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Sample records for lti kanavabrik valmistub

  1. Cyclic LTI Systems in Digital Signal Processing

    DTIC Science & Technology

    1998-06-10

    multirate systems and filter banks , presenting several important differences between...on well-known topics [1], [12], [23], [27] such as multirate systems , filter banks , paraunitary matrices, and state space representations, but this...noncyclic systems , especially pertaining to multirate systems , filter banks , and LTI system theory. 2 0TIC QUALITY XX3FECT» 1 ► Related literature.

  2. Membrane-Induced Folding of the Plant Stress Dehydrin Lti301[OPEN

    PubMed Central

    Eremina, Nadejda

    2016-01-01

    Dehydrins are disordered proteins that are expressed in plants as a response to embryogenesis and water-related stress. The molecular function and structural action of the dehydrins are yet elusive, but increasing evidence points to a role in protecting the structure and functional dynamics of cell membranes. An intriguing example is the cold-induced dehydrin Lti30 that binds to membranes by its conserved K segments. Moreover, this binding can be regulated by pH and phosphorylation and shifts the membrane phase transition to lower temperatures, consistent with the protein’s postulated function in cold stress. In this study, we reveal how the Lti30-membrane interplay works structurally at atomic level resolution in Arabidopsis (Arabidopsis thaliana). Nuclear magnetic resonance analysis suggests that negatively charged lipid head groups electrostatically capture the protein’s disordered K segments, which locally fold up into α-helical segments on the membrane surface. Thus, Lti30 conforms to the general theme of structure-function relationships by folding upon binding, in spite of its disordered, atypically hydrophilic and repetitive sequence signatures. Moreover, the fixed and well-defined structure of the membrane-bound K segments suggests that dehydrins have the molecular prerequisites for higher level binding specificity and regulation, raising new questions about the complexity of their biological function. PMID:27208263

  3. Integral-based event triggering controller design for stochastic LTI systems via convex optimisation

    NASA Astrophysics Data System (ADS)

    Mousavi, S. H.; Marquez, H. J.

    2016-07-01

    The presence of measurement noise in the event-based systems can lower system efficiency both in terms of data exchange rate and performance. In this paper, an integral-based event triggering control system is proposed for LTI systems with stochastic measurement noise. We show that the new mechanism is robust against noise and effectively reduces the flow of communication between plant and controller, and also improves output performance. Using a Lyapunov approach, stability in the mean square sense is proved. A simulated example illustrates the properties of our approach.

  4. A switched state feedback law for the stabilization of LTI systems.

    SciTech Connect

    Santarelli, Keith R.

    2009-09-01

    Inspired by prior work in the design of switched feedback controllers for second order systems, we develop a switched state feedback control law for the stabilization of LTI systems of arbitrary dimension. The control law operates by switching between two static gain vectors in such a way that the state trajectory is driven onto a stable n - 1 dimensional hyperplane (where n represents the system dimension). We begin by briefly examining relevant geometric properties of the phase portraits in the case of two-dimensional systems to develop intuition, and we then show how these geometric properties can be expressed as algebraic constraints on the switched vector fields that are applicable to LTI systems of arbitrary dimension. We then derive necessary and sufficient conditions to ensure stabilizability of the resulting switched system (characterized primarily by simple conditions on eigenvalues), and describe an explicit procedure for designing stabilizing controllers. We then show how the newly developed control law can be applied to the problem of minimizing the maximal Lyapunov exponent of the corresponding closed-loop state trajectories, and we illustrate the closed-loop transient performance of these switched state feedback controllers via multiple examples.

  5. Tunable Membrane Binding of the Intrinsically Disordered Dehydrin Lti30, a Cold-Induced Plant Stress Protein[W

    PubMed Central

    Eriksson, Sylvia K.; Kutzer, Michael; Procek, Jan; Gröbner, Gerhard; Harryson, Pia

    2011-01-01

    Dehydrins are intrinsically disordered plant proteins whose expression is upregulated under conditions of desiccation and cold stress. Their molecular function in ensuring plant survival is not yet known, but several studies suggest their involvement in membrane stabilization. The dehydrins are characterized by a broad repertoire of conserved and repetitive sequences, out of which the archetypical K-segment has been implicated in membrane binding. To elucidate the molecular mechanism of these K-segments, we examined the interaction between lipid membranes and a dehydrin with a basic functional sequence composition: Lti30, comprising only K-segments. Our results show that Lti30 interacts electrostatically with vesicles of both zwitterionic (phosphatidyl choline) and negatively charged phospholipids (phosphatidyl glycerol, phosphatidyl serine, and phosphatidic acid) with a stronger binding to membranes with high negative surface potential. The membrane interaction lowers the temperature of the main lipid phase transition, consistent with Lti30’s proposed role in cold tolerance. Moreover, the membrane binding promotes the assembly of lipid vesicles into large and easily distinguishable aggregates. Using these aggregates as binding markers, we identify three factors that regulate the lipid interaction of Lti30 in vitro: (1) a pH dependent His on/off switch, (2) phosphorylation by protein kinase C, and (3) reversal of membrane binding by proteolytic digest. PMID:21665998

  6. Performance analysis of active disturbance rejection tracking control for a class of uncertain LTI systems.

    PubMed

    Xue, Wenchao; Huang, Yi

    2015-09-01

    The paper considers the tracking problem for a class of uncertain linear time invariant (LTI) systems with both uncertain parameters and external disturbances. The active disturbance rejection tracking controller is designed and the resulting closed-loop system's characteristics are comprehensively studied. In the time-domain, it is proven that the output of closed-loop system can approach its ideal trajectory in the transient process against different kinds of uncertainties by tuning the bandwidth of extended state observer (ESO). In the frequency-domain, different kinds of parameters' influences on the phase margin and the crossover frequency of the resulting control system are illuminated. Finally, the effectiveness and robustness of the controller are verified through the actuator position control system with uncertain parameters and load disturbances in the simulations.

  7. Identification and expression analysis of CjLTI, a novel low temperature responsive gene from Caragana jubata.

    PubMed

    Bhardwaj, Pardeep Kumar; Kaur, Jagdeep; Sobti, Ranbir Chander; Kumar, Sanjay

    2012-03-01

    Using rapid amplification of cDNA ends, a full length cDNA (CjLTI) was cloned from apical buds of Caragana jubata, a plant species that grows under extreme cold. The cDNA obtained was 573 bp long consisting of an open reading frame of 351 bp encoding 116 amino acids. Homology analysis did not exhibit significant similarity with any sequence at NCBI database, therefore it was deduced as a novel gene. Secondary structure analysis suggested that the deduced CjLTI contained 25.86% α-helices, 4.31% β-turns, 6.90% extended strands, and 62.93% random coils. The hydropathy profile suggested CjLTI to be a hydrophobic protein having characteristic features of signal peptides at N-terminus. The gene exhibited down-regulation at 5 min of exposure to low temperature (LT, 4 ± 3 °C) followed by a strong up-regulation after 15 min and onwards. Methyl jasmonate (MJ) lead to up-regulation of CjLTI starting at 5 min onwards. The gene exhibited up- and down-regulation of expression pattern in response to abscisic acid (ABA) and salicylic acid (SA). Mild drought stress slightly up-regulated gene expression and at severe drought (up to 115% reduction in leaf water potential) slight down-regulation of gene expression was observed. These results suggested CjLTI to be a LT responsive gene wherein MJ, ABA and SA pathways might be involved in regulating the gene expression.

  8. A new 3-D ray tracing method based on LTI using successive partitioning of cell interfaces and traveltime gradients

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Zhang, Ting-Ting; Zhang, Xiao-Lei; Yang, Yan; Hu, Ying; Qin, Qian-Qing

    2013-05-01

    We present a new method of three-dimensional (3-D) seismic ray tracing, based on an improvement to the linear traveltime interpolation (LTI) ray tracing algorithm. This new technique involves two separate steps. The first involves a forward calculation based on the LTI method and the dynamic successive partitioning scheme, which is applied to calculate traveltimes on cell boundaries and assumes a wavefront that expands from the source to all grid nodes in the computational domain. We locate several dynamic successive partition points on a cell's surface, the traveltimes of which can be calculated by linear interpolation between the vertices of the cell's boundary. The second is a backward step that uses Fermat's principle and the fact that the ray path is always perpendicular to the wavefront and follows the negative traveltime gradient. In this process, the first-arriving ray path can be traced from the receiver to the source along the negative traveltime gradient, which can be calculated by reconstructing the continuous traveltime field with cubic B-spline interpolation. This new 3-D ray tracing method is compared with the LTI method and the shortest path method (SPM) through a number of numerical experiments. These comparisons show obvious improvements to computed traveltimes and ray paths, both in precision and computational efficiency.

  9. Ligand-Controlled CO2 Activation Mediated by Cationic Titanium Hydride Complexes, [LTiH](+) (L=Cp2 , O).

    PubMed

    Tang, Shi-Ya; Rijs, Nicole J; Li, Jilai; Schlangen, Maria; Schwarz, Helmut

    2015-06-01

    CO2 activation mediated by [LTiH](+) (L=Cp2 , O) is observed in the gas phase at room temperature using electrospray-ionization mass spectrometry, and reaction details are derived from traveling wave ion-mobility mass spectrometry. Wheresas oxygen-atom transfer prevails in the reaction of the oxide complex [OTiH](+) with CO2 , generating [OTi(OH)](+) under the elimination of CO, insertion of CO2 into the metal-hydrogen bond of the cyclopentadienyl complex, [Cp2 TiH](+) , gives rise to the formate complex [Cp2 Ti(O2 CH)](+) . DFT-based methods were employed to understand how the ligand controls the observed variation in reactivity toward CO2 . Insertion of CO2 into the Ti-H bond constitutes the initial step for the reaction of both [Cp2 TiH](+) and [OTiH](+) , thus generating formate complexes as intermediates. In contrast to [Cp2 Ti(O2 CH)](+) which is kinetically stable, facile decarbonylation of [OTi(O2 CH)](+) results in the hydroxo complex [OTi(OH)](+) . The longer lifetime of [Cp2 Ti(O2 CH)](+) allows for secondary reactions with background water, as a result of which, [Cp2 Ti(OH)](+) is formed. Further, computational studies reveal a good linear correlation between the hydride affinity of [LTi](2+) and the barrier for CO2 insertion into various [LTiH](+) complexes. Understanding the intrinsic ligand effects may provide insight into the selective activation of CO2 .

  10. Eigenvalue assignment by minimal state-feedback gain in LTI multivariable systems

    NASA Astrophysics Data System (ADS)

    Ataei, Mohammad; Enshaee, Ali

    2011-12-01

    In this article, an improved method for eigenvalue assignment via state feedback in the linear time-invariant multivariable systems is proposed. This method is based on elementary similarity operations, and involves mainly utilisation of vector companion forms, and thus is very simple and easy to implement on a digital computer. In addition to the controllable systems, the proposed method can be applied for the stabilisable ones and also systems with linearly dependent inputs. Moreover, two types of state-feedback gain matrices can be achieved by this method: (1) the numerical one, which is unique, and (2) the parametric one, in which its parameters are determined in order to achieve a gain matrix with minimum Frobenius norm. The numerical examples are presented to demonstrate the advantages of the proposed method.

  11. Using LTI Dynamics to Identify the Influential Nodes in a Network

    PubMed Central

    Jorswieck, Eduard; Scheunert, Christian

    2016-01-01

    Networks are used for modeling numerous technical, social or biological systems. In order to better understand the system dynamics, it is a matter of great interest to identify the most important nodes within the network. For a large set of problems, whether it is the optimal use of available resources, spreading information efficiently or even protection from malicious attacks, the most important node is the most influential spreader, the one that is capable of propagating information in the shortest time to a large portion of the network. Here we propose the Node Imposed Response (NiR), a measure which accurately evaluates node spreading power. It outperforms betweenness, degree, k-shell and h-index centrality in many cases and shows the similar accuracy to dynamics-sensitive centrality. We utilize the system-theoretic approach considering the network as a Linear Time-Invariant system. By observing the system response we can quantify the importance of each node. In addition, our study provides a robust tool set for various protective strategies. PMID:28030548

  12. Health Education and Activity – Lessening The Inequalities in mental health (HEA – LTI mental health)

    PubMed Central

    Richmond, Georgia; Kenny, Conor; Ahmed, Jabed; Stephenson, Lucy; lindsay, jamie; Earls, Patrick; Mullin, Donncha; Ryland, Howard

    2017-01-01

    Patients suffering from mental health illness have considerably more physical health disease burden than the rest of the population and are more likely to die 10 to 20 years younger compared with their peers. Diabetes, cardiovascular and respiratory disease have been recognised as contributing factors to premature death. Furthermore patients with severe mental illness undertake lower levels of physical activity. The aim of the project was therefore to address the inequalities in physical health that affect patients with mental health illness through designing and implementing a sustainable, transferable, patient-centred education and activity intervention. The objective of the project was to increase patient motivation to change behaviour as a result of physical health interventions by increasing patients' physical health understanding, motivation to change their physical health behaviour, motivation to do exercise and by reducing their anxiety. The method used was a prospective cohort study in four eighteen bed psychosis inpatient units. The units were across two large London hospitals in one Hospital Trust involving male and female inpatients with a range of mental health issues. The intervention was comprised of two components. The first component was a weekly 45 minute teaching group designed in collaboration with patients focusing on the key domains that affect the physical health of mental health patients. Four discussion domains (heart health, diabetes and weight, smoking and lung disease, cancer screening and substance misuse) were undertaken, with each cycle lasting four weeks. The second component was a weekly 45 minute exercise group (‘normalisation activity’) in collaboration with patients and the multidisciplinary team. The intervention was evaluated at the end of each cycle and four cycles in total took place. Weekly pre and post intervention measures were undertaken comprising of a self reported change in understanding, motivation to change physical health behaviours, confidence to change, anxiety and motivation to exercise. The result was a 26% improvement in self-reported understanding across the four domains following teaching. Furthermore patient anxiety reduced by on average 35%, self-reported motivation to change increased by 20%, motivation to do exercise by 26% and confidence to change by 16% as a result of the intervention. The authors conclude that a collaborative approach to education and activity between the Multidisciplinary Team (MDT) and service user results in sustained improvement in understanding of physical health, motivation to change behaviour and to do exercise. It also results in improved confidence and reduced anxiety. PMID:28243443

  13. Gradient Projection Anti-windup Scheme on Constrained Planar LTI Systems

    DTIC Science & Technology

    2010-03-15

    uniqueness results based on Lipschitz continuity of vector fields [7]–[10] do not apply directly. We show that the GPAW compensated system is in fact...K+out (⊂ ∂K+) and ∂K−out (⊂ ∂K−). Classical results on the existence and uniqueness of solutions [7]–[10] rely on Lipschitz continuity of the...d ] . It can be verified [8, Example 3.2, pp. 91 – 92] that the saturation function is globally Lipschitz with unity Lipschitz constant, ie. |sat(α

  14. Health Education and Activity - Lessening The Inequalities in mental health (HEA - LTI mental health).

    PubMed

    Richmond, Georgia; Kenny, Conor; Ahmed, Jabed; Stephenson, Lucy; Lindsay, Jamie; Earls, Patrick; Mullin, Donncha; Ryland, Howard

    2017-01-01

    Patients suffering from mental health illness have considerably more physical health disease burden than the rest of the population and are more likely to die 10 to 20 years younger compared with their peers. Diabetes, cardiovascular and respiratory disease have been recognised as contributing factors to premature death. Furthermore patients with severe mental illness undertake lower levels of physical activity. The aim of the project was therefore to address the inequalities in physical health that affect patients with mental health illness through designing and implementing a sustainable, transferable, patient-centred education and activity intervention. The objective of the project was to increase patient motivation to change behaviour as a result of physical health interventions by increasing patients' physical health understanding, motivation to change their physical health behaviour, motivation to do exercise and by reducing their anxiety. The method used was a prospective cohort study in four eighteen bed psychosis inpatient units. The units were across two large London hospitals in one Hospital Trust involving male and female inpatients with a range of mental health issues. The intervention was comprised of two components. The first component was a weekly 45 minute teaching group designed in collaboration with patients focusing on the key domains that affect the physical health of mental health patients. Four discussion domains (heart health, diabetes and weight, smoking and lung disease, cancer screening and substance misuse) were undertaken, with each cycle lasting four weeks. The second component was a weekly 45 minute exercise group ('normalisation activity') in collaboration with patients and the multidisciplinary team. The intervention was evaluated at the end of each cycle and four cycles in total took place. Weekly pre and post intervention measures were undertaken comprising of a self reported change in understanding, motivation to change physical health behaviours, confidence to change, anxiety and motivation to exercise. The result was a 26% improvement in self-reported understanding across the four domains following teaching. Furthermore patient anxiety reduced by on average 35%, self-reported motivation to change increased by 20%, motivation to do exercise by 26% and confidence to change by 16% as a result of the intervention. The authors conclude that a collaborative approach to education and activity between the Multidisciplinary Team (MDT) and service user results in sustained improvement in understanding of physical health, motivation to change behaviour and to do exercise. It also results in improved confidence and reduced anxiety.

  15. Robustness Analysis of Integrated LPV-FDI Filters and LTI-FTC System for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Khong, Thuan H.; Shin, Jong-Yeob

    2007-01-01

    This paper proposes an analysis framework for robustness analysis of a nonlinear dynamics system that can be represented by a polynomial linear parameter varying (PLPV) system with constant bounded uncertainty. The proposed analysis framework contains three key tools: 1) a function substitution method which can convert a nonlinear system in polynomial form into a PLPV system, 2) a matrix-based linear fractional transformation (LFT) modeling approach, which can convert a PLPV system into an LFT system with the delta block that includes key uncertainty and scheduling parameters, 3) micro-analysis, which is a well known robust analysis tool for linear systems. The proposed analysis framework is applied to evaluating the performance of the LPV-fault detection and isolation (FDI) filters of the closed-loop system of a transport aircraft in the presence of unmodeled actuator dynamics and sensor gain uncertainty. The robustness analysis results are compared with nonlinear time simulations.

  16. LTI system order reduction approach based on asymptotical equivalence and the Co-operation of biology-related algorithms

    NASA Astrophysics Data System (ADS)

    Ryzhikov, I. S.; Semenkin, E. S.; Akhmedova, Sh A.

    2017-02-01

    A novel order reduction method for linear time invariant systems is described. The method is based on reducing the initial problem to an optimization one, using the proposed model representation, and solving the problem with an efficient optimization algorithm. The proposed method of determining the model allows all the parameters of the model with lower order to be identified and by definition, provides the model with the required steady-state. As a powerful optimization tool, the meta-heuristic Co-Operation of Biology-Related Algorithms was used. Experimental results proved that the proposed approach outperforms other approaches and that the reduced order model achieves a high level of accuracy.

