcement, and emergency preparedness and response functions. Under regulatory object coverage is divided into two clusters i.e. licensed nuclear installation and radiation facilities clusters,. There is other regulatory object is radioactive material out of regulatory control. This kind object is new option in the county and there for need priority policy judgement. This paper will discuss the Regulatory infrastructure and functions and it focused on the experience about National Programme Initiative to Prevent Illicit Trafficking for Radioactive Materials out of Regulatory Control at the Border. Regulatory Infrastructure and Functions. In Indonesia the independent regulatory authority ''called BAPETEN'' has been established since early 2000 based on the Act No. 10 year 1997, independent from operator organization and other nuclear research centre. Organization structure of BAPETEN has defined main divisions dealing with developing regulations, perform review and assessments, inspection and enforcement, and emergency preparedness and response, and also covered assessment function as a backup technical support division as a think-tank functions. Regulatory objects are nuclear installations such as three research reactors, Fuel fabrication facility, Isotope production facility, and waste storage facility for spent fuel and dis-used radioactive sources is running well. Recently, Regulatory of radioactive sources out of regulatory control is a new challenges, they need strengthened

Tolerance through Education: How Tolerogenic Dendritic Cells Shape Immunity

Directory of Open Access Journals (Sweden)

Matthias P. Domogalla

2017-12-01

Full Text Available Dendritic cells (DCs are central players in the initiation and control of responses, regulating the balance between tolerance and immunity. Tolerogenic DCs are essential in the maintenance of central and peripheral tolerance by induction of clonal T cell deletion and T cell anergy, inhibition of memory and effector T cell responses, and generation and activation of regulatory T cells. Therefore, tolerogenic DCs are promising candidates for specific cellular therapy of allergic and autoimmune diseases and for treatment of transplant rejection. Studies performed in rodents have demonstrated the efficacy and feasibility of tolerogenic DCs for tolerance induction in various inflammatory diseases. In the last years, numerous protocols for the generation of human monocyte-derived tolerogenic DCs have been established and some first phase I trials have been conducted in patients suffering from autoimmune disorders, demonstrating the safety and efficiency of this cell-based immunotherapy. This review gives an overview about methods and protocols for the generation of human tolerogenic DCs and their mechanisms of tolerance induction with the focus on interleukin-10-modulated DCs. In addition, we will discuss the prerequisites for optimal clinical grade tolerogenic DC subsets and results of clinical trials with tolerogenic DCs in autoimmune diseases.

Passive Fault-tolerant Control of Discrete-time Piecewise Affine Systems against Actuator Faults

DEFF Research Database (Denmark)

Tabatabaeipour, Seyed Mojtaba; Izadi-Zamanabadi, Roozbeh; Bak, Thomas

2012-01-01

In this paper, we propose a new method for passive fault-tolerant control of discrete time piecewise affine systems. Actuator faults are considered. A reliable piecewise linear quadratic regulator (LQR) state feedback is designed such that it can tolerate actuator faults. A sufficient condition f...... is illustrated on a numerical example and a two degree of freedom helicopter....

Fault-tolerant architecture: Evaluation methodology

International Nuclear Information System (INIS)

Battle, R.E.; Kisner, R.A.

1992-08-01

The design and reliability of four fault-tolerant architectures that may be used in nuclear power plant control systems were evaluated. Two architectures are variations of triple-modular-redundant (TMR) systems, and two are variations of dual redundant systems. The evaluation includes a review of methods of implementing fault-tolerant control, the importance of automatic recovery from failures, methods of self-testing diagnostics, block diagrams of typical fault-tolerant controllers, review of fault-tolerant controllers operating in nuclear power plants, and fault tree reliability analyses of fault-tolerant systems

Infectious Tolerance

OpenAIRE

Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

2002-01-01

Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, ...

75 FR 22240 - Cyprodinil; Pesticide Tolerances

Science.gov (United States)

2010-04-28

... commodities. In addition, a high performance liquid chromatography with mass spectrometry (HPLC/MS) method... Executive Order Reviews This final rule establishes tolerances under section 408(d) of FFDCA in response to... types of actions from review under Executive Order 12866, entitled Regulatory Planning and Review (58 FR...

Active and passive fault-tolerant LPV control of wind Turbines

DEFF Research Database (Denmark)

Sloth, Christoffer; Esbensen, Thomas; Stoustrup, Jakob

2010-01-01

This paper addresses the design and comparison of active and passive fault-tolerant linear parameter-varying (LPV) controllers for wind turbines. The considered wind turbine plant model is characterized by parameter variations along the nominal operating trajectory and includes a model of an inci...

Regulatory B and T cell responses in patients with autoimmune thyroid disease and healthy controls

DEFF Research Database (Denmark)

Kristensen, Birte; Hegedüs, Laszlo

2016-01-01

). HT is primarily a T-cell mediated disease, and whether B cells play a pathogenic role in the pathogenesis is still unclear. Both GD and HT are characterized by infiltration of the thyroid gland by self-reactive T cells and B cells. In the first paper of this thesis, the role of regulatory B cells...... (Bregs) and regulatory T cells (Tregs) were investigated in the context of GD and HT. First, we studied the role of the thyroid self-antigen, thyroglobulin (TG) in healthy donors. The self-antigen TG, but not the foreign recall antigen tetanus toxoid (TT), was able to induce interleukin 10 (IL-10......Autoimmune diseases occur due to faulty self-tolerance. Graves' disease (GD) and Hashimoto's thyroiditis (HT) are classic examples of organ-specific autoimmune diseases. GD is an auto-antibody-mediated disease where autoantibodies are produced against the thyroid stimulating hormone receptor (TSHR...

Fault-tolerant design of local controller for the poloidal field converter control system on ITER

International Nuclear Information System (INIS)

Shen, Jun; Fu, Peng; Gao, Ge; He, Shiying; Huang, Liansheng; Zhu, Lili; Chen, Xiaojiao

2016-01-01

Highlights: • The requirements on the Local Control Cubicles (LCC) for ITER Poloidal Field Converter are analyzed. • Decoupled service-based software architecture is proposed to make control loops on LCC running at varying cycle-time. • Fault detection and recovery methods for the LCC are developed to enhance the system. • The performance of the LCC with or without fault-tolerant feature is tested and compared. - Abstract: The control system for the Poloidal Field (PF) on ITER is a synchronously networked control system, which has several kinds of computational controllers. The Local Control Cubicles (LCC) play a critical role in the networked control system for they are the interface to all input and output signals. Thus, some additional work must be done to guarantee the LCCs proper operation under influence of faults. This paper mainly analyzes the system demands of the LCCs and faults which have been encountered recently. In order to handle these faults, decoupled service-based software architecture has been proposed. Based on this architecture, fault detection and system recovery methods, such as redundancy and rejuvenation, have been incorporated to achieve a fault-tolerant private network with the aid of QNX operating system. Unlike the conventional method, this method requires no additional hardware and can be achieved relatively easily. To demonstrate effectiveness the LCCs have been successfully tested during the recent PF Converter Unit performance tests for ITER.

Fault-tolerant design of local controller for the poloidal field converter control system on ITER

Energy Technology Data Exchange (ETDEWEB)

Shen, Jun; Fu, Peng; Gao, Ge; He, Shiying; Huang, Liansheng, E-mail: huangls@ipp.ac.cn; Zhu, Lili; Chen, Xiaojiao

2016-11-15

Highlights: • The requirements on the Local Control Cubicles (LCC) for ITER Poloidal Field Converter are analyzed. • Decoupled service-based software architecture is proposed to make control loops on LCC running at varying cycle-time. • Fault detection and recovery methods for the LCC are developed to enhance the system. • The performance of the LCC with or without fault-tolerant feature is tested and compared. - Abstract: The control system for the Poloidal Field (PF) on ITER is a synchronously networked control system, which has several kinds of computational controllers. The Local Control Cubicles (LCC) play a critical role in the networked control system for they are the interface to all input and output signals. Thus, some additional work must be done to guarantee the LCCs proper operation under influence of faults. This paper mainly analyzes the system demands of the LCCs and faults which have been encountered recently. In order to handle these faults, decoupled service-based software architecture has been proposed. Based on this architecture, fault detection and system recovery methods, such as redundancy and rejuvenation, have been incorporated to achieve a fault-tolerant private network with the aid of QNX operating system. Unlike the conventional method, this method requires no additional hardware and can be achieved relatively easily. To demonstrate effectiveness the LCCs have been successfully tested during the recent PF Converter Unit performance tests for ITER.

A Fault-tolerable Control Scheme for an Open-frame Underwater Vehicle

Directory of Open Access Journals (Sweden)

Huang Hai

2014-05-01

Full Text Available Open-frame is one of the major types of structures of Remote Operated Vehicles (ROV because it is easy to place sensors and operations equipment onboard. Firstly, this paper designed a petri-based recurrent neural network (PRFNN to improve the robustness with response to nonlinear characteristics and strong disturbance of an open-frame underwater vehicle. A threshold has been set in the third layer to reduce the amount of calculations and regulate the training process. The whole network convergence is guaranteed with the selection of learning rate parameters. Secondly, a fault tolerance control (FTC scheme is established with the optimal allocation of thrust. Infinity-norm optimization has been combined with 2-norm optimization to construct a bi-criteria primal-dual neural network FTC scheme. In the experiments and simulation, PRFNN outperformed fuzzy neural networks in motion control, while bi-criteria optimization outperformed 2-norm optimization in FTC, which demonstrates that the FTC controller can improve computational efficiency, reduce control errors, and implement fault tolerable thrust allocation.

Optimal fault-tolerant control strategy of a solid oxide fuel cell system

Science.gov (United States)

Wu, Xiaojuan; Gao, Danhui

2017-10-01

For solid oxide fuel cell (SOFC) development, load tracking, heat management, air excess ratio constraint, high efficiency, low cost and fault diagnosis are six key issues. However, no literature studies the control techniques combining optimization and fault diagnosis for the SOFC system. An optimal fault-tolerant control strategy is presented in this paper, which involves four parts: a fault diagnosis module, a switching module, two backup optimizers and a controller loop. The fault diagnosis part is presented to identify the SOFC current fault type, and the switching module is used to select the appropriate backup optimizer based on the diagnosis result. NSGA-II and TOPSIS are employed to design the two backup optimizers under normal and air compressor fault states. PID algorithm is proposed to design the control loop, which includes a power tracking controller, an anode inlet temperature controller, a cathode inlet temperature controller and an air excess ratio controller. The simulation results show the proposed optimal fault-tolerant control method can track the power, temperature and air excess ratio at the desired values, simultaneously achieving the maximum efficiency and the minimum unit cost in the case of SOFC normal and even in the air compressor fault.

Position, Attitude, and Fault-Tolerant Control of Tilting-Rotor Quadcopter

Science.gov (United States)

Kumar, Rumit

The aim of this thesis is to present algorithms for autonomous control of tilt-rotor quadcopter UAV. In particular, this research work describes position, attitude and fault tolerant control in tilt-rotor quadcopter. Quadcopters are one of the most popular and reliable unmanned aerial systems because of the design simplicity, hovering capabilities and minimal operational cost. Numerous applications for quadcopters have been explored all over the world but very little work has been done to explore design enhancements and address the fault-tolerant capabilities of the quadcopters. The tilting rotor quadcopter is a structural advancement of traditional quadcopter and it provides additional actuated controls as the propeller motors are actuated for tilt which can be utilized to improve efficiency of the aerial vehicle during flight. The tilting rotor quadcopter design is accomplished by using an additional servo motor for each rotor that enables the rotor to tilt about the axis of the quadcopter arm. Tilting rotor quadcopter is a more agile version of conventional quadcopter and it is a fully actuated system. The tilt-rotor quadcopter is capable of following complex trajectories with ease. The control strategy in this work is to use the propeller tilts for position and orientation control during autonomous flight of the quadcopter. In conventional quadcopters, two propellers rotate in clockwise direction and other two propellers rotate in counter clockwise direction to cancel out the effective yawing moment of the system. The variation in rotational speeds of these four propellers is utilized for maneuvering. On the other hand, this work incorporates use of varying propeller rotational speeds along with tilting of the propellers for maneuvering during flight. The rotational motion of propellers work in sync with propeller tilts to control the position and orientation of the UAV during the flight. A PD flight controller is developed to achieve various modes of the

Regulatory philosophy and requirements for radiation control in Canadian uranium mine-mill facilities

International Nuclear Information System (INIS)

Dory, A.B.

1981-10-01

With the point made that radiation exposure is one of the health hazards of uranium mining and accordingly has to be controlled, the Canadian regulatory philosophy is outlined as it pertains to the uranium mining industry. Two extremes in regulatory approach are examined, and the joint regulatory process is explained. Two examples of poor management performance are given, and the role of mine unions in the regulatory process is touched upon. The development of new regulations to cover ventilation and employee training is sketched briefly. The author concludes with a general expression of objectives for the eighties which include improved personal dosimetry

Eating on impulse: Implicit attitudes, self-regulatory resources, and trait self-control as determinants of food consumption.

Science.gov (United States)

Wang, Yan; Wang, Lei; Cui, Xianghua; Fang, Yuan; Chen, Qianqiu; Wang, Ya; Qiang, Yao

2015-12-01

Self-regulatory resources and trait self-control have been found to moderate the impulse-behavior relationship. The current study investigated whether the interaction of self-regulatory resources and trait self-control moderates the association between implicit attitudes and food consumption. One hundred twenty female participants were randomly assigned to either a depletion condition in which their self-regulatory resources were reduced or a no-depletion condition. Participants' implicit attitudes for chocolate were measured with the Single Category Implicit Association Test and self-report measures of trait self-control were collected. The dependent variable was chocolate consumption in an ostensible taste and rate task. Implicit attitudes predicted chocolate consumption in depleted participants but not in non-depleted participants. However, this predictive power of implicit attitudes on eating in depleted condition disappeared in participants with high trait self-control. Thus, trait self-control and self-regulatory resources interact to moderate the prediction of implicit attitude on eating behavior. Results suggest that high trait self-control buffers the effect of self-regulatory depletion on impulsive eating. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulatory control of nuclear safety in Finland. Annual report 2008

International Nuclear Information System (INIS)

Kainulainen, E.

2009-06-01

This report covers the regulatory control of nuclear safety in 2008, including the design, construction and operation of nuclear facilities, as well as nuclear waste management and nuclear materials. The control of nuclear facilities and nuclear waste management, as well as nuclear non-proliferation, concern two STUK departments: Nuclear Reactor Regulation and Nuclear Waste and Material Regulation. It constitutes the report on regulatory control in the field of nuclear energy, which the Radiation and Nuclear Safety Authority (STUK) is required to submit to the Ministry of Employment and the Economy pursuant to section 121 of the Finnish Nuclear Energy Decree. The first parts of the report explain the basics of the nuclear safety regulation included as part of STUK's responsibilities, as well as the objectives of the operations, and briefly introduce the objects of regulation. The chapter concerning the development and implementation of legislation and regulations describes changes in nuclear legislation, as well as the progress of STUK's YVL Guide revision. The chapter also includes a summary of the application of the updated YVL Guides to nuclear facilities. The section concerning the regulation of nuclear facilities contains a complete safety assessment of the nuclear facilities currently in operation or under construction. For the nuclear facilities in operation, the section describes plant operation, events during operation, annual maintenance, development of the plants and their safety, and observations made during monitoring. Data and observations gained during regulatory activities are reviewed with a focus on ensuring the safety functions of nuclear facilities and the integrity of structures and components. The report also includes a description of the oversight of the operations and quality management of organisations, oversight of operational experience feedback activities, and the results of these oversight activities. The radiation safety of nuclear

Tolerogenic dendritic cells for regulatory T cell induction in man

Directory of Open Access Journals (Sweden)

Verena eRaker

2015-11-01

Full Text Available Dendritic cells are (DC highly specialized professional antigen-presenting cells (APC that regulate immune responses, maintaining the balance between tolerance and immunity. Mechanisms via which they can promote central and peripheral tolerance include clonal deletion, inhibition of memory T cell responses, T cell anergy and induction of regulatory T cells. These properties have led to the analysis of human tolerogenic DC as a therapeutic strategy for induction or re-establishment of tolerance. In the recent years, numerous protocols for the generation of human tolerogenic DC have been developed and their tolerogenic mechanisms, including induction of regulatory T cells, are relatively well understood. Phase I trials have been conducted in autoimmune disease, with results that emphasize the feasibility and safety of treatments with tolerogenic DC. Therefore, the scientific rationale for the use of tolerogenic DC therapy in the fields of transplantation medicine and allergic and autoimmune diseases is strong. This review will give an overview on efforts and protocols to generate human tolerogenic DC with focus on IL-10-modulated DC as inducers of regulatory T cells and discuss their clinical applications and challenges faced in further developing this form of immunotherapy.

Nuclear security recommendations on nuclear and other radioactive material out of regulatory control: Recommendations

International Nuclear Information System (INIS)

2011-01-01

The purpose of this publication is to provide guidance to States in strengthening their nuclear security regimes, and thereby contributing to an effective global nuclear security framework, by providing: - Recommendations to States and their competent authorities on the establishment or improvement of the capabilities of their nuclear security regimes, for carrying out effective strategies to deter, detect and respond to a criminal act, or an unauthorized act, with nuclear security implications, involving nuclear or other radioactive material that is out of regulatory control; - Recommendations to States in support of international cooperation aimed at ensuring that any nuclear or other radioactive material that is out of regulatory control, whether originating from within the State or from outside that State, is placed under regulatory control and the alleged offenders are, as appropriate, prosecuted or extradited

Fault Tolerant and Optimal Control of Wind Turbines with Distributed High-Speed Generators

Directory of Open Access Journals (Sweden)

Urs Giger

2017-01-01

Full Text Available In this paper, the control scheme of a distributed high-speed generator system with a total amount of 12 generators and nominal generator speed of 7000 min − 1 is studied. Specifically, a fault tolerant control (FTC scheme is proposed to keep the turbine in operation in the presence of up to four simultaneous generator faults. The proposed controller structure consists of two layers: The upper layer is the baseline controller, which is separated into a partial load region with the generator torque as an actuating signal and the full-load operation region with the collective pitch angle as the other actuating signal. In addition, the lower layer is responsible for the fault diagnosis and FTC characteristics of the distributed generator drive train. The fault reconstruction and fault tolerant control strategy are tested in simulations with several actuator faults of different types.

Two regulatory RNA elements affect TisB-dependent depolarization and persister formation.

Science.gov (United States)

Berghoff, Bork A; Hoekzema, Mirthe; Aulbach, Lena; Wagner, E Gerhart H

2017-03-01

Bacterial survival strategies involve phenotypic diversity which is generated by regulatory factors and noisy expression of effector proteins. The question of how bacteria exploit regulatory RNAs to make decisions between phenotypes is central to a general understanding of these universal regulators. We investigated the TisB/IstR-1 toxin-antitoxin system of Escherichia coli to appreciate the role of the RNA antitoxin IstR-1 in TisB-dependent depolarization of the inner membrane and persister formation. Persisters are phenotypic variants that have become transiently drug-tolerant by arresting growth. The RNA antitoxin IstR-1 sets a threshold for TisB-dependent depolarization under DNA-damaging conditions, resulting in two sub-populations: polarized and depolarized cells. Furthermore, our data indicate that an inhibitory 5' UTR structure in the tisB mRNA serves as a regulatory RNA element that delays TisB translation to avoid inappropriate depolarization when DNA damage is low. Investigation of the persister sub-population further revealed that both regulatory RNA elements affect persister levels as well as persistence time. This work provides an intriguing example of how bacteria exploit regulatory RNAs to control phenotypic heterogeneity. © 2016 John Wiley & Sons Ltd.

Infectious Tolerance

Science.gov (United States)

Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

2002-01-01

Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, freshly isolated CD4+ T helper (Th) cells. This infectious suppressive activity, transferred from CD25+ Treg cells via cell contact, is cell contact–independent and partially mediated by soluble transforming growth factor (TGF)-β. The induction of suppressive properties in conventional CD4+ Th cells represents a mechanism underlying the phenomenon of infectious tolerance. This explains previously published conflicting data on the role of TGF-β in CD25+ Treg cell–induced immunosuppression. PMID:12119350

The Atomic Energy Control Board's regulatory research and support program

International Nuclear Information System (INIS)

1988-04-01

The purpose of the Regulatory Research and Support Program is to augment and extend the capability of the Atomic Energy Control Board's (AECB) regulatory program beyond the capability of in-house resources. The overall objective of the program is to produce pertinent and independent scientific and other knowledge and expertise that will assist the AECB in making correct, timely and credible decisions on regulating the development, application and use of atomic energy. The objectives are achieved through contracted research, development, studies, consultant and other kinds of projects administered by the Research and Radiation Protection Branch (RRB) of the AECB

Oral tolerance induction for human food allergy.

Science.gov (United States)

Noh, Geunwoong; Lee, Jae Ho

2012-04-01

Food allergies are classified as IgE-mediated and non-IgE mediated type. The number of successful reports of immunotherapy, namely tolerance induction for food allergy (TIFA) are increasing, bringing hope for meaningful positive and radical treatment of food allergy. Therapeutic characteristics of the clinical course in TIFA for NFA are different from TIFA for IFA. Cytokines including IL-10, TGF-β and IFN-γ and regulatory cells such as Treg and Breg, are involved in immune tolerance. IFN-γ has been used for tolerance induction of food allergy as an immunomodulatory biologics. A definitive distinction between IgE-mediated and non-IgE-mediated food allergies is absolutely essential for diagnostic and therapeutic purposes. Original SOTI using IFN-γ is more effective then conventional SOTI without IFN-γ. Especially, IFN-γ is absolutely necessary for the tolerance induction of NFA. This review highlights and updates the advances in the conceptual immunological background and the clinical characteristics of oral tolerance induction for food allergy.

Fault tolerant vector control of induction motor drive

International Nuclear Information System (INIS)

Odnokopylov, G; Bragin, A

2014-01-01

For electric composed of technical objects hazardous industries, such as nuclear, military, chemical, etc. an urgent task is to increase their resiliency and survivability. The construction principle of vector control system fault-tolerant asynchronous electric. Displaying recovery efficiency three-phase induction motor drive in emergency mode using two-phase vector control system. The process of formation of a simulation model of the asynchronous electric unbalance in emergency mode. When modeling used coordinate transformation, providing emergency operation electric unbalance work. The results of modeling transient phase loss motor stator. During a power failure phase induction motor cannot save circular rotating field in the air gap of the motor and ensure the restoration of its efficiency at rated torque and speed

Strengthening the regulatory control of consumer goods through international harmonization

International Nuclear Information System (INIS)

Yus Rusdian Akhmad

2013-01-01

The International Atomic Energy Agency (IAEA) is currently working on a recommendation in the form of guidelines for regulating consumer goods. Preparation of this document has a significant dimension of international issues, especially in terms of the application of the principles of justification and application of the concept of exemption. International harmonization among regulators ranging from the regional to the global level is a central issue and considering the complex issues that arise in addition to covering the scientific aspects also involve consideration of the legal aspects or values espoused by any State which may differ from one another. PERKA BAPETEN on consumer goods is still in the preparation stage so that the discussion of the material will be useful for improving the quality of the regulation in time. There is a significant gap of understanding to the related materials by the parties concerned (between local and international parties were among the local party). This paper intends to propose the understanding and views on radiation protection and regulatory control for consumer goods and hopely could contributed significantly to strengthening its regulatory control which is primarily through a reduction in the gap of understanding to the related concept that potentially multi perceptions and encourage stronger cooperation among regulatory bodies. (author)

Alternative approaches to pollution control and waste management: Regulatory and economic instruments

International Nuclear Information System (INIS)

Bernstein, J.D.

1993-01-01

The purpose of the paper is to present an overview of the most common strategies and policy instruments (that is, regulatory and economic) used in developed and developing countries to achieve pollution control and waste management objectives. Although this topic has been at the center of theoretical controversy both within and outside the World Bank, the paper is not intended to contribute to this debate. Rather, its purpose is to explore how regulatory and economic instruments are used to control air and water pollution, protect ground water, and manage solid and hazardous wastes. The paper is directed to policy makers at the national, state, and local levels of government, as well as to other parties responsible for pollution control and waste management programs

Bone marrow chimerism as a strategy to produce tolerance in solid organ allotransplantation.

Science.gov (United States)

Hu, Min; Alexander, Stephen I; Yi, Shounan

2016-12-01

Clinical transplant tolerance has been most successfully achieved combining hematopoietic chimerism with kidney transplantation. This review outlines this strategy in animal models and human transplantation, and possible clinical challenges. Kidney transplant tolerance has been achieved through chimerism in several centers beginning with Massachusetts General Hospital's success with mixed chimerism in human leukocyte antigen (HLA)-mismatched patients and the Stanford group with HLA-matched patients, and the more recent success of the Northwestern protocol achieving full chimerism. This has challenged the original view that stable mixed chimerism is necessary for organ graft tolerance. However, among the HLA-mismatched kidney transplant-tolerant patients, loss of mixed chimerism does not lead to renal-graft rejection, and the development of host Foxp3+ regulatory T cells has been observed. Recent animal models suggest that graft tolerance through bone marrow chimerism occurs through both clonal deletion and regulatory immune cells. Further, Tregs have been shown to improve chimerism in animal models. Animal studies continue to suggest ways to improve our current clinical strategies. Advances in chimerism protocols suggest that tolerance may be clinically achievable with relative safety for HLA-mismatched kidney transplants.

Mechanism of oral tolerance induction to therapeutic proteins.

Science.gov (United States)

Wang, Xiaomei; Sherman, Alexandra; Liao, Gongxian; Leong, Kam W; Daniell, Henry; Terhorst, Cox; Herzog, Roland W

2013-06-15

Oral tolerance is defined as the specific suppression of humoral and/or cellular immune responses to an antigen by administration of the same antigen through the oral route. Due to its absence of toxicity, easy administration, and antigen specificity, oral tolerance is a very attractive approach to prevent unwanted immune responses that cause a variety of diseases or that complicate treatment of a disease. Many researchers have induced oral tolerance to efficiently treat autoimmune and inflammatory diseases in different animal models. However, clinical trials yielded limited success. Thus, understanding the mechanisms of oral tolerance induction to therapeutic proteins is critical for paving the way for clinical development of oral tolerance protocols. This review will summarize progress on understanding the major underlying tolerance mechanisms and contributors, including antigen presenting cells, regulatory T cells, cytokines, and signaling pathways. Potential applications, examples for therapeutic proteins and disease targets, and recent developments in delivery methods are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Accident-tolerant control rod

International Nuclear Information System (INIS)

Ohta, Hirokazu; Sawabe, Takashi; Ogata, Takanari

2013-01-01

Boron carbide (B 4 C) and hafnium (Hf) metal are used for the neutron absorber materials of control rods in BWRs, and silver-indium-cadmium (Ag-In-Cd) alloy is used in PWRs. These materials are clad with stainless steel. The eutectic point of B 4 C and iron (Fe) is about 1150 deg. C and the melting point of Ag-In-Cd alloy is about 800 deg. C, which are lower than the temperature of zircaloy - steam reaction increases rapidly (∼1200 deg. C). Accordingly, it is possible that the control rods melt and collapse before the reactor core is significantly damaged in the case of severe accidents. Since the neutron absorber would be separated from the fuels, there is a risk of re-criticality, when pure water or seawater is injected for emergency cooling. In order to ensure sub-criticality and extend options of emergency cooling in the course of severe accidents, a concept of accident-tolerant control rod (ACT) has been derived. ACT utilises a new absorber material having the following properties: - higher neutron absorption than current control rod; - higher melting or eutectic temperature than 1200 deg. C where rapid zircaloy oxidation occurs; - high miscibility with molten fuel materials. The candidate of a new absorber material for ATC includes gadolinia (Gd 2 O 3 ), samaria (Sm 2 O 3 ), europia (Eu 2 O 3 ), dysprosia (Dy 2 O 3 ), hafnia (HfO 2 ). The melting point of these materials and the liquefaction temperature with Fe are higher than the rapid zircaloy oxidation temperature. ACT will not collapse before the core melt-down. After the core melt-down, the absorber material will be mixed with molten fuel material. The current absorber materials, such as B 4 C, Hf and Ag-In-Cd, are charged at the tip of ATC in which the neutron flux is high, and a new absorber material is charged in the low-flux region. This design could minimise the degradation of a new absorber material by the neutron absorption and the influence of ATC deployment on reactor control procedure. As a

Stabilization of Continuous-Time Random Switching Systems via a Fault-Tolerant Controller

Directory of Open Access Journals (Sweden)

Guoliang Wang

2017-01-01

Full Text Available This paper focuses on the stabilization problem of continuous-time random switching systems via exploiting a fault-tolerant controller, where the dwell time of each subsystem consists of a fixed part and random part. It is known from the traditional design methods that the computational complexity of LMIs related to the quantity of fault combination is very large; particularly system dimension or amount of subsystems is large. In order to reduce the number of the used fault combinations, new sufficient LMI conditions for designing such a controller are established by a robust approach, which are fault-free and could be solved directly. Moreover, the fault-tolerant stabilization realized by a mode-independent controller is considered and suitably applied to a practical case without mode information. Finally, a numerical example is used to demonstrate the effectiveness and superiority of the proposed methods.

TransDetect Identifies a New Regulatory Module Controlling Phosphate Accumulation.

Science.gov (United States)

Pal, Sikander; Kisko, Mushtak; Dubos, Christian; Lacombe, Benoit; Berthomieu, Pierre; Krouk, Gabriel; Rouached, Hatem

2017-10-01

Identifying transcription factor (TFs) cooperation controlling target gene expression is still an arduous challenge. The accuracy of current methods at genome scale significantly drops with the increase in number of genes, which limits their applicability to more complex genomes, like animals and plants. Here, we developed an algorithm, TransDetect, able to predict TF combinations controlling the expression level of a given gene. TransDetect was used to identify novel TF modules regulating the expression of Arabidopsis ( Arabidopsis thaliana ) phosphate transporter PHO1;H3 comprising MYB15, MYB84, bHLH35, and ICE1. These TFs were confirmed to interact between themselves and with the PHO1;H3 promoter. Phenotypic and genetic analyses of TF mutants enable the organization of these four TFs and PHO1;H3 in a new gene regulatory network controlling phosphate accumulation in zinc-dependent manner. This demonstrates the potential of TransDetect to extract directionality in nondynamic transcriptomes and to provide a blueprint to identify gene regulatory network involved in a given biological process. © 2017 American Society of Plant Biologists. All Rights Reserved.

Interleukin 35: A Key Mediator of Suppression and the Propagation of Infectious Tolerance

Directory of Open Access Journals (Sweden)

Brian M Olson

2013-10-01

Full Text Available The importance of regulatory T cells in balancing the effector arm of the immune system is well documented, playing a central role in preventing autoimmunity, facilitating graft tolerance following organ transplantation, and having a detrimental impact on the development of anti-tumor immunity. These regulatory responses use a variety of mechanisms to mediate suppression, including soluble factors. While IL-10 and TGF-β are the most commonly studied immunosuppressive cytokines, the recently identified IL-35 has been shown to have potent suppressive function in vitro and in vivo. Furthermore, not only does IL-35 have the ability to directly suppress effector T cell responses, it is also able to expand regulatory responses by propagating infectious tolerance and generating a potent population of IL-35-expressing inducible regulatory T cells. In this review, we summarize research characterizing the structure and function of IL-35, examine its role in disease, and discuss how it can contribute to the induction of a distinct population of inducible regulatory T cells.

Active fault tolerant control of piecewise affine systems with reference tracking and input constraints

DEFF Research Database (Denmark)

Gholami, M.; Cocquempot, V.; Schiøler, H.

2014-01-01

An active fault tolerant control (AFTC) method is proposed for discrete-time piecewise affine (PWA) systems. Only actuator faults are considered. The AFTC framework contains a supervisory scheme, which selects a suitable controller in a set of controllers such that the stability and an acceptable...... performance of the faulty system are held. The design of the supervisory scheme is not considered here. The set of controllers is composed of a normal controller for the fault-free case, an active fault detection and isolation controller for isolation and identification of the faults, and a set of passive...... fault tolerant controllers (PFTCs) modules designed to be robust against a set of actuator faults. In this research, the piecewise nonlinear model is approximated by a PWA system. The PFTCs are state feedback laws. Each one is robust against a fixed set of actuator faults and is able to track...

Systemic immunological tolerance to ocular antigens is mediated by TRAIL-expressing CD8+ T cells.

Science.gov (United States)

Griffith, Thomas S; Brincks, Erik L; Gurung, Prajwal; Kucaba, Tamara A; Ferguson, Thomas A

2011-01-15

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required Fas ligand-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8(+) regulatory T cells. This study examined the mechanism by which these CD8(+) regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4(+) T cells and led to increased TRAIL expression by splenic CD8(+) T cells. Unlike wild-type mice, Trail(-/-) or Dr5(-/-) mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8(+) T cells from Trail(-/-) mice that were first injected via the AC with Ag were unable to transfer tolerance to naive recipient wild-type mice, but CD8(+) T cells from AC-injected wild-type or Dr5(-/-) mice could transfer tolerance. Importantly, the transferred wild-type (Trail(+/+)) CD8(+) T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail(-/-) CD8(+) T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that "helpless" CD8(+) regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye.

Andrographolide Ameliorate Rheumatoid Arthritis by Promoting the Development of Regulatory T Cells

Directory of Open Access Journals (Sweden)

Muhaimin Rifa’i

2010-10-01

Full Text Available Andrographolide is important material present in Andrographis paniculata. This material can promote T cell to develop into regulatory T cell, CD4+CD25+. CD4+CD25+ regulatory T (Treg cells, a component of the innate immune response, which play a key role in the maintenance of self-tolerance, have become the focus of numerous studies over the last decade. These cells have the potential to be exploited to treat autoimmune disease. These cells inhibit the immune response in an Ag-nonspecific manner, interacting with other T cells. These T cell populations actively control the properties of other immune cells by suppressing their functional activity to prevent autoimmunity but also influence the immune response to allergens as well as against tumor cells and pathogens. In this experiment we showed that active compound from Andrographis paniculata namely andrographolide can induce active regulatory T cell that has an efficacy to cure rheumatoid arthritis mice model.

The effects of age, glucose ingestion and gluco-regulatory control on episodic memory.

Science.gov (United States)

Riby, Leigh Martin; Meikle, Andrew; Glover, Cheryl

2004-09-01

Previous research has been inconclusive regarding the impact of glucose ingestion and gluco-regulatory control on cognitive performance in healthy older adults. The aim of this research was to determine whether glucose specifically enhanced episodic memory in an older population. In addition, the link between individual differences in glucose regulation and the magnitude of the enhancement effect was examined. A within subjects, counterbalanced, crossover design was used with 20 participants (60-80 year olds), each serving as his/her control. Episodic memory was tested by presenting unrelated paired associates followed by immediate and delayed cued recall, and delayed recognition, under single and dual task conditions. In addition, a battery of cognitive tests was administered, including tests of semantic memory, working memory and speed of processing. Glucose ingestion was found to largely facilitate performance of episodic memory. Furthermore, subsidiary analyses found that gluco-regulatory efficiency predicted episodic memory performance in both control and glucose conditions. A boost in performance after glucose ingestion was particularly seen in the episodic memory domain. Notably, strong evidence was provided for the utility of gluco-regulatory control measures as indicators of cognitive decline in the elderly.

Cooperative Fault Tolerant Tracking Control for Multiagent Systems: An Intermediate Estimator-Based Approach.

Science.gov (United States)

Zhu, Jun-Wei; Yang, Guang-Hong; Zhang, Wen-An; Yu, Li

2017-10-17

This paper studies the observer based fault tolerant tracking control problem for linear multiagent systems with multiple faults and mismatched disturbances. A novel distributed intermediate estimator based fault tolerant tracking protocol is presented. The leader's input is nonzero and unavailable to the followers. By applying a projection technique, the mismatched disturbances are separated into matched and unmatched components. For each node, a tracking error system is established, for which an intermediate estimator driven by the relative output measurements is constructed to estimate the sensor faults and a combined signal of the leader's input, process faults, and matched disturbance component. Based on the estimation, a fault tolerant tracking protocol is designed to eliminate the effects of the combined signal. Besides, the effect of unmatched disturbance component can be attenuated by directly adjusting some specified parameters. Finally, a simulation example of aircraft demonstrates the effectiveness of the designed tracking protocol.This paper studies the observer based fault tolerant tracking control problem for linear multiagent systems with multiple faults and mismatched disturbances. A novel distributed intermediate estimator based fault tolerant tracking protocol is presented. The leader's input is nonzero and unavailable to the followers. By applying a projection technique, the mismatched disturbances are separated into matched and unmatched components. For each node, a tracking error system is established, for which an intermediate estimator driven by the relative output measurements is constructed to estimate the sensor faults and a combined signal of the leader's input, process faults, and matched disturbance component. Based on the estimation, a fault tolerant tracking protocol is designed to eliminate the effects of the combined signal. Besides, the effect of unmatched disturbance component can be attenuated by directly adjusting some

Genetic control and regulatory mechanisms of succinoglycan and curdlan biosynthesis in genus Agrobacterium.

Science.gov (United States)

Wu, Dan; Li, Ang; Ma, Fang; Yang, Jixian; Xie, Yutong

2016-07-01

Agrobacterium is a genus of gram-negative bacteria that can produce several typical exopolysaccharides with commercial uses in the food and pharmaceutical fields. In particular, succinoglycan and curdlan, due to their good quality in high yield, have been employed on an industrial scale comparatively early. Exopolysaccharide biosynthesis is a multiple-step process controlled by different functional genes, and various environmental factors cause changes in exopolysaccharide biosynthesis through regulatory mechanisms. In this mini-review, we focus on the genetic control and regulatory mechanisms of succinoglycan and curdlan produced by Agrobacterium. Some key functional genes and regulatory mechanisms for exopolysaccharide biosynthesis are described, possessing a high potential for application in metabolic engineering to modify exopolysaccharide production and physicochemical properties. This review may contribute to the understanding of exopolysaccharide biosynthesis and exopolysaccharide modification by metabolic engineering methods in Agrobacterium.

A New Adaptive Control for Five-Phase Fault-Tolerant Flux-Switching Permanent Magnet Motor

Directory of Open Access Journals (Sweden)

Hongyu Tang

2016-01-01

Full Text Available The five-phase fault-tolerant flux-switching permanent magnet (FT-FSPM motor can offer high efficiency and high fault-tolerant capability. In this paper, its operation principle is presented briefly and its mathematical model is derived. Further, a new adaptive control for an FT-FSPM motor, based on the backstepping method and the sliding mode control strategy, is proposed. According to the backstepping method, the current controllers and voltage control laws are designed to track the speed and minimize the current static error, which enhance the dynamic response and the ability to suppress external disturbances. In order to overcome the influence of parameter variations, according to sliding mode control theory, the virtual control variables and the adaptive algorithm are utilized to approach uncertainty terms. Three Lyapunov functions are designed, and the stability of the closed-loop system is analyzed in detail. Finally, both simulation and experimental results are presented to verify the proposed control method.

U.S. Nuclear Regulatory Commission bases for control of solid materials

International Nuclear Information System (INIS)

Meck, R.A.; Cardille, F.P.; Feldman, C.; Gnugnoli, G.N.; Huffert, A.M.; Klementowicz, S.P.

2002-01-01

The U.S. Nuclear Regulatory Commission (NRC) is considering whether to proceed with rulemaking on the control of solid materials with very low levels of associated radioactivity. The current implementation of clearance by NRC licensees is the context for the decision. Inputs to the decision include information gathering efforts of the Commission in the areas of public workshops, dose assessments and inventories, the recommendations of the National Academies' National Research Council (NAs) on regulatory alternatives, and participation in international efforts by the International Atomic Energy Agency (IAEA). (author)

Sliding observer-based demagnetisation fault-tolerant control in permanent magnet synchronous motors

Directory of Open Access Journals (Sweden)

Changfan Zhang

2017-04-01

Full Text Available This study proposes a fault-tolerant control method for permanent magnet synchronous motors (PMSMs based on the active flux linkage concept, which addresses permanent magnet (PM demagnetisation faults in PMSMs. First, a mathematical model for a PMSM is established based on active flux linkage, and then the effect of PM demagnetisation on the PMSM is analysed. Second, the stator current in the static coordinate is set as the state variable, an observer is designed based on a sliding-mode variable structure, and an equation for active flux linkage is established for dynamic estimation based on the equivalent control principle of sliding-mode variable structure. Finally, the active flux linkage for the next moment is predicted according to the operating conditions of the motor and the observed values of the current active flux linkage. The deadbeat control strategy is applied to eliminate errors in the active flux linkage and realise the objective of fault-tolerant control. A timely and effective control for demagnetisation faults is achieved using the proposed method, which validity and feasibility are verified by the simulation and experiment results.

Fault Tolerant Control: A Simultaneous Stabilization Result

DEFF Research Database (Denmark)

Stoustrup, Jakob; Blondel, V.D.

2004-01-01

This paper discusses the problem of designing fault tolerant compensators that stabilize a given system both in the nominal situation, as well as in the situation where one of the sensors or one of the actuators has failed. It is shown that such compensators always exist, provided that the system...... is detectable from each output and that it is stabilizable. The proof of this result is constructive, and a worked example shows how to design a fault tolerant compensator for a simple, yet challeging system. A family of second order systems is described that requires fault tolerant compensators of arbitrarily...

Fault tolerant control based on active fault diagnosis

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2005-01-01

An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR......) part. The FTC architecture can be applied for additive faults, parametric faults, and for system structural changes. Only parametric faults will be considered in this paper. The main focus in this paper is on the use of the new approach of active fault diagnosis in connection with FTC. The active fault...... diagnosis approach is based on including an auxiliary input in the system. A fault signature matrix is introduced in connection with AFD, given as the transfer function from the auxiliary input to the residual output. This can be considered as a generalization of the passive fault diagnosis case, where...

Engineering tolerance using biomaterials to target and control antigen presenting cells.

Science.gov (United States)

Tostanoski, Lisa H; Gosselin, Emily A; Jewell, Christopher M

2016-05-01

Autoimmune diseases occur when cells of the adaptive immune system incorrectly recognize and attack "self" tissues. Importantly, the proliferation and differentiation of these cells is triggered and controlled by interactions with antigen presenting cells (APCs), such as dendritic cells. Thus, modulating the signals transduced by APCs (e.g., cytokines, costimulatory surface proteins) has emerged as a promising strategy to promote tolerance for diseases such as multiple sclerosis, type 1 diabetes, and lupus. However, many approaches have been hindered by non-specific activity of immunosuppressive or immunoregulatory cues, following systemic administration of soluble factors via traditional injections routes (e.g., subcutaneous, intravenous). Biomaterials offer a unique opportunity to control the delivery of tolerogenic signals in vivo via properties such as controlled particle size, tunable release kinetics, and co-delivery of multiple classes of cargo. In this review, we highlight recent reports that exploit these properties of biomaterials to target APCs and promote tolerance via three strategies, i) passive or active targeting of particulate carriers to APCs, ii) biomaterial-mediated control over antigen localization and processing, and iii) targeted delivery of encapsulated or adsorbed immunomodulatory signals. These reports represent exciting advances toward the goal of more effective therapies for autoimmune diseases, without the broad suppressive effects associated with current clinically-approved therapies.

Regulatory control of radioactivity and nuclear fuel cycle in Canada

International Nuclear Information System (INIS)

Hamel, P.E.; Jennekens, J.H.

1977-05-01

Legislation and regulations giving birth to the Atomic Energy Control Board (AECB) are outlined, as well as current licencing procedures. The AECB bases its health and safety criteria on ICRP recommendations. R and D is funded to aid regulatory activity. Licencing activities cover uranium resource management, uranium mining and milling, nuclear generating stations, heavy water plants, and radioactive waste management. Safeguards, physical security, and international controls are also concerns of the AECB. (E.C.B.)

A Benchmark Evaluation of Fault Tolerant Wind Turbine Control Concepts

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Stoustrup, Jakob

2015-01-01

As the world’s power supply to a larger and larger degree depends on wind turbines, it is consequently and increasingly important that these are as reliable and available as possible. Modern fault tolerant control (FTC) could play a substantial part in increasing reliability of modern wind turbin...... accommodation is handled in software sensor and actuator blocks. This means that the wind turbine controller can continue operation as in the fault free case. The other two evaluated solutions show some potential but probably need improvements before industrial applications....

Exemption from Regulatory Control of Goods Containing Small Amounts of Radioactive Material

International Nuclear Information System (INIS)

2012-01-01

Small amounts of radioactive material may be added to various goods for functional reasons. Several such items are currently available for either professional or personal use. These include ionization chamber smoke detectors, thoriated-tungsten welding rods, luminous dials, electrical devices and electric discharge lamps. Some of these goods may be intended for particular types of market such as cinemas or other places to which the public may have access, but they are unlikely to be provided directly to members of the public. Other goods may be intended for wide scale use and therefore readily available on the market as consumer products through commercial outlets where personal and household products are normally purchased. Members of the public may be exposed to ionizing radiation as a consequence of activities such as transport, storage, use and disposal of such goods. The IAEA safety standards provide the basic requirements for regulatory control of such goods. The most relevant documents are the Governmental, Legal and Regulatory Framework for Safety and the International Basic Safety Standards (hereafter referred to as the BSS). These requirements include notification of a practice to the regulatory body and authorization of the practice by the regulatory body. Provision is made for the exemption of practices from these and other regulatory requirements based on general criteria given in the BSS or any exemption levels specified by the regulatory body on the basis of these criteria. The BSS, which are jointly sponsored by the IAEA and several other international organizations, apply to all facilities and all activities for peaceful purposes that give rise to exposure to radiation. In the interest of harmonization of approaches among Member States, some guidance on the application of the criteria for exemption has been provided in a number of Safety Guides, e.g. Regulatory Control of Radiation Sources, IAEA Safety Standards Series No. GS-G-1.5 (2004) and the

Oral dendritic cells mediate antigen-specific tolerance by stimulating TH1 and regulatory CD4+ T cells.

Science.gov (United States)

Mascarell, Laurent; Lombardi, Vincent; Louise, Anne; Saint-Lu, Nathalie; Chabre, Henri; Moussu, Hélène; Betbeder, Didier; Balazuc, Anne-Marie; Van Overtvelt, Laurence; Moingeon, Philippe

2008-09-01

A detailed characterization of oral antigen-presenting cells is critical to improve second-generation sublingual allergy vaccines. To characterize oral dendritic cells (DCs) within lingual and buccal tissues from BALB/c mice with respect to their surface phenotype, distribution, and capacity to polarize CD4(+) T-cell responses. In situ analysis of oral DCs was performed by immunohistology. Purified DCs were tested in vitro for their capacity to capture, process, and present the ovalbumin antigen to naive CD4(+) T cells. In vivo priming of ovalbumin-specific T cells adoptively transferred to BALB/c mice was analyzed by cytofluorometry in cervical lymph nodes after sublingual administration of mucoadhesive ovalbumin. Three subsets of oral DCs with a distinct tissue distribution were identified: (1) a minor subset of CD207(+) Langerhans cells located in the mucosa itself, (2) a major subpopulation of CD11b(+)CD11c(-) and CD11b(+)CD11c(+) myeloid DCs at the mucosal/submucosal interface, and (3) B220(+)120G8(+) plasmacytoid DCs found in submucosal tissues. Purified myeloid and plasmacytoid oral DCs capture and process the antigen efficiently and are programmed to elicit IFN-gamma and/or IL-10 production together with a suppressive function in naive CD4(+) T cells. Targeting the ovalbumin antigen to oral DCs in vivo by using mucoadhesive particles establishes tolerance in the absence of cell depletion through the stimulation of IFN-gamma and IL-10-producing CD4(+) regulatory T cells in cervical lymph nodes. The oral immune system is composed of various subsets of tolerogenic DCs organized in a compartmentalized manner and programmed to induce T(H)1/regulatory T-cell responses.

Regulatory dendritic cell therapy: from rodents to clinical application.

Science.gov (United States)

Raïch-Regué, Dalia; Glancy, Megan; Thomson, Angus W

2014-10-01

Dendritic cells (DC) are highly-specialized, bone marrow-derived antigen-presenting cells that induce or regulate innate and adaptive immunity. Regulatory or "tolerogenic" DC play a crucial role in maintaining self tolerance in the healthy steady-state. These regulatory innate immune cells subvert naïve or memory T cell responses by various mechanisms. Regulatory DC (DCreg) also exhibit the ability to induce or restore T cell tolerance in many animal models of autoimmune disease or transplant rejection. There is also evidence that adoptive transfer of DCreg can regulate T cell responses in non-human primates and humans. Important insights gained from in vitro studies and animal models have led recently to the development of clinical grade human DCreg, with potential to treat autoimmune disease or enhance transplant survival while reducing patient dependency on immunosuppressive drugs. Phase I trials have been conducted in type-1 diabetes and rheumatoid arthritis, with results that emphasize the feasibility and safety of DCreg therapy. This mini-review will outline how observations made using animal models have been translated into human use, and discuss the challenges faced in further developing this form of regulatory immune cell therapy in the fields of autoimmunity and transplantation. Copyright © 2013 Elsevier B.V. All rights reserved.

Distributed Interplanetary Delay/Disruption Tolerant Network (DTN) Monitor and Control System

Science.gov (United States)

Wang, Shin-Ywan

2012-01-01

The main purpose of Distributed interplanetary Delay Tolerant Network Monitor and Control System as a DTN system network management implementation in JPL is defined to provide methods and tools that can monitor the DTN operation status, detect and resolve DTN operation failures in some automated style while either space network or some heterogeneous network is infused with DTN capability. In this paper, "DTN Monitor and Control system in Deep Space Network (DSN)" exemplifies a case how DTN Monitor and Control system can be adapted into a space network as it is DTN enabled.

Regulatory control of nuclear safety in Finland. Annual report 1998

Energy Technology Data Exchange (ETDEWEB)

Tossavainen, K. [ed.

1999-10-01

The report describes regulatory control of the safe use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in 1998. STUK is the Finnish nuclear safety authority. The submission of this report to the Ministry of Trade and Industry is stipulated in Section 121 of the Nuclear Energy Decree. It was verified by regulatory control that the operation of Finnish NPPs was in compliance with conditions set out in the operating licences of the plants and with regulations currently in force. In addition to supervising the normal operation of the plants, STUK oversaw projects carried out at the plant units, which related to the uprating of their power and the improvement of their safety. STUK issued to the Ministry of Trade and Industry a statement about applications for the renewal of the operating licences of Loviisa and Olkiluoto NPPs, which had been submitted by Imatran Voima Oy and Teollisuuden Voima Oy. Regulatory activities in the field of nuclear waste management were focused on the storage and final disposal of spent fuel as well as the treatment, storage and final disposal of reactor waste. STUK issued a statement to the Ministry of Trade and Industry about an environmental impact assessment programme pertaining to a spent fuel repository project, which had been submitted by Posiva Oy, as well as on Imatran Voima Oy's application concerning the operation of a repository for medium- and low-level reactor waste from Loviisa NPP. The use of nuclear materials was in compliance with the regulations currently in force and also the whereabouts of every batch of nuclear material were ensured by safeguards control. In international safeguards, important changes took place, which were reflected also in safeguards activities at national level. International co-operation continued based on financing both from STUK's budget and from additional sources. The focus of co-operation funded from outside sources was as follows: improvement of the safety of

Regulatory control of nuclear safety in Finland. Annual report 1998

International Nuclear Information System (INIS)

Tossavainen, K.

1999-10-01

The report describes regulatory control of the safe use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in 1998. STUK is the Finnish nuclear safety authority. The submission of this report to the Ministry of Trade and Industry is stipulated in Section 121 of the Nuclear Energy Decree. It was verified by regulatory control that the operation of Finnish NPPs was in compliance with conditions set out in the operating licences of the plants and with regulations currently in force. In addition to supervising the normal operation of the plants, STUK oversaw projects carried out at the plant units, which related to the uprating of their power and the improvement of their safety. STUK issued to the Ministry of Trade and Industry a statement about applications for the renewal of the operating licences of Loviisa and Olkiluoto NPPs, which had been submitted by Imatran Voima Oy and Teollisuuden Voima Oy. Regulatory activities in the field of nuclear waste management were focused on the storage and final disposal of spent fuel as well as the treatment, storage and final disposal of reactor waste. STUK issued a statement to the Ministry of Trade and Industry about an environmental impact assessment programme pertaining to a spent fuel repository project, which had been submitted by Posiva Oy, as well as on Imatran Voima Oy's application concerning the operation of a repository for medium- and low-level reactor waste from Loviisa NPP. The use of nuclear materials was in compliance with the regulations currently in force and also the whereabouts of every batch of nuclear material were ensured by safeguards control. In international safeguards, important changes took place, which were reflected also in safeguards activities at national level. International co-operation continued based on financing both from STUK's budget and from additional sources. The focus of co-operation funded from outside sources was as follows: improvement of the safety of Kola and

Plant Tolerance: A Unique Approach to Control Hemipteran Pests.

Science.gov (United States)

Koch, Kyle G; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

2016-01-01

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest's physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented.

Cytokines affecting CD4+T regulatory cells in transplant tolerance. II. Interferon gamma (IFN-γ) promotes survival of alloantigen-specific CD4+T regulatory cells.

Science.gov (United States)

Nomura, Masaru; Hodgkinson, Suzanne J; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine; Plain, Karren M; Boyd, Rochelle; Hall, Bruce M

2017-06-01

CD4 + T cells that transfer alloantigen-specific transplant tolerance are short lived in culture unless stimulated with specific-donor alloantigen and lymphocyte derived cytokines. Here, we examined if IFN-γ maintained survival of tolerance transferring CD4 + T cells. Alloantigen-specific transplant tolerance was induced in DA rats with heterotopic adult PVG heart allografts by a short course of immunosuppression and these grafts functioned for >100days with no further immunosuppression. In previous studies, we found the CD4 + T cells from tolerant rats that transfer tolerance to an irradiated DA host grafted with a PVG heart, lose their tolerance transferring ability after 3days of culture, either with or without donor alloantigen, and effect rejection of specific-donor grafts. If cultures with specific-donor alloantigen are supplemented by supernatant from ConA activated lymphocytes the tolerance transferring cells survive, suggesting these cells depend on cytokines for their survival. In this study, we found addition of rIFN-γ to MLC with specific-donor alloantigen maintained the capacity of tolerant CD4 + T cells to transfer alloantigen-specific tolerance and their ability to suppress PVG allograft rejection mediated by co-administered naïve CD4 + T cells. IFN-γ suppressed the in vitro proliferation of tolerant CD4 + T cells. Tolerant CD4 + CD25 + T cells did not proliferate in MLC to PVG stimulator cells with no cytokine added, but did when IFN-γ was present. IFN-γ did not alter proliferation of tolerant CD4 + CD25 + T cells to third-party Lewis. Tolerant CD4 + CD25 + T cells' expression of IFN-γ receptor (IFNGR) was maintained in culture when IFN-γ was present. This study suggested that IFN-γ maintained tolerance mediating alloantigen-specific CD4 + CD25 + T cells. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

ALLIANCE: An architecture for fault tolerant, cooperative control of heterogeneous mobile robots

Energy Technology Data Exchange (ETDEWEB)

Parker, L.E.

1995-02-01

This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

Human regulatory B cells control the TFH cell response.

Science.gov (United States)

Achour, Achouak; Simon, Quentin; Mohr, Audrey; Séité, Jean-François; Youinou, Pierre; Bendaoud, Boutahar; Ghedira, Ibtissem; Pers, Jacques-Olivier; Jamin, Christophe

2017-07-01

Follicular helper T (T FH ) cells support terminal B-cell differentiation. Human regulatory B (Breg) cells modulate cellular responses, but their control of T FH cell-dependent humoral immune responses is unknown. We sought to assess the role of Breg cells on T FH cell development and function. Human T cells were polyclonally stimulated in the presence of IL-12 and IL-21 to generate T FH cells. They were cocultured with B cells to induce their terminal differentiation. Breg cells were included in these cultures, and their effects were evaluated by using flow cytometry and ELISA. B-cell lymphoma 6, IL-21, inducible costimulator, CXCR5, and programmed cell death protein 1 (PD-1) expressions increased on stimulated human T cells, characterizing T FH cell maturation. In cocultures they differentiated B cells into CD138 + plasma and IgD - CD27 + memory cells and triggered immunoglobulin secretions. Breg cells obtained by Toll-like receptor 9 and CD40 activation of B cells prevented T FH cell development. Added to T FH cell and B-cell cocultures, they inhibited B-cell differentiation, impeded immunoglobulin secretions, and expanded Foxp3 + CXCR5 + PD-1 + follicular regulatory T cells. Breg cells modulated IL-21 receptor expressions on T FH cells and B cells, and their suppressive activities involved CD40, CD80, CD86, and intercellular adhesion molecule interactions and required production of IL-10 and TGF-β. Human Breg cells control T FH cell maturation, expand follicular regulatory T cells, and inhibit the T FH cell-mediated antibody secretion. These novel observations demonstrate a role for the Breg cell in germinal center reactions and suggest that deficient activities might impair the T FH cell-dependent control of humoral immunity and might lead to the development of aberrant autoimmune responses. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The Design and Semi-Physical Simulation Test of Fault-Tolerant Controller for Aero Engine

Science.gov (United States)

Liu, Yuan; Zhang, Xin; Zhang, Tianhong

2017-11-01

A new fault-tolerant control method for aero engine is proposed, which can accurately diagnose the sensor fault by Kalman filter banks and reconstruct the signal by real-time on-board adaptive model combing with a simplified real-time model and an improved Kalman filter. In order to verify the feasibility of the method proposed, a semi-physical simulation experiment has been carried out. Besides the real I/O interfaces, controller hardware and the virtual plant model, semi-physical simulation system also contains real fuel system. Compared with the hardware-in-the-loop (HIL) simulation, semi-physical simulation system has a higher degree of confidence. In order to meet the needs of semi-physical simulation, a rapid prototyping controller with fault-tolerant control ability based on NI CompactRIO platform is designed and verified on the semi-physical simulation test platform. The result shows that the controller can realize the aero engine control safely and reliably with little influence on controller performance in the event of fault on sensor.

The regulatory control of radiation sources in Australia -- The challenges of a federal system

International Nuclear Information System (INIS)

Loy, J.; Colgan, P.

2001-01-01

The report refers to the challenges that Australia is facing, as a federal nation having a Commonwealth Government and six States and two territories, in establishing appropriate regulatory control of radiation sources. Information on the national inventory of radiation sources and existing regulatory infrastructure, including the system of notification, registration, licensing, inspection and enforcement, is explained in the report. The national provisions for the management of disused sources; the planning, preparedness and response to abnormal events and emergencies; the recovery of control over orphan sources; and education and training; are specifically emphasized. (author)

Regulatory T Cells: Potential Target in Anticancer Immunotherapy

Directory of Open Access Journals (Sweden)

Chi-Mou Juang

2007-09-01

Full Text Available The concept of regulatory T cells was first described in the early 1970s, and regulatory T cells were called suppressive T cells at that time. Studies that followed have demonstrated that these suppressive T cells negatively regulated tumor immunity and contributed to tumor growth in mice. Despite the importance of these studies, there was extensive skepticism about the existence of these cells, and the concept of suppressive T cells left the center stage of immunologic research for decades. Interleukin-2 receptor α-chain, CD25, was first demonstrated in 1995 to serve as a phenotypic marker for CD4+ regulatory cells. Henceforth, research of regulatory T cells boomed. Regulatory T cells are involved in the pathogenesis of cancer, autoimmune disease, transplantation immunology, and immune tolerance in pregnancy. Recent evidence has demonstrated that regulatory T cellmediated immunosuppression is one of the crucial tumor immune evasion mechanisms and the main obstacle of successful cancer immunotherapy. The mechanism and the potential clinical application of regulatory T cells in cancer immunotherapy are discussed.