  17. Gifts, Talents, and the Very Young: Early Childhood Education for Gifted/Talented N/S-LTI-G/T Brief No. 5.

    ERIC Educational Resources Information Center

    Abraham, Willard; And Others

    Compiled are presentations given at the Institute on Gifted/Talented Early Childhood Education in January, 1977. Considered in "Current Myths Concerning Gifted Children" by H. Robinson are the myth of the "giftedness syndrome", the myth of the qualitatively different gifted individual, and myths about educating children with special gifts. M.…

  18. Structural, Thermodynamic, and Functional Mechanisms of Adaptations WrbA and AdoMetDC Proteins in Extremophilic Organisms

    DTIC Science & Technology

    2007-08-15

    70 EXISI - - MDTMGRHI IAELWDCNPEKLNDMEYVERLFVDAALQAGAEVREVAFHKFAPHGVSGVV ISEAHLT’I HSF 70 OCEIH...MDVLGRHIIAELWECNLEKLNNIDFIRDTFVEAAVLAGAEVREVVFHPFAPYGISGVVIISEAHLrIHSF 70 BACSU MTMETMGRHVISELWGCDFDKLNDMDFIEKTFVNAALKSGAEVREVAFHKFAPQGVSGVVIISEA/{LTI HSF 72 PETMO

  19. Nutritional Markers and Body Composition in Hemodialysis Patients

    PubMed Central

    Valtuille, Rodolfo; Casos, Maria Elisa; Fernandez, Elmer Andres; Guinsburg, Adrian; Marelli, Cristina

    2015-01-01

    The aims of this study were to analyse body composition, to detect the presence of undernutrition, and to establish a relationship between undernutrition and the biological markers routinely used as indicators of nutritional status in hemodialysis (HD) patients (pts). We used a body composition monitor (BCM) that expresses body weight in terms of lean tissue mass (LTM) and fat tissue mass (FTM) independent of hydration status. From nine HD units, 934 pts were included. Undernutrition was defined as having a lean tissue index (LTI = LTM/height2) below the 10th percentile of a reference population. Biochemical markers and parameters delivered by BCM were used to compare low LTI and normal LTI groups. Undernutrition prevalence was 58.8% of the population studied. Low LTI pts were older, were significantly more frequently overhydrated, and had been on HD for a longer period of time than the normal LTI group. FTI (FTI = FTM/ height2) was significantly higher in low LTI pts and increased according to BMI. LTI was not influenced by different BMI levels. Albumin and C-reactive protein correlated inversely (r = −0.28). However neither of them was statistically different when considering undernourished and normal LTI pts. Our BCM study was able to show a high prevalence of undernutrition, as expressed by low LTI. In our study, BMI and other common markers, such as albumin, failed to predict malnutrition as determined by BCM. PMID:27347538

  20. Advanced Formation Flight Control.

    DTIC Science & Technology

    1994-12-01

    stabilizes the time dependent linearized plant (7.9) than it is to synthesize a control law which stabilizes the LTI plant (7.5). However, if a stabilizing ... control law is available, Lyapunov’s stabilizability result can also be applied to non LTI scenarios which arise from the application of linearization to

  1. Conceptualization of an R&D Based Learning-to-Innovate Model for Science Education

    ERIC Educational Resources Information Center

    Lai, Oiki Sylvia

    2013-01-01

    The purpose of this research was to conceptualize an R & D based learning-to-innovate (LTI) model. The problem to be addressed was the lack of a theoretical L TI model, which would inform science pedagogy. The absorptive capacity (ACAP) lens was adopted to untangle the R & D LTI phenomenon into four learning processes: problem-solving via…

  2. The architects of B and T cell immune responses.

    PubMed

    Lane, Peter J L

    2008-08-15

    Published work links adult lymphoid tissue-inducer cells (LTi) with T cell-dependent antibody responses. In this issue of Immunity, Tsuji et al. (2008) associate LTi with T cell-independent IgA antibody responses in the gut.

  3. Lymphoid tissue inducer cells: architects of CD4 immune responses in mice and men.

    PubMed

    Kim, M-Y; Kim, K-S; McConnell, F; Lane, P

    2009-07-01

    In this review, we summarize the current understanding of the multiple functions of the mouse lymphoid tissue inducer (LTi) cells in: (i) the development of organized lymphoid tissue, (ii) the generation and maintenance of CD4-dependent immunity in adult lymphoid tissues; and (iii) the regulation of central tolerance in thymus. By contrast with mouse LTi cells, which have been well described, the human equivalent is only just beginning to be characterized. Human LTi-like cells expressing interleukin (IL)-22 have been identified recently and found to differentiate into natural killer (NK) cells. The relationship of LTi cells to NK cells is discussed in the light of several studies reporting a close relationship in the mouse between LTi cells and transcription factor retinoid-related orphan receptor gammat-dependent IL-22 producing NK cells in the gut. We also outline our data suggesting that these cells are present in adult human lymphoid tissues.

  4. Linear Time Invariant Models for Integrated Flight and Rotor Control

    NASA Astrophysics Data System (ADS)

    Olcer, Fahri Ersel

    2011-12-01

    Recent developments on individual blade control (IBC) and physics based reduced order models of various on-blade control (OBC) actuation concepts are opening up opportunities to explore innovative rotor control strategies for improved rotor aerodynamic performance, reduced vibration and BVI noise, and improved rotor stability, etc. Further, recent developments in computationally efficient algorithms for the extraction of Linear Time Invariant (LTI) models are providing a convenient framework for exploring integrated flight and rotor control, while accounting for the important couplings that exist between body and low frequency rotor response and high frequency rotor response. Formulation of linear time invariant (LTI) models of a nonlinear system about a periodic equilibrium using the harmonic domain representation of LTI model states has been studied in the literature. This thesis presents an alternative method and a computationally efficient scheme for implementation of the developed method for extraction of linear time invariant (LTI) models from a helicopter nonlinear model in forward flight. The fidelity of the extracted LTI models is evaluated using response comparisons between the extracted LTI models and the nonlinear model in both time and frequency domains. Moreover, the fidelity of stability properties is studied through the eigenvalue and eigenvector comparisons between LTI and LTP models by making use of the Floquet Transition Matrix. For time domain evaluations, individual blade control (IBC) and On-Blade Control (OBC) inputs that have been tried in the literature for vibration and noise control studies are used. For frequency domain evaluations, frequency sweep inputs are used to obtain frequency responses of fixed system hub loads to a single blade IBC input. The evaluation results demonstrate the fidelity of the extracted LTI models, and thus, establish the validity of the LTI model extraction process for use in integrated flight and rotor control

  5. Predicting the underestimation of the femoral offset in anteroposterior radiographs of the pelvis using 'lesser trochanter index': a 3D CT derived simulated radiographic analysis.

    PubMed

    Boddu, Krishna; Siebachmeyer, Martin; Lakkol, Sandesh; Rajayogeswaran, Brathaban; Kavarthapu, Venu; Li, Patrick L S

    2014-06-01

    We developed 'lesser trochanter index' (LTI) and estimated its accuracy in predicting the underestimation of offset in the anteroposterior (AP) pelvic radiographs. We reconstructed 320 simulated radiographs from the CT scans of 40 adult hips at different rotational projections of 10° increments from 30° internal rotation to 40° external rotation. Underestimation of femoral offset as a percentage was derived from the neck profile angle for all radiographs. Radiographs with an LTI value above 35 were 94% (95% CI, 89%-97%) likely to underestimate femoral offset by more than 5%. Radiographs with LTI between 0 and 30 demonstrated femoral offset within 5% of the true offset (predictive value 100%, CI 87%-100%). LTI could be a useful guide in preoperative templating of hip arthroplasty.

  6. Thermal characteristics of lysine tri-isocyanate and its mixture with water.

    PubMed

    Li, Xin-Rui; Koseki, Hiroshi; Iwata, Yusaku

    2007-04-11

    The thermal reactivity of lysine tri-isocyanate (LTI, 2-isocyanatoethyl-2,6-diisocyanato caproylate) and its mixture with 1% water was investigated after the occurrence of a runaway reaction at a plant. By using a sensitive thermal calorimeter, C80, and an adiabatic calorimeter, ARC, an onset reaction of LTI was observed at 70-100 degrees C and it became vigorous at 175-200 degrees C. The reaction is considered as co-polymerization at this stage, which causes a second decomposition reaction at 200 degrees C if the heat generation is accumulated in the vessel. On the other hand, the presence of water can catalyze LTI at much lower onset temperature and lead to a moderate reaction at 50 degrees C since carbamine is produced and in turn it induces decarbonization of the LTI molecule with significant release of CO2 gas which was detected by a gas chromatography and an FT-IR gas analyzer.

  7. Characteristics of hemophilia patients with factor VIII inhibitors detected by prospective screening

    PubMed Central

    Miller, Connie H.; Rice, Anne S.; Boylan, Brian; Payne, Amanda B.; Kelly, Fiona M.; Escobar, Miguel A.; Gill, Joan; Leissinger, Cindy; Soucie, J. Michael

    2015-01-01

    Characteristics of inhibitors identified by prospective screening may differ from those detected clinically. In a prospective study at 17 hemophilia centers with central inhibitor measurement by Nijmegen-Bethesda assay, 23 (2.8%) of 824 hemophilia A patients had new inhibitors detected: nine high-titer inhibitors (HTI: 7 ≥5.0 NBU plus 2 of 2.6 and 3.4 NBU at immune tolerance induction initiation) and 14 low-titer inhibitors (LTI: 0.5–1.9 NBU). HTI occurred at an earlier age (median 2 years, range 1–18, vs. median 11 years, range 2–61, P = 0.016). Both HTI (22%) and LTI (43%) occurred in non-severe patients. All HTI, but only 64% of LTI, were found to be FVIII-specific by chromogenic Bethesda assay or fluorescence immunoassay (FLI), indicating a high rate of false-positive LTI. Repeat specimens confirmed all HTI, 7/9 LTI, and 7/7 FVIII-specific LTI. FLI results were similar between HTI and FVIII-specific LTI; all included IgG1 and IgG4 subclasses. A comparable prospective study conducted from 1975 to 1979 at 13 U.S. centers found 31 (2.4%) new inhibitors among 1,306 patients. In both studies, one-third of inhibitors occurred in non-severe patients and one-quarter after 150 exposure days (ED). Significant differences were seen in the age at which inhibitors occurred (median 16 years in the older study vs. 5 years currently, P = 0.024) and in ED before inhibitor development, 10% in the older study and 43% currently study occurring within 20 ED, suggesting a temporal change in inhibitor development. Prospective screening detects inhibitors in patients of all severities, ages, and ED. Some LTI, however, are false positives. PMID:26147783

  8. Maternal retinoids control type 3 innate lymphoid cells and set the offspring immunity

    NASA Astrophysics Data System (ADS)

    van de Pavert, Serge A.; Ferreira, Manuela; Domingues, Rita G.; Ribeiro, Hélder; Molenaar, Rosalie; Moreira-Santos, Lara; Almeida, Francisca F.; Ibiza, Sales; Barbosa, Inês; Goverse, Gera; Labão-Almeida, Carlos; Godinho-Silva, Cristina; Konijn, Tanja; Schooneman, Dennis; O'Toole, Tom; Mizee, Mark R.; Habani, Yasmin; Haak, Esther; Santori, Fabio R.; Littman, Dan R.; Schulte-Merker, Stefan; Dzierzak, Elaine; Simas, J. Pedro; Mebius, Reina E.; Veiga-Fernandes, Henrique

    2014-04-01

    The impact of nutritional status during fetal life on the overall health of adults has been recognized; however, dietary effects on the developing immune system are largely unknown. Development of secondary lymphoid organs occurs during embryogenesis and is considered to be developmentally programmed. Secondary lymphoid organ formation depends on a subset of type 3 innate lymphoid cells (ILC3) named lymphoid tissue inducer (LTi) cells. Here we show that mouse fetal ILC3s are controlled by cell-autonomous retinoic acid (RA) signalling in utero, which pre-sets the immune fitness in adulthood. We found that embryonic lymphoid organs contain ILC progenitors that differentiate locally into mature LTi cells. Local LTi cell differentiation was controlled by maternal retinoid intake and fetal RA signalling acting in a haematopoietic cell-autonomous manner. RA controlled LTi cell maturation upstream of the transcription factor RORγt. Accordingly, enforced expression of Rorgt restored maturation of LTi cells with impaired RA signalling, whereas RA receptors directly regulated the Rorgt locus. Finally, we established that maternal levels of dietary retinoids control the size of secondary lymphoid organs and the efficiency of immune responses in the adult offspring. Our results reveal a molecular link between maternal nutrients and the formation of immune structures required for resistance to infection in the offspring.

  9. Effect of Ethyl Ester L-Lysine Triisocyanate addition to produce reactive PLA/PCL bio-polyester blends for biomedical applications.

    PubMed

    Visco, Annamaria; Nocita, Davide; Giamporcaro, Alberto; Ronca, Sara; Forte, Giuseppe; Pistone, Alessandro; Espro, Claudia

    2017-02-16

    We report in this paper the effects of Ethyl Ester L-Lysine Triisocyanate (LTI) on the physical-mechanical properties of Poly(lactide)/Poly(ε-caprolactone) (PLA/PCL) polyesters blends. The PLA/PCL ratios considered were 20/80, 50/50 and 80/20 (wt/wt %) and LTI was added in amounts of 0.0-0.5-1.0 phr. PLA and PCL reacted with LTI during processing in a Brabender twin screw internal mixer to produce block copolymers in-situ. The resulting blends have been characterized by torque measurements, uniaxial tensile tests, Differential Scanning Calorimeter, contact angle measurements with a Phosphate Buffered Saline (PBS) solution, ATR analysis and morphological SEM observations. Experimental results highlighted how LTI enhanced interaction and dispersion of the two components, resulting into a synergic effect in mechanical properties. Mechanical and physical properties can be tailored by changing the blend composition. The most noticeable trend was an increase in ductility of the mixed polymers. Besides, LTI decreased blend's wet ability in PBS and lowered the starting of crystalline phase formation for both polymers, confirming an interaction among them. These reactive blends could find use as biomedical materials, e.g. absorbable suture threads or scaffolds for cellular growth.

  10. Characterization of Mode I Fracture and Morphological Properties of PLLA Blends with Addition of Lysine Triisocyanate

    NASA Astrophysics Data System (ADS)

    Vannaladsaysy, Vilay; Todo, Mitsugu

    Poly(L-lactic acid) (PLLA) was toughened by blending with three different ductile biopolymers such as poly (ε-caprolactone) (PCL), poly(butylene succinate-co-e-caprolactone) (PBSC), poly (butylene succinate-co-L-lactate) (PBSL). The blend ratio was fixed to 50:50. Lysine triisocyanate (LTI) was added to the blends as a compatibilizer. Characterizations such as Fourier transform infra-red (FT-IR) spectroscopy, field-emission electron microscope (FE-SEM), and mode I fracture test were used to characterize the effectiveness of LTI on the mechanical and morphological properties of various PLLA blends. It was found that PLLA/PCL blend shows the highest toughness energy among the binary blends. On the other hand, addition of LTI in PLLA/PBSC blend exhibits the best toughness property. Based on the FE-SEM observation, fractured surfaces of PLLA blends with LTI indicate ductile fracture with dense elongated fibrils. The largest damage zone is generated in the vicinity of crack-trip, suggesting that high energy dissipation occurred in the crack-trip region. FT-IR analysis also suggested that the NCO groups of LTI were acted as a compatibilizer, as the results of interaction between the two phases of the polymer blends.

  11. Robust Stabilization of Uncertain Systems Based on Energy Dissipation Concepts

    NASA Technical Reports Server (NTRS)

    Gupta, Sandeep

    1996-01-01

    Robust stability conditions obtained through generalization of the notion of energy dissipation in physical systems are discussed in this report. Linear time-invariant (LTI) systems which dissipate energy corresponding to quadratic power functions are characterized in the time-domain and the frequency-domain, in terms of linear matrix inequalities (LMls) and algebraic Riccati equations (ARE's). A novel characterization of strictly dissipative LTI systems is introduced in this report. Sufficient conditions in terms of dissipativity and strict dissipativity are presented for (1) stability of the feedback interconnection of dissipative LTI systems, (2) stability of dissipative LTI systems with memoryless feedback nonlinearities, and (3) quadratic stability of uncertain linear systems. It is demonstrated that the framework of dissipative LTI systems investigated in this report unifies and extends small gain, passivity, and sector conditions for stability. Techniques for selecting power functions for characterization of uncertain plants and robust controller synthesis based on these stability results are introduced. A spring-mass-damper example is used to illustrate the application of these methods for robust controller synthesis.

  12. Control design and simulation of systems modeled using ADAMS

    NASA Technical Reports Server (NTRS)

    Sohoni, Vikram N.

    1989-01-01

    A technique for control design and simulation using the ADAMS software and a control design software package is presented. For design of control systems ADAMS generates a minimum realization linear time invariant (LTI), state space representation of multi-body models. This LTI representation can be produced in formats for input to several commercial control design packages. The user can exercise various design strategies in the control design software to arrive at a suitable compensator. The resulting closed loop model can then be simulated using ADAMS. This procedure is illustrated with two examples.

  13. Variable structure control of linear time invariant fractional order systems using a finite number of state feedback law

    NASA Astrophysics Data System (ADS)

    Balochian, Saeed; Sedigh, Ali Khaki; Zare, Asef

    2011-03-01

    In this paper, an approach based on the variable structure control is proposed for stabilization of linear time invariant fractional order systems (LTI-FOS) using a finite number of available state feedback controls, none of which is capable of stabilizing the LTI-FOS by itself. First, a system with integer order derivatives is defined and its existence is proved, which has stability equivalent properties with respect to the fractional system. This makes it possible to use Lyapunov function and convex analysis in order to define the sliding sector and develop a variable structure control which enables the switching between available control gains and stabilizing the fractional order system.

  14. Switching control of linear systems subject to asymmetric actuator saturation

    NASA Astrophysics Data System (ADS)

    Yuan, Chengzhi; Wu, Fen

    2015-01-01

    In this paper, we study the saturation control problem for linear time-invariant (LTI) systems subject to asymmetric actuator saturation under a switching control framework. The LTI plant with asymmetric saturation is first transformed to an equivalent switched linear model with each subsystem subject to symmetric actuator saturation, based on which a dwell-time switching controller augmented with a controller state reset is then developed by using multiple Lyapunov functions. The controller synthesis conditions are formulated as linear matrix inequalities (LMIs), which can be solved efficiently. Simulation results are also included to illustrate the effectiveness and advantages of the proposed approach.