Cytokines affecting CD4+T regulatory cells in transplant tolerance. III. Interleukin-5 (IL-5) promotes survival of alloantigen-specific CD4+ T regulatory cells.

Science.gov (United States)

Hall, Bruce M; Plain, Karren M; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine M; Nomura, Masaru; Boyd, Rochelle; Hodgkinson, Suzanne J

2017-08-01

CD4 + T cells mediate antigen-specific allograft tolerance, but die in culture without activated lymphocyte derived cytokines. Supplementation of the media with cytokine rich supernatant, from ConA activated spleen cells, preserves the capacity of tolerant cells to transfer tolerance and suppress rejection. rIL-2 or rIL-4 alone are insufficient to maintain these cells, however. We observed that activation of naïve CD4 + CD25 + FOXP3 + Treg with alloantigen and the Th2 cytokine rIL-4 induces them to express interleukin-5 specific receptor alpha (IL-5Rα) suggesting that IL-5, a Th2 cytokine that is produced later in the immune response may promote tolerance mediating Treg. This study examined if recombinant IL-5(rIL-5) promoted survival of tolerant CD4 + , especially CD4 + CD25 + T cells. CD4 + T cells, from DA rats tolerant to fully allogeneic PVG heart allografts surviving over 100days without on-going immunosuppression, were cultured with PVG alloantigen and rIL-5. The ability of these cells to adoptively transfer tolerance to specific-donor allograft and suppress normal CD4 + T cell mediated rejection in adoptive DA hosts was examined. Tolerant CD4 + CD25 + T cells' response to rIL-5 and expression of IL-5Rα was also assessed. rIL-5 was sufficient to promote transplant tolerance mediating CD4 + T cells' survival in culture with specific-donor alloantigen. Tolerant CD4 + T cells cultured with rIL-5 retained the capacity to transfer alloantigen-specific tolerance and inhibited naïve CD4 + T cells' capacity to effect specific-donor graft rejection. rIL-5 promoted tolerant CD4 + CD25 + T cells' proliferation in vitro when stimulated with specific-donor but not third-party stimulator cells. Tolerant CD4 + CD25 + T cells expressed IL-5Rα. This study demonstrated that IL-5 promoted the survival of alloantigen-specific CD4 + CD25 + T cells that mediate transplant tolerance. Copyright © 2017 Elsevier B.V. All rights reserved.

Unsolved problems in applying U.S. regulatory guides to control system equipment

International Nuclear Information System (INIS)

Stade, R.E.

1978-01-01

Two current problems encountered when designing control systems to the United States Regulatory Guide requirements are discussed. They are: 1) Level of surge voltages that should be specified when procuring solid state control and instrumentation systems and equipment. 2) The approach to be used qualifying equipment that must meet the aging requirements. (author)

Studies for improvement of regulatory control on the radioactive effluent released from nuclear facilities

International Nuclear Information System (INIS)

Cheong, Jae Hak; Park, H. M.; Song, M. C.; Lee, K. H.; Jang, J. K.; Chun, J. K.; Jeong, K. H.

2005-05-01

This report contains the second-year results of the research project titled 'Studies for Improvement of Regulatory Control on the Radioactive Effluent Released from Nuclear Facilities' and mainly provides technical and strategic approaches to improve performance of regulatory control on the gaseous effluent released from domestic nuclear facilities. The main result contained here includes overview and technical bases of radioactive gaseous effluent control (Chapter 1), reconsideration of the sensitivity requirements for measurement of radioactivity in gaseous effluent sample (Chapter 2), uncertainty analysis of the calculated radioactivity in gaseous effluent (Chapter 3), and improvement of quantification method of noble gas releases (Chapter 4). In addition, analysis of the impact due to combined sampling of particulate from multiple release points (Chapter 5), comparison of domestic nuclear reactors gaseous effluent data to foreign PWRs (Chapter 6), standardized sampling technique for collection of gaseous tritium (Chapter 7), and application of Xe-133 equivalent concept to gaseous effluent control (Chapter 8) are also provided. As a whole, this report provides a generic approach to improve the performance of regulatory control on the gaseous effluent. Therefore, actual enforcement of the recommendations should be preceded by establishment of a series of action plans reflecting on the site- and facility-specific design and operational features

Economic modeling of fault tolerant flight control systems in commercial applications

Science.gov (United States)

Finelli, G. B.

1982-01-01

This paper describes the current development of a comprehensive model which will supply the assessment and analysis capability to investigate the economic viability of Fault Tolerant Flight Control Systems (FTFCS) for commercial aircraft of the 1990's and beyond. An introduction to the unique attributes of fault tolerance and how they will influence aircraft operations and consequent airline costs and benefits is presented. Specific modeling issues and elements necessary for accurate assessment of all costs affected by ownership and operation of FTFCS are delineated. Trade-off factors are presented, aimed at exposing economically optimal realizations of system implementations, resource allocation, and operating policies. A trade-off example is furnished to graphically display some of the analysis capabilities of the comprehensive simulation model now being developed.

Commercialization of radiation tolerant camera

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Bum; Choi, Young Soo; Kim, Sun Ku; Lee, Jong Min; Cha, Bung Hun; Lee, Nam Ho; Byun, Eiy Gyo; Yoo, Seun Wook; Choi, Bum Ki; Yoon, Sung Up; Kim, Hyun Gun; Sin, Jeong Hun; So, Suk Il

1999-12-01

In this project, radiation tolerant camera which tolerates 10{sup 6} - 10{sup 8} rad total dose is developed. In order to develop radiation tolerant camera, radiation effect of camera components was examined and evaluated, and camera configuration was studied. By the result of evaluation, the components were decided and design was performed. Vidicon tube was selected to use by image sensor and non-browning optics and camera driving circuit were applied. The controller needed for CCTV camera system, lens, light, pan/tilt controller, was designed by the concept of remote control. And two type of radiation tolerant camera were fabricated consider to use in underwater environment or normal environment. (author)

Commercialization of radiation tolerant camera

International Nuclear Information System (INIS)

Lee, Yong Bum; Choi, Young Soo; Kim, Sun Ku; Lee, Jong Min; Cha, Bung Hun; Lee, Nam Ho; Byun, Eiy Gyo; Yoo, Seun Wook; Choi, Bum Ki; Yoon, Sung Up; Kim, Hyun Gun; Sin, Jeong Hun; So, Suk Il

1999-12-01

In this project, radiation tolerant camera which tolerates 10 6 - 10 8 rad total dose is developed. In order to develop radiation tolerant camera, radiation effect of camera components was examined and evaluated, and camera configuration was studied. By the result of evaluation, the components were decided and design was performed. Vidicon tube was selected to use by image sensor and non-browning optics and camera driving circuit were applied. The controller needed for CCTV camera system, lens, light, pan/tilt controller, was designed by the concept of remote control. And two type of radiation tolerant camera were fabricated consider to use in underwater environment or normal environment. (author)

Regulatory control of nuclear safety in Finland. Annual report 1997

International Nuclear Information System (INIS)

Tossavainen, K.

1998-08-01

The report describes regulatory control of the use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in Finland in 1997. Nuclear regulatory control ascertained that the operation of Finnish NPPs was in compliance with the conditions set out in operating licences and current regulations. In addition to NPP normal operation, STUK oversaw projects at the plant units relating to power uprating and safety improvements. STUK prepared statements for the Ministry of Trade and Industry about the applications for renewing the operating licenses of Loviisa and Olkiluoto NPPs. The most important items of supervision in nuclear waste management were studies relating to the final disposal of spent fuel from NPPs and the review of the licence application for a repository for low- and intermediate-level reactor waste from Loviisa NPP. Preparation of general safety regulations for the final disposal of spent nuclear fuel, to be published in the form of a Council of State Decision, was started. By safeguards control, the use of nuclear materials was verified to be in compliance with current regulations and that the whereabouts of every batch of nuclear material were always known. Nuclear material safeguards were stepped up to prevent illicit trafficking of nuclear materials and other radioactive materials. In co-operation with the Ministry for Foreign Affairs and the Institute of Seismology (University of Helsinki), preparations were undertaken to implement the Comprehensive Nuclear Test Ban Treaty (CTBT). For enforcement of the Treaty and as part of the international regulatory approach, STUK is currently developing laboratory analyses relating to airborne radioactivity measurements. The focus of co-operation funded by external sources was as follows: improvement of the safety of Kola and Leningrad NPPs, improvement of nuclear waste management in North-West Russia, development of the organizations of nuclear safety authorities in Eastern Europe and development

Design of neuro fuzzy fault tolerant control using an adaptive observer

International Nuclear Information System (INIS)

Anita, R.; Umamaheswari, B.; Viswanathan, B.

2001-01-01

New methodologies and concepts are developed in the control theory to meet the ever-increasing demands in industrial applications. Fault detection and diagnosis of technical processes have become important in the course of progressive automation in the operation of groups of electric drives. When a group of electric drives is under operation, fault tolerant control becomes complicated. For multiple motors in operation, fault detection and diagnosis might prove to be difficult. Estimation of all states and parameters of all drives is necessary to analyze the actuator and sensor faults. To maintain system reliability, detection and isolation of failures should be performed quickly and accurately, and hardware should be properly integrated. Luenberger full order observer can be used for estimation of the entire states in the system for the detection of actuator and sensor failures. Due to the insensitivity of the Luenberger observer to the system parameter variations, state estimation becomes inaccurate under the varying parameter conditions of the drives. Consequently, the estimation performance deteriorates, resulting in ordinary state observers unsuitable for fault detection technique. Therefore an adaptive observe, which can estimate the system states and parameter and detect the faults simultaneously, is designed in our paper. For a Group of D C drives, there may be parameter variations for some of the drives, and for other drives, there may not be parameter variations depending on load torque, friction, etc. So, estimation of all states and parameters of all drives is carried out using an adaptive observer. If there is any deviation with the estimated values, it is understood that fault has occurred and the nature of the fault, whether sensor fault or actuator fault, is determined by neural fuzzy network, and fault tolerant control is reconfigured. Experimental results with neuro fuzzy system using adaptive observer-based fault tolerant control are good, so as

Redefining Strategies to Introduce Tolerance-Inducing Cellular Therapy in Human beings to Combat Autoimmunity and Transplantation Reactions

NARCIS (Netherlands)

ten Brinke, Anja; Joosten, Irma; van Ham, S. Marieke; van Kooten, Cees; Prakken, Berent Jan

2014-01-01

Clinical translation of tolerance-inducing cell therapies requires a novel approach focused on innovative networks, patient involvement, and, foremost, a fundamental paradigm shift in thinking from both Academia, and Industry and Regulatory Agencies. Tolerance-inducing cell products differ

Redundant and fault-tolerant algorithms for real-time measurement and control systems for weapon equipment.

Science.gov (United States)

Li, Dan; Hu, Xiaoguang

2017-03-01

Because of the high availability requirements from weapon equipment, an in-depth study has been conducted on the real-time fault-tolerance of the widely applied Compact PCI (CPCI) bus measurement and control system. A redundancy design method that uses heartbeat detection to connect the primary and alternate devices has been developed. To address the low successful execution rate and relatively large waste of time slices in the primary version of the task software, an improved algorithm for real-time fault-tolerant scheduling is proposed based on the Basic Checking available time Elimination idle time (BCE) algorithm, applying a single-neuron self-adaptive proportion sum differential (PSD) controller. The experimental validation results indicate that this system has excellent redundancy and fault-tolerance, and the newly developed method can effectively improve the system availability. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Fault tolerant control for steam generators in nuclear power plant

International Nuclear Information System (INIS)

Deng Zhihong; Shi Xiaocheng; Xia Guoqing; Fu Mingyu

2010-01-01

Based on the nonlinear system with stochastic noise, a bank of extended Kalman filters is used to estimate the state of sensors. It can real-time detect and isolate the single sensor fault, and reconstruct the sensor output to keep steam generator water level stable. The simulation results show that the methodology of employing a bank of extended Kalman filters for steam generator fault tolerant control design is feasible. (authors)

Regulatory control of radiation sources in Germany

International Nuclear Information System (INIS)

Coy, K.

1998-01-01

The regulatory programme governing the safe use of radioisotopes in Germany is based on the federal legislation enacted as Atomic Energy Control Act (Atomgesetz) and Radiation Protection Ordinance (Strahlen-schutzverordnung) and its implementation by the competent authorities of the individual states. Despite this highly decentralized infrastructure of enforcement the basic principles of regulations described in this paper such as authorization criteria, conditions imposed as well as depth and intensity of inspection balanced according to the individual radiation hazard involved are harmonized to the greatest possible extent by regular coordination among the competent authorities as well as a series of technical regulations such as standards and guidelines. (author)

Interrelation between results of individual dosimetric control and regulatory control in Cuba

International Nuclear Information System (INIS)

Diaz Bernal, E.D.; Jova Sed, L.A.; Capote Ferrera, E.; Lopez Bejerano, G.M.

1997-01-01

The increasing use of various applications of ionizing radiation in Cuba made it necessary to create a harmonic system of facilities that guarantees the radiological safety of radiation workers, the public and the environment. Therefore, in 1985 a Centre of Radiation Protection and Hygiene (CPHR) was created. Thereafter, in 1991, the regulatory function and the inspection of radiological and nuclear safety was assigned to the National Centre of Nuclear Safety. The introduction of this service has provided the regulatory body with a tool to control the existing situation with respect to registration and licensing. The results of the service in the period 1994-1996 and a comparison with previous years are given. The results obtained reflect that the system of supervision in general has guaranteed keeping levels of doses low. The dose values registered demonstrate the possibility to establish in the country as a does limit an annual average dose limit of 20 mSv which might rise to but shall on no account exceed 50 mSv per year without the need for costly investment and based on organizational measures

Regulatory Strategy to Control Radon Exposure in Pakistan

International Nuclear Information System (INIS)

Younus, Irfan; Cho, Kun Woo

2012-01-01

Pakistan Nuclear Regulatory Authority (PNRA) was established in 2001 with one of the objectives to ensure the protection of workers, general public and the environment from the harmful effects of naturally occurring and artificially produced ionizing radiations by formulating and implementing the effective regulations. Radon is a naturally occurring odorless, colorless, tasteless, imperceptible to senses and chemically inert radioactive gas which is produced continuously from the natural decay of U-238, U-235 and Th-232 in most soils, rocks and water all over the earth. High levels of radon in the soil and rock are primarily responsible for indoor radon problems. Therefore when inhaled with air, there much probability that radon decay products will stay and decay in the lungs. If stayed in the lungs, the radiation may damage the cells causing lung cancer. Hence the radon problems have been taken seriously in most of the developed countries of the world. Radon reference levels for dwellings and workplaces have been set and the general public has been made alert of radon through newspapers and electronic media. In Pakistan, neither publicity campaign nor radon measurement and control programmes have been started countrywide. Rather small individual efforts for the sake of interest have been done to investigate the radon in some specific area or institution. This paper presents the regulatory strategy to control radon exposure for the sake of radiation protection of public and workers in Pakistan

A Multi-Environment Thermal Control System With Freeze-Tolerant Radiator

Science.gov (United States)

Chen, Weibo; Fogg, David; Mancini, Nick; Steele, John; Quinn, Gregory; Bue, Grant; Littibridge, Sean

2013-01-01

Future space exploration missions require advanced thermal control systems (TCS) to dissipate heat from spacecraft, rovers, or habitats operating in environments that can vary from extremely hot to extremely cold. A lightweight, reliable TCS is being developed to effectively control cabin and equipment temperatures under widely varying heat loads and ambient temperatures. The system uses freeze-tolerant radiators, which eliminate the need for a secondary circulation loop or heat pipe systems. Each radiator has a self-regulating variable thermal conductance to its ambient environment. The TCS uses a nontoxic, water-based working fluid that is compatible with existing lightweight aluminum heat exchangers. The TCS is lightweight, compact, and requires very little pumping power. The critical characteristics of the core enabling technologies were demonstrated. Functional testing with condenser tubes demonstrated the key operating characteristics required for a reliable, freeze-tolerant TCS, namely (1) self-regulating thermal conductance with short transient responses to varying thermal loads, (2) repeatable performance through freeze-thaw cycles, and (3) fast start-up from a fully frozen state. Preliminary coolant tests demonstrated that the corrosion inhibitor in the water-based coolant can reduce the corrosion rate on aluminum by an order of magnitude. Performance comparison with state-of-the-art designs shows significant mass and power saving benefits of this technology.

REGULATORY T CELLS AND VASECTOMY

Science.gov (United States)

Rival, Claudia; Wheeler, Karen; Jeffrey, Sarah; Qiao, Hui; Luu, Brian; Tewalt, Eric F; Engelhard, Victor H; Tardif, Stephen; Hardy, Daniel; del Rio, Roxana; Teuscher, Cory; Tung, Kenneth

2013-01-01

CD4+CD25+ regulatory T cells (Tregs) strongly influence the early and late autoimmune responses to meiotic germ cell antigens (MGCA) and the gonadal immunopathology in vasectomized mice. This is supported by the published and recently acquired information presented here. Within 24 hours of unilateral vasectomy (uni-vx) the ipsilateral epididymis undergoes epithelial cell apoptosis followed by necrosis, severe inflammation, and granuloma formation. Unexpectedly, vasectomy alone induced MGCA-specific tolerance. In contrast, uni-vx plus simultaneous Treg depletion resulted in MGCA-specific autoimmune response and bilateral autoimmune orchitis. Both tolerance and autoimmunity were strictly linked to the early epididymal injury. We now discovered that testicular autoimmunity in uni-vx mice did not occur when Treg depletion was delayed by one week. Remarkably, this delayed Treg depletion also prevented tolerance induction. Therefore, tolerance depends on a rapid de novo Treg response to MGCA exposed after vasectomy. Moreover, tolerance was blunted in mice genetically deficient in PD-1 ligand, suggesting the involvement of induced Treg. We conclude that pre-existing natural Treg prevents post-vasectomy autoimmunity, whereas vasectomy-induced Treg maintains post-vasectomy tolerance. We further discovered that vasectomized mice were still resistant to autoimmune orchitis induction for at least 12–16 months; thus, tolerance is long-lasting. Although significant sperm autoantibodies of low titers became detectable in uni-vx mice at seven months, the antibody titers fluctuated over time, suggesting a dynamic “balance” between the autoimmune and tolerance states. Finally, we observed severe epididymal fibrosis and hypo-spermatogenesis at 12 months after uni-vx: findings of highly critical clinical significance. PMID:24080233

Mechanisms of food processing and storage-related stress tolerance in Clostridium botulinum.

Science.gov (United States)

Dahlsten, Elias; Lindström, Miia; Korkeala, Hannu

2015-05-01

Vegetative cultures of Clostridium botulinum produce the extremely potent botulinum neurotoxin, and may jeopardize the safety of foods unless sufficient measures to prevent growth are applied. Minimal food processing relies on combinations of mild treatments, primarily to avoid deterioration of the sensory qualities of the food. Tolerance of C. botulinum to minimal food processing is well characterized. However, data on effects of successive treatments on robustness towards further processing is lacking. Developments in genetic manipulation tools and the availability of annotated genomes have allowed identification of genetic mechanisms involved in stress tolerance of C. botulinum. Most studies focused on low temperature, and the importance of various regulatory mechanisms in cold tolerance of C. botulinum has been demonstrated. Furthermore, novel roles in cold tolerance were shown for metabolic pathways under the control of these regulators. A role for secondary oxidative stress in tolerance to extreme temperatures has been proposed. Additionally, genetic mechanisms related to tolerance to heat, low pH, and high salinity have been characterized. Data on genetic stress-related mechanisms of psychrotrophic Group II C. botulinum strains are scarce; these mechanisms are of interest for food safety research and should thus be investigated. This minireview encompasses the importance of C. botulinum as a food safety hazard and its central physiological characteristics related to food-processing and storage-related stress. Special attention is given to recent findings considering genetic mechanisms C. botulinum utilizes in detecting and countering these adverse conditions. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Control of radioactive sources in industry through regulatory inspections

International Nuclear Information System (INIS)

Leocadio, J.C.; Ramalho, A.T.; Pinho, A.S.; Lourenco, M.M.J.; Nicola, M.S.; D'Avila, R.L.; Melo, I.F.; Cucco, A.C.S.

2005-01-01

In Brazil, the applications of ionizing radiation in industry are accomplished about 900 radioactive facilities, which handle approximately 3.000 radiation sources. The control of radioactive sources used in industrial installations authorized by the Brazilian Nuclear Energy Commission (CNEN) is accomplished by Servico de Radioprotecao na Industria Radiativa (SERIR) of the Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ, Brazil. This service carries out regulatory inspections in the practices of industrial radiography, nuclear gauges, industrial irradiators and oil wells logging. The frequency of inspections depends on the type of practice, ranging from a year to 5 years, depending on the risk involved. This paper presents a brief description of the situation of radiation safety in the use of radioactive sources in the industries of the country. The results obtained with regulatory inspections at industrial installations demonstrate that the conditions of safety and radiation protection in these facilities are satisfactory when compared with the technical regulations, both national and international

Hypoxia tolerance in reptiles, amphibians, and fishes: life with variable oxygen availability.

Science.gov (United States)

Bickler, Philip E; Buck, Leslie T

2007-01-01

The ability of fishes, amphibians, and reptiles to survive extremes of oxygen availability derives from a core triad of adaptations: profound metabolic suppression, tolerance of ionic and pH disturbances, and mechanisms for avoiding free-radical injury during reoxygenation. For long-term anoxic survival, enhanced storage of glycogen in critical tissues is also necessary. The diversity of body morphologies and habitats and the utilization of dormancy have resulted in a broad array of adaptations to hypoxia in lower vertebrates. For example, the most anoxia-tolerant vertebrates, painted turtles and crucian carp, meet the challenge of variable oxygen in fundamentally different ways: Turtles undergo near-suspended animation, whereas carp remain active and responsive in the absence of oxygen. Although the mechanisms of survival in both of these cases include large stores of glycogen and drastically decreased metabolism, other mechanisms, such as regulation of ion channels in excitable membranes, are apparently divergent. Common themes in the regulatory adjustments to hypoxia involve control of metabolism and ion channel conductance by protein phosphorylation. Tolerance of decreased energy charge and accumulating anaerobic end products as well as enhanced antioxidant defenses and regenerative capacities are also key to hypoxia survival in lower vertebrates.

Tolerating dissimilar other when primed with death: neural evidence of self-control engaged by interdependent people in Japan.

Science.gov (United States)

Yanagisawa, Kuniaki; Kashima, Emiko S; Moriya, Hiroki; Masui, Keita; Furutani, Kaichiro; Yoshida, Hiroshi; Ura, Mitsuhiro; Nomura, Michio

2017-06-01

Mortality salience (MS) has been shown to lead to derogation of others with dissimilar worldviews, yet recent research has shown that Asian-Americans who presumably adopt an interdependent self-construal (SC) tend to reveal greater tolerance after MS induction. In the present study, we demonstrated that Japanese individuals who are high on interdependent SC indeed show greater tolerance toward worldview-threatening other in the MS (vs control) condition, thus replicating the prior research. Extending this research, we also found that interdependent people's tolerance toward worldview-threatening other was mediated by increased activity in the right ventrolateral prefrontal cortex in the MS condition. These data suggested that when exposed to death-related stimuli, highly interdependent individuals may spontaneously activate their neural self-control system which may serve to increase tolerance toward others. © The Author (2017). Published by Oxford University Press.

Recent advances in utilizing transcription factors to improve plant abiotic stress tolerance by transgenic technology

Directory of Open Access Journals (Sweden)

Hongyan eWang

2016-02-01

Full Text Available Agricultural production and quality are adversely affected by various abiotic stresses worldwide and this will be exacerbated by the deterioration of global climate. To feed a growing world population, it is very urgent to breed stress-tolerant crops with higher yields and improved qualities against multiple environmental stresses. Since conventional breeding approaches had marginal success due to the complexity of stress tolerance traits, the transgenic approach is now being popularly used to breed stress-tolerant crops. So identifying and characterizing the the critical genes involved in plant stress responses is an essential prerequisite for engineering stress-tolerant crops. Far beyond the manipulation of single functional gene, engineering certain regulatory genes has emerged as an effective strategy now for controlling the expression of many stress-responsive genes. Transcription factors (TFs are good candidates for genetic engineering to breed stress-tolerant crop because of their role as master regulators of many stress-responsive genes. Many TFs belonging to families AP2/EREBP, MYB, WRKY, NAC, bZIP have been found to be involved in various abiotic stresses and some TF genes have also been engineered to improve stress tolerance in model and crop plants. In this review, we take five large families of TFs as examples and review the recent progress of TFs involved in plant abiotic stress responses and their potential utilization to improve multiple stress tolerance of crops in the field conditions.

Implementation of fault-tolerant quantum logic gates via optimal control

International Nuclear Information System (INIS)

Nigmatullin, R; Schirmer, S G

2009-01-01

The implementation of fault-tolerant quantum gates on encoded logic qubits is considered. It is shown that transversal implementation of logic gates based on simple geometric control ideas is problematic for realistic physical systems suffering from imperfections such as qubit inhomogeneity or uncontrollable interactions between qubits. However, this problem can be overcome by formulating the task as an optimal control problem and designing efficient algorithms to solve it. In particular, we can find solutions that implement all of the elementary logic gates in a fixed amount of time with limited control resources for the five-qubit stabilizer code. Most importantly, logic gates that are extremely difficult to implement using conventional techniques even for ideal systems, such as the T-gate for the five-qubit stabilizer code, do not appear to pose a problem for optimal control.

NAC transcription factor JUNGBRUNNEN1 enhances drought tolerance in tomato

KAUST Repository

Thirumalaikumar, Venkatesh P.

2017-06-22

Water deficit (drought stress) massively restricts plant growth and the yield of crops; reducing the deleterious effects of drought is therefore of high agricultural relevance. Drought triggers diverse cellular processes including the inhibition of photosynthesis, the accumulation of cell-damaging reactive oxygen species, and gene expression reprogramming, besides others. Transcription factors (TF) are central regulators of transcriptional reprogramming and expression of many TF genes is affected by drought, including members of the NAC family. Here, we identify the NAC factor JUNGBRUNNEN1 (JUB1) as a regulator of drought tolerance in tomato (Solanum lycopersicum). Expression of tomato JUB1 (SlJUB1) is enhanced by various abiotic stresses, including drought. Inhibiting SlJUB1 by virus-induced gene silencing drastically lowers drought tolerance concomitant with an increase in ion leakage, an elevation of hydrogen peroxide (H2 O2 ) levels, and a decrease of the expression of various drought-responsive genes. In contrast, overexpression of AtJUB1 from Arabidopsis thaliana increases drought tolerance in tomato, alongside with a higher relative leaf water content during drought and reduced H2 O2 levels. AtJUB1 was previously shown to stimulate expression of DREB2A, a TF involved in drought responses, and of the DELLA genes GAI and RGL1. We show here that SlJUB1 similarly controls the expression of the tomato orthologs SlDREB1, SlDREB2, and SlDELLA. Furthermore, AtJUB1 directly binds to the promoters of SlDREB1, SlDREB2 and SlDELLA in tomato. Our study highlights JUB1 as a transcriptional regulator of drought tolerance and suggests considerable conservation of the abiotic stress-related gene regulatory networks controlled by this NAC factor between Arabidopsis and tomato. This article is protected by copyright. All rights reserved.

The Neural Correlates of Self-Regulatory Fatigability During Inhibitory Control of Eye Blinking.

Science.gov (United States)

Abi-Jaoude, Elia; Segura, Barbara; Cho, Sang Soo; Crawley, Adrian; Sandor, Paul

2018-05-30

The capacity to regulate urges is an important human characteristic associated with a range of social and health outcomes. Self-regulatory capacity has been postulated to have a limited reserve, which when depleted leads to failure. The authors aimed to investigate the neural correlates of self-regulatory fatigability. Functional MRI was used to detect brain activations in 19 right-handed healthy subjects during inhibition of eye blinking, in a block design. The increase in number of blinks during blink inhibition from the first to the last block was used as covariate of interest. There was an increase in the number of eye blinks escaping inhibitory control across blink inhibition blocks, whereas there was no change in the number of eye blinks occurring during rest blocks. Inhibition of blinking activated a wide network bilaterally, including the inferior frontal gyrus, dorsolateral prefrontal cortex, dorsal anterior cingulate cortex, supplementary motor area, and caudate. Deteriorating performance was associated with activity in orbitofrontal cortex, ventromedial prefrontal cortex, rostroventral anterior cingulate cortex, precuneus, somatosensory, and parietal areas. As anticipated, effortful eye-blink control resulted in activation of prefrontal control areas and regions involved in urge and interoceptive processing. Worsening performance was associated with activations in brain areas involved in urge, as well as regions involved in motivational evaluation. These findings suggest that self-regulatory fatigability is associated with relatively less recruitment of prefrontal cortical regions involved in executive control.

The antianginal efficacy and tolerability of controlled-release metoprolol once daily

DEFF Research Database (Denmark)

Egstrup, K; Gundersen, T; Härkönen, R

1988-01-01

In a randomized, double-blind, cross-over study treatment with a new controlled-release (CR) preparation of metoprolol, given once daily, was compared with treatment with conventional metoprolol tablets, given twice daily, in 115 patients with stable effort angina pectoris. The patients were...... questionnaire. When all patients were analysed together there were no differences in antianginal efficacy between the two treatment regimens. However, when the group taking 200 mg daily was analysed separately better exercise tolerance was found during metoprolol CR therapy, as measured by onset of chest pain...... and ST-segment change, compared with conventional metoprolol therapy. The two formulations were well tolerated. When given once daily in a total daily dose of 100 mg, the CR preparation induced less adverse effects than the conventional tablets, 50 mg twice daily. It was concluded that the new metoprolol...

Dynamic Output Feedback Based Active Decentralized Fault-Tolerant Control for Reconfigurable Manipulator with Concurrent Failures

Directory of Open Access Journals (Sweden)

Yuanchun Li

2015-01-01

Full Text Available The goal of this paper is to describe an active decentralized fault-tolerant control (ADFTC strategy based on dynamic output feedback for reconfigurable manipulators with concurrent actuator and sensor failures. Consider each joint module of the reconfigurable manipulator as a subsystem, and treat the fault as the unknown input of the subsystem. Firstly, by virtue of linear matrix inequality (LMI technique, the decentralized proportional-integral observer (DPIO is designed to estimate and compensate the sensor fault online; hereafter, the compensated system model could be derived. Then, the actuator fault is estimated similarly by another DPIO using LMI as well, and the sufficient condition of the existence of H∞ fault-tolerant controller in the dynamic output feedback is presented for the compensated system model. Furthermore, the dynamic output feedback controller is presented based on the estimation of actuator fault to realize active fault-tolerant control. Finally, two 3-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in simulation. The main advantages of the proposed scheme lie in that it can handle the concurrent faults act on the actuator and sensor on the same joint module, as well as there is no requirement of fault detection and isolation process; moreover, it is more feasible to the modularity of the reconfigurable manipulator.

Alloreactive regulatory T cells allow the generation of mixed chimerism and transplant tolerance

Directory of Open Access Journals (Sweden)

Paulina eRuiz

2015-11-01

Full Text Available The induction of donor-specific transplant tolerance is one of the main goals of modern immunology. Establishment of a mixed chimerism state in the transplant recipient has proven to be a suitable strategy for the induction of long-term allograft tolerance; however, current experimental recipient preconditioning protocols have many side effects, and are not feasible for use in future therapies. In order to improve the current mixed chimerism induction protocols, we developed a non-myeloablative bone-marrow transplant protocol using retinoic acid induced alloantigen-specific Tregs, clinically available immunosuppressive drugs and lower doses of irradiation. We demonstrate that retinoic acid induced alloantigen-specific Tregs in addition to a non-myeloablative bone-marrow transplant protocol generates stable mixed chimerism and induce tolerance to allogeneic secondary skin allografts in mice. Therefore, the establishment of mixed chimerism through the use of donor-specific Tregs rather than non-specific immunosuppression could have a potential use in organ transplantation.

Fault-tolerant reference generation for model predictive control with active diagnosis of elevator jamming faults

NARCIS (Netherlands)

Ferranti, L.; Wan, Y.; Keviczky, T.

2018-01-01

This paper focuses on the longitudinal control of an Airbus passenger aircraft in the presence of elevator jamming faults. In particular, in this paper, we address permanent and temporary actuator jamming faults using a novel reconfigurable fault-tolerant predictive control design. Due to their

Implementation of fault tolerant control for modular multilevel converter using EtherCAT communication

DEFF Research Database (Denmark)

Burlacu, Paul Dan; Mathe, Laszlo; Rejas, Marcos

2015-01-01

Modular Multilevel Converter (MMC) is very promising technology this days. It offers fault tolerant capabilities and ensures high efficiency with low output voltage harmonic content which results in need for smaller filter size. A disadvantage of the system is that the control becomes more...

Tolerance induced by anti-DNA Ig peptide in (NZB×NZW)F1 lupus mice impinges on the resistance of effector T cells to suppression by regulatory T cells.

Science.gov (United States)

Yu, Yiyun; Liu, Yaoyang; Shi, Fu-Dong; Zou, Hejian; Hahn, Bevra H; La Cava, Antonio

2012-03-01

We have previously shown that immune tolerance induced by the anti-DNA Ig peptide pCons in (NZB×NZW)F(1) (NZB/W) lupus mice prolonged survival of treated animals and delayed the appearance of autoantibodies and glomerulonephritis. Part of the protection conferred by pCons could be ascribed to the induction of regulatory T cells (T(Reg)) that suppressed the production of anti-DNA antibodies in a p38 MAPK-dependent fashion. Here we show that another effect of pCons in the induction of immune tolerance in NZB/W lupus mice is the facilitation of effector T cell suppression by T(Reg). These new findings indicate that pCons exerts protective effects in NZB/W lupus mice by differentially modulating the activity of different T cell subsets, implying new considerations in the design of T(Reg)-based approaches to modulate T cell autoreactivity in SLE. Copyright © 2011 Elsevier Inc. All rights reserved.

Adaptive extended-state observer-based fault tolerant attitude control for spacecraft with reaction wheels

Science.gov (United States)

Ran, Dechao; Chen, Xiaoqian; de Ruiter, Anton; Xiao, Bing

2018-04-01

This study presents an adaptive second-order sliding control scheme to solve the attitude fault tolerant control problem of spacecraft subject to system uncertainties, external disturbances and reaction wheel faults. A novel fast terminal sliding mode is preliminarily designed to guarantee that finite-time convergence of the attitude errors can be achieved globally. Based on this novel sliding mode, an adaptive second-order observer is then designed to reconstruct the system uncertainties and the actuator faults. One feature of the proposed observer is that the design of the observer does not necessitate any priori information of the upper bounds of the system uncertainties and the actuator faults. In view of the reconstructed information supplied by the designed observer, a second-order sliding mode controller is developed to accomplish attitude maneuvers with great robustness and precise tracking accuracy. Theoretical stability analysis proves that the designed fault tolerant control scheme can achieve finite-time stability of the closed-loop system, even in the presence of reaction wheel faults and system uncertainties. Numerical simulations are also presented to demonstrate the effectiveness and superiority of the proposed control scheme over existing methodologies.

Immunity and tolerance to fungi in hematopoietic transplantation: Principles and perspectives

Directory of Open Access Journals (Sweden)

Agostinho eCarvalho

2012-06-01

Full Text Available Resistance and tolerance are two complementary host defence mechanism that increase fitness in response to low-virulence fungi. Resistance is meant to reduce pathogen burden during infection through innate and adaptive immune mechanisms, whereas tolerance mitigate the substantial cost of resistance to host fitness through a multitude of anti-inflammatory mechanisms, including immunological tolerance. In experimental fungal infections, both defense mechanisms are activated through the delicate equilibrium between Th1/Th17 cells, which provide antifungal resistance, and regulatory T cells limiting the consequences of the ensuing inflammatory pathology.Indoleamine 2,3-dioxygenase (IDO, a rate-limiting enzyme in the tryptophan catabolism, plays a key role in induction of tolerance against fungi. Both hematopoietic and nonhematopoietic compartments contribute to the resistance/tolerance balance against Aspergillus fumigatus via the involvement of selected innate receptors converging on IDO. Several genetic polymorphisms in pattern recognition receptors influence resistance and tolerance to fungal infections in human hematopoietic transplantation. Thus, tolerance mechanisms may be exploited for novel diagnostics and therapeutics against fungal infections and diseases.

A balance of activity in brain control and reward systems predicts self-regulatory outcomes.

Science.gov (United States)

Lopez, Richard B; Chen, Pin-Hao A; Huckins, Jeremy F; Hofmann, Wilhelm; Kelley, William M; Heatherton, Todd F

2017-05-01

Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily life. Sixty-nine chronic dieters, a population known for frequent lapses in self-control, completed a food cue-reactivity task during an fMRI scanning session, followed by a weeklong sampling of daily eating behaviors via ecological momentary assessment. We related participants' food cue activity in brain systems associated with executive control and reward to real-world eating patterns. Specifically, a balance score representing the amount of activity in brain regions associated with self-regulatory control, relative to automatic reward-related activity, predicted dieters' control over their eating behavior during the following week. This balance measure may reflect individual self-control capacity and be useful for examining self-regulation success in other domains and populations. © The Author (2017). Published by Oxford University Press.

Systemic immunological tolerance to ocular antigens is mediated by TNF-related apoptosis-inducing ligand (TRAIL)-expressing CD8+ T cells*

Science.gov (United States)

Griffith, Thomas S.; Brincks, Erik L.; Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.

2010-01-01

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required FasL-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8+ regulatory T cells. The present study examined the mechanism by which these CD8+ regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4+ T cells, and led to increased TRAIL expression by splenic CD8+ T cells. Unlike wildtype mice, Trail−/− or Dr5−/− mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8+ T cells from Trail−/− mice that were first injected AC with Ag were unable to transfer tolerance to naïve recipient wildtype mice, but CD8+ T cells from AC-injected wildtype or Dr5−/− mice could transfer tolerance. Importantly, the transferred wildtype (Trail+/+) CD8+ T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail−/− CD8+ T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that “helpless” CD8+ regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye. PMID:21169546

Workshop on rules for exemption from regulatory control: Proceedings

International Nuclear Information System (INIS)

1989-04-01

This conference report documents the proceedings of an International Workshop on the subject of exempting radiation sources and practices from regulatory control. The purpose of the workshop was to provide national regulatory authorities an opportunity to exchange information on their respective approaches and practices involving exemptions and to enhance international understanding and cooperation on the derivation and practical application of the underlying principles. In addition, input from the workshop was intended to assist the NRC in the development of a policy statement on this issue. The workshop was divided into five sessions. During the first four sessions, papers were presented which defined the relative terms and concepts, outlined the national situations and approaches to the establishment and development of exemption rules, identified and discussed the existing issues, and gave the status of the international guidelines on exemption rules. The fifth session was devoted to summarizing the workshop and identifying the areas of consensus, the outstanding issues and the areas for future work. Individual papers were processed separately for the data base

Use and regulatory control of dental X-ray installations

International Nuclear Information System (INIS)

1999-01-01

In the guide the safety requirements concerning dental X-ray installations and their use, prerequisities for exemption from a safety licence, and regulatory control are presented. The guide applies to conventional dental X-ray installations, by which an image is created on an X-ray film or other image receptor placed inside the mouth, and panorama tomography installations for dentition and the cephalostats associated with these. The guide does not apply to multitechnique tomography installations intended for the special imaging of the skull or jaws

Mathematical modeling of the implications of dominant tolerance for tumor biology and the response to combination therapy

International Nuclear Information System (INIS)

Leon, Kalet; Garcia, Karina; Lage, Agustin

2008-01-01

The existence of regulatory T lymphocytes (Tregs) that can control effector lymphocytes within the context of autoimmune, infectious and tumoral diseases is definitely accepted in current immunological research. Tregs confirm the theory of dominant tolerance, which holds that the choice of antigen rejection or tolerance in the immune system is the result of a dynamic equilibrium between populations of effector and regulatory T lymphocytes. The present paper summarizes the result of a recent theoretical study using mathematical modeling to analyze the dynamic interplay between T lymphocyte populations in the absence or presence of tumors and in response to different therapeutic treatments. The resulting model, developed at the Center of Molecular Immunology, which received an award from the Cuban Academy of Sciences in 2002, includes tumor cells and can simulate the effect of antitumoral mono- or combination therapies, by taking into account the way in which certain dynamic properties of tumors can, under specific circumstances, lead to the spontaneous expansion of Tregs populations. One of the advantages of the model is the prediction of several new strategies for the differential treatment of tumors, depending upon their ability of inducing the expansion of regulatory T cells. This is the first model available for the study of the impact of Tregs on the growth of malignant tumors, with results supported by international publications. Additionally, the model predicts the practical effects of several combination therapies, including vaccines, the excision of the tumor and depletion of lymphocyte populations. (Author)

Specific oral tolerance induction with raw hen's egg in children with very severe egg allergy: a randomized controlled trial.

Science.gov (United States)

Dello Iacono, Iride; Tripodi, Salvatore; Calvani, Mauro; Panetta, Valentina; Verga, Maria Carmela; Miceli Sopo, Stefano

2013-02-01

Treatment of severe egg allergy is avoidance of hen's egg (HE) and carrying self-injectable epinephrine. Specific oral tolerance induction (SOTI) seems a promising alternative treatment. However, some aspects of SOTI are still considered experimental. We evaluated the efficacy and safety of an original 6-month SOTI protocol in children with very severe HE allergy using raw HE emulsion. Twenty children (age range: 5-11 yr) were randomized equally into a SOTI treatment group and a control group. The treatment group started SOTI and underwent a second challenge 6 months later. Control children were kept on an egg-free diet for 6 months and then underwent a second challenge. After 6 months, 9/10 children of the SOTI group (90%) achieved partial tolerance (at least 10 ml, but <40 ml of raw HE emulsion, in a single dose) and 1 (10%) was able to tolerate only 5 ml (no tolerance). After 6 months, nine control children tested positive to the second challenge at a dose ≤0.9 ml of raw HE emulsion, and one reacted to 1.8 ml (SOTI vs. control group p<0.0001). All children in the SOTI group had side effects, but no child had a grade 5 reaction according to the Sampson grading. Six months of SOTI with raw HE emulsion resulted in partial tolerance, with regular intake, in a significant percentage of children with severe egg allergy. © 2012 John Wiley & Sons A/S.

Notification: Implementation of Executive Order 13771, “Reducing Regulation and Controlling Regulatory Costs”

Science.gov (United States)

Project #OA&E-FY18-0177, April 10, 2018. The OIG plans to begin preliminary research on the Office of the Administrator's Office of Policy implementation of Executive Order 13771, Reducing Regulation and Controlling Regulatory Costs.

Regulatory control of physical protection systems

International Nuclear Information System (INIS)

Rajdeep; Mayya, Y.S.

2017-01-01

The safety of facilities in BARC is under the regulatory oversight of BSC. The security architecture for these facilities incorporates multiple layers of Physical Protection Systems. The demands of safety may sometimes conflict with the needs of security. Realizing the need to identify these interfaces and extend the regulatory coverage to Physical Protection Systems, a Standing Committee named Physical Protection System Review Committee (PPSRC) has been constituted as a 2"n"d tier entity of BSC. PPSRC includes experts from various domains concerned with nuclear security, viz. physical protection systems, cyber security, radiation safety, security operations, technical services and security administration

Model checking optimal finite-horizon control for probabilistic gene regulatory networks.

Science.gov (United States)

Wei, Ou; Guo, Zonghao; Niu, Yun; Liao, Wenyuan

2017-12-14

Probabilistic Boolean networks (PBNs) have been proposed for analyzing external control in gene regulatory networks with incorporation of uncertainty. A context-sensitive PBN with perturbation (CS-PBNp), extending a PBN with context-sensitivity to reflect the inherent biological stability and random perturbations to express the impact of external stimuli, is considered to be more suitable for modeling small biological systems intervened by conditions from the outside. In this paper, we apply probabilistic model checking, a formal verification technique, to optimal control for a CS-PBNp that minimizes the expected cost over a finite control horizon. We first describe a procedure of modeling a CS-PBNp using the language provided by a widely used probabilistic model checker PRISM. We then analyze the reward-based temporal properties and the computation in probabilistic model checking; based on the analysis, we provide a method to formulate the optimal control problem as minimum reachability reward properties. Furthermore, we incorporate control and state cost information into the PRISM code of a CS-PBNp such that automated model checking a minimum reachability reward property on the code gives the solution to the optimal control problem. We conduct experiments on two examples, an apoptosis network and a WNT5A network. Preliminary experiment results show the feasibility and effectiveness of our approach. The approach based on probabilistic model checking for optimal control avoids explicit computation of large-size state transition relations associated with PBNs. It enables a natural depiction of the dynamics of gene regulatory networks, and provides a canonical form to formulate optimal control problems using temporal properties that can be automated solved by leveraging the analysis power of underlying model checking engines. This work will be helpful for further utilization of the advances in formal verification techniques in system biology.

Transient fault tolerant control for vehicle brake-by-wire systems

International Nuclear Information System (INIS)

Huang, Shuang; Zhou, Chunjie; Yang, Lili; Qin, Yuanqing; Huang, Xiongfeng; Hu, Bowen

2016-01-01

Brake-by-wire (BBW) systems that have no mechanical linkage between the brake pedal and the brake mechanism are expected to improve vehicle safety through better braking capability. However, transient faults in BBW systems can cause dangerous driving situations. Most existing research in this area focuses on the brake control mechanism, but very few studies try to solve the problem associated with transient fault propagation and evolution in the brake control system hierarchy. In this paper, a hierarchical transient fault tolerant scheme with embedded intelligence and resilient coordination for BBW system is proposed based on the analysis of transient fault propagation characteristics. In this scheme, most transient faults are tackled rapidly by a signature-based detection method at the node level, and the remaining transient faults, which cannot be detected directly at the node level and could degrade the system performance through fault propagation and evolution, are detected and recovered through function and structure models at the system level. To jointly accommodate these BBW transient faults at the system level, a sliding mode control algorithm and a task reallocation strategy are designed. A simulation platform based on Architecture Analysis and Design Language (AADL) is established to evaluate the task reallocation strategy, and a hardware-in-the-loop simulation is carried out to validate the proposed scheme systematically. Experimental results show the effectiveness of this new approach to BBW systems. - Highlights: • We propose a hierarchical transient fault tolerant scheme for BBW systems. • A sliding mode algorithm and a task strategy are designed to tackle transient fault. • The effectiveness of the scheme is verified in both simulation and HIL environments.

A Piecewise Affine Hybrid Systems Approach to Fault Tolerant Satellite Formation Control

DEFF Research Database (Denmark)

Grunnet, Jacob Deleuran; Larsen, Jesper Abildgaard; Bak, Thomas

2008-01-01

In this paper a procedure for modelling satellite formations   including failure dynamics as a piecewise-affine hybrid system is   shown. The formulation enables recently developed methods and tools   for control and analysis of piecewise-affine systems to be applied   leading to synthesis of fault...... tolerant controllers and analysis of   the system behaviour given possible faults.  The method is   illustrated using a simple example involving two satellites trying   to reach a specific formation despite of actuator faults occurring....

Principles for the exemption of radiation sources and practices from regulatory control

International Nuclear Information System (INIS)

1988-01-01

Radiation sources, including equipment and installations, which emit ionizing radiations, are potentially harmful to health and their use should therefore be regulated. Some types of radiation source, however, do not need to be subject to regulatory control, because they present such a low hazard that it would be a needless waste of time and effort to exercise control by a regulatory process and they can therefore be exempted from it. An Advisory Group Meeting was convened in Vienna in March 1988 sponsored jointly by the IAEA and NEA. This Safety Guide is the result of that meeting and represents a first international consensus on the subject of exemption principles. This document is issued as an IAEA Safety Guide since it recommends a procedure which might be followed in implementing the Basic Safety Standards (BSS) for Radiation Protection. Its purpose is to recommend a policy on exemptions from the BSS system of notification, registration and licensing. 15 refs

Tolerance to drought and salt stress in plants: Unraveling the signaling networks

Directory of Open Access Journals (Sweden)

Dortje eGolldack

2014-04-01

Full Text Available Tolerance of plants to abiotic stressors such as drought and salinity is triggered by complex multicomponent signaling pathways to restore cellular homeostasis and promote survival. Major plant transcription factor families such as bZIP, NAC, AP2/ERF and MYB orchestrate regulatory networks underlying abiotic stress tolerance. Sucrose nonfermenting 1-related protein kinase 2 (SnRK2 and MAPK pathways contribute to initiation of stress adaptive downstream responses and promote plant growth and development. As a convergent point of multiple abiotic cues, cellular effects of environmental stresses are not only imbalances of ionic and osmotic homeostasis but also impaired photosynthesis, cellular energy depletion, and redox imbalances. Recent evidence of regulatory systems that link sensing and signaling of environmental conditions and the intracellular redox status have shed light on interfaces of stress and energy signaling. ROS (reactive oxygen species cause severe cellular damage by peroxidation and de-esterification of membrane lipids, however, current models also define a pivotal signaling function of ROS in triggering tolerance against stress. Recent research advances suggest and support a regulatory role of ROS in the cross talks of stress triggered hormonal signaling such as the abscisic acid (ABA pathway and endogenously induced redox and metabolite signals. Here, we discuss and review the versatile molecular convergence in the abiotic stress responsive signaling networks in the context of ROS and lipid derived signals and the specific role of stomatal signaling.

Controlling fuel costs: Procurement strategies and regulatory standards

International Nuclear Information System (INIS)

Einhorn, H.A.; Levi, B.I.

1992-01-01

Since the oil price shocks and inflation of the 1970s, regulatory authorities and utilities have devoted considerable attention to controlling energy costs while maintaining reliable service. Although much of this concern has been directed towards capital cost containment, increasing scrutiny has been applied to a broad range of variable costs, especially to fuel procurement expenditures. With some 40% to 65% of the electric utility industry's annual operation and maintenance expenses paid to secure fuel supplies, even a small difference in fuel costs could have a substantial impact on costs to ratepayers. This increased attention to fuel cost containment can be expected to intensify as implementation of the 1990 amendments to the Clean Air Act affects fuel purchase decisions. To assure that fuel is purchased in a responsible and cost-effective manner, some state jurisdictions have initiated periodic reviews (audits) of the procurement practices that electric utilities follow when purchasing fuel. While a utility must demonstrate how it purchases fuel, there is wide variation in interest and scope of audits among jurisdictions. In this paper, the authors review: (1) the regulatory environment within which fuel procurement and audits occur, and (2) some particularly controversial issues that will receive increasing attention as the practice of conducting fuel procurement audits spreads

Tolerance to and cross tolerance between ethanol and nicotine.

Science.gov (United States)

Collins, A C; Burch, J B; de Fiebre, C M; Marks, M J

1988-02-01

Female DBA mice were subjected to one of four treatments: ethanol-containing or control diets, nicotine (0.2, 1.0, 5.0 mg/kg/hr) infusion or saline infusion. After removal from the liquid diets or cessation of infusion, the animals were challenged with an acute dose of ethanol or nicotine. Chronic ethanol-fed mice were tolerant to the effects of ethanol on body temperature and open field activity and were cross tolerant to the effects of nicotine on body temperature and heart rate. Nicotine infused animals were tolerant to the effects of nicotine on body temperature and rotarod performance and were cross tolerant to the effects of ethanol on body temperature. Ethanol-induced sleep time was decreased in chronic ethanol- but not chronic nicotine-treated mice. Chronic drug treatment did not alter the elimination rate of either drug. Chronic ethanol treatment did not alter the number or affinity of brain nicotinic receptors whereas chronic nicotine treatment elicited an increase in the number of [3H]-nicotine binding sites. Tolerance and cross tolerance between ethanol and nicotine is discussed in terms of potential effects on desensitization of brain nicotinic receptors.

Consigned regulatory control and effect of the owner's welding quality under the EPC mode in Fangjiashan nuclear power project

International Nuclear Information System (INIS)

Wang Qun; Gu Tao; Wei Lianfeng; Li Hongjun

2012-01-01

Under EPC management mode, how to optimize resources allocation and realize effective management and control over key control points is a big difficulty facing the owner. From the owner's point of view, and through summary of practices, the paper introduces and analyses the mode and effect of consigned regulatory control over the weld quality of Fangjiashan nuclear power project. And some recognitions and point of views on popularization of specialized and consigned regulatory control are put forward. (authors)

Parameter Estimation Analysis for Hybrid Adaptive Fault Tolerant Control

Science.gov (United States)

Eshak, Peter B.

Research efforts have increased in recent years toward the development of intelligent fault tolerant control laws, which are capable of helping the pilot to safely maintain aircraft control at post failure conditions. Researchers at West Virginia University (WVU) have been actively involved in the development of fault tolerant adaptive control laws in all three major categories: direct, indirect, and hybrid. The first implemented design to provide adaptation was a direct adaptive controller, which used artificial neural networks to generate augmentation commands in order to reduce the modeling error. Indirect adaptive laws were implemented in another controller, which utilized online PID to estimate and update the controller parameter. Finally, a new controller design was introduced, which integrated both direct and indirect control laws. This controller is known as hybrid adaptive controller. This last control design outperformed the two earlier designs in terms of less NNs effort and better tracking quality. The performance of online PID has an important role in the quality of the hybrid controller; therefore, the quality of the estimation will be of a great importance. Unfortunately, PID is not perfect and the online estimation process has some inherited issues; the online PID estimates are primarily affected by delays and biases. In order to ensure updating reliable estimates to the controller, the estimator consumes some time to converge. Moreover, the estimator will often converge to a biased value. This thesis conducts a sensitivity analysis for the estimation issues, delay and bias, and their effect on the tracking quality. In addition, the performance of the hybrid controller as compared to direct adaptive controller is explored. In order to serve this purpose, a simulation environment in MATLAB/SIMULINK has been created. The simulation environment is customized to provide the user with the flexibility to add different combinations of biases and delays to

Comparative genomics of metabolic capacities of regulons controlled by cis-regulatory RNA motifs in bacteria.

Science.gov (United States)

Sun, Eric I; Leyn, Semen A; Kazanov, Marat D; Saier, Milton H; Novichkov, Pavel S; Rodionov, Dmitry A

2013-09-02

In silico comparative genomics approaches have been efficiently used for functional prediction and reconstruction of metabolic and regulatory networks. Riboswitches are metabolite-sensing structures often found in bacterial mRNA leaders controlling gene expression on transcriptional or translational levels.An increasing number of riboswitches and other cis-regulatory RNAs have been recently classified into numerous RNA families in the Rfam database. High conservation of these RNA motifs provides a unique advantage for their genomic identification and comparative analysis. A comparative genomics approach implemented in the RegPredict tool was used for reconstruction and functional annotation of regulons controlled by RNAs from 43 Rfam families in diverse taxonomic groups of Bacteria. The inferred regulons include ~5200 cis-regulatory RNAs and more than 12000 target genes in 255 microbial genomes. All predicted RNA-regulated genes were classified into specific and overall functional categories. Analysis of taxonomic distribution of these categories allowed us to establish major functional preferences for each analyzed cis-regulatory RNA motif family. Overall, most RNA motif regulons showed predictable functional content in accordance with their experimentally established effector ligands. Our results suggest that some RNA motifs (including thiamin pyrophosphate and cobalamin riboswitches that control the cofactor metabolism) are widespread and likely originated from the last common ancestor of all bacteria. However, many more analyzed RNA motifs are restricted to a narrow taxonomic group of bacteria and likely represent more recent evolutionary innovations. The reconstructed regulatory networks for major known RNA motifs substantially expand the existing knowledge of transcriptional regulation in bacteria. The inferred regulons can be used for genetic experiments, functional annotations of genes, metabolic reconstruction and evolutionary analysis. The obtained genome

Regulatory control of nuclear facility valves and their actuators

International Nuclear Information System (INIS)

1993-01-01

The methods and procedures by which the Finnish Centre for Radiation and Nuclear Safety (STUK) regulates valves and their actuators in nuclear power plants and in other nuclear facilities are specified in the guide. The scope of regulation depends on the Safety Class of the valve and the actuator in question. The Safety Classification principles for the systems, structures and components of the nuclear power plants are described in the guide YVL 2.1 and the regulatory control of the nuclear facility safety valves is described in the guide YVL 5.4

Control of Metastatic Progression by microRNA Regulatory Networks

Science.gov (United States)

Pencheva, Nora; Tavazoie, Sohail F.

2015-01-01

Aberrant microRNA (miRNA) expression is a defining feature of human malignancy. Specific miRNAs have been identified as promoters or suppressors of metastatic progression. These miRNAs control metastasis through divergent or convergent regulation of metastatic gene pathways. Some miRNA regulatory networks govern cell-autonomous cancer phenotypes, while others modulate the cell-extrinsic composition of the metastatic microenvironment. The use of small RNAs as probes into the molecular and cellular underpinnings of metastasis holds promise for the identification of candidate genes for potential therapeutic intervention. PMID:23728460

Adaptive Fault-Tolerant Synchronization Control of a Class of Complex Dynamical Networks With General Input Distribution Matrices and Actuator Faults.

Science.gov (United States)

Li, Xiao-Jian; Yang, Guang-Hong

2017-03-01

This paper is concerned with the problem of adaptive fault-tolerant synchronization control of a class of complex dynamical networks (CDNs) with actuator faults and unknown coupling weights. The considered input distribution matrix is assumed to be an arbitrary matrix, instead of a unit one. Within this framework, an adaptive fault-tolerant controller is designed to achieve synchronization for the CDN. Moreover, a convex combination technique and an important graph theory result are developed, such that the rigorous convergence analysis of synchronization errors can be conducted. In particular, it is shown that the proposed fault-tolerant synchronization control approach is valid for the CDN with both time-invariant and time-varying coupling weights. Finally, two simulation examples are provided to validate the effectiveness of the theoretical results.

Nuclear Security Recommendations on Nuclear and Other Radioactive Material out of Regulatory Control: Recommendations

International Nuclear Information System (INIS)

2011-01-01

This publication presents recommendations for the nuclear security of nuclear and other radioactive material that is out of regulatory control. It is based on national experiences and practices and guidance publications in the field of security as well as the nuclear security related international instruments. The recommendations include guidance for States with regard to the nuclear security of nuclear and other radioactive material that has been reported as being out of regulatory control as well as for material that is lost, missing or stolen but has not been reported as such, or has been otherwise discovered. In addition, these recommendations adhere to the detection and assessment of alarms and alerts and to a graded response to criminal or unauthorized acts with nuclear security implications

A Controlled Trial of CPAP Therapy on Metabolic Control in Individuals with Impaired Glucose Tolerance and Sleep Apnea

Science.gov (United States)

Weinstock, Tanya G.; Wang, Xuelei; Rueschman, Michael; Ismail-Beigi, Faramarz; Aylor, Joan; Babineau, Denise C.; Mehra, Reena; Redline, Susan

2012-01-01

Study Objectives: To address whether treatment of sleep apnea improves glucose tolerance. Design: Randomized, double-blind crossover study. Setting: Sleep clinic referrals. Patients: 50 subjects with moderate to severe sleep apnea (AHI > 15) and impaired glucose tolerance. Interventions: Subjects were randomized to 8 weeks of CPAP or sham CPAP, followed by the alternate therapy after a one-month washout. After each treatment, subjects underwent 2-hour OGTT, polysomnography, actigraphy, and measurements of indices of glucose control. Measurements and Results: The primary outcome was normalization of the mean 2-h OGTT; a secondary outcome was improvement in the Insulin Sensitivity Index (ISI (0,120). Subjects were 42% men, mean age of 54 (10), BMI of 39 (8), and AHI of 44 (27). Baseline fasting glucose was 104 (12), and mean 2-h OGTT was 110 (57) mg/dL. Seven subjects normalized their mean 2-h OGTT after CPAP but not after sham CPAP, while 5 subjects normalized after sham CPAP but not after CPAP. Overall, there was no improvement in ISI (0,120) between CPAP and sham CPAP (3.6%; 95% CI: [-2.2%, 9.7%]; P = 0.22). However, in those subjects with baseline AHI ≥ 30 (n = 25), there was a 13.3% (95% CI: [5.2%, 22.1%]; P CPAP compared to sham CPAP. Conclusions: This study did not show that IGT normalizes after CPAP in subjects with moderate sleep apnea and obesity. However, insulin sensitivity improved in those with AHI ≥ 30, suggesting beneficial metabolic effects of CPAP in severe sleep apnea. Clinical Trials Information: ClinicalTrials.gov Identifier: NCT01385995. Citation: Weinstock TG; Wang X; Rueschman M; Ismail-Beigi F; Aylor J; Babineau DC; Mehra R; Redline S. A controlled trial of CPAP therapy on metabolic control in individuals with impaired glucose tolerance and sleep apnea. SLEEP 2012;35(5):617-625. PMID:22547887

Balancing technical and regulatory concerns related to testing and control of performance assessment software

International Nuclear Information System (INIS)

Seitz, R.R.; Matthews, S.D.; Kostelnik, K.M.