  15. Swarming Unmanned Aerial Vehicles: Concept Development and Explementation, A State of the Art Review on Flight and Mission Control

    DTIC Science & Technology

    2003-12-01

    studied mainly for Linear Time Invariant (LTI) systems, without or with state variables and/or control constraints [35]. All MPC controllers share...requires extensive simulation studies and avionics manufacturers sometimes offer dedicated softwares for aircraft simulator including avionics models...Kim, D.Necsulescu, Autonomous Mobile Vehicles for Motion on Uneven and Inclined Surfaces, Electromotion, Quaterly Int. Journal, Vol 5, No

  16. A Decision Tool for Selecting a Sustainable Learning Technology Intervention

    ERIC Educational Resources Information Center

    Raji, Maryam; Zualkernan, Imran

    2016-01-01

    Education is a basic human right. In pursuit of this right, governments in developing countries and their donors often invest scarce resources in educational initiatives that are sometimes not sustainable. This paper addresses the problem of selecting a sustainable learning technology intervention (LTI) for a typical developing country. By solving…

  17. Exogenous administration of chronic corticosterone affects hepatic cholesterol metabolism in broiler chickens showing long or short tonic immobility.

    PubMed

    Liu, Jie; Duan, Yujing; Hu, Yun; Sun, Lili; Wang, Song; Fu, Wenyan; Ni, Yingdong; Zhao, Ruqian

    2016-01-01

    Tonic immobility (TI) is an innate characteristic of animals related to fear or stress response. Animals can be classified into long TI (LTI) and short TI (STI) phenotypes based on TI test duration. In this study, effect of TI phenotype, chronic corticosterone administration (CORT), and their interaction on cholesterol metabolism in liver was evaluated in broilers. LTI broilers showed higher level of cholesterol in liver compared to STI chickens (p<0.05), and CORT significantly increased hepatic cholesterol content (p<0.01). Real-time PCR results showed that both TI and CORT potentially altered ABCA1 and CYP7A1 gene expressions (0.05LTI broilers showed higher level of HMGCR protein expression in liver than STI (p<0.05). These results indicate that chronic CORT administration causes hepatic cholesterol accumulation in broiler chickens mainly by enhancing cholesterol synthesis and uptake into liver. LTI chickens had higher amount of total cholesterol in liver, which might be associated with an increase of hepatic HMGCR protein expression. However, there is no interaction between TI and CORT on cholesterol metabolism in liver of broilers.

  18. A local identification method for linear parameter-varying systems based on interpolation of state-space matrices and least-squares approximation

    NASA Astrophysics Data System (ADS)

    Ferranti, Francesco; Rolain, Yves

    2017-01-01

    This paper proposes a novel state-space matrix interpolation technique to generate linear parameter-varying (LPV) models starting from a set of local linear time-invariant (LTI) models estimated at fixed operating conditions. Since the state-space representation of LTI models is unique up to a similarity transformation, the state-space matrices need to be represented in a common state-space form. This is needed to avoid potentially large variations as a function of the scheduling parameters of the state-space matrices to be interpolated due to underlying similarity transformations, which might degrade the accuracy of the interpolation significantly. Underlying linear state coordinate transformations for a set of local LTI models are extracted by the computation of similarity transformation matrices by means of linear least-squares approximations. These matrices are then used to transform the local LTI state-space matrices into a form suitable to achieve accurate interpolation results. The proposed LPV modeling technique is validated by pertinent numerical results.

  19. The State of the Art of Computer Programming

    DTIC Science & Technology

    1976-06-01

    46 .3. ; ["vrn, Shimon, 239. f • 173 : Flye Samnte-Marie, Camille, .580. lti Z1 174 elvhir Ficlrr, David Allen Llq Hamlet , P’rince of D)enmark, 228... Shakespeare , William, 228, 465. I )-I L191 dele Shih-ehih, Chu entry ii 192 Steel(- Jr., Guy I,ewir (-Quux), 594. 193 Strong, Hovey Raymond, Jr., 556

  20. Working Group on Ice Forces; State-of-the-Art Report (3rd),

    DTIC Science & Technology

    1987-09-01

    a Lo -ta stucture : An e X Ter imental ;tUdy. Proceedings, Eighth nierinatioiial Conference on Port an(! ocean Engineering (POAC), Nn,’rssa,-rssuiag...rlct’ire of a flawed sample is given by Hallam (1986, this * *~. . i- i lti-.rItion let its suppose the sample to be cubic of side hiv - roguir f laws

  1. A Singular Perturbation Approach for Time-Domain Assessment of Phase Margin

    NASA Technical Reports Server (NTRS)

    Zhu, J. Jim; Yang, Xiaojing; Hodel, A Scottedward

    2010-01-01

    This paper considers the problem of time-domain assessment of the Phase Margin (PM) of a Single Input Single Output (SISO) Linear Time-Invariant (LTI) system using a singular perturbation approach, where a SISO LTI fast loop system, whose phase lag increases monotonically with frequency, is introduced into the loop as a singular perturbation with a singular perturbation (time-scale separation) parameter Epsilon. First, a bijective relationship between the Singular Perturbation Margin (SPM) max and the PM of the nominal (slow) system is established with an approximation error on the order of Epsilon(exp 2). In proving this result, relationships between the singular perturbation parameter Epsilon, PM of the perturbed system, PM and SPM of the nominal system, and the (monotonically increasing) phase of the fast system are also revealed. These results make it possible to assess the PM of the nominal system in the time-domain for SISO LTI systems using the SPM with a standardized testing system called "PM-gauge," as demonstrated by examples. PM is a widely used stability margin for LTI control system design and certification. Unfortunately, it is not applicable to Linear Time-Varying (LTV) and Nonlinear Time-Varying (NLTV) systems. The approach developed here can be used to establish a theoretical as well as practical metric of stability margin for LTV and NLTV systems using a standardized SPM that is backward compatible with PM.

  2. Determination of Lakeshore Technical Institute Associate Degree Nursing Graduates' Nursing Competencies Level.

    ERIC Educational Resources Information Center

    Schrader, Marvin A.

    In an effort to determine the effectiveness of Lakeshore Technical Institute's (LTI's) Associate Degree Nursing (ADN) program, questionnaires were administered to 1982 program graduates (N=45) and their employers (N=43) requesting an assessment of the graduates' preparedness to perform 39 nursing functions. Responses were submitted to a…

  3. Comparison Sensitivity Design of Output Feedback Systems Using State Observers.

    DTIC Science & Technology

    1978-01-01

    of sensitivity reduction in feedback systems which use state observers for dynamic compensation is considered leading to a design procedure which...results developed using state observers in the compensator dynamics. All systems discussed are assumed to be linear time invariant (LTI) systems which are state controllable and state observable. (Author)

  4. US EPA, Pesticide Product Label, , 03/20/1975

    EPA Pesticide Factsheets

    2011-04-21

    ... AUHI1a .. .i4 S ~"aula~ Lt;i Spot. ... oecu4. Po ~ct 4rci~ ~~£, tat~~~ ccnd~tic~~ ~av~~ d~{~t !\\r~ 4~~a) :,cat~d. 0: ~ct eO'lt~~i~ar~ ~al~' bu ...

  5. Sufficient condition for stabilization of linear time invariant fractional order switched systems and variable structure control stabilizers.

    PubMed

    Balochian, Saeed; Sedigh, Ali Khaki

    2012-01-01

    This paper presents the stabilization problem of a linear time invariant fractional order (LTI-FO) switched system with order 1LTI-FO switched system with order 1LTI-FO switched system so that each state in the state space is inside at least one sliding sector with its corresponding subsystem, where the Lyapunov function found by the extremum seeking control is decreasing. Finally, a switching control law is designed to switch the LTI-FO switched system among subsystems to ensure the decrease of the Lyapunov function in the state space. Simulation results are given to show the effectiveness of the proposed VS controller.

  6. The incidence of lymphocytic thyroid infiltration and Hashimoto's thyroiditis increased in patients operated for benign goiter over a 31-year period.

    PubMed

    Ott, Johannes; Meusel, Moritz; Schultheis, Andrea; Promberger, Regina; Pallikunnel, Shannon Joan; Neuhold, Nikolaus; Hermann, Michael

    2011-09-01

    The incidence of Hashimoto's thyroiditis (HT) seems to have increased over the last several decades. Since there is a lack of recent studies in the literature that evaluate this phenomenon on a histological basis, we aimed to assess the incidence of lymphocytic thyroid infiltration (LTI) in our large surgical patient collective over a 31-year period. In our study, a total of 1,050 patients who had undergone uni- or bilateral thyroid surgery for benign goiter were included (150 patients in each group, during 1979 to 2009). The stored histological sections of the removed thyroid specimens were re-analyzed, including routine grading of LTI severity on a scale of 0-4, according to Williams and Doniach. Positive correlations were seen for the incidences of LTI grading (0-4) (r = 0.077, p = 0.013) and HT (r = 0.044, p = 0.078) over the years. Furthermore, when comparing the years 1979-1989 and 1994-2009, i.e., before and after the second iodine prophylaxis had been introduced in Austria, a higher incidence of HT was found for the later years (2 out of 450, 0.4%, vs. 6 out of 600, 1.0%, respectively; p < 0.0001). In conclusion, the data demonstrate that the incidence of LTI and HT has increased substantially over the last 31 years.

  7. Molecular mechanism of enzyme inhibition: prediction of the three-dimensional structure of the dimeric trypsin inhibitor from Leucaena leucocephala by homology modelling.

    PubMed

    Sattar, Rabia; Ali, Syed Abid; Kamal, Mustafa; Khan, Aftab Ahmed; Abbasi, Atiya

    2004-02-13

    Serine proteinase inhibitors are widely distributed in nature and inhibit the activity of enzymes like trypsin and chymotrypsin. These proteins interfere with the physiological processes such as germination, maturation and form the first line of defense against the attack of seed predator. The most thoroughly examined plant serine proteinase inhibitors are found in the species of the families Leguminosae, Graminae, and Solanaceae. Leucaena leucocephala belongs to the family Leguminosae. It is widely used both as an ornamental tree as well as cattle food. We have constructed a three-dimensional model of a serine proteinase inhibitor from L. leucocephala seeds (LTI) complexed with trypsin. The model was built based on its comparative homology with soybean trypsin inhibitor (STI) using the program, MODELLER6. The quality of the model was assessed stereochemically by PROCHECK. LTI shows structural features characteristic of the Kunitz type trypsin inhibitor and shows 39% residue identity with STI. LTI consists of 172 amino acid residues and is characterized by two disulfide bridges. The protein is a dimer with the two chains being linked by a disulfide bridge. Despite the high similarity in the overall tertiary structure, significant differences exist at the active site between STI and LTI. The present study aims at analyzing these interactions based on the available amino acid sequences and structural data. We have also studied some functional sites such as phosphorylation, myristoylation, which can influence the inhibitory activity or complexation with other molecules. Some of the differences observed at the active site and functional sites can explain the unique features of LTI.

  8. Adapting acceptance and commitment therapy for parents of children with life-threatening illness: pilot study.

    PubMed

    Burke, Kylie; Muscara, Frank; McCarthy, Maria; Dimovski, Anica; Hearps, Stephen; Anderson, Vicki; Walser, Robyn

    2014-03-01

    We piloted a novel parent-targeted intervention, Take A Breath (TAB), for parents of children diagnosed with a life-threatening illness (LTI) with the aim of reducing parental distress. Parents were assisted to adapt to their child's diagnosis, treatment, and recovery via TAB's combined acceptance and commitment therapy (ACT) and problem-solving skills training (PSST) approach. Participants were 11 parents of children with a diagnosis of cancer, or who had life-saving cardiac surgery at least 4 months prior. Parents completed questionnaires at pre, post, and 6-month follow-up assessing parent posttraumatic stress symptoms (PTSS), the emotional impact of the child's LTI (e.g., feelings of uncertainty, guilt and sorrow, emotional resources), and psychological elements targeted by the intervention (parental psychological flexibility and mindfulness). Parents reported significant reductions in PTSS and emotional impact from their child's LTI, along with significant improvements in parental psychological flexibility and mindfulness. Effect sizes were medium to large, and improvements were maintained at 6-month follow-up. Our pilot indicates the TAB intervention has promise for preventing or reducing parental distress associated with child LTI and warrants more rigorous evaluation. Although preliminary, these findings suggest that targeting parents' subjective perceptions of their child's LTI may be an effective approach to reducing parental distress. Our results also indicate the potential for such an approach to be adopted across diverse child diagnoses in the acute pediatric setting. Further, our findings provide early indications that ACT combined with PSST is an appropriate therapeutic approach within this context.

  9. Low lean tissue mass is an independent risk factor for mortality in patients with stages 4 and 5 non-dialysis chronic kidney disease

    PubMed Central

    Abad, Soraya; Macías, Nicolás; Aragoncillo, Inés; Santos, Alba; Galán, Isabel; Cedeño, Santiago; Manuel López-Gómez, Juan

    2017-01-01

    Abstract Background: Mortality in patients with stages 4 and 5 chronic kidney disease (CKD) is higher than in the general population. Body composition predicts mortality. Our objective was to evaluate the effect of body composition on mortality in patients with stages 4 and 5 non-dialysis CKD. Methods: We performed a prospective study of 356 patients with stages 4 and 5 non-dialysis CKD. At baseline, we recorded general characteristics, history of cardiovascular events, body composition, serum inflammatory markers, nutrition and cardiac biomarkers. Body composition was analysed using bioimpedance spectroscopy. We recorded the lean tissue index (LTI), fat tissue index (FTI) and overhydration (OH). During a median (range) follow-up of 22 (3–49) months, we recorded mortality, cardiovascular events and progress to renal replacement therapy. Results: At baseline, mean (± standard deviation) age was 67 ± 13 years (men 64%; diabetes 36%). Mean body mass index was 28.2 ± 12.8 kg/m2, the FTI was 12.3 ± 5.6 kg/m2, the LTI was 15.7 ± 3.4 kg/m2 and median (interquartile range) OH was 0.6 (−0.4 to 1.5) L. Sixty-four (18%) patients died during follow-up. The univariate Cox analysis showed an association between mortality and age, low LTI, high Charlson comorbidity index, previous cardiovascular events, OH, low albumin and prealbumin levels, and high C-reactive protein levels. Kaplan–Meier analysis revealed higher survival in patients with a higher LTI (log-rank, 9.47; P = 0.002). The multivariate Cox analysis confirmed an association between mortality and low LTI (P = 0.031), previous cardiovascular events (P = 0.003) and high Charlson comorbidity index (P = 0.01). We did not find any association between body composition and cardiovascular events or renal replacement therapy. Conclusions: A low LTI is an independent factor for mortality in patients with stages 4 and 5 CKD.

  10. Pharmacokinetics and pharmacodynamics of ch14.18/CHO in relapsed/refractory high-risk neuroblastoma patients treated by long-term infusion in combination with IL-2.

    PubMed

    Siebert, Nikolai; Eger, Christin; Seidel, Diana; Jüttner, Madlen; Zumpe, Maxi; Wegner, Danilo; Kietz, Silke; Ehlert, Karoline; Veal, Gareth J; Siegmund, Werner; Weiss, Michael; Loibner, Hans; Ladenstein, Ruth; Lode, Holger N

    2016-01-01

    Ch14.18 manufactured in Chinese hamster ovary (CHO) cells is currently being evaluated in clinical trials. Short-term infusion (STI) (8-20 h/day; 4-5 days) of 100 mg/m2 ch14.18/CHO (dinutiximab β) per cycle in combination with cytokines is standard treatment of neuroblastoma (NB) patients. As pain is a limiting factor, we investigated a novel delivery method by continuous long-term infusion (LTI) of 100 mg/m2 over 10 days. 53 NB patients were treated with 5-6 cycles of 6 × 106 IU/m2 subcutaneous interleukin-2 (d 1-5, 8-12), LTI of 100 mg/m2 ch14.18/CHO (d 8-18) and 160 mg/m2 oral 13-cis-retinoic acid (d 22-35). Human anti-chimeric antibody (HACA), antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity were determined. With LTI, we observed a maximum concentration of ch14.18/CHO (Cmax) of 12.56 ± 0.68 µg/ml and a terminal half-life time (t1/2 β) of 32.7 ± 16.2 d. The clearance values for LTI and STI of 0.54 ± 0.13 and 0.41 ± 0.29 L/d m2 and area under the serum concentration-time curve (AUC) values of 189.6 ± 41.4 and 284.8 ± 156.8 µg×d/ml, respectively, were not significantly different. Importantly, we detected ch14.18/CHO trough concentration of ≥ 1 µg/ml at time points preceding subsequent antibody infusions after cycle 1, allowing a persistent activation of antibody effector mechanisms over the entire treatment period of 6 months. HACA responses were observed in 10/53 (19%) patients, similar to STI (21%), indicating LTI had no effect on the immunogenicity of ch14.18/CHO. In conclusion, LTI of ch14.18/CHO induced effector mechanisms over the entire treatment period, and may therefore emerge as the preferred delivery method of anti-GD2 immunotherapy to NB patients.

  11. Comparison of kinetic and extended magnetohydrodynamics computational models for the linear ion temperature gradient instability in slab geometry

    NASA Astrophysics Data System (ADS)

    Schnack, D. D.; Cheng, J.; Barnes, D. C.; Parker, S. E.