1990-01-01

What activities are required to assure that a performance assessment (PA) computer code operates as it is intended? Answers to this question will vary depending on the individual's area of expertise. Different perspectives on testing and control of PA software are discussed based on interpretations of the testing and control process associated with the different involved parties. This discussion leads into the presentation of a general approach to software testing and control that address regulatory requirements. Finally, the need for balance between regulatory and scientific concerns is illustrated through lessons learned in previous implementations of software testing and control programs. Configuration control and software testing are required to provide assurance that a computer code performs as intended. Configuration control provides traceability and reproducibility of results produced with PA software and provides a system to assure that users have access to the current version of the software. Software testing is conducted to assure that the computer code has been written properly, solution techniques have been properly implemented, and the software is capable of representing the behavior of the specific system to be modeled. Comprehensive software testing includes: software analysis, verification testing, benchmark testing, and site-specific calibration/validation testing

Tasco®, a Product of Ascophyllum nodosum, Imparts Thermal Stress Tolerance in Caenorhabditis elegans

Directory of Open Access Journals (Sweden)

Franklin Evans

2011-11-01

Full Text Available Tasco®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. Tasco® water extract (TWE at 300 µg/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 °C treated with 300 µg/mL and 600 µg/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of Tasco® imparted thermal stress

Development of an interface for an ultrareliable fault-tolerant control system and an electronic servo-control unit

Science.gov (United States)

Shaver, Charles; Williamson, Michael

1986-01-01

The NASA Ames Research Center sponsors a research program for the investigation of Intelligent Flight Control Actuation systems. The use of artificial intelligence techniques in conjunction with algorithmic techniques for autonomous, decentralized fault management of flight-control actuation systems is explored under this program. The design, development, and operation of the interface for laboratory investigation of this program is documented. The interface, architecturally based on the Intel 8751 microcontroller, is an interrupt-driven system designed to receive a digital message from an ultrareliable fault-tolerant control system (UFTCS). The interface links the UFTCS to an electronic servo-control unit, which controls a set of hydraulic actuators. It was necessary to build a UFTCS emulator (also based on the Intel 8751) to provide signal sources for testing the equipment.

CEGB philosophy and experience with fault-tolerant micro-computer application for power plant controls

International Nuclear Information System (INIS)

Clinch, D.A.L.

1986-01-01

From the mid-1960s until the late 1970s, automatic modulating control of the main boiler plant on CEGB fossil-fired power stations was largely implemented with hard wired electronic equipment. Mid-way through this period, the CEGB formulated a set of design requirements for this type of equipment; these laid particular emphasis on the fault tolerance of a control system and specified the nature of the interfaces with a control desk and with plant regulators. However, the automatic control of an Advanced Gas Cooled Reactor (AGR) is based upon measured values which are derived by processing a large number of thermocouple signals. This is more readily implemented digitally than with hard-wired equipment. Essential to the operation of an AGR power station is a data processing (DP) computer for monitoring the plant; so the first group of AGR power stations, designed in the 1960s, employed their DP computers for modulating control. Since the late 1970s, automatic modulating control of major plants, for new power stations and for re-fits on established power stations, has been implemented with micro-computers. Wherever practicable, the policy formulated earlier for hard-wired equipment has been retained, particularly in respect of the interfaces. This policy forms the foundation of the fault tolerance of these micro-computer systems

Validation of gamma irradiator controls for quality and regulatory compliance

International Nuclear Information System (INIS)

Harding, R.B.; Pinteric, F.J.A.

1995-01-01

Since 1978 the U.S. Food and Drug Administration (FDA) has had both the legal authority and the Current Good Manufacturing Practice (CGMP) regulations in place to require irradiator owners who process medical devices to produce evidence of Irradiation Process Validation. One of the key components of Irradiation Process Validation is the validation of the irradiator controls. However, it is only recently that FDA audits have focused on this component of the process validation. What is Irradiator Control System Validation? What constitutes evidence of control? How do owners obtain evidence? What is the irradiator supplier's role in validation? How does the ISO 9000 Quality Standard relate to the FDA's CGMP requirement for evidence of Control System Validation? This paper presents answers to these questions based on the recent experiences of Nordion's engineering and product management staff who have worked with several US-based irradiator owners. This topic - Validation of Irradiator Controls - is a significant regulatory compliance and operations issues within the irradiator suppliers' and users' community. (author)

Long-term tolerability of inhaled human insulin (Exubera) in patients with poorly controlled type 2 diabetes

DEFF Research Database (Denmark)

Barnett, A H; Lange, P; Dreyer, M

2007-01-01

OBJECTIVE: Inhaled human insulin (Exubera; EXU) has shown encouraging tolerability in short-term trials. We evaluated the safety profile of EXU after long-term exposure. DESIGN: In two, open-label, 2-year studies patients poorly controlled on a sulphonylurea were randomised to adjunctive EXU...... or metformin (study 1) and patients poorly controlled on metformin were randomised to adjunctive EXU or the sulphonylurea, glibenclamide (study 2). PATIENTS: The studies included 446 (study 1) and 476 (study 2) patients with type 2 diabetes, no clinically significant respiratory disease and glycosylated....... There was no discernable effect of long-term EXU therapy on pulmonary gas exchange. Insulin antibody binding reached a plateau at 6 months and did not correlate with HbA(1c) or lung function changes. Glycaemic control was maintained over 2 years. CONCLUSIONS: Exubera was well tolerated during long-term use. Pulmonary...

Dendritic cells in oral tolerance in the gut.

Science.gov (United States)

Rescigno, Maria

2011-09-01

Oral tolerance is a process that allows generation of systemic unresponsiveness to food antigens. Hence if the same antigen is introduced systemically even under immunogenic conditions it does not induce immune responsiveness. Dendritic cells (DCs) have been identified as essential players in this process. DCs in the gut are located in a strategic position as they can interact directly with luminal antigens or indirectly after their transcytosis across epithelial cells. DCs can then migrate to associated lymphoid tissues to induce tolerance. Antigen presenting cells in the gut are specialized in function and have divided their labour so that there are cells capable to migrate to the draining mesenteric lymph node for induction of T regulatory cells, while other subsets are resident and are required to enforce tolerance locally in the gut after food antigen exposure. In this review, I shall summarize the characteristics of antigen presenting cells in the gut and their involvement in oral tolerance induction. In addition, I will also emphasize that tolerance to food allergens may be contributed by plasmacytoid DCs in the liver that participate to the elimination or anergy of allergen-specific CD8 T cells. Hence specialized functions are associated to different subsets of antigen presenting cells and different organs. © 2011 Blackwell Publishing Ltd.

Regulatory control of nuclear safety in Finland. Annual report 1999

Energy Technology Data Exchange (ETDEWEB)

Tossavainen, K. [ed.

2000-06-01

This report concerns the regulatory control of nuclear energy in Finland in 1999. Its submission to the Ministry of Trade and Industry by the Finnish Radiation and Nuclear Safety Authority (STUK) is stipulated in section 121 of the Nuclear Energy Decree. STUK's regulatory work was focused on the operation of the Finnish nuclear power plants as well as on nuclear waste management and safeguards of nuclear materials. The operation of the Finnish nuclear power plants was in compliance with the conditions set out in their operating licences and with current regulations, with the exception of some inadvertent deviations from the Technical Specifications. No plant events endangering the safe use of nuclear energy occurred. The individual doses of all nuclear power plant workers remained below the dose threshold. The collective dose of the workers was low, compared internationally, and did not exceed STUK's guidelines at either nuclear power plant. The radioactive releases were minor and the dose calculated on their basis for the most exposed individual in the vicinity of the plant was well below the limit established in a decision of the Council of State at both Loviisa and Olkiluoto nuclear power plants. STUK issued statements to the Ministry of Trade and Industry about the environmental impact assessment programme reports on the possible nuclear power plant projects at Olkiluoto and Loviisa and about the continued operation of the research reactor in Otaniemi, Espoo. A Y2k-related safety assessment of the Finnish nuclear power plants was completed in December. In nuclear waste management STUK's regulatory work was focused on spent fuel storage and final disposal plans as well as on the treatment, storage and final disposal of reactor waste. No events occurred in nuclear waste management that would have endangered safety. A statement was issued to the Ministry of Trade and Industry about an environmental impact assessment report on a proposed final

Regulatory control of nuclear safety in Finland. Annual report 1999

International Nuclear Information System (INIS)

Tossavainen, K.

2000-06-01

This report concerns the regulatory control of nuclear energy in Finland in 1999. Its submission to the Ministry of Trade and Industry by the Finnish Radiation and Nuclear Safety Authority (STUK) is stipulated in section 121 of the Nuclear Energy Decree. STUK's regulatory work was focused on the operation of the Finnish nuclear power plants as well as on nuclear waste management and safeguards of nuclear materials. The operation of the Finnish nuclear power plants was in compliance with the conditions set out in their operating licences and with current regulations, with the exception of some inadvertent deviations from the Technical Specifications. No plant events endangering the safe use of nuclear energy occurred. The individual doses of all nuclear power plant workers remained below the dose threshold. The collective dose of the workers was low, compared internationally, and did not exceed STUK's guidelines at either nuclear power plant. The radioactive releases were minor and the dose calculated on their basis for the most exposed individual in the vicinity of the plant was well below the limit established in a decision of the Council of State at both Loviisa and Olkiluoto nuclear power plants. STUK issued statements to the Ministry of Trade and Industry about the environmental impact assessment programme reports on the possible nuclear power plant projects at Olkiluoto and Loviisa and about the continued operation of the research reactor in Otaniemi, Espoo. A Y2k-related safety assessment of the Finnish nuclear power plants was completed in December. In nuclear waste management STUK's regulatory work was focused on spent fuel storage and final disposal plans as well as on the treatment, storage and final disposal of reactor waste. No events occurred in nuclear waste management that would have endangered safety. A statement was issued to the Ministry of Trade and Industry about an environmental impact assessment report on a proposed final disposal facility for

A population dynamics analysis of the interaction between adaptive regulatory T cells and antigen presenting cells.

Directory of Open Access Journals (Sweden)

David Fouchet

Full Text Available BACKGROUND: Regulatory T cells are central actors in the maintenance of tolerance of self-antigens or allergens and in the regulation of the intensity of the immune response during infections by pathogens. An understanding of the network of the interaction between regulatory T cells, antigen presenting cells and effector T cells is starting to emerge. Dynamical systems analysis can help to understand the dynamical properties of an interaction network and can shed light on the different tasks that can be accomplished by a network. METHODOLOGY AND PRINCIPAL FINDINGS: We used a mathematical model to describe a interaction network of adaptive regulatory T cells, in which mature precursor T cells may differentiate into either adaptive regulatory T cells or effector T cells, depending on the activation state of the cell by which the antigen was presented. Using an equilibrium analysis of the mathematical model we show that, for some parameters, the network has two stable equilibrium states: one in which effector T cells are strongly regulated by regulatory T cells and another in which effector T cells are not regulated because the regulatory T cell population is vanishingly small. We then simulate different types of perturbations, such as the introduction of an antigen into a virgin system, and look at the state into which the system falls. We find that whether or not the interaction network switches from the regulated (tolerant state to the unregulated state depends on the strength of the antigenic stimulus and the state from which the network has been perturbed. CONCLUSION/SIGNIFICANCE: Our findings suggest that the interaction network studied in this paper plays an essential part in generating and maintaining tolerance against allergens and self-antigens.

Mechanisms Controlling Species Responses to Climate Change: Thermal Tolerances and Shifting Range Limits. (Invited)

Science.gov (United States)

Sage, R. F.; Bykova, O.; Coiner, H.

2010-12-01

One of the main effects of anthropogenic climate change will be widespread shifts in species distribution, with the common assumption that they will migrate to higher elevation and latitude. While this assumption is supported by migration patterns following climate warming in the past 20,000 years, it has not been rigorously evaluated in terms of physiological mechanism, despite the implication that migration in response to climate warming is controlled by some form of thermal adaptation. We have been evaluating the degree to which species range limits are controlled by physiological patterns of thermal tolerance in bioinvaders of North America. Bioinvaders presumably have few biotic controls over their distribution and thus are more likely to fully exploit their thermal niche. In cheatgrass (Bromus tectorum), the minimum lethal temperature in winter is -32C, which corresponds to the mean winter minimum temperature at its northern range limit. In red brome (Bromus rubens), the minimum lethal temperature is also near -32C, which is well below the minimum winter temperature near -20C that corresponds to its northern distribution limit. In kudzu (Pueraria lobata), the minimum lethal temperature is near -20C, which corresponds to the midwinter minimum at its northern distribution limit; however, overwintering kudzu tissues are insulated by soil and snow cover, and thus do not experience lethal temperatures at kudzu's northern range limit. These results demonstrate that some invasive species can exploit the potential range defined by their low temperature tolerance and thus can be predicted by mechanistic models to migrate to higher latitudes with moderation of winter cold. The distribution of other invaders such as kudzu and red brome are not controlled by tolerance of midwinter cold. Developing mechanistic models of their distributions, and how these might change with climate warming, will require extensive physiological study.

Tolerance to MHC class II disparate allografts through genetic modification of bone marrow

Science.gov (United States)

Jindra, Peter T.; Tripathi, Sudipta; Tian, Chaorui; Iacomini, John; Bagley, Jessamyn

2012-01-01

Induction of molecular chimerism through genetic modification of bone marrow is a powerful tool for the induction of tolerance. Here we demonstrate for the first time that expression of an allogeneic MHC class II gene in autologous bone marrow cells, resulting in a state of molecular chimerism, induces tolerance to MHC class II mismatched skin grafts, a stringent test of transplant tolerance. Reconstitution of recipients with syngeneic bone marrow transduced with retrovirus encoding H-2I-Ab (I-Ab) resulted the long-term expression of the retroviral gene product on the surface of MHC class II-expressing bone marrow derived cell types. Mechanistically, tolerance was maintained by the presence of regulatory T cells, which prevented proliferation and cytokine production by alloreactive host T cells. Thus, the introduction of MHC class II genes into bone marrow derived cells through genetic engineering results in tolerance. These results have the potential to extend the clinical applicability of molecular chimerism for tolerance induction. PMID:22833118

Sensor-driven, fault-tolerant control of a maintenance robot

International Nuclear Information System (INIS)

Moy, M.M.; Davidson, W.M.

1987-01-01

A robot system has been designed to do routine maintenance tasks on the Sandia Pulsed Reactor (SPR). The use of this Remote Maintenance Robot (RMR) is expected to significantly reduce the occupational radiation exposure of the reactor operators. Reactor safety was a key issue in the design of the robot maintenance system. Using sensors to detect error conditions and intelligent control to recover from the errors, the RMR is capable of responding to error conditions without creating a hazard. This paper describes the design and implementation of a sensor-driven, fault-tolerant control for the RMR. Recovery from errors is not automatic; it does rely on operator assistance. However, a key feature of the error recovery procedure is that the operator is allowed to reenter the programmed operation after the error has been corrected. The recovery procedure guarantees that the moving components of the system will not collide with the reactor during recovery

Development and implementation of the regulatory control of sources in Latin American Model Project countries

International Nuclear Information System (INIS)

Ferruz Cruz, P.

2001-01-01

After a general assessment of the situation regarding radiation safety and the radiation protection infrastructure in Latin American countries, several of them were invited to participate in a Model Project oriented, in some cases, towards establishing a mechanism for national regulatory control of radiation sources, and in others, towards upgrading their national control programme. All these activities aimed at reaching an effective and sustainable radiation protection infrastructure based on international basic safety standards. The paper presents a general overview of the current situation with regard to radiation protection within the Model Project countries in Latin America after almost five years of activities. It includes: the implementation of regulatory issues; the control of occupational, medical and public exposures; emergency response and waste safety issues. The paper also presents some lessons learned during implementation concerning the numerous activities involved in this interregional project. (author)

Key Regulatory Issues for Digital Instrumentation and Control Systems at Nuclear Power Plants

International Nuclear Information System (INIS)

Korsah, Kofi; Wood, Richard Thomas

2008-01-01

To help reduce the uncertainty associated with application of digital instrumentation and controls (I and C) technology in nuclear power plants, the Nuclear Regulatory Commission (NRC) has issued six Interim Staff Guidance (ISG) documents that address the current regulatory positions on what are considered the significant digital I and C issues. These six documents address the following topics: Cyber Security, Diversity and Defense-in-Depth, Risk Informed Digital I and C Regulation, Communication issues, Human Factors and the Digital I and C Licensing Process (currently issued as Draft). After allowing for further refinement based on additional technical insight gathered by NRC staff through near-term research and detailed review of relevant experience, it is expected that updated positions ultimately will be incorporated into regulatory guides and staff review procedures. This paper presents an overview of the guidance provided by the NRC-issued ISGs on key technology considerations (i.e., the first five documents above) for safety-related digital I and C systems.

Environment and T regulatory cells in allergy.

Science.gov (United States)

Braga, M; Schiavone, C; Di Gioacchino, G; De Angelis, I; Cavallucci, E; Lazzarin, F; Petrarca, C; Di Gioacchino, M

2012-04-15

The central role of T regulatory cells in the responses against harmless environmental antigens has been confirmed by many studies. Impaired T regulatory cell function is implicated in many pathological conditions, particularly allergic diseases. The "hygiene hypothesis" suggests that infections and infestations may play a protective role for allergy, whereas environmental pollutants favor the development of allergic diseases. Developing countries suffer from a variety of infections and are also facing an increasing diffusion of environmental pollutants. In these countries allergies increase in relation to the spreading use of xenobiotics (pesticides, herbicides, pollution, etc.) with a rate similar to those of developed countries, overcoming the protective effects of infections. We review here the main mechanisms of non-self tolerance, with particular regard to relations between T regulatory cell activity, infections and infestations such as helminthiasis, and exposure to environmental xenobiotics with relevant diffusion in developing countries. Copyright © 2010 Elsevier B.V. All rights reserved.

Regulatory T cells: immune suppression and beyond

OpenAIRE

Wan, Yisong Y

2010-01-01

Foxp3-expressing regulatory T cells (Tregs) were originally identified as critical in maintaining self-tolerance and immune homeostasis. The immunosuppressive functions of Tregs are widely acknowledged and have been extensively studied. Recent studies have revealed many diverse roles of Tregs in shaping the immune system and the inflammatory response. This review will discuss our efforts as well as the efforts of others towards understanding the multifaceted function of Treg...

IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

Science.gov (United States)

Tran, Giang T; Hodgkinson, Suzanne J; Carter, Nicole M; Verma, Nirupama D; Plain, Karren M; Boyd, Rochelle; Robinson, Catherine M; Nomura, Masaru; Killingsworth, Murray; Hall, Bruce M

2012-05-10

Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

International Nuclear Information System (INIS)

1997-11-01

The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference

Core Transcriptional Regulatory Circuit Controlled by the TAL1 Complex in Human T Cell Acute Lymphoblastic Leukemia

OpenAIRE

Sanda, Takaomi; Lawton, Lee N.; Barrasa, M. Inmaculada; Fan, Zi Peng; Kohlhammer, Holger; Gutierrez, Alejandro; Ma, Wenxue; Tatarek, Jessica; Ahn, Yebin; Kelliher, Michelle A.; Jamieson, Catriona H.M.; Staudt, Louis M.; Young, Richard A.; Look, A. Thomas

2012-01-01

The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T-cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3 and RUNX1. We show that TAL1 forms a positive interconnected auto-regulatory loop with GATA3 and RUNX1, and that the TAL1 complex directly activates the MY...

A balance of activity in brain control and reward systems predicts self-regulatory outcomes

OpenAIRE

Lopez, Richard B.; Chen, Pin-Hao A.; Huckins, Jeremy F.; Hofmann, Wilhelm; Kelley, William M.; Heatherton, Todd F.

2017-01-01

Abstract Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily lif...

Artificial sweeteners and mixture of food additives cause to break oral tolerance and induce food allergy in murine oral tolerance model for food allergy.

Science.gov (United States)

Yamashita, H; Matsuhara, H; Miotani, S; Sako, Y; Matsui, T; Tanaka, H; Inagaki, N

2017-09-01

Processed foods are part of daily life. Almost all processed foods contain food additives such as sweeteners, preservatives and colourants. From childhood, it is difficult to avoid consuming food additives. It is thought that oral tolerance for food antigens is acquired during early life. If tolerance fails, adverse immune responses to food proteins may occur. We hypothesized that food additives prevent acquisition of oral tolerance and aimed to verify the safety of food additives. We induced experimental oral tolerance in mice for ovalbumin (OVA), a food antigen, by previous oral treatment with OVA before sensitization with OVA injections. Food additives were administered at the induction of oral tolerance, and food allergy was induced by repeated administration of OVA. Symptoms of food allergy were defined as a change in body temperature and allergic diarrhoea. Saccharin sodium and a mixture of food additives inhibited acquisition of oral tolerance. Hypothermia and allergic diarrhoea with elevation of OVA-specific IgE were induced in the murine model of oral tolerance. Analyses of antigen-presenting cells in mesenteric lymph nodes showed that food additives affected their manner of migration. Additionally, food additives decreased the proportion of CD25 hi regulatory T cells among CD4 + T cells in the mesenteric lymph nodes. A large amount of food additives may prevent acquisition of oral tolerance. Intake of food additives in early life may increase the risk of food allergies. © 2017 John Wiley & Sons Ltd.

Fault-tolerant Control of Discrete-time LPV systems using Virtual Actuators and Sensors

DEFF Research Database (Denmark)

Tabatabaeipour, Mojtaba; Stoustrup, Jakob; Bak, Thomas

2015-01-01

This paper proposes a new fault-tolerant control (FTC) method for discrete-time linear parameter varying (LPV) systems using a reconfiguration block. The basic idea of the method is to achieve the FTC goal without re-designing the nominal controller by inserting a reconfiguration block between......, it transforms the output of the controller for the faulty system such that the stability and performance goals are preserved. Input-to-state stabilizing LPV gains of the virtual actuator and sensor are obtained by solving linear matrix inequalities (LMIs). We show that separate design of these gains guarantees....... Finally, the effectiveness of the method is demonstrated via a numerical example and stator current control of an induction motor....

Deciphering the genetic regulatory code using an inverse error control coding framework.

Energy Technology Data Exchange (ETDEWEB)

Rintoul, Mark Daniel; May, Elebeoba Eni; Brown, William Michael; Johnston, Anna Marie; Watson, Jean-Paul

2005-03-01

We have found that developing a computational framework for reconstructing error control codes for engineered data and ultimately for deciphering genetic regulatory coding sequences is a challenging and uncharted area that will require advances in computational technology for exact solutions. Although exact solutions are desired, computational approaches that yield plausible solutions would be considered sufficient as a proof of concept to the feasibility of reverse engineering error control codes and the possibility of developing a quantitative model for understanding and engineering genetic regulation. Such evidence would help move the idea of reconstructing error control codes for engineered and biological systems from the high risk high payoff realm into the highly probable high payoff domain. Additionally this work will impact biological sensor development and the ability to model and ultimately develop defense mechanisms against bioagents that can be engineered to cause catastrophic damage. Understanding how biological organisms are able to communicate their genetic message efficiently in the presence of noise can improve our current communication protocols, a continuing research interest. Towards this end, project goals include: (1) Develop parameter estimation methods for n for block codes and for n, k, and m for convolutional codes. Use methods to determine error control (EC) code parameters for gene regulatory sequence. (2) Develop an evolutionary computing computational framework for near-optimal solutions to the algebraic code reconstruction problem. Method will be tested on engineered and biological sequences.

Fault tolerant control with torque limitation based on fault mode for ten-phase permanent magnet synchronous motor

Directory of Open Access Journals (Sweden)

Guo Hong

2015-10-01

Full Text Available This paper proposes a novel fault tolerant control with torque limitation based on the fault mode for the ten-phase permanent magnet synchronous motor (PMSM under various open-circuit and short-circuit fault conditions, which includes the optimal torque control and the torque limitation control based on the fault mode. The optimal torque control is adopted to guarantee the ripple-free electromagnetic torque operation for the ten-phase motor system under the post-fault condition. Furthermore, we systematically analyze the load capacity of the ten-phase motor system under different fault modes. And a torque limitation control approach based on the fault mode is proposed, which was not available earlier. This approach is able to ensure the safety operation of the faulted motor system in long operating time without causing the overheat fault. The simulation result confirms that the proposed fault tolerant control for the ten-phase motor system is able to guarantee the ripple-free electromagnetic torque and the safety operation in long operating time under the normal and fault conditions.

Technical and regulatory challenges for digital instrumentation and control and control room systems in nuclear plants

International Nuclear Information System (INIS)

Torok, R.; Naser, J.; Harris, T.; Keithline, K.

2006-01-01

There are several unsettled technical and licensing issues in the areas of instrumentation and control (I and C), human factors, and updated control room designs that need coordinated, proactive industry attention. Some of these issues are already causing protracted regulatory reviews for existing plants, and left untreated, may cause substantial delays and increased costs for new plant combined construction and operating license approvals. Both industry and the NRC will have roles in resolving the key issues and addressing them in future design efforts and regulatory reviews. Where action is needed, the industry will want to minimize costs and risks by defining industry consensus solutions with corresponding technical bases. NEI has formed a working group to coordinate industry efforts and communications with NRC staff. The working group will also help determine priorities and coordinate both new and existing plant resources. EPRI will provide technical input and guidance for the working group. In order to be able to conduct reviews in a timely fashion, the NRC will likely need to enhance and expand staff resources as existing plants are upgraded and new plant reviews become more active. The industry initiative began with a workshop sponsored by EPRI and NEI on March 28-29, 2006, which led to the creation of the NEI working group. The working group has now identified and prioritized important generic issues, established resolution paths and schedules, and identified the roles of various stakeholders including utility companies, EPRI, NEI, vendors and the NRC. Through the course of this initiative I and C issues for both existing and new plants are being addressed. This paper describes the key I and C related technical and regulatory issues and their implications for new and operating plants, and provides a status report on the efforts to resolve them. (authors)

Fault-tolerant design of adaptive digital control systems for power plant components

International Nuclear Information System (INIS)

Parlos, A.G.; Menon, S.K.

1992-01-01

An adaptive controller has been designed for the water level of a Westinghouse type U-tube steam generator, and its operation has been demonstrated in the entire power range via computer simulations. The proposed design exhibits improved performance, at low operating powers, a,s compared to existing controller types. The continuous-time controller design is performed systematically via the Linear Quadratic Gaussian/Loop Transfer Recovery method, followed by gain adaptation allowing controller operation in the entire power range. Digital implementation of the controller is accomplished by a digital redesign which results in matching the digital and continuous-time system and controller states. It is only at this stage of the control system design process that issues such as microprocessor induced quantization effects are taken into account. The use of computer-aided-design software greatly expedites the design cycle, allowing the designer to maximize the controller stability robustness to uncertainties via numerous iterations. This inherent controller robustness can be exploited to tolerate incipient plant faults, such as deteriorating U-tube heat transfer properties, without significant loss of controller performance

1985 seminar on power plant digital control and fault-tolerant microcomputers: proceedings

International Nuclear Information System (INIS)

Divakaruni, S.M.

1986-09-01

An EPRI Seminar to address Power Plant Digital Controls and Fault-Tolerant Microcomputers Technology was hosted by Arizona Public Service Company in Phoenix, Arizona on April 9-12, 1986. The attendees represented a broad spectrum of US and foreign utilities, architect and consulting firms, and NSSS and computer system hardware vendors. These proceedings contain the text of the formal presentations as well as the papers and slides used during the short courses offered

Fault Diagnosis and Fault-Tolerant Control of Wind Turbines via a Discrete Time Controller with a Disturbance Compensator

Directory of Open Access Journals (Sweden)

Yolanda Vidal

2015-05-01

Full Text Available This paper develops a fault diagnosis (FD and fault-tolerant control (FTC of pitch actuators in wind turbines. This is accomplished by combining a disturbance compensator with a controller, both of which are formulated in the discrete time domain. The disturbance compensator has a dual purpose: to estimate the actuator fault (which is used by the FD algorithm and to design the discrete time controller to obtain an FTC. That is, the pitch actuator faults are estimated, and then, the pitch control laws are appropriately modified to achieve an FTC with a comparable behavior to the fault-free case. The performance of the FD and FTC schemes is tested in simulations with the aero-elastic code FAST.

Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-11-01

The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference. Refs, figs, tabs.

Perspectives on Regulatory T Cell Therapies

OpenAIRE

Probst-Kepper, Michael; Kröger, Andrea; Garritsen, Henk S.P.; Buer, Jan

2009-01-01

Adoptive transfer in animal models clearly indicate an essential role of CD4+ CD25+ FOXP3+ regulatory T (Treg) cells in prevention and treatment of autoimmune and graft-versus-host disease. Thus, Treg cell therapies and development of drugs that specifically enhance Treg cell function and development represent promising tools to establish dominant tolerance. So far, lack of specific markers to differentiate human Treg cells from activated CD4+ CD25+ effector T cells, which also express FOXP3 ...