    2013-06-01

    We perform linear stability studies of the ion temperature gradient (ITG) instability in unsheared slab geometry using kinetic and extended magnetohydrodynamics (MHD) models, in the regime k∥/k⊥≪1. The ITG is a parallel (to B) sound wave that may be destabilized by finite ion Larmor radius (FLR) effects in the presence of a gradient in the equilibrium ion temperature. The ITG is stable in both ideal and resistive MHD; for a given temperature scale length LTi0, instability requires that either k⊥ρi or ρi/LTi0 be sufficiently large. Kinetic models capture FLR effects to all orders in either parameter. In the extended MHD model, these effects are captured only to lowest order by means of the Braginskii ion gyro-viscous stress tensor and the ion diamagnetic heat flux. We present the linear electrostatic dispersion relations for the ITG for both kinetic Vlasov and extended MHD (two-fluid) models in the local approximation. In the low frequency fluid regime, these reduce to the same cubic equation for the complex eigenvalue ω =ωr+iγ. An explicit solution is derived for the growth rate and real frequency in this regime. These are found to depend on a single non-dimensional parameter. We also compute the eigenvalues and the eigenfunctions with the extended MHD code NIMROD, and a hybrid kinetic δf code that assumes six-dimensional Vlasov ions and isothermal fluid electrons, as functions of k⊥ρi and ρi/LTi0 using a spatially dependent equilibrium. These solutions are compared with each other, and with the predictions of the local kinetic and fluid dispersion relations. Kinetic and fluid calculations agree well at and near the marginal stability point, but diverge as k⊥ρi or ρi/LTi0 increases. There is good qualitative agreement between the models for the shape of the unstable global eigenfunction for LTi0/ρi=30 and 20. The results quantify how far fluid calculations can be extended accurately into the kinetic regime. We conclude that for the linear ITG

  12. Colonic Patch and colonic SILT development are independent and differentially-regulated events

    PubMed Central

    Baptista, AP; Olivier, BJ; Goverse, G; Greuter, M; Knippenberg, M; Kusser, K; Domingues, RG.; Veiga-Fernandes, H; Luster, AD; Lugering, A; Randall, TD; Cupedo, T; Mebius, RE

    2012-01-01

    Intestinal lymphoid tissues have to simultaneously ensure protection against pathogens and tolerance towards commensals. Despite such vital functions, their development in the colon is poorly understood. Here, we show that the two distinct lymphoid tissues of the colon–colonic patches and colonic SILTs–can easily be distinguished based on anatomical location, developmental timeframe and cellular organization. Furthermore, whereas colonic patch development depended on CXCL13-mediated LTi cell clustering followed by LTα-mediated consolidation, early LTi clustering at SILT anlagen did not require CXCL13, CCR6 or CXCR3. Subsequent dendritic cell recruitment to and gp38+VCAM-1+ lymphoid stromal cell differentiation within SILTs required LTα; B cell recruitment and follicular dendritic cell differentiation depended on MyD88-mediated signalling, but not the microflora. In conclusion, our data demonstrate that different mechanisms, mediated mainly by programmed stimuli, induce the formation of distinct colonic lymphoid tissues, therefore suggesting that these tissues may have different functions. PMID:22990625

  13. Stabilising compensators for linear time-varying differential systems

    NASA Astrophysics Data System (ADS)

    Oberst, Ulrich

    2016-04-01

    In this paper, we describe a constructive test to decide whether a given linear time-varying (LTV) differential system admits a stabilising compensator for the control tasks of tracking, disturbance rejection or model matching and construct and parametrise all of them if at least one exists. In analogy to the linear time-invariant (LTI) case, the ring of stable rational functions, noncommutative in the LTV situation, and the Kučera-Youla parametrisation play prominent parts in the theory. We transfer Blumthaler's thesis from the LTI to the LTV case and sharpen, complete and simplify the corresponding results in the book 'Linear Time-Varying Systems' by Bourlès and Marinescu.

  14. Coarse mode aerosol measurement using a Low Turbulence Inlet

    NASA Astrophysics Data System (ADS)

    Brooke, J.; Bart, M.; Trembath, J.; McQuaid, J. B.; Brooks, B. J.; Osborne, S.

    2012-04-01

    The Sahara desert is a major natural source of global mineral dust emissions (Forster et al., 2007) through the mobilisation and lifting of dust particles into the atmosphere from dust storms. A significant fraction of this dust is in the aerosol coarse mode (Weinzierl et al., 2009). It is highlighted of the difficulty in making accurate and reliable measurements from an aircraft platform, particularly that of coarse mode aerosol (Wendisch et al., 2004). To achieve the measurement of a representative aerosol sample an aerosol inlet, on an aircraft, is required for the delivery of the sample to the instruments making the measurements. Inlet design can modify aerosol size distribution through either underestimating due to aerosol losses or overestimation due to enhancements. The Low Turbulence Inlet (LTI) was designed to improve inlet efficiency. This is achieved by reducing turbulence flow within the tip of the inlet, reducing impaction of particles to the walls of the inlet (Wilson et al., 2004). The LTI further maintains isokinetic sampling flow (free stream velocity, U0 and sampling velocity, U are equal to 1). Dust aerosol over the Sahara desert provides an excellent environment to test and quantify the capabilities of the LTI on the FAAM BAe 146, whilst enabling in-situ dust measurement. The LTI was operated during the Fennec field campaign in June 2011 with 11 flights during the campaign over Mauritania and Mali. We are using the LTI to provide critical information on the sampling characteristics of the inlet used by nearly all aerosol instruments inside the aircraft (AMS, Nephelometer, PSAP, and CCN). Inlet experiments were performed with identical Optical Particle Counters (OPC) connected to the rosemount and LTI with size distribution for each inlet measured and Rosemount enhancements determined. Rosemount inlet enhancements were determined to be 2 to 4 times for particles up to 2.5 µm. A key parameter in aerosol measurement is size distribution, in which

  15. A method for designing robust multivariable feedback systems

    NASA Technical Reports Server (NTRS)

    Milich, David Albert; Athans, Michael; Valavani, Lena; Stein, Gunter

    1988-01-01

    A new methodology is developed for the synthesis of linear, time-invariant (LTI) controllers for multivariable LTI systems. The aim is to achieve stability and performance robustness of the feedback system in the presence of multiple unstructured uncertainty blocks; i.e., to satisfy a frequency-domain inequality in terms of the structured singular value. The design technique is referred to as the Causality Recovery Methodology (CRM). Starting with an initial (nominally) stabilizing compensator, the CRM produces a closed-loop system whose performance-robustness is at least as good as, and hopefully superior to, that of the original design. The robustness improvement is obtained by solving an infinite-dimensional, convex optimization program. A finite-dimensional implementation of the CRM was developed, and it was applied to a multivariate design example.

  16. Reliable regulation in decentralised control systems

    NASA Astrophysics Data System (ADS)

    Locatelli, Arturo; Schiavoni, Nicola

    2011-03-01

    This article addresses the design of decentralised regulators which supply the control systems with signal tracking and disturbance rejection. This property has to be attained, to the maximum possible extent, even when instrumentation faults occur, thus causing the opening of some feedback loops. The problem is tackled for LTI asymptotically stable plants, subject to perturbations, under the assumption that the Laplace transforms of the exogenous signals have multiple poles on the imaginary axis. The proposed regulator is composed of an LTI nominal controller supervised by a reconfiguration block. Once the actions of the reconfiguration block have been settled, the synthesis of the nominal controller is reformulated as a suitable regulation problem. A constructive sufficient condition for its solvability is established. This condition turns out to be also necessary if the exogenous signals are polynomial in time.

  17. Project Selection in Monolithic Organizations.

    DTIC Science & Technology

    1974-08-01

    Financing in Canada. University of Western (June 1973) Ontario. 4. Blair Little School of Business The Assessment of Markets for the R.G. Cooper...Sp~cialement des Entreprises Utilisant des Techniques de Production Avancies. (dfcembre 1973) 17. I. Vertinsky Fac~lty of Commerce and Project...P.J. Halpern Studies, University of by Forest Products Industries. Toronto. (Nay 1975) 30. J.C.T. Nko Faculty of Commerce and Venture Capital Financing

  18. Dead Zone Oscillator Control for Communication-Free Synchronization of Paralleled, Three-Phase, Current-Controlled Inverters

    DTIC Science & Technology

    2016-05-11

    social networks [10]. The electrical circuit-equivalent of the Dead-Zone oscillator is shown in Figure 2 [8]. The voltage-dependent current source g(Vosc...in an LTI electrical power network ,” IEEE Trans. Circuits Syst. I, vol. 61, no. 3, pp. 834–844, 2014. [Online]. Available: http://ieeexplore.ieee.org...stamp/stamp.jsp?arnumber=6701226 [6] F. Dörfler, M. Chertkov, and F. Bullo, “Synchronization in complex oscillator networks and smart grids

  19. Property Investigation of Laser Cladded, Laser Melted and Electron Beam Melted Ti-Al6-V4

    DTIC Science & Technology

    2006-05-01

    melting follows a specific pattern, usually a scan strategy optimised in regard to speed, surface quality and residual stresses generated. The process...unlimited 13. SUPPLEMENTARY NOTES See also ADM202748. Cost Effective Manufacture via Net Shape Processing (Rentabilite de fabrication par un traitement ...Modulus [GPa] 116 120 116 Source EADS Arcam EADS Annea l 6 x MA MA stress relief 0 4 8 12 16 1000 1200 Y ie ld S tre ng th Y S , U lti m at e

  20. Results on Cyclic Signal Processing Systems,

    DTIC Science & Technology

    1998-01-01

    8] Vaidyanathan, P. P. Multirate systems and filter banks , Prentice Hall, 1993. [9] Vaidyanathan, P. P., and Kirac, A. "Theory of cyclic filter ...91125 Abstract We present a state space description for cyclic LTI sys- tems which find applications in cyclic filter banks and wavelets. We also...in a unified way by using the realization matrix defined by the state space description. 1. INTRODUCTION Cyclic digital filters and filter banks

  1. Synthesis Methods for Robust Passification and Control

    NASA Technical Reports Server (NTRS)

    Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

    2000-01-01

    The research effort under this cooperative agreement has been essentially the continuation of the work from previous grants. The ongoing work has primarily focused on developing passivity-based control techniques for Linear Time-Invariant (LTI) systems. During this period, there has been a significant progress made in the area of passivity-based control of LTI systems and some preliminary results have also been obtained for nonlinear systems, as well. The prior work has addressed optimal control design for inherently passive as well as non- passive linear systems. For exploiting the robustness characteristics of passivity-based controllers the passification methodology was developed for LTI systems that are not inherently passive. Various methods of passification were first proposed in and further developed. The robustness of passification was addressed for multi-input multi-output (MIMO) systems for certain classes of uncertainties using frequency-domain methods. For MIMO systems, a state-space approach using Linear Matrix Inequality (LMI)-based formulation was presented, for passification of non-passive LTI systems. An LMI-based robust passification technique was presented for systems with redundant actuators and sensors. The redundancy in actuators and sensors was used effectively for robust passification using the LMI formulation. The passification was designed to be robust to an interval-type uncertainties in system parameters. The passification techniques were used to design a robust controller for Benchmark Active Control Technology wing under parametric uncertainties. The results on passive nonlinear systems, however, are very limited to date. Our recent work in this area was presented, wherein some stability results were obtained for passive nonlinear systems that are affine in control.

  2. Airborne Sensor Potential for Habitat Evaluation Procedures (HEP).

    DTIC Science & Technology

    1986-02-01

    guidelines for the d, vol-Ipitnet (A airborne sensor 3ppi ic~tions to the US Fish and Wililtifc...fr.iq J.Iqjsn *uld q~jq pooCg - A0,I- P.9A -41100fi uPall- -iied qus. o .;A (W.3 P.S’-.9. .1JI1OP. ua.l.t:4 𔃻𔃾lti P.,SC)Pts r.- aaop s0ul-~r9Iw

  3. A High Altitude Infrared Radiance Model

    DTIC Science & Technology

    1977-11-30

    too. W N.ao ow %a S MV 0 ) weOK 4%NK06 W411404~MP mww.0O` 0 N U𔃾%~N se t QDO % O P0 ON 0) a 1%r𔄃ltI C, w 0m94N N~~~~~~~~~ U’ U’ * 0 10 g0 104.* 01

  4. Are the Current Classifications and Radiographic Measurements for Trochlear Dysplasia Appropriate in the Skeletally Immature Patient?

    PubMed Central

    Stepanovich, Matthew; Bomar, James D.; Pennock, Andrew T.

    2016-01-01

    Background: The assessment and classification of trochlear dysplasia in pediatric patients has yet to be well documented or validated. Purpose: To examine several different measurements/classifications of trochlear dysplasia in skeletally immature patients to assess inter- and intraobserver reliability and to determine which best correlates with patellar instability. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Radiographs and magnetic resonance imaging (MRI) scans of 36 skeletally immature patients undergoing surgery for patellar instability were compared with 27 age-matched cohort patients who had similar imaging for an acute knee injury but no clinical evidence of patellar instability. Trochlear dysplasia was measured/classified using the radiographic and MRI Dejour classifications, the trochlear depth index (TDI), the lateral trochlear inclination (LTI), and the medial condyle trochlear offset (MCTO). Additionally, the tibial tubercle–trochlear groove (TT-TG) distance was calculated for all patients. Inter- and intraobserver reliability of each measurement, as well as the ability to discriminate patients with patellar instability, were evaluated. Results: Inadequate radiographs prevented the radiographic Dejour classification from being assessed in 78% of cases. The MRI Dejour classification had the lowest inter- and intraobserver reliabilities (κ = 0.687 and 0.596, respectively); all other measurements were greater than 0.80. The TDI, LTI, and MCTO all significantly differentiated patients with patellar instability compared with those with no instability, with critical cutoffs of 3 mm, 17°, and 1 mm, respectively. Patients with a TDI <3 mm or MCTO <1 mm were 33 and 38 times more likely to have patellar instability, respectively. The TT-TG was directly correlated with trochlear dysplasia severity. Conclusion: Trochlear dysplasia is common in skeletally immature patients with patellar instability. The objective assessment of

  5. Synthetic Infrared Scene: Improving the KARMA IRSG Module and Signature Modelling Tool SMAT

    DTIC Science & Technology

    2011-03-01

    Desmeules Alexandre Bastien Louis Tanguay Informatique inc. Geoffroy Rivet-Sabourin Technologie Intelligence Image inc. Prepared By: Louis Tanguay... Informatique inc. 825 Boulevard Lebourgneuf, Bureau 204 Québec, Canada G2J 0B9 Contractor’s Document Number: LTI-SIS-2011-1 Contract Project Manager...Alexandre Bastien Louis Tanguay Informatique inc. Geoffroy Rivet-Sabourin Technologie Intelligence Image inc. Prepared By: Louis Tanguay

  6. Oakland Harbor. Deep-Draft Navigation Improvements. Design Memorandum Number 1, General Design and Final Supplement 1 to the Environmental Impact Statement, Alameda County, California.

    DTIC Science & Technology

    1988-03-01

    sites on the-basis of less potential impacts on fisheries and the Farallon Islands ational marine Sanctuary. The S1 and BIA sites are 24 nautical oles...eavigtLon inprovements Almned County, California(Sept. 1987) 2) Zone of Siting VeaibilLty Analysis for the San * ranoiaeo/oulf of the Farallones ...Report (Dec. 1987) 5) Baseline Survey and Bite Selection for Ooean Disposal, Gulf of the Farallones (Nybakken et al., 1984) 6) San Prancisoo Bay Dredged

  7. Mitigation and Treatment of Radiation-Induced Thoracic Injury With a Cyclooxygenase-2 Inhibitor, Celecoxib

    SciTech Connect

    Hunter, Nancy R.; Valdecanas, David; Liao Zhongxing; Milas, Luka; Thames, Howard D.; Mason, Kathy A.

    2013-02-01

    Purpose: To test whether a cyclooxygenase-2 inhibitor (celecoxib) could reduce mortality resulting from radiation-induced pneumonitis. Methods and Materials: Celecoxib was given to mice twice daily for 40 consecutive days starting on the day of local thoracic irradiation (LTI) or 40 or 80 days later. C3Hf/KamLaw mice were observed for morbidity, and time to death was determined. Results were analyzed using the Cox proportional hazards model. Results: Timing of celecoxib relative to LTI determined efficacy. A significant reduction in time to death was achieved only when celecoxib was started 80 days after LTI, corresponding to the time when pneumonitis is expressed. For these mice the reduction in mortality was quantified as a hazard ratio for mortality of treated vs untreated of 0.36 (95% confidence interval [CI] 0.24-0.53), thus significantly less than 1.0. Correspondingly, the median lethal dose for treated mice (12.9 Gy; 95% CI 12.55-13.25 Gy) was significantly (P=.026) higher than for untreated mice (12.4 Gy; 95% CI 12.2-12.65 Gy). Conclusions: Celecoxib significantly reduced lung toxicity when administered months after LTI when the deleterious effects of radiation were expressed. The schedule-dependent reduction in fatal pneumonitis suggests that celecoxib could be clinically useful by reintroduction of treatment months after completion of radiation therapy. These findings may be important for designing clinical trials using cyclooxygenase-2 inhibitors to treat radiation-induced lung toxicity as a complement to concurrent radiation therapy of lung cancers.

  8. Constrained Trajectory Optimization Using Pseudospectral Methods (Preprint)

    DTIC Science & Technology

    2008-08-05

    at itu de , d eg POST SPOCS Figure 5. Trajectory Comparison of Integration Method Comparison IV.B. Basic Optimization Comparison The second set of...1500 2000 2500 3000 20 30 40 50 60 70 80 90 100 110 120 Altitude Time, sec A lti tu de , k m POST SPOCS Figure 7. Altitude Comparison of the First...Coordinates Z , k m POST SPOCS Figure 8. Range Comparison of the First Optimization Comparison 13 of 33 American Institute of Aeronautics and

  9. Translation Invariant Extensions of Finite Volume Measures

    NASA Astrophysics Data System (ADS)

    Goldstein, S.; Kuna, T.; Lebowitz, J. L.; Speer, E. R.

    2017-02-01

    We investigate the following questions: Given a measure μ _Λ on configurations on a subset Λ of a lattice L, where a configuration is an element of Ω ^Λ for some fixed set Ω , does there exist a measure μ on configurations on all of L, invariant under some specified symmetry group of L, such that μ _Λ is its marginal on configurations on Λ ? When the answer is yes, what are the properties, e.g., the entropies, of such measures? Our primary focus is the case in which L=Z^d and the symmetries are the translations. For the case in which Λ is an interval in Z we give a simple necessary and sufficient condition, local translation invariance ( LTI), for extendibility. For LTI measures we construct extensions having maximal entropy, which we show are Gibbs measures; this construction extends to the case in which L is the Bethe lattice. On Z we also consider extensions supported on periodic configurations, which are analyzed using de Bruijn graphs and which include the extensions with minimal entropy. When Λ subset Z is not an interval, or when Λ subset Z^d with d>1, the LTI condition is necessary but not sufficient for extendibility. For Z^d with d>1, extendibility is in some sense undecidable.

  10. Lagrangian simulations and interannual variability of anchovy egg and larva dispersal in the Sicily Channel

    NASA Astrophysics Data System (ADS)

    Palatella, Luigi; Bignami, Francesco; Falcini, Federico; Lacorata, Guglielmo; Lanotte, Alessandra S.; Santoleri, Rosalia

    2014-02-01

    The interannual variability in the transport of anchovy eggs and larvae in the Sicily Channel, relatively to the period 1999-2012, is studied by means of numerical simulations of the Mediterranean Forecasting System (MFS) circulation model provided by INGV. Subgrid-scale dynamics not resolved by the MFS model is parameterized in terms of kinematic fields. The latter affect small-scale tracer relative dispersion, while leaving the mean large-scale advection substantially unchanged. A Lagrangian Transport Index (LTI) can be defined to characterize the efficiency of the main currents, e.g., the Atlantic Ionian Stream, in connecting spawning and nursery areas to each other. In our case, this indicator comes from the first arrival time statistics of tracers traveling from a spawning area near Sciacca to a nursery area in proximity of Cape Passero. We observe, on the basis of LTI values, that there are years when the Lagrangian connectivity is very efficient (2004, 2008, 2012) and years when it is weak (2000, 2001, 2003, 2010). Lagrangian indicators like the LTI concur to explain observed fluctuations of larval density and, also, can be employed, more in general, in multivariate models of population dynamics.

  11. Development of Fearfulness in Birds: Genetic Factors Modulate Non-Genetic Maternal Influences

    PubMed Central

    Houdelier, Cécilia; Lumineau, Sophie; Bertin, Aline; Guibert, Floriane; De Margerie, Emmanuel; Augery, Matthieu; Richard-Yris, Marie-Annick

    2011-01-01

    The development of fearfulness and the capacity of animals to cope with stressful events are particularly sensitive to early experience with mothers in a wide range of species. However, intrinsic characteristics of young animals can modulate maternal influence. This study evaluated the effect of intrinsic fearfulness on non-genetic maternal influence. Quail chicks, divergently selected for either higher (LTI) or lower fearfulness (STI) and from a control line (C), were cross-fostered by LTI or STI mothers. Behavioural tests estimated the chicks' emotional profiles after separation from the mother. Whatever their genotype, the fearfulness of chicks adopted by LTI mothers was higher than that of chicks adopted by STI mothers. However, genetic background affected the strength of maternal effects: the least emotional chicks (STI) were the least affected by early experience with mothers. We demonstrated that young animal's intrinsic fearfulness affects strongly their sensitivity to non-genetic maternal influences. A young animal's behavioural characteristics play a fundamental role in its own behavioural development processes. PMID:21298038

  12. Hemispheric differences in corticospinal excitability and in transcallosal inhibition in relation to degree of handedness.

    PubMed

    Davidson, Travis; Tremblay, François

    2013-01-01

    In this study, we examined hemispheric differences in corticospinal excitability and in transcallosal inhibition in a selected group of young adults (n = 34) grouped into three handedness categories (RH: strongly right-handed, n = 17; LH: strongly left-handed, n = 10; MH: mixed-handed, n = 7) based on laterality quotients (LQ) derived from the Edinburgh Handedness Inventory. Performance measures were also used to derive a laterality index reflecting right-left asymmetries in manual dexterity (Dextli) and in finger tapping speed (Speedli). Corticospinal excitability was assessed in each hemisphere by means of transcranial magnetic stimulation (TMS) using the first dorsal interosseus as the target muscle. TMS measures consisted of resting motor threshold (rMT), motor evoked potential (MEP) recruitment curve (RC) and the contralateral silent period (cSP) with the accompanying MEP facilitation. Hemispheric interactions were assessed by means of the ipsilateral silent period (iSP) to determine the onset latency and the duration of transcallosal inhibition (i.e., LTI and DTI). Analysis of hemispheric variations in measures of corticospinal excitability revealed no major asymmetries in relation to degrees of laterality or handedness, with the exception of a rightward increase in rMTs in the LH group. Similarly, no clear asymmetries were found when looking at hemispheric variations in measures of transcallosal inhibition. However, a large group effect was detected for LTI measures, which were found to be significantly shorter in the MH group than in either the LH or RH group. MH participants also tended to show longer DTI than the other participants. Further inspection of overall variations in LTI and DTI measures as a function of LQs revealed that both variables followed a non-linear relationship, which was best described by a 2(nd) order polynomial function. Overall, these findings provide converging evidence for a link between mixed-handedness and more efficient

  13. Response of Archaeal and Bacterial Soil Communities to Changes Associated with Outdoor Cattle Overwintering

    PubMed Central

    Chroňáková, Alica; Schloter-Hai, Brigitte; Radl, Viviane; Endesfelder, David; Quince, Christopher; Elhottová, Dana; Šimek, Miloslav; Schloter, Michael

    2015-01-01

    Archaea and bacteria are important drivers for nutrient transformations in soils and catalyse the production and consumption of important greenhouse gases. In this study, we investigate changes in archaeal and bacterial communities of four Czech grassland soils affected by outdoor cattle husbandry. Two show short-term (3 years; STI) and long-term impact (17 years; LTI), one is regenerating from cattle impact (REG) and a control is unaffected by cattle (CON). Cattle manure (CMN), the source of allochthonous microbes, was collected from the same area. We used pyrosequencing of 16S rRNA genes to assess the composition of archaeal and bacterial communities in each soil type and CMN. Both short- and long- term cattle impact negatively altered archaeal and bacterial diversity, leading to increase of homogenization of microbial communities in overwintering soils over time. Moreover, strong shifts in the prokaryotic communities were observed in response to cattle overwintering, with the greatest impact on archaea. Oligotrophic and acidophilic microorganisms (e.g. Thaumarchaeota, Acidobacteria, and α-Proteobacteria) dominated in CON and expressed strong negative response to increased pH, total C and N. Whereas copiotrophic and alkalophilic microbes (e.g. methanogenic Euryarchaeota, Firmicutes, Chloroflexi, Actinobacteria, and Bacteroidetes) were common in LTI showing opposite trends. Crenarchaeota were also found in LTI, though their trophic interactions remain cryptic. Firmicutes, Bacteroidetes, Methanobacteriaceae, and Methanomicrobiaceae indicated the introduction and establishment of faecal microbes into the impacted soils, while Chloroflexi and Methanosarcinaceae suggested increased abundance of soil-borne microbes under altered environmental conditions. The observed changes in prokaryotic community composition may have driven corresponding changes in soil functioning. PMID:26274496

  14. Activation of the Kaposi's Sarcoma-Associated Herpesvirus Major Latency Locus by the Lytic Switch Protein RTA (ORF50)

    PubMed Central

    Matsumura, Satoko; Fujita, Yuriko; Gomez, Evan; Tanese, Naoko; Wilson, Angus C.

    2005-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) maintains a latent infection in primary effusion lymphoma cells but can be induced to enter full lytic replication by exposure to a variety of chemical inducing agents or by expression of the KSHV-encoded replication and transcription activator (RTA) protein. During latency, only a few viral genes are expressed, and these include the three genes of the so-called latency transcript (LT) cluster: v-FLIP (open reading frame 71 [ORF71]), v-cyclin (ORF72), and latency-associated nuclear antigen (ORF73). During latency, all three open reading frames are transcribed from a common promoter as part of a multicistronic mRNA. Subsequent alternative mRNA splicing and internal ribosome entry allows for the expression of each protein. Here, we show that transcription of LT cassette mRNA can be induced by RTA through the activation of a second promoter (LTi) immediately downstream of the constitutively active promoter (LTc). We identified a minimal cis-regulatory region, which overlaps with the promoter for the bicistronic K14/v-GPCR delayed early gene that is transcribed in the opposite direction. In addition to a TATA box at −30 relative to the LTi mRNA start sites, we identified three separate RTA response elements that are also utilized by the K14/v-GPCR promoter. Interestingly, LTi is unresponsive to sodium butyrate, a potent inducer of lytic replication. This suggests there is a previously unrecognized class of RTA-responsive promoters that respond to direct, but not indirect, induction of RTA. These studies highlight the fact that induction method can influence the precise program of viral gene expression during early events in reactivation and also suggest a mechanism by which RTA contributes to establishment of latency during de novo infections. PMID:15956592

  15. Association of Fluid Status and Body Composition with Physical Function in Patients with Chronic Kidney Disease

    PubMed Central

    Hsiao, Shih-Ming; Tsai, Yi-Chun; Chen, Hui-Mei; Lin, Ming-Yen; Chiu, Yi-Wen; Chen, Tzu-Hui; Wang, Shu-Li; Hsiao, Pei-Ni; Kung, Lan-Fang; Hwang, Shang-Jyh; Huang, Mei-Feng; Yeh, Yi-Chun; Chen, Cheng-Sheng; Kuo, Mei-Chuan

    2016-01-01

    Background Impairment of physical function and abnormal body composition are the major presentations in patients with chronic kidney disease (CKD). The aim of this study is to investigate the relationship between body composition and physical function in CKD patients. Methods This cross-sectional study enrolled 172 of CKD stages 1–5 from February 2013 to September 2013. Handgrip strength (upper extremity muscle endurance), 30-second chair-stand test (lower extremity muscle endurance) and 2-minute step test (cardiorespiratory endurance) were used as indices of physical function. Body composition, including fluid status (extracellular water/total body water, ECW/TBW), lean tissue index (LTI), and fat tissue index (FTI), was measured using a bioimpedance spectroscopy method. Results All patients with high ECW/TBW had lower handgrip strength and 30-second chair-stand than those with low ECW/TBW (P<0.001 and P = 0.002). CKD patients with high FTI had lower handgrip strength and 30-second chair-stand than those with low FTI (P<0.001 and P = 0.002). These patients with low LTI had lower handgrip strength than those with high LTI (P = 0.04). In multivariate analysis, high ECW/TBW was positively associated with decreased handgrip strength (β = -41.17, P = 0.03) in CKD patients. High FTI was significantly correlated with decreased times of 30-second chair-stand (β = -0.13, P = 0.01). There was no significant relationship between body composition and 2-minute step test. Conclusions Our results show a significant association of impaired upper and lower extremity muscle endurance with high fluid status and fat tissue. Evaluation of body composition may assist in indentifying physical dysfunction earlier in CKD patients. PMID:27798648

  16. Physical - mechanical characterization of poly(lactide)/poly (ɛ-caprolactone) blends with ethyl ester L-lysine triisocyanate as reactive agent

    NASA Astrophysics Data System (ADS)

    Nocita, Davide; Visco, Annamaria; Espro, Claudia

    2016-05-01

    A study on physical and mechanical properties of PLA/PCL polyesters reactive blends, obtained by adding LTI was made with the aim to apply these blends in biomedical field, for example for absorbable suture threads or scaffolds for cellular growth. Polyesters based reactive blends were obtained by internal mixing, and it was find out the possibility of finely control the characteristic properties of those materials by varying the weight fraction of the two components and the amount of reactive agent. Blends of different composition were characterized by torque measurements, uniaxial traction test and wet-ability.

  17. Standardized Methods for Electronic Shearography

    NASA Technical Reports Server (NTRS)

    Lansing, Matthew D.

    1997-01-01

    Research was conducted in development of operating procedures and standard methods to evaluate fiber reinforced composite materials, bonded or sprayed insulation, coatings, and laminated structures with MSFC electronic shearography systems. Optimal operating procedures were developed for the Pratt and Whitney Electronic Holography/Shearography Inspection System (EH/SIS) operating in shearography mode, as well as the Laser Technology, Inc. (LTI) SC-4000 and Ettemeyer SHS-94 ISTRA shearography systems. Operating practices for exciting the components being inspected were studied, including optimal methods for transient heating with heat lamps and other methods as appropriate to enhance inspection capability.

  18. Refractive Index of Silicon and Germanium and Its Wavelength and Temperature Derivatives.

    DTIC Science & Technology

    1979-03-01

    59. Tauc , J., Abraham, A., Pajasova, L., Grigorovici, R., and Vancu, A., "Optical Properties of Non-Crystalline Semiconductors," in Physics of Non...259 onm 1 84 9!. vojn: .p r us TlI II io L, rinc 11 1US I11L ni . 3 1.98’ ,iii til n i,:n ;Ivvi i Li o i Ili LtI loi ,I ,.kii d.i / T ’I 2 .1) 11 L...index measured using interference method. 40 (T-298 K) Amorphous germanium thin film prepared Tauc , J., Abraham, A., 159) 0.695 4.742 by evaporation

  19. Parallel Estimators and Communication in Spacecraft Formations

    NASA Technical Reports Server (NTRS)

    Smith, Roy S.; Hadaegh, Fred Y.

    2005-01-01

    This paper investigates the closed-loop dynamics of systems controlled via parallel estimators. This structure arises in formation flying problems when each spacecraft bases its control action on an internal estimate of the complete formation state. For LTI systems a separation principle shows that the necessary and sufficient conditions for overall system stability are more stringent than the single controller case; the controllers' open-loop dynamics necessarily appear in the closed-loop dynamics. Communication amongst the spacecraft can be used to specify the complete system dynamics and a framework for integrating the design of the communication links into the formation flying control design problem is presented.

  20. Stability and Drag Reduction in a Boundary Layer with Microbubbles.

    DTIC Science & Technology

    1988-02-01

    Joao M. P. Correia Neves : DTICŔ ’ It~iELECTE D , AR 2 2 1988-’DMTM.,O STAU-S. Approved for pubac rel , Ditr’bUtion Untimited ~T1(1INllAL REPORT 88 3 ...2a. SECURITY CLASSIFICATION AUTHORITY 3 DISTRIBUr’ION/AVAILABIuLTY OF REPORT 2b. DECLASSIFICATION/OOWNGRAOING SCHEDULE Unlimited 4 PERFORMING...12 2.2 A Simple Hollow Vortex Sheet .............. .13 2.3 A Symmetric Hollow Vortex Sheet ............ . 18’. 3 . EVOLUTION OF A HOLLOW VORTEX SHEET

  1. Variable Cycle Engine Control System Definition Study. Turbine Engine Technology Demonstrator Component Development Program, Project 668A. Controls Development Program

    DTIC Science & Technology

    1976-03-01

    JULY 1973 to MARCH 1976 Approved for public rtlease; distribution unlimited DDC R 191r Alit V0tCE, AKt *IRO-10ROU14,40N LAHIORATf0lty .71 L y ~j Alit...engine parameters to "scheduled" optimal poramelric relationships successfully attained minimum sfc and maximum thrust at all the selected test points in... test plan woa formulated for the JTD control system. Table of Contents Page 1.0 Introduction 1-1 2.0 Summary 2- 1 3.0 Joint Technology Demonstrator

  2. Conceptualization of an R&D Based Learning-to-Innovate Model for Science Education

    NASA Astrophysics Data System (ADS)

    Lai, Oiki Sylvia

    The purpose of this research was to conceptualize an R & D based learning-to-innovate (LTI) model. The problem to be addressed was the lack of a theoretical L TI model, which would inform science pedagogy. The absorptive capacity (ACAP) lens was adopted to untangle the R & D LTI phenomenon into four learning processes: problem-solving via knowledge acquisition, incremental improvement via knowledge participation, scientific discovery via knowledge creation, and product design via knowledge productivity. The four knowledge factors were the latent factors and each factor had seven manifest elements as measured variables. The key objectives of the non experimental quantitative survey were to measure the relative importance of the identified elements and to explore the underlining structure of the variables. A questionnaire had been prepared, and was administered to more than 155 R & D professionals from four sectors - business, academic, government, and nonprofit. The results showed that every identified element was important to the R & D professionals, in terms of improving the related type of innovation. The most important elements were highlighted to serve as building blocks for elaboration. In search for patterns of the data matrix, exploratory factor analysis (EF A) was performed. Principal component analysis was the first phase of EF A to extract factors; while maximum likelihood estimation (MLE) was used to estimate the model. EF A yielded the finding of two aspects in each kind of knowledge. Logical names were assigned to represent the nature of the subsets: problem and knowledge under knowledge acquisition, planning and participation under knowledge participation, exploration and discovery under knowledge creation, and construction and invention under knowledge productivity. These two constructs, within each kind of knowledge, added structure to the vague R & D based LTI model. The research questions and hypotheses testing were addressed using correlation

  3. Multi-modal Interfacing for Human-Robot Interaction

    DTIC Science & Technology

    2001-01-01

    the final state of having turned in a particular direction u Locative goals u “there” “the waypoint” “table” N C A R A I Object and Gesture ... Recognition n Structured-light range finder (camera + laser) u output: 2D range data n 16 ultra-sonic sonars u output: range data out to 25’ n 16 active...mechanical gestures, we hope to achieve dynam ic autonomy and an integrated m u lti-modal interface. N C A R A I Future Plans • Extend gesture

  4. Environmental Assessment for Closure of Cesspools and Implementation of Wastewater Management and Treatment Measures at Bellows Air Force Station, Hawaii

    DTIC Science & Technology

    2014-06-20

    sites as traditional Hawaiian in origin is pending identification and radiocarbon dating of wood charcoal from these associations (Dye and Sholin...information if it does not display a currently valid OMB control number. 1. REPORT DATE 30 JUN 2014 2. REPORT TYPE Environmental Assessment 3. DATES ...Wing Date : ~D Q:lH1 U lti ~c---=T=o---.---:-A-=cT=I:-::O-:-:N--,--s=I-=G=NA""T=u::RE:::-;(S::-~-rn-~-mA-:e)-,~=!:=:::~:--~=~--:D:--:~::T=E-RY ST~E

  5. Investigation for South Fill Area, United States Military Academy, West Point, New York.

    DTIC Science & Technology

    1980-08-01

    NEW UNC 970PLATE A13 (SHEET 2 OF 2) A17 go I ~ iA Coeff c ent Peor amJ4lty, k", 10" c/us 0.1 0.2 0.3 0.40.65 1 2 3 4 5 10 20 251.6 . 0 1.5 1.14...STRAIN INCR.__ C 0 1 5 1 20. AXIAL STRAIN. Yo INITIAL DIAMETER, IN. 1-38 1.38 1.38 CONTROLLED-STRAIN TEST INITIAL HEIGHT. IN. 3.00 3.00 3.00

  6. JSEP Annual Report

    DTIC Science & Technology

    1993-03-01

    matrix T) passed through an LTI all-zero filter b(z) given by [AI-Dhahtr] b(z)1 -1 ]t (11) A closed - form expression for T In terms of b(z) and G...Block diagram of the pole zero model of Rsubopt. flmdi It can be shown [Lev-Arl],[Ai-Dhahlrj that the W order whitening filter of has the form : 0...equal to j. We have found a closed form expression for the expected gain, i, for the trajectory T,. As special cases of the general solution we obtain

  7. Real-time assessment of a linear pyroelectric sensor array for object classication

    NASA Astrophysics Data System (ADS)

    White, William E., III; Brown, Jeremy B.; Chari, Srikant; Jacobs, Eddie L.

    2010-10-01

    Pyroelectric linear arrays can be used to generate profiles of targets. Simulations have shown that generated profiles can be used to classify human and animal targets. A pyroelectric array system was used to collect data and classify targets as either human or non-human in real time. The pyroelectric array system consists of a 128-element Dias 128LTI pyroelectric linear array, an F/0.86 germanium lens, and an 18F4550 pic microcontroller for A/D conversion and communication. The classifier used for object recognition was trained using data collected in petting zoos and tested using data collected at the US-Mexico border in Arizona.