Output Information Based Fault-Tolerant Iterative Learning Control for Dual-Rate Sampling Process with Disturbances and Output Delay

Directory of Open Access Journals (Sweden)

Hongfeng Tao

2018-01-01

Full Text Available For a class of single-input single-output (SISO dual-rate sampling processes with disturbances and output delay, this paper presents a robust fault-tolerant iterative learning control algorithm based on output information. Firstly, the dual-rate sampling process with output delay is transformed into discrete system in state-space model form with slow sampling rate without time delay by using lifting technology; then output information based fault-tolerant iterative learning control scheme is designed and the control process is turned into an equivalent two-dimensional (2D repetitive process. Moreover, based on the repetitive process stability theory, the sufficient conditions for the stability of system and the design method of robust controller are given in terms of linear matrix inequalities (LMIs technique. Finally, the flow control simulations of two flow tanks in series demonstrate the feasibility and effectiveness of the proposed method.

15 CFR 750.11 - Shipping tolerances.

Science.gov (United States)

2010-01-01

... in the ECCN applicable to your item reads “ $ value” or “in $ value”, there is no shipping tolerance... is no shipping tolerance with respect to the number of units. However, the value of all of your... shipping tolerance on this license because the items are controlled by an ECCN where “$ value” is the...

Supervisory Fault Tolerant Control of the GTM UAV Using LPV Methods

Directory of Open Access Journals (Sweden)

Péni Tamás

2015-03-01

Full Text Available A multi-level reconfiguration framework is proposed for fault tolerant control of over-actuated aerial vehicles, where the levels indicate how much authority is given to the reconfiguration task. On the lowest, first level the fault is accommodated by modifying only the actuator/sensor configuration, so the fault remains hidden from the baseline controller. A dynamic reallocation scheme is applied on this level. The allocation mechanism exploits the actuator/sensor redundancy available on the aircraft. When the fault cannot be managed at the actuator/sensor level, the reconfiguration process has access to the baseline controller. Based on the LPV control framework, this is done by introducing fault-specific scheduling parameters. The baseline controller is designed to provide an acceptable performance level along all fault scenarios coded in these scheduling variables. The decision on which reconfiguration level has to be initiated in response to a fault is determined by a supervisor unit. The method is demonstrated on a full six-degrees-of-freedom nonlinear simulation model of the GTM UAV.

[CD4 + CD25 + regulatory T cells and their importance to human illnesses].

Science.gov (United States)

Kelsen, Jens; Hvas, Christian Lodberg; Agnholt, Jørgen; Dahlerup, Jens F

2006-01-03

Regulatory T cells ensure a balanced immune response that is competent both to fight pathogens, at the same time, to recognize self-antigens and commensals as harmless. Regulatory mechanisms are essential in preventing autoimmune disorders but may also facilitate the progression of malignant diseases and the establishment of latent infections via suppression of the host immune response. Regulatory T cells arise in the thymus, and regulatory T cell function can be induced in the periphery, so-called infectious tolerance. An absolute or relative defect in regulatory T cell function may contribute to the development of autoimmune disorders such as rheumatoid arthritis, type 1 diabetes mellitus, multiple sclerosis and chronic inflammatory bowel disease. Regulatory T cell therapy is a tempting strategy for reestablishing the immune balance and thus preventing or reversing these disorders. Reestablishment of the immune balance may be accomplished by adoptive transfer of ex vivo-propagated regulatory T cells or by induction of regulatory functions locally in the organs, although such strategies are in their infancy in human research.

Neural correlates of preparatory and regulatory control over positive and negative emotion.

Science.gov (United States)

Seo, Dongju; Olman, Cheryl A; Haut, Kristen M; Sinha, Rajita; MacDonald, Angus W; Patrick, Christopher J

2014-04-01

This study used functional magnetic resonance imaging to investigate brain activation during preparatory and regulatory control while participants (N = 24) were instructed either to simply view or decrease their emotional response to, pleasant, neutral or unpleasant pictures. A main effect of emotional valence on brain activity was found in the right precentral gyrus, with greater activation during positive than negative emotion regulation. A main effect of regulation phase was evident in the bilateral anterior prefrontal cortex (PFC), precuneus, posterior cingulate cortex, right putamen and temporal and occipital lobes, with greater activity in these regions during preparatory than regulatory control. A valence X regulation interaction was evident in regions of ventromedial PFC and anterior cingulate cortex, reflecting greater activation while regulating negative than positive emotion, but only during active emotion regulation (not preparation). Conjunction analyses revealed common brain regions involved in differing types of emotion regulation including selected areas of left lateral PFC, inferior parietal lobe, temporal lobe, right cerebellum and bilateral dorsomedial PFC. The right lateral PFC was additionally activated during the modulation of both positive and negative valence. Findings demonstrate significant modulation of brain activity during both preparation for, and active regulation of positive and negative emotional states.

THE ROLE OF SELF-REGULATORY AUDITING ASSOCIATIONS IN ARRANGEMENT OF AUDIT ACTIVITIES QUALITY CONTROL

Directory of Open Access Journals (Sweden)

Zinaida P. Arharova

2013-01-01

Full Text Available The role of self-regulatory organizations in audit activities quality control is revealed in this article. Creation of a united audit association is the basis of certain regulating and auditing functions transfer from the government to the public sector.

Effects of methadone hydrochloride on the growth of organotypic cerebellar cultures prepared from methadone-tolerant and control rats.

Science.gov (United States)

Willson, N J; Schneider, J F; Roizin, L; Fleiss, J F; Rivers, W; Demartini, J E

1976-11-01

Male and female Sprague-Dawley rats were given dl-methadone (5 mg/kg) for at least 3 months and then mated. The drug was continued throughout pregnancy and after delivery. The newly born pups were divided into two groups. One group was tested for in vivo methadone tolerance, while the animals in the othergroup were used to prepare organotypic cerebellar cultures. Various amounts of dl-methadone were added to the media of half of these cerebellum cultures. The effect of the drug in the medium was assessed by measuring explant outgrowth. Similar experiments were carried out with control animals. Statistical analysis of the data obtained in the in vivo portion of the experiment indicates that the pups of methadone-treated mothers tolerate methadone better than those of untreated mothers. The culture experiments revealed that the addition of methadone to the medium reduced explant outgrowth size and this was a dose-related effect. Also, there was significantly less outgrowth from explants prepared using pups of methadone-treated mothers as compared to the controls. There was no significant difference in the effect of methadone on the growth of cultures prepared from the methadone-tolerant and control animals.

A hybrid robust fault tolerant control based on adaptive joint unscented Kalman filter.

Science.gov (United States)

Shabbouei Hagh, Yashar; Mohammadi Asl, Reza; Cocquempot, Vincent

2017-01-01

In this paper, a new hybrid robust fault tolerant control scheme is proposed. A robust H ∞ control law is used in non-faulty situation, while a Non-Singular Terminal Sliding Mode (NTSM) controller is activated as soon as an actuator fault is detected. Since a linear robust controller is designed, the system is first linearized through the feedback linearization method. To switch from one controller to the other, a fuzzy based switching system is used. An Adaptive Joint Unscented Kalman Filter (AJUKF) is used for fault detection and diagnosis. The proposed method is based on the simultaneous estimation of the system states and parameters. In order to show the efficiency of the proposed scheme, a simulated 3-DOF robotic manipulator is used. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Fault-Tolerant Region-Based Control of an Underwater Vehicle with Kinematically Redundant Thrusters

Directory of Open Access Journals (Sweden)

Zool H. Ismail

2014-01-01

Full Text Available This paper presents a new control approach for an underwater vehicle with a kinematically redundant thruster system. This control scheme is derived based on a fault-tolerant decomposition for thruster force allocation and a region control scheme for the tracking objective. Given a redundant thruster system, that is, six or more pairs of thrusters are used, the proposed redundancy resolution and region control scheme determine the number of thruster faults, as well as providing the reference thruster forces in order to keep the underwater vehicle within the desired region. The stability of the presented control law is proven in the sense of a Lyapunov function. Numerical simulations are performed with an omnidirectional underwater vehicle and the results of the proposed scheme illustrate the effectiveness in terms of optimizing the thruster forces.

Intelligent on-line fault tolerant control for unanticipated catastrophic failures.

Science.gov (United States)

Yen, Gary G; Ho, Liang-Wei

2004-10-01

As dynamic systems become increasingly complex, experience rapidly changing environments, and encounter a greater variety of unexpected component failures, solving the control problems of such systems is a grand challenge for control engineers. Traditional control design techniques are not adequate to cope with these systems, which may suffer from unanticipated dynamic failures. In this research work, we investigate the on-line fault tolerant control problem and propose an intelligent on-line control strategy to handle the desired trajectories tracking problem for systems suffering from various unanticipated catastrophic faults. Through theoretical analysis, the sufficient condition of system stability has been derived and two different on-line control laws have been developed. The approach of the proposed intelligent control strategy is to continuously monitor the system performance and identify what the system's current state is by using a fault detection method based upon our best knowledge of the nominal system and nominal controller. Once a fault is detected, the proposed intelligent controller will adjust its control signal to compensate for the unknown system failure dynamics by using an artificial neural network as an on-line estimator to approximate the unexpected and unknown failure dynamics. The first control law is derived directly from the Lyapunov stability theory, while the second control law is derived based upon the discrete-time sliding mode control technique. Both control laws have been implemented in a variety of failure scenarios to validate the proposed intelligent control scheme. The simulation results, including a three-tank benchmark problem, comply with theoretical analysis and demonstrate a significant improvement in trajectory following performance based upon the proposed intelligent control strategy.

Neuroadaptive Fault-Tolerant Control of Nonlinear Systems Under Output Constraints and Actuation Faults.

Science.gov (United States)

Zhao, Kai; Song, Yongduan; Shen, Zhixi

2018-02-01

In this paper, a neuroadaptive fault-tolerant tracking control method is proposed for a class of time-delay pure-feedback systems in the presence of external disturbances and actuation faults. The proposed controller can achieve prescribed transient and steady-state performance, despite uncertain time delays and output constraints as well as actuation faults. By combining a tangent barrier Lyapunov-Krasovskii function with the dynamic surface control technique, the neural network unit in the developed control scheme is able to take its action from the very beginning and play its learning/approximating role safely during the entire system operational envelope, leading to enhanced control performance without the danger of violating compact set precondition. Furthermore, prescribed transient performance and output constraints are strictly ensured in the presence of nonaffine uncertainties, external disturbances, and undetectable actuation faults. The control strategy is also validated by numerical simulation.

Comparing genomes to computer operating systems in terms of the topology and evolution of their regulatory control networks.

Science.gov (United States)

Yan, Koon-Kiu; Fang, Gang; Bhardwaj, Nitin; Alexander, Roger P; Gerstein, Mark

2010-05-18

The genome has often been called the operating system (OS) for a living organism. A computer OS is described by a regulatory control network termed the call graph, which is analogous to the transcriptional regulatory network in a cell. To apply our firsthand knowledge of the architecture of software systems to understand cellular design principles, we present a comparison between the transcriptional regulatory network of a well-studied bacterium (Escherichia coli) and the call graph of a canonical OS (Linux) in terms of topology and evolution. We show that both networks have a fundamentally hierarchical layout, but there is a key difference: The transcriptional regulatory network possesses a few global regulators at the top and many targets at the bottom; conversely, the call graph has many regulators controlling a small set of generic functions. This top-heavy organization leads to highly overlapping functional modules in the call graph, in contrast to the relatively independent modules in the regulatory network. We further develop a way to measure evolutionary rates comparably between the two networks and explain this difference in terms of network evolution. The process of biological evolution via random mutation and subsequent selection tightly constrains the evolution of regulatory network hubs. The call graph, however, exhibits rapid evolution of its highly connected generic components, made possible by designers' continual fine-tuning. These findings stem from the design principles of the two systems: robustness for biological systems and cost effectiveness (reuse) for software systems.

Regulatory B and T cell responses in patients with autoimmune thyroid disease and healthy controls

DEFF Research Database (Denmark)

Kristensen, Birte

2016-01-01

Autoimmune diseases occur due to faulty self-tolerance. Graves' disease (GD) and Hashimoto's thyroiditis (HT) are classic examples of organ-specific autoimmune diseases. GD is an auto-antibody-mediated disease where autoantibodies are produced against the thyroid stimulating hormone receptor (TSHR...... (Bregs) and regulatory T cells (Tregs) were investigated in the context of GD and HT. First, we studied the role of the thyroid self-antigen, thyroglobulin (TG) in healthy donors. The self-antigen TG, but not the foreign recall antigen tetanus toxoid (TT), was able to induce interleukin 10 (IL-10......) secretion by B cells and CD4+ T cells. These IL-10 producing B cells (B10 cells) from healthy donors were enriched with the CD5+ and CD24hi phenotype. In addition, TG was able to induce IL-6 production by B cells. In contrast, TT induced production of Th1-type pro-inflammatory cytokines including interferon...

Monitoring control program as a tool for regulatory control

International Nuclear Information System (INIS)

Silva Peres, Sueli da; Lauria, Dejanaira C.; Martins, Nadia S.F.; Rio, Monica A.P.

2008-01-01

Full text: The Institute of Radiation Protection and Dosimetry (IRD) of the Brazilian Commission of Nuclear Energy (CNEN) is responsible for developing, establishing and carrying out an independent assessment to verify the adequacy, effectiveness and accuracy of environmental radiological control carried out by licensed and controlled facilities. This independent assessment is performed by Environmental Monitoring Control Program (MCP). The MCP is a regulatory control and its main goal is to provide public and environment with an appropriate protection level against harmful effects of ionising radiation. The main purpose of the MCP is to verify whether applicable requirements prescribed by legislation are met, the environmental radiological control of the facilities are adequate and effective and the facilities are able to generate valid measuring results. The MCP is carried out in order to evaluate the quality of environmental radiation monitoring programs (EMP) and the effectiveness of their implementation, sampling conditions in the field, changes of environmental aspects in the impact area, adequacy of and adherence to procedures established and other applicable documents, technical competence of the staff and the necessary resources to ensure the required quality of the EMP. The MCP has been performed by activities should include inspecting and auditing of several types of nuclear and radioactive facilities. The inspection programme include the joint sampling program (CCP). The aim of the CCP is to check data of environmental monitoring of operator. The MCP was implemented in 1994. Ever since several problems related to the environmental control performed by operator was identified. The most important of them include problems related to the preparation and analysis of environmental samples, training of personnel, necessary resources, adherence of procedures to the purpose of the monitoring, fulfillment of procedures established, adequacy of the EMP and EMP

International principles for exemption from regulatory control and their application to waste management

International Nuclear Information System (INIS)

Linsley, G.S.

1989-01-01

This paper describes the main features of the international consensus on principles for exempting radiation sources and practices from regulatory control reached at a meeting in Vienna in March 1988. Some remaining problems, both of a philosophical and technical nature especially related to the application of the principles to radioactive waste disposal, are discussed

Predictors of Immunosuppressive Regulatory T Lymphocytes in Healthy Women

International Nuclear Information System (INIS)

Hampras, S. S.; Nesline, M.; Davis, W.; Moysich, K. B.; Wallace, P. K.; Odunsi, K.; Furlani, N.

2012-01-01

Immunosuppressive regulatory T (Treg) cells play an important role in antitumor immunity, self-tolerance, transplantation tolerance, and attenuation of allergic response. Higher proportion of Treg cells has been observed in peripheral blood of cancer cases compared to controls. Little is known about potential epidemiological predictors of Treg cell levels in healthy individuals. We conducted a cross-sectional study including 75 healthy women, between 20 and 80 years of age, who participated in the Data Bank and Bio Repository (DBBR) program at Roswell Park Cancer Institute (RPCI), Buffalo, NY, USA. Peripheral blood levels of CD4 + CD25 + FOXP3 + Treg cells were measured using flow cytometric analysis. A range of risk factors was evaluated using Wilcoxon Rank-Sum test, Kruskal-Wallis test, and linear regression. Age, smoking, medications for treatment of osteoporosis, postmenopausal status, body mass index (BMI), and hormone replacement therapy (HRT) were found to be significant positive predictors of Treg cell levels in peripheral blood (π≤0.05 ). Higher education, exercise, age at first birth, oral contraceptives, and use of Ibuprofen were found be significant (π<0.05) negative predictors of Treg levels. Thus, various epidemiological risk factors might explain interindividual variation in immune response to pathological conditions, including cancer.

Regulatory T cells in radiotherapeutic responses

Directory of Open Access Journals (Sweden)

Dörthe eSchaue

2012-08-01

Full Text Available Radiation therapy (RT can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling danger. The multiple mechanisms that can be evoked include a shift towards a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs, suppressor macrophages and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the brakes on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer.

Regulatory T Cells in Radiotherapeutic Responses

International Nuclear Information System (INIS)

Schaue, Dörthe; Xie, Michael W.; Ratikan, Josephine A.; McBride, William H.

2012-01-01

Radiation therapy (RT) can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling “danger.” The multiple mechanisms that can be evoked include a shift toward a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs), suppressor macrophages, and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the “brakes” on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer.

Distributed fault-tolerant time-varying formation control for high-order linear multi-agent systems with actuator failures.

Science.gov (United States)

Hua, Yongzhao; Dong, Xiwang; Li, Qingdong; Ren, Zhang

2017-11-01

This paper investigates the fault-tolerant time-varying formation control problems for high-order linear multi-agent systems in the presence of actuator failures. Firstly, a fully distributed formation control protocol is presented to compensate for the influences of both bias fault and loss of effectiveness fault. Using the adaptive online updating strategies, no global knowledge about the communication topology is required and the bounds of actuator failures can be unknown. Then an algorithm is proposed to determine the control parameters of the fault-tolerant formation protocol, where the time-varying formation feasible conditions and an approach to expand the feasible formation set are given. Furthermore, the stability of the proposed algorithm is proven based on the Lyapunov-like theory. Finally, two simulation examples are given to demonstrate the effectiveness of the theoretical results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Tolerance Verification of Micro and Nano Structures on Polycarbonate Substrates

DEFF Research Database (Denmark)

Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

2010-01-01

Micro and nano structures are an increasing challenge in terms of tolerance verification and process quality control: smaller dimensions led to a smaller tolerance zone to be evaluated. This paper focuses on the verification of CD, DVD and HD-DVD nanoscale features. CD tolerance features are defi......Micro and nano structures are an increasing challenge in terms of tolerance verification and process quality control: smaller dimensions led to a smaller tolerance zone to be evaluated. This paper focuses on the verification of CD, DVD and HD-DVD nanoscale features. CD tolerance features...

Research and regulatory review

International Nuclear Information System (INIS)

Macleod, J.S.; Fryer, D.R.H.

1979-01-01

To enable the regulatory review to be effectively undertaken by the regulatory body, there is a need for it to have ready access to information generated by research activities. Certain advantages have been seen to be gained by the regulatory body itself directly allocating and controlling some portion of these activities. The princial reasons for reaching this conclusion are summarised and a brief description of the Inspectorates directly sponsored programme outlined. (author)

Adaptive Fault-Tolerant Tracking Control of Nonaffine Nonlinear Systems with Actuator Failure

Directory of Open Access Journals (Sweden)

Hongcheng Zhou

2014-01-01

Full Text Available This paper proposes an adaptive fault-tolerant control scheme for nonaffine nonlinear systems. A model approximation method which is a solution that bridges the gap between affine and nonaffine control systems is developed firstly. A joint estimation approach is based on unscented Kalman filter, in which both failure parameters and states are simultaneously estimated by means of the argument state vector composed of the unknown faults and states. Then, stability analysis is given for the closed-loop system. Finally, the proposed approach is verified using a three-degree-of-freedom simulation of a typical fighter aircraft and the significantly improved system response demonstrates the practical potential of the theoretic results obtained.

Enforcement of radiation safety standards and experience in the regulatory control of exposures

International Nuclear Information System (INIS)

Krishnamurthi, T.N.

1997-01-01

Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author)

Soybean Salt Tolerance 1 (GmST1) Reduces ROS Production, Enhances ABA Sensitivity, and Abiotic Stress Tolerance in Arabidopsis thaliana.

Science.gov (United States)

Ren, Shuxin; Lyle, Chimera; Jiang, Guo-Liang; Penumala, Abhishek

2016-01-01

Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative reverse transcription-polymerase chain reaction analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1 kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops.

Soybean salt tolerance 1 (GmST1 reduces ROS production, enhances ABA sensitivity and abiotic stress tolerance in Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Shuxin eRen

2016-04-01

Full Text Available Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species (ROS under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative RT-PCR analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops.

Regulatory perspective on digital instrumentation and control systems for future advanced nuclear power plants

International Nuclear Information System (INIS)

Chiramal, M.

1993-01-01

This paper deals with the question of using digital technology in instrumentation and control systems for modern nuclear power reactors. The general opinion in the industry and among NRC staff is that such technology provides the opportunity for enhanced safety and reliable reactor operations. The major concern is the safe application of this technology so as to avoid common mode or common cause failures in systems. There are great differences between digital and analog system components. SECY-91-292 identifies some general regulatory concerns with regard to digital systems. There is clearly a lack of adequate regulatory direction on the application of digital equipment at this time, but the issue is being addressed by the industry, outside experts, and NRC staff. NRC staff presents a position on the issue of defense-in-depth and diversity with regard to insuring plant safety. Independent manual controls and readouts must be available to allow safe shutdown and monitoring of the plant in the event of safety system failures

Nuclear Security Recommendations on Nuclear and other Radioactive Material out of Regulatory Control: Recommendations (Spanish Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication presents recommendations for the nuclear security of nuclear and other radioactive material that is out of regulatory control. It is based on national experiences and practices and guidance publications in the field of security as well as the nuclear security related international instruments. The recommendations include guidance for States with regard to the nuclear security of nuclear and other radioactive material that has been reported as being out of regulatory control as well as for material that is lost, missing or stolen but has not been reported as such, or has been otherwise discovered. In addition, these recommendations adhere to the detection and assessment of alarms and alerts and to a graded response to criminal or unauthorized acts with nuclear security implications.

Nuclear Security Recommendations on Nuclear and Other Radioactive Material out of Regulatory Control: Recommendations (Arabic Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication presents recommendations for the nuclear security of nuclear and other radioactive material that is out of regulatory control. It is based on national experiences and practices and guidance publications in the ? field of security as well as the nuclear security related international instruments. The recommendations include guidance for States with regard to the nuclear security of nuclear and other radioactive material that has been reported as being out of regulatory control as well as for material that is lost, missing or stolen but has not been reported as such, or has been otherwise discovered. In addition, these recommendations adhere to the detection and assessment of alarms and alerts and to a graded response to criminal or unauthorized acts with nuclear security implications.

Nuclear Security Recommendations on Nuclear and Other Radioactive Material out of Regulatory Control: Recommendations (Russian Edition)

International Nuclear Information System (INIS)

2011-01-01

This publication presents recommendations for the nuclear security of nuclear and other radioactive material that is out of regulatory control. It is based on national experiences and practices and guidance publications in the field of security as well as the nuclear security related international instruments. The recommendations include guidance for States with regard to the nuclear security of nuclear and other radioactive material that has been reported as being out of regulatory control as well as for material that is lost, missing or stolen but has not been reported as such, or has been otherwise discovered. In addition, these recommendations adhere to the detection and assessment of alarms and alerts and to a graded response to criminal or unauthorized acts with nuclear security implications.

Congestion control for vehicular delay tolerant network routing protocols

OpenAIRE

Oham, Chuka Finbars

2014-01-01

The Vehicular Delay Tolerant Network (VDTN) is a special and challenging type of the Delay Tolerant Network because of its high mobility, frequent disconnections and nodal congestion features. These challenging features make it prone to congestion which leads to a considerable amount of message drops in the network. To minimize the impact of congestion in the network, we designed and implemented the Congestion Aware Spray and Wait (CASaW) routing protocol. We varied the buffer sizes of the no...

On the Interplay between Entropy and Robustness of Gene Regulatory Networks

Directory of Open Access Journals (Sweden)

Bor-Sen Chen

2010-05-01

Full Text Available The interplay between entropy and robustness of gene network is a core mechanism of systems biology. The entropy is a measure of randomness or disorder of a physical system due to random parameter fluctuation and environmental noises in gene regulatory networks. The robustness of a gene regulatory network, which can be measured as the ability to tolerate the random parameter fluctuation and to attenuate the effect of environmental noise, will be discussed from the robust H∞ stabilization and filtering perspective. In this review, we will also discuss their balancing roles in evolution and potential applications in systems and synthetic biology.

A Regulatory Circuit Composed of a Transcription Factor, IscR, and a Regulatory RNA, RyhB, Controls Fe-S Cluster Delivery.

Science.gov (United States)

Mandin, Pierre; Chareyre, Sylvia; Barras, Frédéric

2016-09-20

Fe-S clusters are cofactors conserved through all domains of life. Once assembled by dedicated ISC and/or SUF scaffolds, Fe-S clusters are conveyed to their apo-targets via A-type carrier proteins (ATCs). Escherichia coli possesses four such ATCs. ErpA is the only ATC essential under aerobiosis. Recent studies reported a possible regulation of the erpA mRNA by the small RNA (sRNA) RyhB, which controls the expression of many genes under iron starvation. Surprisingly, erpA has not been identified in recent transcriptomic analysis of the iron starvation response, thus bringing into question the actual physiological significance of the putative regulation of erpA by RyhB. Using an sRNA library, we show that among 26 sRNAs, only RyhB represses the expression of an erpA-lacZ translational fusion. We further demonstrate that this repression occurs during iron starvation. Using mutational analysis, we show that RyhB base pairs to the erpA mRNA, inducing its disappearance. In addition, IscR, the master regulator of Fe-S homeostasis, represses expression of erpA at the transcriptional level when iron is abundant, but depleting iron from the medium alleviates this repression. The conjunction of transcriptional derepression by IscR and posttranscriptional repression by RyhB under Fe-limiting conditions is best described as an incoherent regulatory circuit. This double regulation allows full expression of erpA at iron concentrations for which Fe-S biogenesis switches from the ISC to the SUF system. We further provide evidence that this regulatory circuit coordinates ATC usage to iron availability. Regulatory small RNAs (sRNAs) have emerged as major actors in the control of gene expression in the last few decades. Relatively little is known about how these regulators interact with classical transcription factors to coordinate genetic responses. We show here how an sRNA, RyhB, and a transcription factor, IscR, regulate expression of an essential gene, erpA, in the bacterium E

Robust Fault Tolerant Control for a Class of Time-Delay Systems with Multiple Disturbances

Directory of Open Access Journals (Sweden)

Songyin Cao

2013-01-01

Full Text Available A robust fault tolerant control (FTC approach is addressed for a class of nonlinear systems with time delay, actuator faults, and multiple disturbances. The first part of the multiple disturbances is supposed to be an uncertain modeled disturbance and the second one represents a norm-bounded variable. First, a composite observer is designed to estimate the uncertain modeled disturbance and actuator fault simultaneously. Then, an FTC strategy consisting of disturbance observer based control (DOBC, fault accommodation, and a mixed H2/H∞ controller is constructed to reconfigure the considered systems with disturbance rejection and attenuation performance. Finally, simulations for a flight control system are given to show the efficiency of the proposed approach.

Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Material

International Nuclear Information System (INIS)

Egidi, P.V.

1999-01-01

Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented

Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Materials

Energy Technology Data Exchange (ETDEWEB)

Egidi, P.V.

1999-03-02

Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented.

Role of the interplay between quorum sensing regulator VqsR and the Pseudomonas quinolone signal in mediating carbapenem tolerance in Pseudomonas aeruginosa.

Science.gov (United States)

Viducic, Darija; Murakami, Keiji; Amoh, Takashi; Ono, Tsuneko; Miyake, Yoichiro

2017-06-01

Pseudomonas aeruginosa coordinates its response to environmental conditions through activation of a quorum sensing (QS) system. In this study, we investigated the regulatory interaction between the QS transcriptional regulator VqsR and the Pseudomonas quinolone signal (PQS) through integration of sigma factor RpoS, and we addressed whether one of the pathways controlling carbapenem tolerance can be attributed to VqsR. We demonstrate that vqsR expression at the transcriptional level is regulated by pqsA, pqsR, and pqsE. Assessment of the transcriptional expression of vqsR, lasI, rhlI, and qscR in ΔpqsA and ΔpqsAΔrpoS mutants provided insight into pqsA- and rpoS-dependent regulation of vqsR and vqsR-controlled genes. Exogenously supplemented PQS reversed expression of vqsR and vqsR-controlled genes in the ΔpqsA mutant to wild-type levels, but failed to increase expression levels of lasI and qscR in the ΔpqsAΔrpoS mutant to levels observed in wild-type PAO1. The ΔvqsR mutant showed reduced survival when challenged with carbapenems compared to wild-type PAO1. Introduction of a pqsA mutation into the ΔvqsR mutant completely abolished its carbapenem-sensitive phenotype. We conclude that a regulatory link between PQS and vqsR exists, and that RpoS is important in their interaction. We also demonstrate that VqsR affects carbapenem tolerance. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The Regulatory Small RNA MarS Supports Virulence of Streptococcus pyogenes.

Science.gov (United States)

Pappesch, Roberto; Warnke, Philipp; Mikkat, Stefan; Normann, Jana; Wisniewska-Kucper, Aleksandra; Huschka, Franziska; Wittmann, Maja; Khani, Afsaneh; Schwengers, Oliver; Oehmcke-Hecht, Sonja; Hain, Torsten; Kreikemeyer, Bernd; Patenge, Nadja

2017-09-25

Small regulatory RNAs (sRNAs) play a role in the control of bacterial virulence gene expression. In this study, we investigated an sRNA that was identified in Streptococcus pyogenes (group A Streptococcus, GAS) but is conserved throughout various streptococci. In a deletion strain, expression of mga, the gene encoding the multiple virulence gene regulator, was reduced. Accordingly, transcript and proteome analyses revealed decreased expression of several Mga-activated genes. Therefore, and because the sRNA was shown to interact with the 5' UTR of the mga transcript in a gel-shift assay, we designated it MarS for m ga-activating regulatory sRNA. Down-regulation of important virulence factors, including the antiphagocytic M-protein, led to increased susceptibility of the deletion strain to phagocytosis and reduced adherence to human keratinocytes. In a mouse infection model, the marS deletion mutant showed reduced dissemination to the liver, kidney, and spleen. Additionally, deletion of marS led to increased tolerance towards oxidative stress. Our in vitro and in vivo results indicate a modulating effect of MarS on virulence gene expression and on the pathogenic potential of GAS.