  8. Preformulation Studies of Selected Pretreatment and Therapeutic Compounds

    DTIC Science & Technology

    1983-07-01

    NUMBER OF PAGES WHICH DO NOT REPRODUCE LEGIBLY.. ttAD _ ___ Preformulation Stuldies of Selected Pretreatment e and Therapeutic Compounds Annual...Selected Pretreatment and Therapeutic Compounds Annual Progress Report July 1, 1982 to June 30, 1983 John L. Lach Douglas R. Flanagan Lloyd E. Matheson... tpo I AV. _____________ oIp#, 4 -I .-r--. - .-- --. Jr.Lti l0 t fl@.1.I v_____ - - nhy-A-- -a., X V71- 4rS..Ul a t.~ pjeme . . 1-3 .1 eh It

  9. Hybrid Approaches and Industrial Applications of Pattern Recognition,

    DTIC Science & Technology

    1980-10-01

    generally carried out by human operators with the aid of high power and low power microscopes ; it includes essentially the Leads, die and wire bonding, and...view of a muLti-lens microscope . The subcell images are also assumed to be thresholded and digitized on a few gray levels. Ll 3.4 Algorithm #1: Matching...reLiabiLity physics symposium. 3. T. I. Bajenesco, Initiation a La fiabilite en electronique moderne, Masson, Paris, 1978. 4. L. F. Pau, Failure Diagnosis and

  10. U.S. Navy Marine Climatic Atlas of the World. Volume 6. Arctic Ocean

    DTIC Science & Technology

    1963-02-01

    obivrvoiiom laootimg viiib>l>iy I«H than 2 nouticol m<lti nil iS (0 \\ o( oN NW wwfk wtn ottompamad by «i W*y Iw Ikon 3 mfct) ’ 0 ’aplacai bat whan...IS1BILITY CHART 131 w 30" <»nla0» F.«qu*nc> ©t Vu.b.Uy *5 NoutKOl M1W1 TO i - -■’ i.j- F(«(]u»n{y pt Vitibilit>«v i*ti iKon amount <r

  11. Robust fault detection observer design for linear uncertain systems

    NASA Astrophysics Data System (ADS)

    Wei, Xiukun; Verhaegen, Michel

    2011-01-01

    This article addresses the fault detection observer design issue for linear time invariant (LTI) systems with additive or multiplicative uncertainties, which are also subject to unknown disturbances. The observer design is investigated under the ℋ∞/ℋ- index framework using the generalised KYP lemma in the finite-frequency domain. Sufficient conditions for the existence of such a fault detection observer are given in terms of linear matrix inequalities (LMIs). The threshold design issue is discussed and a method for estimating the worst undetectable fault size is proposed. The effectiveness of the proposed algorithms is illustrated by numerical simulation examples.

  12. US Army Aviation Engineering Flight Activity (USAAEFA) Author Report Bibliography. 1961-1981,

    DTIC Science & Technology

    1982-06-01

    8217" Hi<ro 5~l 71)8 Stahl lty vAnd Cont rol MAJ .. Benson Aoigventitton Svster. )qli-- eltir ’f’’rt I’r.Iliml narv Airwiorthion,’ [In 19X’’ MA.I J3. In I F...Jun 1961 MA.I N. ’l.t I iller . Ie - I’rilIl narv "li.irlin I & II, G. Yarokiw ’i IM r,i leIt N. 4-h-1200-(12 HAA It. Ii I MAl Ii. Chambers

  13. Defense Science Board 1988 Summer Study on the Defense Industrial and Technology Base. Volume 2. Subgroup Appendices

    DTIC Science & Technology

    1988-12-01

    hingtono D.C. 2030143140 99 220Z PREFACE This volume of the report of the 1988 Defense Science Board Summer Study on the Defense Industrial and Technology ...and Technology Base, Volume I. Accession For NTIS GRA&I DTIC TAB Unnnnounced U icati~~ Distribution/ Avatlbii lty Codes Av ih and/or Dist Spec ial .L.A...Jrtt1O8 n an Mah" IN DEFENSE SCIENCE BOARD TASK FORCE ON THE DEFENSE INDUSTRIAL AND TECHNOLOGY BASE Mr. Robert A. Fuhrman, Chairman Mr. William A

  14. Design, Analysis and Implementation of the Primary Operation, RETRIEVE-COMMON, of the Multi-Backend Database System (MBDS).

    DTIC Science & Technology

    1985-06-01

    Hsiang -lung Tung 2 8 lane 46 Ming- Chuan Road Ctia-i CiLty Taiwan 600 Pepublic of 6hina tit 148 •, 1,,J., ., FILMED 4.~ 0-85 DTIC p.0 ...DATABASE SYSTEM (MBDS) by ~i. Hsiang -Lung Tung June 1985 Thesis Advisor: David K. Hsiao -’-" Approved for public release; distribution is unlimited P- A...Desi n. Analysis and Implementation of the grimazy operation Retriee-Coamon of the Rulti-BAckbnd Datafase System (MBDS by Hsiang -Lung Tung

  15. Occupational Emergency Medicine - Introduction

    DTIC Science & Technology

    2011-01-01

    4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to a penalty for failing to comply with...Under Title III, companie covered under the Hazard Communication Standard are r qulred to make their chemica l inventor ies known to emergency response...anagement howe ver. misp)"l’ed . OCClIj1illi.ll1illllleliicilll’ h olli - ia lly, ~ llb ~l)(’ciJ lty of I’rcvellliV l- Illedi cine, which dut’~ ind "d

  16. Colonic patch and colonic SILT development are independent and differentially regulated events.

    PubMed

    Baptista, A P; Olivier, B J; Goverse, G; Greuter, M; Knippenberg, M; Kusser, K; Domingues, R G; Veiga-Fernandes, H; Luster, A D; Lugering, A; Randall, T D; Cupedo, T; Mebius, R E

    2013-05-01

    Intestinal lymphoid tissues have to simultaneously ensure protection against pathogens and tolerance toward commensals. Despite such vital functions, their development in the colon is poorly understood. Here, we show that the two distinct lymphoid tissues of the colon-colonic patches and colonic solitary intestinal lymphoid tissues (SILTs)-can easily be distinguished based on anatomical location, developmental timeframe, and cellular organization. Furthermore, whereas colonic patch development depended on CXCL13-mediated lymphoid tissue inducer (LTi) cell clustering followed by LTα-mediated consolidation, early LTi clustering at SILT anlagen did not require CXCL13, CCR6, or CXCR3. Subsequent dendritic cell recruitment to and gp38(+)VCAM-1(+) lymphoid stromal cell differentiation within SILTs required LTα; B-cell recruitment and follicular dendritic cell differentiation depended on MyD88-mediated signaling, but not the microflora. In conclusion, our data demonstrate that different mechanisms, mediated mainly by programmed stimuli, induce the formation of distinct colonic lymphoid tissues, therefore suggesting that these tissues may have different functions.

  17. Incorporation of SemiSpan SuperSonic Transport (S4T) Aeroservoelastic Models into SAREC-ASV Simulation

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.; Pototzky, Anthony S.; Stevens, William L.

    2010-01-01

    The Simulink-based Simulation Architecture for Evaluating Controls for Aerospace Vehicles (SAREC-ASV) was modified to incorporate linear models representing aeroservoelastic characteristics of the SemiSpan SuperSonic Transport (S4T) wind-tunnel model. The S4T planform is for a Technology Concept Aircraft (TCA) design from the 1990s. The model has three control surfaces and is instrumented with accelerometers and strain gauges. Control laws developed for wind-tunnel testing for Ride Quality Enhancement, Gust Load Alleviation, and Flutter Suppression System functions were implemented in the simulation. The simulation models open- and closed-loop response to turbulence and to control excitation. It provides time histories for closed-loop stable conditions above the open-loop flutter boundary. The simulation is useful for assessing the potential impact of closed-loop control rate and position saturation. It also provides a means to assess fidelity of system identification procedures by providing time histories for a known plant model, with and without unmeasured turbulence as a disturbance. Sets of linear models representing different Mach number and dynamic pressure conditions were implemented as MATLAB Linear Time Invariant (LTI) objects. Configuration changes were implemented by selecting which LTI object to use in a Simulink template block. A limited comparison of simulation versus wind-tunnel results is shown.

  18. A study of Helmholtz resonators to stabilize thermoacoustically driven pressure oscillations.

    PubMed

    Zalluhoglu, Umut; Olgac, Nejat

    2016-04-01

    This paper studies passive control of thermoacoustic instabilities from an unconventional mathematical perspective. These instabilities are notoriously known to result from the complex dynamic exchange between the unsteady heat release and the acoustic waves within a finite volume such as a combustor. One possible passive control strategy is to utilize Helmholtz resonators. Under certain simplifications, the ensemble combustion dynamics including the resonators reduces to a linear-time invariant-multiple time-delayed system (LTI-MTDS). As the main contribution of the paper, an exact analytical procedure is proposed to determine the placement of the resonators to avoid instabilities. A unique mathematical paradigm, called the cluster treatment of characteristic roots, is used to accomplish this task. It declares exactly the necessary and sufficient stability conditions for an LTI-MTDS in the space of the system parameters. This concept paper is written with the mindset that this analytical tool can invite yet unexplored design capabilities for similar noise control applications where acoustic dampers are used.

  19. Energy Confinement Recovery in Low Collisionality ITER Shape Plasmas with Applied Resonant Magnetic Perturbations (RMPs)

    NASA Astrophysics Data System (ADS)

    Cui, L.; Grierson, B.; Logan, N.; Nazikian, R.

    2016-10-01

    Application of RMPs to low collisionality (ν*e < 0.4) ITER shape plasmas on DIII-D leads to a rapid reduction in stored energy due to density pumpout that is sometimes followed by a gradual recovery in the plasma stored energy. Understanding this confinement recovery is essential to optimize the confinement of RMP plasmas in present and future devices such as ITER. Transport modeling using TRANSP+TGLF indicates that the core a/LTi is stiff in these plasmas while the ion temperature gradient is much less stiff in the pedestal region. The reduction in the edge density during pumpout leads to an increase in the core ion temperature predicted by TGLF based on experimental data. This is correlated to the increase in the normalized ion heat flux. Transport stiffness in the core combined with an increase in the edge a/LTi results in an increase of the plasma stored energy, consistent with experimental observations. For plasmas where the edge density is controlled using deuterium gas puffs, the effect of the RMP on ion thermal confinement is significantly reduced. Work supported by US DOE Grant DE-FC02-04ER54698 and DE-AC02-09CH11466.

  20. A solid frame for the window on cognition: Modelling event-related pupil responses

    PubMed Central

    Korn, Christoph W.; Bach, Dominik R.

    2016-01-01

    Pupil size is often used to infer central processes, including attention, memory, and emotion. Recent research spotlights its relation to behavioral variables from decision-making models and to neural variables such as locus coeruleus activity or cortical oscillations. As yet, a unified and principled approach for analyzing pupil responses is lacking. Here, we seek to establish a formal, quantitative forward model for pupil responses by describing them with linear time invariant (LTI) systems. Based on empirical data from human participants, we show that a combination of two LTI systems can parsimoniously explain approximately all variance evoked by illuminance changes. Notably, the model makes a counter-intuitive prediction that pupil constriction dominates the responses to darkness flashes, as in previous empirical reports. This prediction was quantitatively confirmed for responses to light and darkness flashes in an independent group of participants. Crucially, illuminance- and non-illuminance-related inputs to the pupillary system are presumed to share a common final pathway, comprised of muscles and nerve terminals. Hence, we can harness our illuminance-based model to estimate the temporal evolution of this neural input for an auditory oddball task, an emotional words task, and a visual detection task. Onset and peak latencies of the estimated neural inputs furnish plausible hypotheses for the complexity of the underlying neural circuit. To conclude, this mathematical description of pupil responses serves as a prerequisite to refine their relation to behavioral and brain indices of cognitive processes. PMID:26894512

  1. Unique and redundant functions of NKp46+ ILC3s in models of intestinal inflammation.

    PubMed

    Song, Christina; Lee, Jacob S; Gilfillan, Susan; Robinette, Michelle L; Newberry, Rodney D; Stappenbeck, Thaddeus S; Mack, Matthias; Cella, Marina; Colonna, Marco

    2015-10-19

    Group 3 ILCs (ILC3s) are innate sources of IL-22 and IL-17 and include lymphoid tissue-inducer (LTi)-like and NKp46(+) subsets. Both depend on RORγt and aryl hydrocarbon receptor, but NKp46(+)ILC3s also require Notch and T-bet for their development and are transcriptionally distinct. The extent to which these subsets have unique functions, especially in the context of T cell- and B cell-sufficient mice, remains largely unclear. To investigate the specific function of NKp46(+)ILC3s among other ILC3 subsets and T cells, we generated mice selectively lacking NKp46(+)ILC3s or all ILC3s and crossed them to T cell-deficient mice, thus maintaining B cells in all mice. In mice lacking T cells, NKp46(+)ILC3s were sufficient to promote inflammatory monocyte accumulation in the anti-CD40 innate colitis model through marked production of GM-CSF. In T cell-competent mice, lack of NKp46(+)ILCs had no impact on control of intestinal C. rodentium infection, whereas lack of all ILC3s partially impaired bacterial control. Thus, NKp46(+)ILC3s have a unique capacity to promote inflammation through GM-CSF-induced accumulation of inflammatory monocytes, but are superseded by LTi-like ILC3s and T cells in controlling intestinal bacterial infection.

  2. Elastic Model Transitions: a Hybrid Approach Utilizing Quadratic Inequality Constrained Least Squares (LSQI) and Direct Shape Mapping (DSM)

    NASA Technical Reports Server (NTRS)

    Jurenko, Robert J.; Bush, T. Jason; Ottander, John A.

    2014-01-01

    A method for transitioning linear time invariant (LTI) models in time varying simulation is proposed that utilizes both quadratically constrained least squares (LSQI) and Direct Shape Mapping (DSM) algorithms to determine physical displacements. This approach is applicable to the simulation of the elastic behavior of launch vehicles and other structures that utilize multiple LTI finite element model (FEM) derived mode sets that are propagated throughout time. The time invariant nature of the elastic data for discrete segments of the launch vehicle trajectory presents a problem of how to properly transition between models while preserving motion across the transition. In addition, energy may vary between flex models when using a truncated mode set. The LSQI-DSM algorithm can accommodate significant changes in energy between FEM models and carries elastic motion across FEM model transitions. Compared with previous approaches, the LSQI-DSM algorithm shows improvements ranging from a significant reduction to a complete removal of transients across FEM model transitions as well as maintaining elastic motion from the prior state.

  3. Design and control of a bio-inspired soft wearable robotic device for ankle-foot rehabilitation.

    PubMed

    Park, Yong-Lae; Chen, Bor-rong; Pérez-Arancibia, Néstor O; Young, Diana; Stirling, Leia; Wood, Robert J; Goldfield, Eugene C; Nagpal, Radhika

    2014-03-01

    We describe the design and control of a wearable robotic device powered by pneumatic artificial muscle actuators for use in ankle-foot rehabilitation. The design is inspired by the biological musculoskeletal system of the human foot and lower leg, mimicking the morphology and the functionality of the biological muscle-tendon-ligament structure. A key feature of the device is its soft structure that provides active assistance without restricting natural degrees of freedom at the ankle joint. Four pneumatic artificial muscles assist dorsiflexion and plantarflexion as well as inversion and eversion. The prototype is also equipped with various embedded sensors for gait pattern analysis. For the subject tested, the prototype is capable of generating an ankle range of motion of 27° (14° dorsiflexion and 13° plantarflexion). The controllability of the system is experimentally demonstrated using a linear time-invariant (LTI) controller. The controller is found using an identified LTI model of the system, resulting from the interaction of the soft orthotic device with a human leg, and model-based classical control design techniques. The suitability of the proposed control strategy is demonstrated with several angle-reference following experiments.

  4. Evidence for an evolutionary antagonism between Mrr and Type III modification systems

    PubMed Central

    Tesfazgi Mebrhatu, Mehari; Wywial, Ewa; Ghosh, Anirban; Michiels, Chris W.; Lindner, Ariel B.; Taddei, François; Bujnicki, Janusz M.; Van Melderen, Laurence; Aertsen, Abram

    2011-01-01

    The Mrr protein of Escherichia coli is a laterally acquired Type IV restriction endonuclease with specificity for methylated DNA. While Mrr nuclease activity can be elicited by high-pressure stress in E. coli MG1655, its (over)expression per se does not confer any obvious toxicity. In this study, however, we discovered that Mrr of E. coli MG1655 causes distinct genotoxicity when expressed in Salmonella typhimurium LT2. Genetic screening enabled us to contribute this toxicity entirely to the presence of the endogenous Type III restriction modification system (StyLTI) of S. typhimurium LT2. The StyLTI system consists of the Mod DNA methyltransferase and the Res restriction endonuclease, and we revealed that expression of the LT2 mod gene was sufficient to trigger Mrr activity in E. coli MG1655. Moreover, we could demonstrate that horizontal acquisition of the MG1655 mrr locus can drive the loss of endogenous Mod functionality present in S. typhimurium LT2 and E. coli ED1a, and observed a strong anti-correlation between close homologues of MG1655 mrr and LT2 mod in the genome database. This apparent evolutionary antagonism is further discussed in the light of a possible role for Mrr as defense mechanism against the establishment of epigenetic regulation by foreign DNA methyltransferases. PMID:21504983

  5. Linear dynamic analysis of multi-mesh transmissions containing external, rigid gears

    NASA Astrophysics Data System (ADS)

    Vinayak, H.; Singh, R.; Padmanabhan, C.

    1995-08-01

    This paper extends the multi-body dynamics modeling strategy for a gear pair [6] to multi-mesh transmissions with external, fixed center, helical or spur gears. Each gear is modeled as a rigid body with six degrees of freedom. A multi-dimensional, position-dependent formulation is used to describe the gear mesh stiffness which is assumed to be distributed along the line of action. A simplified model of the shaft-bearing subsystems is included since the focus of this study is on the gear dynamics. Excitation to the system is considered in the form of either external torque pulsation or internal static transmission error. The governing equations are linearized to yield a formulation with position or time-varying coefficients (LTV). Subsequently, three examples of linearized time-invariant (LTI) transmission systems are solved, and eigensolution predictions of the multi-body dynamics model compare very well with finite element calculations. Then the periodic response of a non-unity gear pair system is studied in depth. New results including a comparison between LTI and LTV models are presented. It has been demonstrated that both time and frequency domain solutions can be efficiently and accurately constructed by using the multi-term harmonic balance method, provided that several shaft and gear mesh harmonics are included.