Fault Diagnosis and Fault-tolerant Control of Modular Multi-level Converter High-voltage DC System

DEFF Research Database (Denmark)

Liu, Hui; Ma, Ke; Wang, Chao

2016-01-01

of failures and lower the reliability of the MMC-HVDC system. Therefore, research on the fault diagnosis and fault-tolerant control of MMC-HVDC system is of great significance in order to enhance the reliability of the system. This paper provides a comprehensive review of fault diagnosis and fault handling...

Effective Regulatory Control of Radioactive Sources in Taiwan

International Nuclear Information System (INIS)

Liu, W.; Yuan, C.; Fan, S.; Su, S.

2004-01-01

Since the incident of radioactively contaminated buildings first surfaced in Taiwan in 1992, efforts have been made by AEC (Atomic Energy Council) of Taiwan to prevent recurrence of similar incidents involving radioactive materials and to achieve effective regulatory control over radioactive sources. The most important milestone is when AEC began to enforce IRPA he Ionizing Radiation Protection Act with the promulgation of 18 relevant regulations on Feb. 1, 2003. In order to enhance accountability of radioactive material and equipment capable of producing ionizing radiation, AEC develops and begins implementing a RPCS Radiation Protection Control System which is a powerful tool in controlling radiation safety and security. In addition, AEC develops a monthly registration program via internet, an o n-line reporting system f or owners/operators of radioactive sources, to improve monitoring of sealed sources (in-use and not-in-use). The registration requirement applies to 469 licensees possessing about 3,000 sealed sources in Taiwan. Because of the threat of orphan sources, AEC has made great efforts in preventing their contamination of construction steel material by establishing and enforcing the RPMMPIRCB Regulation for Preventive Measures and Management Plans for Incident of Radioactively Contaminated Buildings. To comply with this regulation, all 19 of Taiwan's steel factories with melting furnace have installed portal-type radiation detection system to monitor incoming scrap metal. (Author)

Regulatory Immunotherapy in Bone Marrow Transplantation

Directory of Open Access Journals (Sweden)

Vanessa Morales-Tirado

2011-01-01

Full Text Available Every year individuals receive hematopoietic stem cell transplantation (HSCT to eradicate malignant and nonmalignant disease. The immunobiology of allotransplantation is an area of ongoing discovery, from the recipient's conditioning treatment prior to the transplant to the donor cell populations responsible for engraftment, graft-versus-host disease, and graft-versus-tumor effect. In this review, we focus on donor-type immunoregulatory T cells, namely, natural killer T cells (NKT and regulatory T cells (Treg, and their current and potential roles in tolerance induction after allogeneic HSCT.

Fault tolerant control of a three-phase three-wire shunt active filter system based on reliability analysis

Energy Technology Data Exchange (ETDEWEB)

Poure, P. [Laboratoire d' Instrumentation Electronique de Nancy LIEN, EA 3440, Nancy-Universite, Faculte des Sciences et Techniques, BP 239, 54506 Vandoeuvre Cedex (France); Weber, P.; Theilliol, D. [Centre de Recherche en Automatique de Nancy UMR 7039, Nancy-Universite, CNRS, Faculte des Sciences et Techniques, BP 239, 54506 Vandoeuvre Cedex (France); Saadate, S. [Groupe de Recherches en Electrotechnique et Electronique de Nancy UMR 7037, Nancy-Universite, CNRS, Faculte des Sciences et Techniques, BP 239, 54506 Vandoeuvre Cedex (France)

2009-02-15

This paper deals with fault tolerant shunt three-phase three-wire active filter topologies for which reliability is very important in industry applications. The determination of the optimal reconfiguration structure among various ones with or without redundant components is discussed based on reliability criteria. First, the reconfiguration of the inverter is detailed and a fast fault diagnosis method for power semi-conductor or driver fault detection and compensation is presented. This method avoids false fault detection due to power semi-conductors switching. The control architecture and algorithm are studied and a fault tolerant control strategy is considered. Simulation results in open and short circuit cases validate the theoretical study. Finally, the reliability of the studied three-phase three-wire filter shunt active topologies is analyzed to determine the optimal one. (author)

Enforcement of radiation safety standards and experience in the regulatory control of exposures

Energy Technology Data Exchange (ETDEWEB)

Krishnamurthi, T N [Health and Safety Div., Atomic Energy Regulatory Board, Mumbai (India)

1997-11-01

Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author). 3 refs, 2 tabs.

Oral Gene Application Using Chitosan-DNA Nanoparticles Induces Transferable Tolerance

Science.gov (United States)

Ensminger, Stephan M.; Spriewald, Bernd M.

2012-01-01

Oral tolerance is a promising approach to induce unresponsiveness to various antigens. The development of tolerogenic vaccines could be exploited in modulating the immune response in autoimmune disease and allograft rejection. In this study, we investigated a nonviral gene transfer strategy for inducing oral tolerance via antigen-encoding chitosan-DNA nanoparticles (NP). Oral application of ovalbumin (OVA)-encoding chitosan-DNA NP (OVA-NP) suppressed the OVA-specific delayed-type hypersensitivity (DTH) response and anti-OVA antibody formation, as well as spleen cell proliferation following OVA stimulation. Cytokine expression patterns following OVA stimulation in vitro showed a shift from a Th1 toward a Th2/Th3 response. The OVA-NP-induced tolerance was transferable from donor to naïve recipient mice via adoptive spleen cell transfer and was mediated by CD4+CD25+ T cells. These findings indicate that nonviral oral gene transfer can induce regulatory T cells for antigen-specific immune modulation. PMID:22933401

Regulatory T-cells and autoimmunity.

LENUS (Irish Health Repository)

Ni Choileain, Niamh

2012-02-03

Approximately 20% of the population is affected by autoimmune or inflammatory diseases mediated by an abnormal immune response. A characteristic feature of autoimmune disease is the selective targeting of a single cell type, organ or tissue by certain populations of autoreactive T-cells. Examples of such diseases include rheumatoid arthritis, insulin-dependent diabetes mellitus, and systemic lupus erythematosus (SLE), all of which are characterized by chronic inflammation, tissue destruction and target organ malfunction. Although strong evidence links most autoimmune diseases to specific genes, considerable controversy prevails regarding the role of regulatory T-cell populations in the disease process. These cells are now also believed to play a key role in mediating transplantation tolerance and inhibiting the induction of tumor immunity. Though the concept of therapeutic immune regulation aimed at treating autoimmune pathology has been validated in many animal models, the development of strategies for the treatment of human autoimmune disorders remains in its infancy. The main obstacles to this include the conflicting findings of different model systems, as well as the contrasting functions of regulatory T-cells and cytokines involved in the development of such disorders. This review examines the role of regulatory T-cells in the pathogenesis of autoimmunity and describes the therapeutic potential of these cells for the prevention of immune-mediated pathologies in the future. Although much remains to be learned about such pathologies, a clearer understanding of the mechanisms by which regulatory T-cells function will undoubtedly lead to exciting new possibilities for immunotherapeutics.

Regulatory networks in pollen development under cold stress

Directory of Open Access Journals (Sweden)

Kamal Dev Sharma

2016-03-01

Full Text Available Cold stress modifies anthers’ metabolic pathways to induce pollen sterility. Cold-tolerant plants, unlike the susceptible ones, produce high proportion of viable pollen. Anthers in susceptible plants, when exposed to cold stress, increase abscisic acid (ABA metabolism and reduce ABA catabolism. Increased ABA negatively regulates expression of tapetum cell wall bound invertase and monosaccharide transport genes resulting in distorted carbohydrate pool in anther. Cold-stress also reduces endogenous levels of the bioactive gibberellins (GAs, GA4 and GA7, in susceptible anthers by repression of the GA biosynthesis genes. Here we discuss recent findings on mechanisms of cold susceptibility in anthers which determine pollen sterility. We also discuss differences in regulatory pathways between cold-stressed anthers of susceptible and tolerant plants that decide pollen sterility or viability.

Robust Fault-Tolerant Control for Satellite Attitude Stabilization Based on Active Disturbance Rejection Approach with Artificial Bee Colony Algorithm

Directory of Open Access Journals (Sweden)

Fei Song

2014-01-01

Full Text Available This paper proposed a robust fault-tolerant control algorithm for satellite stabilization based on active disturbance rejection approach with artificial bee colony algorithm. The actuating mechanism of attitude control system consists of three working reaction flywheels and one spare reaction flywheel. The speed measurement of reaction flywheel is adopted for fault detection. If any reaction flywheel fault is detected, the corresponding fault flywheel is isolated and the spare reaction flywheel is activated to counteract the fault effect and ensure that the satellite is working safely and reliably. The active disturbance rejection approach is employed to design the controller, which handles input information with tracking differentiator, estimates system uncertainties with extended state observer, and generates control variables by state feedback and compensation. The designed active disturbance rejection controller is robust to both internal dynamics and external disturbances. The bandwidth parameter of extended state observer is optimized by the artificial bee colony algorithm so as to improve the performance of attitude control system. A series of simulation experiment results demonstrate the performance superiorities of the proposed robust fault-tolerant control algorithm.

Regulatory control, legislation and framework

International Nuclear Information System (INIS)

Parthasarathy, K.S.

1998-01-01

The legislation and regulations, a regulatory authority to authorise and inspect the regulated activities and to enforce the legislation and regulations, sufficient financial and man-power resources are the essential parts of a national infrastructure to implement the Basic Safety Standards. The legal framework consists of legislation (Act passed by Parliament) and the regulations (framed by the government and endorsed by the Parliament). This paper is primarily deals with the the legal framework set up in India for atomic energy activities

The peer effect on pain tolerance.

Science.gov (United States)

Engebretsen, Solveig; Frigessi, Arnoldo; Engø-Monsen, Kenth; Furberg, Anne-Sofie; Stubhaug, Audun; de Blasio, Birgitte Freiesleben; Nielsen, Christopher Sivert

2018-05-19

Twin studies have found that approximately half of the variance in pain tolerance can be explained by genetic factors, while shared family environment has a negligible effect. Hence, a large proportion of the variance in pain tolerance is explained by the (non-shared) unique environment. The social environment beyond the family is a potential candidate for explaining some of the variance in pain tolerance. Numerous individual traits have previously shown to be associated with friendship ties. In this study, we investigate whether pain tolerance is associated with friendship ties. We study the friendship effect on pain tolerance by considering data from the Tromsø Study: Fit Futures I, which contains pain tolerance measurements and social network information for adolescents attending first year of upper secondary school in the Tromsø area in Northern Norway. Pain tolerance was measured with the cold-pressor test (primary outcome), contact heat and pressure algometry. We analyse the data by using statistical methods from social network analysis. Specifically, we compute pairwise correlations in pain tolerance among friends. We also fit network autocorrelation models to the data, where the pain tolerance of an individual is explained by (among other factors) the average pain tolerance of the individual's friends. We find a significant and positive relationship between the pain tolerance of an individual and the pain tolerance of their friends. The estimated effect is that for every 1 s increase in friends' average cold-pressor tolerance time, the expected cold-pressor pain tolerance of the individual increases by 0.21 s (p-value: 0.0049, sample size n=997). This estimated effect is controlled for sex. The friendship effect remains significant when controlling for potential confounders such as lifestyle factors and test sequence among the students. Further investigating the role of sex on this friendship effect, we only find a significant peer effect of male friends

Regulatory control of radioactivity and nuclear fuel cycle in Canada

International Nuclear Information System (INIS)

Hamel, P.E.; Jennekens, J.H.

1977-01-01

The mining of pitchblende for the extraction of radium some four decades ago resulted in a largely unwanted by-product, uranium, which set the stage for Canada to be one of the first countires in the world to embark upon a nuclear energy program. From this somewhat unusual beginning, the Canadian program expanded beyond mining of uranium-bearing ores to include extensive research and development in the field of radio-isotope applications, research and power reactors, nuclear-fuel conversion and fabrication facilities, heavy-water production plants and facilities for the management of radioactive wastes. As in the case of any major technological development, nuclear energy poses certain risks on the part of those directly engaged in the industry and on the part of the general public. What characterizes these risks is not so much their physical nature as the absence of long-term experience and the confidence resulting from it. The early development of regulatory controls in the nuclear field in Canada was very much influenced by security considerations but subsequently evolved to include radiological protection and safety requirements commensurate with the expanding application of nuclear energy to a wide spectrum of peaceful uses. A review of Canadian nuclear regulatory experience will reveal that the risks posed by the peaceful uses of nuclear energy can be controlled in such a manner as to ensure a high level of safety. Recent events and development have shown however that emphasis on the risks associated with low-probability, high-consequence events must not be allowed to mask the importance of health and safety measures covering the entire fuel cycle

40 CFR 94.6 - Regulatory structure.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Regulatory structure. 94.6 Section 94... for Compression-Ignition Marine Engines § 94.6 Regulatory structure. This section provides an overview of the regulatory structure of this part. (a) The regulations of this Part 94 are intended to control...

Active fault tolerance control of a wind turbine system using an unknown input observer with an actuator fault

Directory of Open Access Journals (Sweden)

Li Shanzhi

2018-03-01

Full Text Available This paper proposes a fault tolerant control scheme based on an unknown input observer for a wind turbine system subject to an actuator fault and disturbance. Firstly, an unknown input observer for state estimation and fault detection using a linear parameter varying model is developed. By solving linear matrix inequalities (LMIs and linear matrix equalities (LMEs, the gains of the unknown input observer are obtained. The convergence of the unknown input observer is also analysed with Lyapunov theory. Secondly, using fault estimation, an active fault tolerant controller is applied to a wind turbine system. Finally, a simulation of a wind turbine benchmark with an actuator fault is tested for the proposed method. The simulation results indicate that the proposed FTC scheme is efficient.

76 FR 67236 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing...

Science.gov (United States)

2011-10-31

... a foreign financial institution, and as part of the corporate control transaction, the foreign... subsidiaries, both of which are U.S. non-broker-dealer financial institutions, and as part of the corporate...-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing and Immediate...

Bacterial lipoprotein-induced self-tolerance and cross-tolerance to LPS are associated with reduced IRAK-1 expression and MyD88-IRAK complex formation.

LENUS (Irish Health Repository)

Li, Chong Hui

2012-02-03

Tolerance to bacterial cell-wall components may represent an essential regulatory mechanism during bacterial infection. We have demonstrated previously that the inhibition of nuclear factor (NF)-kappaB and mitogen-activated protein kinase activation was present in bacterial lipoprotein (BLP) self-tolerance and its cross-tolerance to lipopolysaccharide (LPS). In this study, the effect of BLP-induced tolerance on the myeloid differentiation factor 88 (MyD88)-dependent upstream signaling pathway for NF-kappaB activation in vitro was examined further. When compared with nontolerant human monocytic THP-1 cells, BLP-tolerant cells had a significant reduction in tumor necrosis factor alpha (TNF-alpha) production in response to a high-dose BLP (86+\\/-12 vs. 6042+\\/-245 ng\\/ml, P < 0.01) or LPS (341+\\/-36 vs. 7882+\\/-318 ng\\/ml, P < 0.01) stimulation. The expression of Toll-like receptor 2 (TLR2) protein was down-regulated in BLP-tolerant cells, whereas no significant differences in TLR4, MyD88, interleukin-1 receptor-associated kinase 4 (IRAK-4), and TNF receptor-associated factor 6 expression were observed between nontolerant and BLP-tolerant cells, as confirmed by Western blot analysis. The IRAK-1 protein was reduced markedly in BLP-tolerant cells, although IRAK-1 mRNA expression remained unchanged as revealed by real-time reverse transcriptase-polymerase chain reaction analysis. Furthermore, decreased MyD88-IRAK immunocomplex formation, as demonstrated by immunoprecipitation, was observed in BLP-tolerant cells following a second BLP or LPS stimulation. BLP pretreatment also resulted in a marked inhibition in total and phosphorylated inhibitor of kappaB-alpha (IkappaB-alpha) expression, which was not up-regulated by subsequent BLP or LPS stimulation. These results demonstrate that in addition to the down-regulation of TLR2 expression, BLP tolerance is associated with a reduction in IRAK-1 expression, MyD88-IRAK association, and IkappaB-alpha phosphorylation. These

An overview of the gene regulatory network controlling trichome development in the model plant, Arabidopsis

Directory of Open Access Journals (Sweden)

Sitakanta ePattanaik

2014-06-01

Full Text Available Trichomes are specialized epidermal cells located on aerial parts of plants and are associated with a wide array of biological processes. Trichomes protect plants from adverse conditions including UV light and herbivore attack and are also an important source of a number of phytochemicals. The simple unicellular trichomes of Arabidopsis serve as an excellent model to study molecular mechanism of cell differentiation and pattern formation in plants. The emerging picture suggests that the developmental process is controlled by a transcriptional network involving three major groups of transcription factors: the R2R3 MYB, basic helix-loop-helix (bHLH and WD40 repeat (WDR protein. These regulatory proteins form a trimeric activator complex that positively regulates trichome development. The single repeat R3 MYBs act as negative regulators of trichome development. They compete with the R2R3 MYBs to bind the bHLH factor and form a repressor complex. In addition to activator-repressor mechanism, a depletion mechanism may operate in parallel during trichome development. In this mechanism, the bHLH factor traps the WDR protein which results in depletion of WDR protein in neighboring cells. Consequently, the cells with high levels of bHLH and WDR proteins are developed into trichomes. A group of C2H2 zinc finger TFs has also been implicated in trichome development. Phytohormones, including gibberellins and jasmonic acid, play significant roles in this developmental process. Recently, microRNAs have been shown to be involved in trichome development. Furthermore, it has been demonstrated that the activities of the key regulatory proteins involved in trichome development are controlled by the 26S/ubiquitin proteasome system (UPS, highlighting the complexity of the regulatory network controlling this developmental process. To complement several excellent recent relevant reviews, this review focuses on the transcriptional network and hormonal interplay

Fault detection and fault tolerant control of a smart base isolation system with magneto-rheological damper

International Nuclear Information System (INIS)

Wang, Han; Song, Gangbing

2011-01-01

Fault detection and isolation (FDI) in real-time systems can provide early warnings for faulty sensors and actuator signals to prevent events that lead to catastrophic failures. The main objective of this paper is to develop FDI and fault tolerant control techniques for base isolation systems with magneto-rheological (MR) dampers. Thus, this paper presents a fixed-order FDI filter design procedure based on linear matrix inequalities (LMI). The necessary and sufficient conditions for the existence of a solution for detecting and isolating faults using the H ∞ formulation is provided in the proposed filter design. Furthermore, an FDI-filter-based fuzzy fault tolerant controller (FFTC) for a base isolation structure model was designed to preserve the pre-specified performance of the system in the presence of various unknown faults. Simulation and experimental results demonstrated that the designed filter can successfully detect and isolate faults from displacement sensors and accelerometers while maintaining excellent performance of the base isolation technology under faulty conditions

Regulatory philosophy and requirements for radiation control in Canadian uranium mine-mill facilities

International Nuclear Information System (INIS)

Dory, A.B.

1981-10-01

The approach the Canadian Atomic Energy Control Board takes in licensing uranium mine/mill facilities is based on a minimum of rigidly set regulatory requirements. The regulations state only the basic objectives: the obligation to acquire a licence, some administrative and reporting requirements, and exposure limits. The regulations are supported by a set of regulatory guides. The operator always has the option of following different procedures if he can demonstrate that they will produce the same or better results. Good relationships exist between the AECB and mine management as well as trade unions. Under this approach, however, it is difficult to take action against uncooperative parties. The Board has decided that a somewhat more formalized system is necessary. New regulations are being drafted, giving more detailed licensing and administrative requirements and covering the areas of ventilation and worker and supervisor education more thoroughly

Sub-circuits of a gene regulatory network control a developmental epithelial-mesenchymal transition.

Science.gov (United States)

Saunders, Lindsay R; McClay, David R

2014-04-01

Epithelial-mesenchymal transition (EMT) is a fundamental cell state change that transforms epithelial to mesenchymal cells during embryonic development, adult tissue repair and cancer metastasis. EMT includes a complex series of intermediate cell state changes including remodeling of the basement membrane, apical constriction, epithelial de-adhesion, directed motility, loss of apical-basal polarity, and acquisition of mesenchymal adhesion and polarity. Transcriptional regulatory state changes must ultimately coordinate the timing and execution of these cell biological processes. A well-characterized gene regulatory network (GRN) in the sea urchin embryo was used to identify the transcription factors that control five distinct cell changes during EMT. Single transcription factors were perturbed and the consequences followed with in vivo time-lapse imaging or immunostaining assays. The data show that five different sub-circuits of the GRN control five distinct cell biological activities, each part of the complex EMT process. Thirteen transcription factors (TFs) expressed specifically in pre-EMT cells were required for EMT. Three TFs highest in the GRN specified and activated EMT (alx1, ets1, tbr) and the 10 TFs downstream of those (tel, erg, hex, tgif, snail, twist, foxn2/3, dri, foxb, foxo) were also required for EMT. No single TF functioned in all five sub-circuits, indicating that there is no EMT master regulator. Instead, the resulting sub-circuit topologies suggest EMT requires multiple simultaneous regulatory mechanisms: forward cascades, parallel inputs and positive-feedback lock downs. The interconnected and overlapping nature of the sub-circuits provides one explanation for the seamless orchestration by the embryo of cell state changes leading to successful EMT.

Role of CTA1R7K-COL-DD as a novel therapeutic mucosal tolerance-inducing vector for treatment of collagen-induced arthritis.

Science.gov (United States)

Hasselberg, Annemarie; Schön, Karin; Tarkowski, Andrej; Lycke, Nils

2009-06-01

To determine whether a cholera toxin-derived, novel immunomodulating fusion protein, CTA1R7K-COL-DD, carrying the class II major histocompatibility complex H-2q-restricted type II collagen peptide aa 259-274, can induce therapeutic tolerance and prevent collagen-induced arthritis (CIA) when administered intranasally in DBA/1 mice, and to assess whether ADP-ribosylation at the mucosal membranes exerts a regulatory function such that the outcome of tolerance or immune enhancement can be controlled. DBA/1 mice with CIA were treated intranasally with CTA1R7K-COL-DD. The therapeutic effect was monitored for 46 days after the onset of disease. Clinical scoring of disease, histologic examination of inflammation, and bone erosion were assessed, and cytokine levels were determined in the serum or supernatants from splenocytes stimulated with recall antigen. The protective effect of CTA1R7K-COL-DD resulted in roughly 60% of the mice having no clinical signs or histologic evidence of disease after treatment, and those with CIA had significantly milder disease with less bone erosion. The protective status was associated with lower serum titers of IgG1, IgG2a, IgG2b, and IgG3 anticollagen and a substantial decrease in the production of interleukin-6 (IL-6), IL-17, and interferon-gamma, while levels of IL-10 were markedly up-regulated both in the serum and at the T cell level. The enzymatically inactive mutant fusion protein CTA1R7K-COL-DD provided substantial therapeutic protection against CIA following intranasal administration. The mechanism behind the effect appears to be mediated by peptide-specific regulatory T cells induced by mucosal exposure to the peptide containing CTA1R7K-COL-DD vector. In addition, ADP-ribosylation at the mucosal membranes acts as a key regulator controlling mucosal tolerance or immunity.

Energy reduction for a dual circuit cooling water system using advanced regulatory control

International Nuclear Information System (INIS)

Muller, C.J.; Craig, I.K.

2016-01-01

Highlights: • Potentially reduce energy required by a dual circuit cooling water system by 30%. • Accomplished using an advanced regulatory control and switching strategy. • No formal process model is required. • Can be implemented on control system hardware commonly used in industry. - Abstract: Various process utilities are used in the petrochemical industry as auxiliary variables to facilitate the addition/removal of energy to/from the process, power process equipment and inhibit unwanted reaction. Optimisation activities usually focus on the process itself or on the utility consumption though the generation and distribution of these utilities are often overlooked in this regard. Many utilities are prepared or generated far from the process plant and have to be transported or transmitted, giving rise to more losses and potential inefficiencies. To illustrate the potential benefit of utility optimisation, this paper explores the control of a dual circuit cooling water system with focus on energy reduction subject process constraints. This is accomplished through the development of an advanced regulatory control (ARC) and switching strategy which does not require the development of a system model, only rudimentary knowledge of the behaviour of the process and system constraints. The novelty of this manuscript lies in the fact that it demonstrates that significant energy savings can be obtained by applying ARC to a process utility containing both discrete and continuous dynamics. Furthermore, the proposed ARC strategy does not require a plant model, uses only existing plant equipment, and can be implemented on control system hardware commonly used in industry. The simulation results indicate energy saving potential in the region of 30% on the system under investigation.

Conserved cis-regulatory regions in a large genomic landscape control SHH and BMP-regulated Gremlin1 expression in mouse limb buds

Directory of Open Access Journals (Sweden)

Zuniga Aimée

2012-08-01

Full Text Available Abstract Background Mouse limb bud is a prime model to study the regulatory interactions that control vertebrate organogenesis. Major aspects of limb bud development are controlled by feedback loops that define a self-regulatory signalling system. The SHH/GREM1/AER-FGF feedback loop forms the core of this signalling system that operates between the posterior mesenchymal organiser and the ectodermal signalling centre. The BMP antagonist Gremlin1 (GREM1 is a critical node in this system, whose dynamic expression is controlled by BMP, SHH, and FGF signalling and key to normal progression of limb bud development. Previous analysis identified a distant cis-regulatory landscape within the neighbouring Formin1 (Fmn1 locus that is required for Grem1 expression, reminiscent of the genomic landscapes controlling HoxD and Shh expression in limb buds. Results Three highly conserved regions (HMCO1-3 were identified within the previously defined critical genomic region and tested for their ability to regulate Grem1 expression in mouse limb buds. Using a combination of BAC and conventional transgenic approaches, a 9 kb region located ~70 kb downstream of the Grem1 transcription unit was identified. This region, termed Grem1 Regulatory Sequence 1 (GRS1, is able to recapitulate major aspects of Grem1 expression, as it drives expression of a LacZ reporter into the posterior and, to a lesser extent, in the distal-anterior mesenchyme. Crossing the GRS1 transgene into embryos with alterations in the SHH and BMP pathways established that GRS1 depends on SHH and is modulated by BMP signalling, i.e. integrates inputs from these pathways. Chromatin immunoprecipitation revealed interaction of endogenous GLI3 proteins with the core cis-regulatory elements in the GRS1 region. As GLI3 is a mediator of SHH signal transduction, these results indicated that SHH directly controls Grem1 expression through the GRS1 region. Finally, all cis-regulatory regions within the Grem1

Regulatory Myeloid Cells in Transplantation

Science.gov (United States)

Rosborough, Brian R.; Raïch-Regué, Dàlia; Turnquist, Heth R.; Thomson, Angus W.

2013-01-01

Regulatory myeloid cells (RMC) are emerging as novel targets for immunosuppressive (IS) agents and hold considerable promise as cellular therapeutic agents. Herein, we discuss the ability of regulatory macrophages (Mreg), regulatory dendritic cells (DCreg) and myeloid-derived suppressor cells (MDSC) to regulate alloimmunity, their potential as cellular therapeutic agents and the IS agents that target their function. We consider protocols for the generation of RMC and the selection of donor- or recipient-derived cells for adoptive cell therapy. Additionally, the issues of cell trafficking and antigen (Ag) specificity following RMC transfer are discussed. Improved understanding of the immunobiology of these cells has increased the possibility of moving RMC into the clinic to reduce the burden of current IS agents and promote Ag-specific tolerance. In the second half of this review, we discuss the influence of established and experimental IS agents on myeloid cell populations. IS agents believed historically to act primarily on T cell activation and proliferation are emerging as important regulators of RMC function. Better insights into the influence of IS agents on RMC will enhance our ability to develop cell therapy protocols to promote the function of these cells. Moreover, novel IS agents may be designed to target RMC in situ to promote Ag-specific immune regulation in transplantation and usher in a new era of immune modulation exploiting cells of myeloid origin. PMID:24092382

Regulatory competence and social communication in term and preterm infants at 12 months corrected age. Results from a randomized controlled trial.

Science.gov (United States)

Olafsen, Kåre S; Rønning, John A; Handegård, Bjørn Helge; Ulvund, Stein Erik; Dahl, Lauritz Bredrup; Kaaresen, Per Ivar

2012-02-01

Temperamental regulatory competence and social communication in term and preterm infants at 12 months corrected age was studied in a randomized controlled intervention trial aimed at enhancing maternal sensitive responsiveness. Surviving infants communication with the Early Social Communication Scales. Preterm intervention infants with low regulatory competence had higher responding to joint attention than preterm control infants. A sensitizing intervention may moderate the association between temperament and social communication, and thus allow an alternative functional outlet for preterm infants low in regulatory competence. The finding may have implications for conceptualizations of the role of early sensitizing interventions in promoting important developmental outcomes for premature infants. Copyright © 2011 Elsevier Inc. All rights reserved.

Assessment of regulatory effectiveness. Peer discussions on regulatory practices

International Nuclear Information System (INIS)

1999-09-01

This report arises from the seventh series of peer discussions on regulatory practices entitled 'Assessment of Regulatory Effectiveness'. The term 'regulatory effectiveness' covers the quality of the work and level of performance of a regulatory body. In this sense, regulatory effectiveness applies to regulatory body activities aimed at preventing safety degradation and ensuring that an acceptable level of safety is being maintained by the regulated operating organizations. In addition, regulatory effectiveness encompasses the promotion of safety improvements, the timely and cost effective performance of regulatory functions in a manner which ensures the confidence of the operating organizations, the general public and the government, and striving for continuous improvements to performance. Senior regulators from 22 Member States participated in two peer group discussions during March and May 1999. The discussions were focused on the elements of an effective regulatory body, possible indicators of regulatory effectiveness and its assessment. This report presents the outcome of these meetings and recommendations of good practices identified by senior regulators, which do not necessarily reflect those of the governments of the nominating Member States, the organizations they belong to, or the International Atomic Energy Agency. In order to protect people and the environment from hazards associated with nuclear facilities, the main objective of a nuclear regulatory body is to ensure that a high level of safety in the nuclear activities under its jurisdiction is achieved, maintained and within the control of operating organizations. Even if it is possible to directly judge objective safety levels at nuclear facilities, such safety levels would not provide an exclusive indicator of regulatory effectiveness. The way the regulatory body ensures the safety of workers and the public and the way it discharges its responsibilities also determine its effectiveness. Hence the

Fault Diagnosis and Fault Tolerant Control with Application on a Wind Turbine Low Speed Shaft Encoder

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Sardi, Hector Eloy Sanchez; Escobet, Teressa

2015-01-01

tolerant control of wind turbines using a benchmark model. In this paper, the fault diagnosis scheme is improved and integrated with a fault accommodation scheme which enables and disables the individual pitch algorithm based on the fault detection. In this way, the blade and tower loads are not increased...

Small RNA-Controlled Gene Regulatory Networks in Pseudomonas putida

DEFF Research Database (Denmark)

Bojanovic, Klara

evolved numerous mechanisms to controlgene expression in response to specific environmental signals. In addition to two-component systems, small regulatory RNAs (sRNAs) have emerged as major regulators of gene expression. The majority of sRNAs bind to mRNA and regulate their expression. They often have...... multiple targets and are incorporated into large regulatory networks and the RNA chaper one Hfq in many cases facilitates interactions between sRNAs and their targets. Some sRNAs also act by binding to protein targets and sequestering their function. In this PhD thesis we investigated the transcriptional....... Detailed insights into the mechanisms through which P. putida responds to different stress conditions and increased understanding of bacterial adaptation in natural and industrial settings were gained. Additionally, we identified genome-wide transcription start sites, andmany regulatory RNA elements...

Regulatory control of Chinese Proprietary Medicines in Singapore.

Science.gov (United States)

Yee, Shen-Kuan; Chu, Swee-Seng; Xu, Yi-Min; Choo, Peck-Lin

2005-02-01

In Singapore, there has been a growing public interest in traditional Chinese medicine (TCM), which plays an important role in the healthcare system. With effect from 1 September 1999, the control on Chinese Proprietary Medicines (CPM) was implemented in three phases over a span of 3 years. Under the CPM regulatory framework, CPM importers, wholesalers, manufacturers and re-packers must be licensed and CPM products assessed and listed by the health authority before they are allowed for sale. Product assessment is based on the criteria of safety and quality which include limits of toxic heavy metals and microbial contents. During the 3-year CPM listing exercise, irregularities were detected, including intrinsic toxicity, adulteration, substitution, contamination, misidentification, non-traditional and/or inappropriate usage, incorrect preparation, inappropriate labelling, exaggerated claims and/or advertising. The full implementation of CPM control by September 2001 saw the listing of 7943 CPM products and brought about an improvement in the quality and safety of CPM in Singapore as well as the removal of sub-standard, fake/imitation and adulterated products. The standards of practices by local CPM dealers have also been raised. These improvements have, in turn, increased the level of public confidence in CPM products in Singapore.

Modeling the effector - regulatory T cell cross-regulation reveals the intrinsic character of relapses in Multiple Sclerosis

Directory of Open Access Journals (Sweden)

Torrealdea Javier

2011-07-01

Full Text Available Abstract Background The relapsing-remitting dynamics is a hallmark of autoimmune diseases such as Multiple Sclerosis (MS. Although current understanding of both cellular and molecular mechanisms involved in the pathogenesis of autoimmune diseases is significant, how their activity generates this prototypical dynamics is not understood yet. In order to gain insight about the mechanisms that drive these relapsing-remitting dynamics, we developed a computational model using such biological knowledge. We hypothesized that the relapsing dynamics in autoimmunity can arise through the failure in the mechanisms controlling cross-regulation between regulatory and effector T cells with the interplay of stochastic events (e.g. failure in central tolerance, activation by pathogens that are able to trigger the immune system. Results The model represents five concepts: central tolerance (T-cell generation by the thymus, T-cell activation, T-cell memory, cross-regulation (negative feedback between regulatory and effector T-cells and tissue damage. We enriched the model with reversible and irreversible tissue damage, which aims to provide a comprehensible link between autoimmune activity and clinical relapses and active lesions in the magnetic resonances studies in patients with Multiple Sclerosis. Our analysis shows that the weakness in this negative feedback between effector and regulatory T-cells, allows the immune system to generate the characteristic relapsing-remitting dynamics of autoimmune diseases, without the need of additional environmental triggers. The simulations show that the timing at which relapses appear is highly unpredictable. We also introduced targeted perturbations into the model that mimicked immunotherapies that modulate effector and regulatory populations. The effects of such therapies happened to be highly dependent on the timing and/or dose, and on the underlying dynamic of the immune system. Conclusion The relapsing dynamic in MS

Characteristic Analysis and Fault-Tolerant Control of Circulating Current for Modular Multilevel Converters under Sub-Module Faults

Directory of Open Access Journals (Sweden)

Wen Wu

2017-11-01

Full Text Available A modular multilevel converter (MMC is considered to be a promising topology for medium- or high-power applications. However, a significantly increased amount of sub-modules (SMs in each arm also increase the risk of failures. Focusing on the fault-tolerant operation issue for the MMC under SM faults, the operation characteristics of MMC with different numbers of faulty SMs in the arms are analyzed and summarized in this paper. Based on the characteristics, a novel circulating current-suppressing (CCS fault-tolerant control strategy comprised of a basic control unit (BCU and virtual resistance compensation control unit (VRCCU in two parts is proposed, which has three main features: (i it can suppress the multi-different frequency components of the circulating current under different SM fault types simultaneously; (ii it can help fast limiting of the transient fault current caused at the faulty SM bypassed moment; and (iii it does not need extra communication systems to acquire the information of the number of faulty SMs. Moreover, by analyzing the stability performance of the proposed controller using the Root-Locus criterion, the election principle of the value of virtual resistance is revealed. Finally, the efficiency of the control strategy is confirmed with the simulation and experiment studies under different fault conditions.

Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial

Directory of Open Access Journals (Sweden)

Liu Yuefei

2012-08-01

Full Text Available Abstract Background Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is “exercise-induced hyperammonemia”. Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS on training tolerance, training effect, and stress-recovery state. Methods Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session. Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9, branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12 or isocaloric placebo (control group, n = 12 daily. Results The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, Prd week of training increased significantly in the control group (P Conclusions Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance by KAS is associated with effects on ammonia homeostasis requires further observation.

Small Business Administration Semiannual Regulatory Agenda

Science.gov (United States)

2010-12-20

... small business concerns owned and controlled by women, and to women wishing to start a small business... Business Administration Semiannual Regulatory Agenda] Part XVII Small Business Administration Semiannual Regulatory Agenda [[Page 79864

Regulatory control and safety of radiation and radioactive sources in Bangladesh

International Nuclear Information System (INIS)

Mollah, A.S.

2001-01-01

The application of ionizing radiation and radioactive sources in different fields such as, medicine, industry, agriculture, research and teaching is constantly increasing in Bangladesh. Any system enacted to control exposure to ionizing radiation has as primary objective the protection of health of people against the deleterious effects of radiation. Establishing the appropriate level of radiological protection and safety of radiation sources used in practice or intervention attains this objective. The regulatory program governing the safe use of radioactive and radiation sources in Bangladesh is based on the legislation enacted as Nuclear Safety and Radiation Control (NSRC) Act-93 and NSRC Rules-97 and its implementation by the competent authority. The radiation control infrastructures and procedure are described as well as their functioning for the implementation of relevant activities such as licensing, regular inspection, personal dose monitoring, emergency preparedness, etc. The issue of security of radiation source is dealt in close relation with the preparation and use of the inventory of all radiation sources in the country

Regulatory control for safe usage of ionizing radiation sources in Bangladesh

International Nuclear Information System (INIS)

Mollah, A.S.

2008-01-01

Full text: In Bangladesh, there is a widespread and continuos growth in the use of the ionizing radiation sources both radioactive materials and radiation generating equipment in the field of industry, medicine, agriculture, research, teaching etc. In industry, they are employed in production as well as quality control such as non-destructive testing (radiography), nucleonic gauging, radiotracer techniques and in radiation processing. Medical applications of ionizing radiation include X-ray radiography, X-ray fluoroscopy, CT scan, mammography, nuclear medicine, beam therapy and brachytherapy. Besides radioisotopes are also used for research applications, viz., scattering experiments, tracer studies, etc. In agriculture, the uptake of nutrients by soil, and parts of plants are studied using suitable radionuclides. In all the above applications radioisotopes in two forms namely sealed sources and open sources in different chemical forms are employed with source strengths varying from micro curies to mega curies. The benefits to man from the use of ionizing radiation and sources of radiation are accompanied by risks which may result from exposure of man to ionizing radiation. In order to have an effective control on the use of radiation sources and to ensure radiological safety of the user as well as the public, Government of Bangladesh has promulgated Nuclear Safety and Radiation Control (NSRC) rules 1997 under the NSRC Act 1993. The Bangladesh Atomic Energy commission (BAEC) is the competent authority for formulating rules and regulations for ensuring radiological safety. BAEC is legally responsible for developing and strengthening the necessary radiation protection infrastructure in the country through the effective enforcement and implementation of regulatory requirements, criteria, obligations, guiding, codes etc. in order to save man and the related environment from the deleterious effects of ionizing radiation. In Bangladesh, only those persons who have been

Comparative analysis of alfalfa (Medicago sativa L.) leaf transcriptomes reveals genotype-specific salt tolerance mechanisms.

Science.gov (United States)

Lei, Yunting; Xu, Yuxing; Hettenhausen, Christian; Lu, Chengkai; Shen, Guojing; Zhang, Cuiping; Li, Jing; Song, Juan; Lin, Honghui; Wu, Jianqiang

2018-02-15

Soil salinity is an important factor affecting growth, development, and productivity of almost all land plants, including the forage crop alfalfa (Medicago sativa). However, little is known about how alfalfa responds and adapts to salt stress, particularly among different salt-tolerant cultivars. Among seven alfalfa cultivars, we found that Zhongmu-1 (ZM) is relatively salt-tolerant and Xingjiang Daye (XJ) is salt-sensitive. Compared to XJ, ZM showed slower growth under low-salt conditions, but exhibited stronger tolerance to salt stress. RNA-seq analysis revealed 2237 and 1125 differentially expressed genes (DEGs) between ZM and XJ in the presence and absence of salt stress, among which many genes are involved in stress-related pathways. After salt treatment, compared with the controls, the number of DEGs in XJ (19373) was about four times of that in ZM (4833). We also detected specific differential gene expression patterns: In response to salt stress, compared with XJ, ZM maintained relatively more stable expression levels of genes related to the ROS and Ca 2+ pathways, phytohormone biosynthesis, and Na + /K + transport. Notably, several salt resistance-associated genes always showed greater levels of expression in ZM than in XJ, including a transcription factor. Consistent with the suppression of plant growth resulting from salt stress, the expression of numerous photosynthesis- and growth hormone-related genes decreased more dramatically in XJ than in ZM. By contrast, the expression levels of photosynthetic genes were lower in ZM under low-salt conditions. Compared with XJ, ZM is a salt-tolerant alfalfa cultivar possessing specific regulatory mechanisms conferring exceptional salt tolerance, likely by maintaining high transcript levels of abiotic and biotic stress resistance-related genes. Our results suggest that maintaining this specific physiological status and/or plant adaptation to salt stress most likely arises by inhibition of plant growth in ZM through

The Importance of the Nurse Cells and Regulatory Cells in the Control of T Lymphocyte Responses

Directory of Open Access Journals (Sweden)

María Guadalupe Reyes García

2013-01-01

Full Text Available T lymphocytes from the immune system are bone marrow-derived cells whose development and activities are carefully supervised by two sets of accessory cells. In the thymus, the immature young T lymphocytes are engulfed by epithelial “nurse cells” and retained in vacuoles, where most of them (95% are negatively selected and removed when they have an incomplete development or express high affinity autoreactive receptors. The mature T lymphocytes that survive to this selection process leave the thymus and are controlled in the periphery by another subpopulation of accessory cells called “regulatory cells,” which reduce any excessive immune response and the risk of collateral injuries to healthy tissues. By different times and procedures, nurse cells and regulatory cells control both the development and the functions of T lymphocyte subpopulations. Disorders in the T lymphocytes development and migration have been observed in some parasitic diseases, which disrupt the thymic microenvironment of nurse cells. In other cases, parasites stimulate rather than depress the functions of regulatory T cells decreasing T-mediated host damages. This paper is a short review regarding some features of these accessory cells and their main interactions with T immature and mature lymphocytes. The modulatory role that neurotransmitters and hormones play in these interactions is also revised.

A radiation tolerance study of the ALICE TPC Readout Control Unit 2

CERN Document Server

Zhao, Chengxin; Balk, Helge; Alme, Johan

2017-11-17

ALICE is a general-purpose detector that is designed to study the physics of quark-gluon plasma. The Time Projection Chamber (TPC) is one of the major detectors of ALICE. The TPC electronics consists of 4356 Front-end cards (FECs), which are controlled by 216 Readout Control Units (RCU). Each RCU connects to between 18 and 25 FECs using a multi-drop bus. In LHC Run1, the Readout Control Unit 1 (RCU1) performed even better than specification. However, in Run2 the energy of colliding beams is increased from 8 TeV to 14 TeV (maximum value) and higher luminosity, which leads to larger event size and higher radiation load on the electronics. As a solution, the Readout Control Unit 2 (RCU2) is designed to provide faster readout speed and improved radiation tolerance with respect to the RCU1. The RCU2 is conceptually similar to the RCU1 and it reuses the existing infrastructure and readout architecture of the TPC electronics. However, the multi-drop bus is split into four branches from the two branches and the bandw...

Salt Tolerance in Soybean

Institute of Scientific and Technical Information of China (English)

Tsui-Hung Phang; Guihua Shao; Hon-Ming Lam

2008-01-01

Soybean is an Important cash crop and its productivity is significantly hampered by salt stress. High salt Imposes negative impacts on growth, nodulation, agronomy traits, seed quality and quantity, and thus reduces the yield of soybean. To cope with salt stress, soybean has developed several tolerance mechanisms, including: (I) maintenance of ion homeostasis; (ii) adjustment in response to osmotic stress; (iii) restoration of osmotic balance; and (iv) other metabolic and structural adaptations. The regulatory network for abiotic stress responses in higher plants has been studied extensively in model plants such as Arabidopsis thaliana. Some homologous components involved in salt stress responses have been identified in soybean. In this review, we tried to integrate the relevant works on soybean and proposes a working model to descdbe Its salt stress responses at the molecular level.

Delegação e controle político das agências reguladoras no Brasil Delegation and political control of the regulatory agencies in Brazil

Directory of Open Access Journals (Sweden)

Fernanda Meirelles

2006-08-01

Full Text Available A partir de um esforço de sistematização dos mecanismos de controle político previstos no modelo institucional originalmente concebido para as agências reguladoras, este artigo avalia os mecanismos de controle político presentes no arcabouço institucional das agências reguladoras independentes (ARIs brasileiras e analisa as alterações relacionadas ao controle político introduzidas pelo projeto de lei encaminhado pelo governo ao Congresso em 12 de abril de 2004. Após contextualizar o debate sobre o controle político das ARIs no Brasil, o artigo discute as relações entre delegação e responsabilização. Em seguida, na busca de um parâmetro para avaliar o modelo brasileiro de agências reguladoras (ARs, identifica os instrumentos de controle político utilizados na experiência americana. Finalmente, avalia a realidade institucional atual das ARIs brasileiras e comenta as contribuições do recente projeto de lei em relação ao controle político das agências.This article systematizes the political control mechanisms provided by the institutional model originally conceived for the regulatory agencies in order to assess the political control mechanisms in the institutional framework of the Brazilian independent regulatory agencies (IRAs and analyze the political control changes introduced by the law proposed by the government to Congress in April 12, 2004. After putting into context the debate on political control over the Brazilian IRAs, the article discusses the relationship between delegation and accountability. Then, so as to find a parameter for assessing the Brazilian regulatory agency model, it identifies the political control mechanisms used by the American experience. Finally, it assesses the current institutional situation of the Brazilian IRAs and comments on the contribution of the recent law proposal in relation to agency political control.

Furfural-tolerant Zymomonas mobilis derived from error-prone PCR-based whole genome shuffling and their tolerant mechanism.

Science.gov (United States)

Huang, Suzhen; Xue, Tingli; Wang, Zhiquan; Ma, Yuanyuan; He, Xueting; Hong, Jiefang; Zou, Shaolan; Song, Hao; Zhang, Minhua

2018-04-01

Furfural-tolerant strain is essential for the fermentative production of biofuels or chemicals from lignocellulosic biomass. In this study, Zymomonas mobilis CP4 was for the first time subjected to error-prone PCR-based whole genome shuffling, and the resulting mutants F211 and F27 that could tolerate 3 g/L furfural were obtained. The mutant F211 under various furfural stress conditions could rapidly grow when the furfural concentration reduced to 1 g/L. Meanwhile, the two mutants also showed higher tolerance to high concentration of glucose than the control strain CP4. Genome resequencing revealed that the F211 and F27 had 12 and 13 single-nucleotide polymorphisms. The activity assay demonstrated that the activity of NADH-dependent furfural reductase in mutant F211 and CP4 was all increased under furfural stress, and the activity peaked earlier in mutant than in control. Also, furfural level in the culture of F211 was also more rapidly decreased. These indicate that the increase in furfural tolerance of the mutants may be resulted from the enhanced NADH-dependent furfural reductase activity during early log phase, which could lead to an accelerated furfural detoxification process in mutants. In all, we obtained Z. mobilis mutants with enhanced furfural and high concentration of glucose tolerance, and provided valuable clues for the mechanism of furfural tolerance and strain development.

Through the regulatory hoop

International Nuclear Information System (INIS)

Kirner, N.P.

1985-01-01

There are many regulatory hoops through which waste generators, brokers, and disposal site operators must jump to dispose of waste safely. As the proposed exclusionary date of January 1, 1986, approaches, these regulatory hoops have the distinct possibility of multiplying or at least changing shape. The state of Washington, in its role as an Agreement State with the US Nuclear Regulatory Commission, licenses and inspects the commercial operator of the Northwest Compact's low-level radioactive waste disposal site on the Hanford Reservation. Washington has received as much as 53%, or 1.4 million cubic feet per year, of the nation's total volume of waste disposed. To control such a large volume of waste, a regulatory program involving six agencies has developed over the years in Washington

Membrane-bound Dickkopf-1 in Foxp3+ regulatory T cells suppresses T-cell-mediated autoimmune colitis.

Science.gov (United States)

Chae, Wook-Jin; Park, Jong-Hyun; Henegariu, Octavian; Yilmaz, Saliha; Hao, Liming; Bothwell, Alfred L M

2017-10-01

Induction of tolerance is a key mechanism to maintain or to restore immunological homeostasis. Here we show that Foxp3 + regulatory T (Treg) cells use Dickkopf-1 (DKK-1) to regulate T-cell-mediated tolerance in the T-cell-mediated autoimmune colitis model. Treg cells from DKK-1 hypomorphic doubleridge mice failed to control CD4 + T-cell proliferation, resulting in CD4 T-cell-mediated autoimmune colitis. Thymus-derived Treg cells showed a robust expression of DKK-1 but not in naive or effector CD4 T cells. DKK-1 expression in Foxp3 + Treg cells was further increased upon T-cell receptor stimulation in vitro and in vivo. Interestingly, Foxp3 + Treg cells expressed DKK-1 in the cell membrane and the functional inhibition of DKK-1 using DKK-1 monoclonal antibody abrogated the suppressor function of Foxp3 + Treg cells. DKK-1 expression was dependent on de novo protein synthesis and regulated by the mitogen-activated protein kinase pathway but not by the canonical Wnt pathway. Taken together, our results highlight membrane-bound DKK-1 as a novel Treg-derived mediator to maintain immunological tolerance in T-cell-mediated autoimmune colitis. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd.

Dysregulation of CD4+CD25+CD127lowFOXP3+ regulatory T cells in HIV-infected pregnant women

DEFF Research Database (Denmark)

Kolte, Lilian; Gaardbo, Julie C; Karlsson, Ingrid

2010-01-01

Pregnancy represents a major challenge to immunologic tolerance. How the fetal "semiallograft" evades maternal immune attack is unknown. Pregnancy success may involve alteration of both central (thymic) and peripheral tolerance mechanisms. HIV infection is characterized by CD4(+) T-cell depletion...... prospectively during pregnancy and postpartum. A significant expansion of CD4(+)CD25(+)CD127(low)FoxP3(+) regulatory T cells indicating alteration of peripheral tolerance was seen during second trimester, but only in HIV-negative women. HIV-infected women had lower CD4 counts, lower thymic output and Th-2...

Regulatory agencies and regulatory risk

OpenAIRE

Knieps, Günter; Weiß, Hans-Jörg

2008-01-01

The aim of this paper is to show that regulatory risk is due to the discretionary behaviour of regulatory agencies, caused by a too extensive regulatory mandate provided by the legislator. The normative point of reference and a behavioural model of regulatory agencies based on the positive theory of regulation are presented. Regulatory risk with regard to the future behaviour of regulatory agencies is modelled as the consequence of the ex ante uncertainty about the relative influence of inter...

Dual RNA regulatory control of a Staphylococcus aureus virulence factor.

Science.gov (United States)

Chabelskaya, Svetlana; Bordeau, Valérie; Felden, Brice

2014-04-01

In pathogens, the accurate programming of virulence gene expression is essential for infection. It is achieved by sophisticated arrays of regulatory proteins and ribonucleic acids (sRNAs), but in many cases their contributions and connections are not yet known. Based on genetic, biochemical and structural evidence, we report that the expression pattern of a Staphylococcus aureus host immune evasion protein is enabled by the collaborative actions of RNAIII and small pathogenicity island RNA D (SprD). Their combined expression profiles during bacterial growth permit early and transient synthesis of Sbi to avoid host immune responses. Together, these two sRNAs use antisense mechanisms to monitor Sbi expression at the translational level. Deletion analysis combined with structural analysis of RNAIII in complex with its novel messenger RNA (mRNA) target indicate that three distant RNAIII domains interact with distinct sites of the sbi mRNA and that two locations are deep in the sbi coding region. Through distinct domains, RNAIII lowers production of two proteins required for avoiding innate host immunity, staphylococcal protein A and Sbi. Toeprints and in vivo mutational analysis reveal a novel regulatory module within RNAIII essential for attenuation of Sbi translation. The sophisticated translational control of mRNA by two differentially expressed sRNAs ensures supervision of host immune escape by a major pathogen.

Review of light water reactor regulatory requirements: Assessment of selected regulatory requirements that may have marginal importance to risk: Postaccident sampling system, Turbine missiles, Combustible gas control, Charcoal filters

International Nuclear Information System (INIS)

Scott, W.B.; Jamison, J.D.; Stoetzel, G.A.; Tabatabai, A.S.; Vo, T.V.

1987-05-01

In a study commissioned by the Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory (PNL) evaluated the costs and benefits of modifying regulatory requirements in the areas of the postaccident sampling system, turbine rotor design reviews and inspections, combustible gas control for inerted Boiling Water Reactor (BWR) containments, and impregnated charcoal filters in certain plant ventilation systems. The basic framework for the analyses was that presented in the Regulatory Analysis Guidelines (NUREG/BR-0058) and in the Handbook for Value-Impact Assessment (NUREG/CR-3568). The effects of selected modifications to regulations were evaluated in terms of such factors as public risk and costs to industry and NRC. The results indicate that potential modifications of the regulatory requirements in three of the four areas would have little impact on public risk. In the fourth area, impregnated charcoal filters in building ventilation systems do appear to limit risks to the public and plant staff. Revisions in the severe accident source term assumptions, however, may reduce the theoretical value of charcoal filters. The cost analysis indicated that substantial savings in operating costs may be realized by changing the interval of turbine rotor inspections. Small to moderate operating cost savings may be realized through postulated modifications to the postaccident sampling system requirements and to the requirements for combustible gas control in inerted BWR containments. Finally, the use of impregnated charcoal filters in ventilation systems appears to be the most cost-effective method of reducing radioiodine concentrations

The catabolite repression control protein Crc plays a role in the development of antimicrobial-tolerant subpopulations in Pseudomonas aeruginosa biofilms

DEFF Research Database (Denmark)

Zhang, Lianbo; Chiang, Wen-Chi; Gao, Qingguo

2012-01-01

Bacteria form complex surface-attached biofilm communities in nature. Biofilm cells differentiate into subpopulations which display tolerance towards antimicrobial agents. However, the signal transduction pathways regulating subpopulation differentiation in biofilms are largely unelucidated. In t....... In the present study, we show that the catabolite repression control protein Crc regulates the metabolic state of Pseudomonas aeruginosa cells in biofilms, and plays an important role in the development of antimicrobial-tolerant subpopulations in P. aeruginosa biofilms....

Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

Directory of Open Access Journals (Sweden)

Muhammad Iqbal

2013-09-01

Full Text Available The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant and Inqlab-91 (salt-tolerant cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls and evaluated under saline (15 dS m-1 and nonsaline (2.84 dS m-1 conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

The MTP1 promoters from Arabidopsis halleri reveal cis-regulating elements for the evolution of metal tolerance.

Science.gov (United States)

Fasani, Elisa; DalCorso, Giovanni; Varotto, Claudio; Li, Mingai; Visioli, Giovanna; Mattarozzi, Monica; Furini, Antonella

2017-06-01

In the hyperaccumulator Arabidopsis halleri, the zinc (Zn) vacuolar transporter MTP1 is a key component of hypertolerance. Because protein sequences and functions are highly conserved between A. halleri and Arabidopsis thaliana, Zn tolerance in A. halleri may reflect the constitutively higher MTP1 expression compared with A. thaliana, based on copy number expansion and different cis regulation. Three MTP1 promoters were characterized in A. halleri ecotype I16. The comparison with the A. thaliana MTP1 promoter revealed different expression profiles correlated with specific cis-acting regulatory elements. The MTP1 5' untranslated region, highly conserved among A. thaliana, Arabidopsis lyrata and A. halleri, contains a dimer of MYB-binding motifs in the A. halleri promoters absent in the A. thaliana and A. lyrata sequences. Site-directed mutagenesis of these motifs revealed their role for expression in trichomes. A. thaliana mtp1 transgenic lines expressing AtMTP1 controlled by the native A. halleri promoter were more Zn-tolerant than lines carrying mutations on MYB-binding motifs. Differences in Zn tolerance were associated with different distribution of Zn among plant organs and in trichomes. The different cis-acting elements in the MTP1 promoters of A. halleri, particularly the MYB-binding sites, are probably involved in the evolution of Zn tolerance. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Induction of transplantation tolerance to fully mismatched cardiac allografts by T cell mediated delivery of alloantigen

Science.gov (United States)

Tian, Chaorui; Yuan, Xueli; Jindra, Peter T.; Bagley, Jessamyn; Sayegh, Mohamed H.; Iacomini, John

2010-01-01

Induction of transplantation tolerance has the potential to allow for allograft acceptance without the need for life-long immunosuppression. Here we describe a novel approach that uses delivery of alloantigen by mature T cells to induce tolerance to fully allogeneic cardiac grafts. Adoptive transfer of mature alloantigen-expressing T cells into myeloablatively conditioned mice results in long-term acceptance of fully allogeneic heart transplants without evidence of chronic rejection. Since myeloablative conditioning is clinically undesirable we further demonstrated that adoptive transfer of mature alloantigen-expressing T cells alone into mice receiving non-myeloablative conditioning resulted in long-term acceptance of fully allogeneic heart allografts with minimal evidence of chronic rejection. Mechanistically, tolerance induction involved both deletion of donor-reactive host T cells and the development of regulatory T cells. Thus, delivery of alloantigen by mature T cells induces tolerance to fully allogeneic organ allografts in non-myeloablatively conditioned recipients, representing a novel approach for tolerance induction in transplantation. PMID:20452826

Fault detection and fault-tolerant control for nonlinear systems

CERN Document Server

Li, Linlin

2016-01-01

Linlin Li addresses the analysis and design issues of observer-based FD and FTC for nonlinear systems. The author analyses the existence conditions for the nonlinear observer-based FD systems to gain a deeper insight into the construction of FD systems. Aided by the T-S fuzzy technique, she recommends different design schemes, among them the L_inf/L_2 type of FD systems. The derived FD and FTC approaches are verified by two benchmark processes. Contents Overview of FD and FTC Technology Configuration of Nonlinear Observer-Based FD Systems Design of L2 nonlinear Observer-Based FD Systems Design of Weighted Fuzzy Observer-Based FD Systems FTC Configurations for Nonlinear Systems< Application to Benchmark Processes Target Groups Researchers and students in the field of engineering with a focus on fault diagnosis and fault-tolerant control fields The Author Dr. Linlin Li completed her dissertation under the supervision of Prof. Steven X. Ding at the Faculty of Engineering, University of Duisburg-Essen, Germany...

Establishing exemption and clearance criteria by the regulatory authority

International Nuclear Information System (INIS)

Salih, A.E.A.

2012-04-01

This Project work discusses the relationship between the concepts of exemption and clearance, and their practical use in the overall scheme of regulatory control of practices. It also discusses how exemptions and clearance is established and the scope of its applications for regulatory control. The concept of general clearance levels for any type of material and any possible pathway of disposal is also introduced in this work. Guidance of the Group of Experts establishing scenarios for general clearance, parameter values, and a nuclide-specific list of calculated clearance levels is also presented. Regulatory authorities are required to develop guidance on exemption and clearance levels to assist licensees and registrants to know which practices and sources within practices are exempted from regulatory control and those to be cleared from further controls. Exemption and clearance levels are tools for assisting the Regulatory Authority to optimize the use of resources. (author)