  6. A methodology for the synthesis of robust feedback systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Milich, David Albert

    1988-01-01

    A new methodology is developed for the synthesis of linear, time-variant (LTI) controllers for multivariable LTI systems. The resulting closed-loop system is nominally stable and exhibits a known level of performance. In addition, robustness of the feedback system is guaranteed, i.e., stability and performance are retained in the presence of multiple unstructured uncertainty blocks located at various points in the feedback loop. The design technique is referred to as the Causality Recovery Methodology (CRM). The CRM relies on the Youla parameterization of all stabilizing compensators to ensure nominal stability of the feedback system. A frequency-domain inequality in terms of the structured singular value mu defines the robustness specification. The optimal compensator, with respect to the mu condition, is shown to be noncausal in general. The aim of the CRM is to find a stable, causal transfer function matrix that approximates the robustness characteristics of the optimal solution. The CRM, via a series of infinite-dimensional convex programs, produces a closed-loop system whose performance robustness is at least as good as that of any initial design. The algorithm is approximated by a finite dimensional process for the purposes of implementation. Two numerical examples confirm the potential viability of the CRM concept; however, the robustness improvement comes at the expense of increased computational burden and compensator complexity.

  7. Carbohydrate concentrations and freezing stress resistance of silver birch buds grown under elevated temperature and ozone.

    PubMed

    Riikonen, Johanna; Kontunen-Soppela, Sari; Vapaavuori, Elina; Tervahauta, Arja; Tuomainen, Marjo; Oksanen, Elina

    2013-03-01

    The effects of slightly elevated temperature (+0.8 °C), ozone (O3) concentration (1.3 × ambient O3 concentration) and their combination on over-wintering buds of Betula pendula Roth were studied after two growing seasons of exposure in the field. Carbohydrate concentrations, freezing stress resistance (FSR), bud dry weight to fresh weight ratio, and transcript levels of cytochrome oxidase (COX), alternative oxidase (AOX) and dehydrin (LTI36) genes were studied in two clones (clones 12 and 25) in December. Elevated temperature increased the bud dry weight to fresh weight ratio and the ratio of raffinose family oligosaccharides to sucrose and the transcript levels of the dehydrin (LTI36) gene (in clone 12 only), but did not alter the FSR of the buds. Genotype-specific alterations in carbohydrate metabolism were found in the buds grown under elevated O3. The treatments did not significantly affect the transcript level of the COX or AOX genes. No clear pattern of an interactive effect between elevated temperature and O3 concentration was found. According to these data, the increase in autumnal temperatures and slightly increasing O3 concentrations do not increase the risk for freeze-induced damage in winter in silver birch buds, although some alterations in bud physiology occur.

  8. The effect of diazepam administration during pregnancy or labor on the heart rate variability of the newborn infant.

    PubMed

    van Geijn, H P; Jongsma, H W; Doesburg, W H; Lemmens, W A; de Haan, J; Eskes, T K

    1980-03-01

    Maternal diazepam medication during labor reduces beat-to-beat variability of the fetal heart rate. In this study, the prolongation of the effect was examined in the newborn. The mother received diazepam: (A) during labor as a tranquilizer, (B) daily in low doses at the end of pregnancy, or (C) in high doses i.v. for (pre-)eclampsia. A control group had no analgesic or sedative during pregnancy or labor. The electrocardiogram (ECG) was recorded daily from each newborn during the first 6 days after birth. After preprocessing of the ECG, the median R-R interval, the long-term irregularity index (LTI index) and the interval difference index (ID index) were calculated. A cubic spline interpolation method was applied to compare the various groups with respect to these heart rate parameters. The median R-R interval showed no particular differences in trend for all groups. The LTI index was decreased in the first days after birth in the chronic diazepam (B), and in the diazepam infusion groups (C), but statistical significance was not reached. The ID index was significantly decreased in the first 1-2 days in the newborns of the acute and chronic diazepam group. In the diazepam infusion group, an even longer lasting effect was observed. Maternal diazepam medication affects the beat-to-beat variability in the newborn. The duration of the effect is dependent on dosage and route of administration.

  9. Non-linear dynamic analysis of geared systems, part 2

    NASA Technical Reports Server (NTRS)

    Singh, Rajendra; Houser, Donald R.; Kahraman, Ahmet

    1990-01-01

    A good understanding of the steady state dynamic behavior of a geared system is required in order to design reliable and quiet transmissions. This study focuses on a system containing a spur gear pair with backlash and periodically time-varying mesh stiffness, and rolling element bearings with clearance type non-linearities. A dynamic finite element model of the linear time-invariant (LTI) system is developed. Effects of several system parameters, such as torsional and transverse flexibilities of the shafts and prime mover/load inertias, on free and force vibration characteristics are investigated. Several reduced order LTI models are developed and validated by comparing their eigen solution with the finite element model results. Several key system parameters such as mean load and damping ratio are identified and their effects on the non-linear frequency response are evaluated quantitatively. Other fundamental issues such as the dynamic coupling between non-linear modes, dynamic interactions between component non-linearities and time-varying mesh stiffness, and the existence of subharmonic and chaotic solutions including routes to chaos have also been examined in depth.

  10. Stability Assessment and Tuning of an Adaptively Augmented Classical Controller for Launch Vehicle Flight Control

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen; Zhu, J. Jim; Adami, Tony; Berry, Kyle; Grammar, Alex; Orr, Jeb S.; Best, Eric A.

    2014-01-01

    Recently, a robust and practical adaptive control scheme for launch vehicles [ [1] has been introduced. It augments a classical controller with a real-time loop-gain adaptation, and it is therefore called Adaptive Augmentation Control (AAC). The loop-gain will be increased from the nominal design when the tracking error between the (filtered) output and the (filtered) command trajectory is large; whereas it will be decreased when excitation of flex or sloshing modes are detected. There is a need to determine the range and rate of the loop-gain adaptation in order to retain (exponential) stability, which is critical in vehicle operation, and to develop some theoretically based heuristic tuning methods for the adaptive law gain parameters. The classical launch vehicle flight controller design technics are based on gain-scheduling, whereby the launch vehicle dynamics model is linearized at selected operating points along the nominal tracking command trajectory, and Linear Time-Invariant (LTI) controller design techniques are employed to ensure asymptotic stability of the tracking error dynamics, typically by meeting some prescribed Gain Margin (GM) and Phase Margin (PM) specifications. The controller gains at the design points are then scheduled, tuned and sometimes interpolated to achieve good performance and stability robustness under external disturbances (e.g. winds) and structural perturbations (e.g. vehicle modeling errors). While the GM does give a bound for loop-gain variation without losing stability, it is for constant dispersions of the loop-gain because the GM is based on frequency-domain analysis, which is applicable only for LTI systems. The real-time adaptive loop-gain variation of the AAC effectively renders the closed-loop system a time-varying system, for which it is well-known that the LTI system stability criterion is neither necessary nor sufficient when applying to a Linear Time-Varying (LTV) system in a frozen-time fashion. Therefore, a

  11. OSRD Reports: Bibliography and Index of Declassified Reports Having OSRD Numbers

    DTIC Science & Technology

    1947-06-01

    lillti. tD HI ,’.00 Ph ".00. OSRD 116 ’BL QI)f (I-SO. toftlllt. J. L, WId OIadoel1, "arrl. M. 11 .ortUl. phllta for til. ,roduetlOft of liquid 0...1071) H .... leo. Jr. ..,de.ta for , .. lIted Uk_ff of ,1,,1 ., • .; t"’l r: u .. .,d th. ,rtYllltion 0’ ,I .. t Injury tD the ,1,,1.,.. ’ro...34lty. I".Utul, of OpUc. ’ Ald. tD "IIIIIt vl.ton: EJt.ft.𔃺II of the _topic yl.lblllt1. ClInt to atSQA and to IOODA. Ita, 1M!. ’SO dr ... I

  12. Performance of HTGR fertile particles irradiated in HFIR capsule HT-32

    SciTech Connect

    Long, E.L. Jr.; Robbins, J.M.; Tiegs, T.N.; Kania, M.J.

    1980-04-01

    The HT-32 experiment was an uninstrumented capsule irradiated for four cycles in the target position of the High-Flux Isotope Reactor (HFIR). The experiment was designed to: provide supplemental simulated fuel rods for thermal transport and expansion measurements; test fertile kernels with Al/sub 2/O/sub 3/ and SiO/sub 2/ additives for improved fission product retention; study the stability and permeability of low-temperature isotropic (LTI) pyrocarbon coatings; test Biso- and Triso-coatings derived in a large (0.24-m-dia) coating furnace with a frit distributor; investigate the performance of particles with an outer layer of SiC both as loose particles and as resin-bonded fuel rods; and evaluate high-density alumina as a potential high-temperature thermometry sheathing material.

  13. Modeling and Control for an Asymmetric Hydraulic Active Suspension System

    NASA Astrophysics Data System (ADS)

    Kim, Wanil; Won, Sangchul

    In this paper we present a model for an automotive active suspension system which includes the dynamics of an asymmetric hydraulic actuator. In this model the force exerted by a single-rod cylinder is regarded as an internal state, and the sum of the oil flow rates through the orifice of a servo valve as the control input. We obtain a linear time-invariant (LTI) state state equation and propose a force-tracking-free one-step control method which can accept various linear control techniques. An optimal state-feedback control is applied as an example. Quarter car test rig experiment results show the effectiveness of the proposed approach in modeling and control.

  14. Generalized Sampling Theorem for Bandpass Signals

    NASA Astrophysics Data System (ADS)

    Prokes, Ales

    2006-12-01

    The reconstruction of an unknown continuously defined function[InlineEquation not available: see fulltext.] from the samples of the responses of[InlineEquation not available: see fulltext.] linear time-invariant (LTI) systems sampled by the[InlineEquation not available: see fulltext.]th Nyquist rate is the aim of the generalized sampling. Papoulis (1977) provided an elegant solution for the case where[InlineEquation not available: see fulltext.] is a band-limited function with finite energy and the sampling rate is equal to[InlineEquation not available: see fulltext.] times cutoff frequency. In this paper, the scope of the Papoulis theory is extended to the case of bandpass signals. In the first part, a generalized sampling theorem (GST) for bandpass signals is presented. The second part deals with utilizing this theorem for signal recovery from nonuniform samples, and an efficient way of computing images of reconstructing functions for signal recovery is discussed.

  15. Real-Time Feedback Control of Flow-Induced Cavity Tones. Part 1; Fixed-Gain Control

    NASA Technical Reports Server (NTRS)

    Kegerise, M. A.; Cabell, R. H.; Cattafesta, L. N., III

    2006-01-01

    A generalized predictive control (GPC) algorithm was formulated and applied to the cavity flow-tone problem. The control algorithm demonstrated multiple Rossiter-mode suppression at fixed Mach numbers ranging from 0.275 to 0.38. Controller performance was evaluated with a measure of output disturbance rejection and an input sensitivity transfer function. The results suggest that disturbances entering the cavity flow are collocated with the control input at the cavity leading edge. In that case, only tonal components of the cavity wall-pressure fluctuations can be suppressed and arbitrary broadband pressure reduction is not possible with the present sensor/actuator arrangement. In the control-algorithm development, the cavity dynamics were treated as linear and time invariant (LTI) for a fixed Mach number. The experimental results lend support to that treatment.

  16. Multipurpose Arcade Combat Simulator Development to Improve Soldier Shooting Skills with the M16A3 Rifle

    DTIC Science & Technology

    1992-07-01

    101 ( ot SF11.! its CIP 1(2024 IVf SFC TEI IHISTI ID! 123 DIE SCLIO TIC SFC lID 1121 IDE 00 LDE SE4 SEE030 IDE (SFI), .Y TIGET I Cl? V1 115110 $TE SID...DUFFSl IF Slots IDE SIC CI? I’D fill ID0E 1255 :IS EYCl. IT loVE ltI 101 EDC 10 119 iIT040 VATTI DIE BUFFER IF Slots IS ODD SIT SFC HIMTJ I if0 0SET Dit...Of BUFFER lED. LDA (SFB( ,T CLC $?I EVIL :SET UP Fot :50 STOPOFF II III. CLC IDC SIB L1 -10 ADDITIOE OF 119111 i5! SPIT ABC 0! PAL ICC GITIO :OFFSET

  17. Electroacoustics modeling of piezoelectric welders for ultrasonic additive manufacturing processes

    NASA Astrophysics Data System (ADS)

    Hehr, Adam; Dapino, Marcelo J.

    2016-04-01

    Ultrasonic additive manufacturing (UAM) is a recent 3D metal printing technology which utilizes ultrasonic vibrations from high power piezoelectric transducers to additively weld similar and dissimilar metal foils. CNC machining is used intermittent of welding to create internal channels, embed temperature sensitive components, sensors, and materials, and for net shaping parts. Structural dynamics of the welder and work piece influence the performance of the welder and part quality. To understand the impact of structural dynamics on UAM, a linear time-invariant model is used to relate system shear force and electric current inputs to the system outputs of welder velocity and voltage. Frequency response measurements are combined with in-situ operating measurements of the welder to identify model parameters and to verify model assumptions. The proposed LTI model can enhance process consistency, performance, and guide the development of improved quality monitoring and control strategies.

  18. Matrix method for eigenstructure assignment - The multi-input case with application

    NASA Astrophysics Data System (ADS)

    Pradhan, S.; Modi, V. J.; Bhat, M. S.; Misra, A. K.

    1992-08-01

    The eigenvalue and eigenstructure assignment procedure has found application in a wide variety of control problems. In this paper a method for assigning eigenstructure to a Linear Time Invariant (LTI) multiinput system is proposed. The algorithm determines a matrix, which has eigenvalues and eigenvectors at the desired locations. It is obtained from the knowledge of the open-loop system and the desired eigenstructure. Solution of the matrix equation, involving unknown controller gains, open-loop system matrices, and desired eigenvalues and eigenvectors, results in the state feedback controller. The proposed algorithm requires the closed-loop eigenvalues to be different from those of the open-loop case. This apparent constraint can easily be overcome by a negligible shift in the values. Application of the procedure is illustrated through the offset control of a satellite supported, from an orbiting platform, by a flexible tether.

  19. Utility of the Revised Level of Service Inventory (LSI-R) in predicting recidivism after long-term incarceration.

    PubMed

    Manchak, Sarah M; Skeem, Jennifer Lynne; Douglas, Kevin S

    2008-12-01

    Assessing an inmate's risk for recidivism may become more challenging as the length of incarceration increases. Although the population of Long-Term Inmates (LTIs) is burgeoning, no risk assessment tools have been specifically validated for this group. Based on a sample of 1,144 inmates released in a state without parole, we examine the utility of the Level of Service Inventory-Revised (LSI-R) in assessing risk of general and violent felony recidivism for LTIs (n = 555). Results indicate that (a) the LSI-R moderately predicts general, but not necessarily violent, recidivism, and (b) this predictive utility is not moderated by LTI status, and is based in part on ostensibly dynamic risk factors. Implications for informing parole decision-making and risk management for LTIs are discussed.

  20. Feasibility Study of Improved Methods for Riverbank Stabilization

    DTIC Science & Technology

    1964-11-01

    stabilization, that of sun drying, has been used for many cen- turies in making adobe . However, the hardening which o ccu1· s during this process is...lbwn • ••lty 0. tl4-0 "* ’ · otf.J, .)to ..... ,oo t O UO ... I r -o ... . ,. l lo:•t Stl 0 1’ •• hiCh d-~Uiy 0 t41·0.M-\\ 1, •oo. r., HIO )! • SOl > 10...This does not include an~r ballast to keep the mattress in place. The problem of impermeability is one that could be sol ved by mak- ing more

  1. Proceedings of the Seventh Annual Mechanics of Composites Review, held 28-30 October 1981, Dayton, Ohio.

    DTIC Science & Technology

    1982-04-01

    in supplying the program listings. Acession For _ N TIS GV;&I * DTIC VS U,:axnounced Justification... Dric V8rD Distributin/J Avait &b lty Codes ...composites problems and this is a rare opportunity to put four of them before a group with the capabilities assembled here. First; the idea of...C)+1 - -l a -i -c C’.J Li 0 LUJ a LJ CD C) ( L= <zC -10- Liin LLCL 4- II : Cl) - OL -C 0 a Li OQ ’ 0 0.i a a w r-l L C+4C- Q.0 oU L.F- a ii ( Lo CD

  2. Antiwindup analysis and design approaches for MIMO systems

    NASA Technical Reports Server (NTRS)

    Marcopoli, Vincent R.; Phillips, Stephen M.

    1993-01-01

    Performance degradation of multiple-input multiple-output (MIMO) control systems having limited actuators is often handled by augmenting the controller with an antiwindup mechanism, which attempts to maintain system performance when limits are encountered. The goals of this paper are: 1) to develop a method to analyze antiwindup systems to determine precisely what stability and performance degradation is incurred under limited conditions. It is shown that by reformulating limited actuator commands as resulting from multiplicative perturbations to the corresponding controller requests, mu-analysis tools can be utilized to obtain quantitative measures of stability and performance degradation. 2) To propose a linear, time invariant (LTI) criterion on which to base the antiwindup design. These analysis and design methods are illustrated through the evaluation of two competing antiwindup schemes augmenting the controller of a Short Take-Off and Vertical Landing (STOVL) aircraft in transition flight.

  3. Antiwindup analysis and design approaches for MIMO systems

    NASA Technical Reports Server (NTRS)

    Marcopoli, Vincent R.; Phillips, Stephen M.

    1994-01-01

    Performance degradation of multiple-input multiple-output (MIMO) control systems having limited actuators is often handled by augmenting the controller with an antiwindup mechanism, which attempts to maintain system performance when limits are encountered. The goals of this paper are: (1) To develop a method to analyze antiwindup systems to determine precisely what stability and performance degradation is incurred under limited conditions. It is shown that by reformulating limited actuator commands as resulting from multiplicative perturbations to the corresponding controller requests, mu-analysis tools can be utilized to obtain quantitative measures of stability and performance degradation. (2) To propose a linear, time invariant (LTI) criterion on which to base the antiwindup design. These analysis and design methods are illustrated through the evaluation of two competing antiwindup schemes augmenting the controller of a Short Take-Off and Vertical Landing (STOVL) aircraft in transition flight.

  4. Compact tunable silicon photonic differential-equation solver for general linear time-invariant systems.

    PubMed

    Wu, Jiayang; Cao, Pan; Hu, Xiaofeng; Jiang, Xinhong; Pan, Ting; Yang, Yuxing; Qiu, Ciyuan; Tremblay, Christine; Su, Yikai

    2014-10-20

    We propose and experimentally demonstrate an all-optical temporal differential-equation solver that can be used to solve ordinary differential equations (ODEs) characterizing general linear time-invariant (LTI) systems. The photonic device implemented by an add-drop microring resonator (MRR) with two tunable interferometric couplers is monolithically integrated on a silicon-on-insulator (SOI) wafer with a compact footprint of ~60 μm × 120 μm. By thermally tuning the phase shifts along the bus arms of the two interferometric couplers, the proposed device is capable of solving first-order ODEs with two variable coefficients. The operation principle is theoretically analyzed, and system testing of solving ODE with tunable coefficients is carried out for 10-Gb/s optical Gaussian-like pulses. The experimental results verify the effectiveness of the fabricated device as a tunable photonic ODE solver.

  5. Separation of U-238 and Np-237 nuclei by gamma-quanta intermediate energies

    NASA Astrophysics Data System (ADS)

    Kazakov, A. A.; Kezerashvili, G. Y.; Lazareva, T. Y.; Nedorezov, V. G.; Skrinskiy, A. N.; Sudov, A. S.; Tumaykin, G. M.; Shatunov, Y. M.

    1986-01-01

    A system employing a beam of backscattered Compton quanta based on the e(+)e(-) accumulating complex and an LTI-701 solid state laser is employed to measure the average photoseparation and separability cross sections of U234 and Np237 nuclei at energies ranging from 150 to 170 MeV. The findings contradict the predictions of existing models based on photon-meson nuclear excitation, and suggest that one of the most probable mechanisms underlying the excitation of nuclei by gamma quanta with intermediate energies, in addition to the photogeneration of pions, is the generation of e(+)e(-) pairs in the field of the nucleus: the gamma quanta wavelength energies in this region becomes comparable to the nucleon dimension, so that collective nuclear excitations are generally suppressed.

  6. ARDS (Automated Requirements Development System) User’s Manual. Volume 1. Document Analysis. Revision

    DTIC Science & Technology

    1983-11-01

    nti ouet a encmltd wo otput areavaiab42 a 7 Allrefrenes inther ene istandin he ex iEU n page 42eenelstn INPUTSAMPLE DIPRINOU p page 66 43 INPUT SAMPLE...Air Force Base, Massachusetts S7 sit C ~L 1183 D >Project No. 5720 Cl Prepared by I) ,\\ p I\\dh puhhi ,clIcasc. di[ t ,huit,, tnut ICILtd , THE MITRE...Corporation LAI_ __p_ _ _ _ _ _ _ _ _ 6 . A D D R E S S I C’lty . S la t an d I I C o d e I 7 . A D D R E S S ( C i t y . S t a te e n d Z i P

  7. Stromal Cell Subsets Directing Neonatal Spleen Regeneration

    PubMed Central

    Tan, Jonathan K. H.; Watanabe, Takeshi

    2017-01-01

    Development of lymphoid tissue is determined by interactions between stromal lymphoid tissue organiser (LTo) and hematopoietic lymphoid tissue inducer (LTi) cells. A failure for LTo to receive appropriate activating signals during embryogenesis through lymphotoxin engagement leads to a complete cessation of lymph node (LN) and Peyer’s patch development, identifying LTo as a key stromal population for lymphoid tissue organogenesis. However, little is known about the equivalent stromal cells that induce spleen development. Here, by dissociating neonatal murine spleen stromal tissue for re-aggregation and transplant into adult mouse recipients, we have identified a MAdCAM-1+CD31+CD201+ spleen stromal organizer cell-type critical for new tissue formation. This finding provides an insight into the regulation of post-natal spleen tissue organogenesis, and could be exploited in the development of spleen regenerative therapies. PMID:28067323

  8. McClellan AFB, California Revised Uniform Summary of Surface Weather Observations (RUSSWO) Parts A-F.

    DTIC Science & Technology

    1981-07-01

    pFvOoMO oP NI FOR A WoLTI . ... . . .T - - " - Z- . 4, l ’ GLObAL CLIMATOLOGY BRANCH S LO AFETAC VALUES A. 4,EATHER SERVICE/MAC EXTREME SNOW DEPTH...HOURLY OBSERVATIONS) 27_1 MCCLFLLAN AFE CA b9-7G.73-?2, mAV STATION STATION NAME YEAs MONTH ALL WEATHEP .b0 - 380 CLASS HOURS IL.S.T.I CONDITION SPEED...28. 3 .4 3 10 9 34.1 34o4 35*1 36.8 37.1 I705 3705 37.5 37.7 380 38. 4,2 >18000 21. 28. 32., 32.4 34*5 34.8 35.7 37.5 37.8 38.3 38.3 38.3 38.5 38.8

  9. Bases of Radio Direction Finding, Part II

    DTIC Science & Technology

    1977-12-22

    FTD-ID(RS)T-2232-77 Part 2 of 2 FOREIGN TECHNOLOGY DIVISION BASES OF RADIO DIRECTION FINDING by I. S. Kukes, M. Ye. Starik -3- 0DAM Approved for...FOREIGN TECHNOLOGY DI- FOREIGN TECHNOLOGY DIVISION I VISION. j WP.AFB, OHIO. FTD- ID(RS)T-2232-77 Date22 Dec 1977 Table of Contents U.S. Board on...2939, Nt 8, LTI). 3. 11.2 WI ir-p x( o a~ B. B OcitowiwN -punpcKi:. si’Hovim’ paAisonve.1CI* MONil . PCJA.-.It3A. OTA. A9JI1041-1oTS, .1943. 11.3. C a R

  10. Transport coefficient computation based on input/output reduced order models

    NASA Astrophysics Data System (ADS)

    Hurst, Joshua L.

    The guiding purpose of this thesis is to address the optimal material design problem when the material description is a molecular dynamics model. The end goal is to obtain a simplified and fast model that captures the property of interest such that it can be used in controller design and optimization. The approach is to examine model reduction analysis and methods to capture a specific property of interest, in this case viscosity, or more generally complex modulus or complex viscosity. This property and other transport coefficients are defined by a input/output relationship and this motivates model reduction techniques that are tailored to preserve input/output behavior. In particular Singular Value Decomposition (SVD) based methods are investigated. First simulation methods are identified that are amenable to systems theory analysis. For viscosity, these models are of the Gosling and Lees-Edwards type. They are high order nonlinear Ordinary Differential Equations (ODEs) that employ Periodic Boundary Conditions. Properties can be calculated from the state trajectories of these ODEs. In this research local linear approximations are rigorously derived and special attention is given to potentials that are evaluated with Periodic Boundary Conditions (PBC). For the Gosling description LTI models are developed from state trajectories but are found to have limited success in capturing the system property, even though it is shown that full order LTI models can be well approximated by reduced order LTI models. For the Lees-Edwards SLLOD type model nonlinear ODEs will be approximated by a Linear Time Varying (LTV) model about some nominal trajectory and both balanced truncation and Proper Orthogonal Decomposition (POD) will be used to assess the plausibility of reduced order models to this system description. An immediate application of the derived LTV models is Quasilinearization or Waveform Relaxation. Quasilinearization is a Newton's method applied to the ODE operator

  11. New Manning System Field Evaluation

    DTIC Science & Technology

    1985-11-01

    iC -anizat.iuo . The 7th ID(L) merits care£-jl a.tei’tion in future evaluation research. In any caJe., the data at. nand 1joi i. to leadership au Lhe...o ew unItits. IidofuIndad WUtly b j uIliCJ t o Itave di ic u1Lty t al1k I Ig i iot~ f l a1y w i L It theair moldiurt atLsal I I I.tiodad of j ainitig...prelvious war, alterable only by death, wounding, disease , breakdown, or the need to refit end retrain a unit was now changed to one in which a fixed term

  12. Cramer-Rao bound on watermark desynchronization parameter estimation accuracy

    NASA Astrophysics Data System (ADS)

    Sadasivam, Shankar; Moulin, Pierre

    2007-02-01

    Various decoding algorithms have been proposed in the literature to combat desynchronization attacks on quantization index modulation (QIM) blind watermarking schemes. Nevertheless, these results have been fairly poor so far. The need to investigate fundamental limitations on the decoder's performance under a desynchronization attack is thus clear. In this paper, we look at the class of estimator-decoders which estimate the desynchronization attack parameter(s) for using in the decoding step. We model the desynchronization attack as an arbitrary (but invertible) linear time-invariant (LTI) system. We then come up with an encoding-decoding scheme for these attacks on cubic QIM watermarking schemes, and derive Cramer-Rao bounds on the estimation error for the desynchronization parameter at the decoder. As an example, we consider the case of a cyclic shift attack and present some numerical findings.

  13. Using Qualitative Hazard Analysis to Guide Quantitative Safety Analysis

    NASA Technical Reports Server (NTRS)

    Shortle, J. F.; Allocco, M.

    2005-01-01

    Quantitative methods can be beneficial in many types of safety investigations. However, there are many difficulties in using quantitative m ethods. Far example, there may be little relevant data available. This paper proposes a framework for using quantitative hazard analysis to prioritize hazard scenarios most suitable for quantitative mziysis. The framework first categorizes hazard scenarios by severity and likelihood. We then propose another metric "modeling difficulty" that desc ribes the complexity in modeling a given hazard scenario quantitatively. The combined metrics of severity, likelihood, and modeling difficu lty help to prioritize hazard scenarios for which quantitative analys is should be applied. We have applied this methodology to proposed concepts of operations for reduced wake separation for airplane operatio ns at closely spaced parallel runways.

  14. Model Structures and Algorithms for Identification of Aerodynamic Models for Flight Dynamics Applications

    NASA Technical Reports Server (NTRS)

    Prasanth, Ravi K.; Klein, Vladislav; Murphy, Patrick C.; Mehra, Raman K.

    2005-01-01

    This paper describes model structures and parameter estimation algorithms suitable for the identification of unsteady aerodynamic models from input-output data. The model structures presented are state space models and include linear time-invariant (LTI) models and linear parameter-varying (LPV) models. They cover a wide range of local and parameter dependent identification problems arising in unsteady aerodynamics and nonlinear flight dynamics. We present a residue algorithm for estimating model parameters from data. The algorithm can incorporate apriori information and is described in detail. The algorithms are evaluated on the F-16XL wind-tunnel test data from NAS Langley Research Center. Results of numerical evaluation are presented. The paper concludes with a discussion major issues and directions for future work.

  15. USAF Warrior Studies: Air Superiority in World War 2 and Korea,

    DTIC Science & Technology

    1983-01-01

    i ’ ccrci ’N sri cc (iii ,c :is’ Ii ’ 1 41 ’’ a p i- i lti ii IlC rii. I/ 1111w fti , l . mill ftc’l \\cu \\’k il/iwS p ’~4i4 ti i ’ 1 Si s ti,1r iiii...Pr Ii rpp, (I4:1p 1.l11pCi \\ (I pl1I )I Lr PN 11 Prr )11 B 1 ( lCt ( p I CF I’ ’ l lp r pI PpIlt o I iii’ ’IP L al, I [pif I . it I I pI I pp NI I Nuit

  16. Construction of energy-stable projection-based reduced order models

    DOE PAGES

    Kalashnikova, Irina; Barone, Matthew F.; Arunajatesan, Srinivasan; ...

    2014-12-15

    Our paper aims to unify and extend several approaches for building stable projection-based reduced order models (ROMs) using the energy method and the concept of “energy-stability”. Attention is focused on linear time-invariant (LTI) systems. First, an approach for building energy stable Galerkin ROMs for linear hyperbolic or incompletely parabolic systems of partial differential equations (PDEs) using continuous projection is proposed. The key idea is to apply to the system a transformation induced by the Lyapunov function for the system, and to build the ROM in the transformed variables. The result of this procedure will be a ROM that is energy-stablemore » for any choice of reduced basis. It is shown that, for many PDE systems, the desired transformation is induced by a special inner product, termed the “symmetry inner product”. Next, attention is turned to building energy-stable ROMs via discrete projection. A discrete counterpart of the continuous symmetry inner product, termed the “Lyapunov inner product”, is derived. Moreover, it is shown that the Lyapunov inner product can be computed in a black-box fashion for a stable LTI system ari sing from the discretization of a system of PDEs in space. Projection in this inner product guarantees a ROM that is energy-stable, again for any choice of reduced basis. Connections between the Lyapunov inner product and the inner product induced by the balanced truncation algorithm are made. We also made comparisons between the symmetry inner product and the Lyapunov inner product. Performance of ROMs constructed using these inner products is evaluated on several benchmark test cases.« less

  17. Construction of energy-stable projection-based reduced order models

    SciTech Connect

    Kalashnikova, Irina; Barone, Matthew F.; Arunajatesan, Srinivasan; van Bloemen Waanders, Bart G.

    2014-12-15

    Our paper aims to unify and extend several approaches for building stable projection-based reduced order models (ROMs) using the energy method and the concept of “energy-stability”. Attention is focused on linear time-invariant (LTI) systems. First, an approach for building energy stable Galerkin ROMs for linear hyperbolic or incompletely parabolic systems of partial differential equations (PDEs) using continuous projection is proposed. The key idea is to apply to the system a transformation induced by the Lyapunov function for the system, and to build the ROM in the transformed variables. The result of this procedure will be a ROM that is energy-stable for any choice of reduced basis. It is shown that, for many PDE systems, the desired transformation is induced by a special inner product, termed the “symmetry inner product”. Next, attention is turned to building energy-stable ROMs via discrete projection. A discrete counterpart of the continuous symmetry inner product, termed the “Lyapunov inner product”, is derived. Moreover, it is shown that the Lyapunov inner product can be computed in a black-box fashion for a stable LTI system ari sing from the discretization of a system of PDEs in space. Projection in this inner product guarantees a ROM that is energy-stable, again for any choice of reduced basis. Connections between the Lyapunov inner product and the inner product induced by the balanced truncation algorithm are made. We also made comparisons between the symmetry inner product and the Lyapunov inner product. Performance of ROMs constructed using these inner products is evaluated on several benchmark test cases.

  18. The distribution of Escherichia coli serovars, virulence genes, gene association and combinations and virulence genes encoding serotypes in pathogenic E. coli recovered from diarrhoeic calves, sheep and goat.

    PubMed

    Osman, K M; Mustafa, A M; Elhariri, M; Abdelhamed, G S

    2013-02-01

    Ruminants, especially cattle, have been implicated as a principal reservoir of one of the enterovirulent Escherichia coli pathotypes. The detection of the virulence genes in diarrhoeic calves and small ruminants has not been studied in Egypt. To determine the occurrence, serotypes and the virulence gene markers, stx1, stx2, hylA, Flic(h7) , stb, F41, K99, sta, F17, LT-I, LT-II and eae, rectal swabs were taken from diarrhoeic calves, sheep and goats and subjected to bacterial culture and PCR. The E. coli prevalence rate in the diarrhoeic animals was 63.6% in calves, 27.3% in goat and 9.1% in sheep. The 102 E. coli strains isolated from the calves, goat and sheep were 100% haemolytic non-verotoxic and fitted into the Eagg group. The isolates belonged to seven O serogroups (O25, O78, O86, O119, O158, O164 and O157). The eae gene was detected in six of the strains isolated from the calves. The 102 bovine, ovine and caprine E. coli strains isolated in this study were negative for stx1, stx2, F41, LT-I and Flic(h7) genes. The highest gene combinations were found to occur in the form of 24/102 isolates (23.5%) that carried the F17 gene predominantly associated with eaeA, hylA, K99 and Stb genes in the calves, while the hylA, K99 and Sta were the only genes found to be in conjunction in both calves and goats (6/102; 5.9% each). Our data show that in Egypt, large and small ruminants could be a potential source of infection in humans.

  19. [New reliable methods for the diagnose of protein-energy wasting in hemodialysis patients].

    PubMed

    Castellano-Gasch, Sandra; Palomares-Sancho, Inés; Molina-Núñez, Manuel; Ramos-Sánchez, Rosa; Merello-Godino, José I; Maduell, Francisco

    2014-10-01

    Introducción: La depleción proteico-calórica (protein- energy wasting, PEW) definida como pérdida de masa muscular y grasa del organismo, supone un importante factor de riesgo cardiovascular en los pacientes en diálisis. Para su diagnóstico se requiere de la presencia de tres características: bioquímicas (albúmina, prealbúmina o colesterol bajos), descenso de masa corporal (índice de masa corporal, pérdida de peso o de grasa) y reducción de masa muscular (evaluada mediante creatinina o área muscular del brazo). El Objetivo del presente estudio es demostrar que el índice de tejido magro (LTI) obtenido por bioimpedancia espectroscópica (BIS) es un parámetro válido para el diagnóstico de depleción proteico- calórica. Métodos: Estudio transversal de 1369 pacientes con dos mediciones de BCM entre las que transcurren seis meses, en los que analizamos parámetros analíticos y de bioimpedancia espectroscópica . Resultados: El índice de tejido magro aportado por el BCM (Body Composition Monitor) cuantifica la masa magra del paciente y se correlaciona con parámetros tradicionales (albúmina plasmática) y no-tradicionales (IRE y PCR) de depleción proteico-calórica sin verse alterado por la situación hídrica del paciente. Conclusiones: El LTI es un parámetro de masa magra fácil de obtener cuyo seguimiento y monitorización nos puede ayudar a diagnosticar situaciones de riesgo para nuestros pacientes como la depleción proteico-calórica.

  20. Non-linear dynamic analysis of geared systems. Final Report Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Singh, Rajendra; Houser, Donald R.; Kahraman, Ahmet

    1990-01-01

    Under driving conditions, a typical geared system may be subjected to large dynamic loads. Also, the vibration level of the geared system is directly related to the noise radiated from the gear box. The steady state dynamic behavior of the system is examined in order to design reliable and quiet transmissions. The scope is limited to a system containing a spur gear pair with backlash and periodically time varying mesh stiffness, and rolling element bearings with clearance type nonlinearities. The internal static transmission error at the gear mesh, which is of importance from high frequency noise and vibration control view point, is considered in the formulation in sinusoidal or periodic form. A dynamic finite element model of the linear time invariant (LTI) system is developed. Effects of several system parameters, such as torsional and transverse flexibilities of the shafts and prime mover/load inertias, on free and forced vibration characteristics are investigated. Several reduced order LTI models are developed and validated by comparing their eigen solutions with the finite element model results. Using the reduced order formulations, a three degree of freedom dynamic model is developed which includes nonlinearities associated with radical clearances in the radial rolling element bearings, backlash between a spur gear pair and periodically varying gear mesh stiffness. As a limiting case, a single degree of freedom model of the spur gear pair with backlash is considered and mathematical conditions for tooth separation and back collision are defined. Both digital simulation technique and analytical models such as method of harmonic balance and the method of multiple scales were used to develop the steady state frequency response characteristics for various nonlinear and/or time varying cases.

  1. OsPEX11, a Peroxisomal Biogenesis Factor 11, Contributes to Salt Stress Tolerance in Oryza sativa

    PubMed Central

    Cui, Peng; Liu, Hongbo; Islam, Faisal; Li, Lan; Farooq, Muhammad A.; Ruan, Songlin; Zhou, Weijun

    2016-01-01

    Peroxisomes are single membrane-bound organelles, whose basic enzymatic constituents are catalase and H2O2-producing flavin oxidases. Previous reports showed that peroxisome is involved in numerous processes including primary and secondary metabolism, plant development and abiotic stress responses. However, knowledge on the function of different peroxisome genes from rice and its regulatory roles in salt and other abiotic stresses is limited. Here, a novel prey protein, OsPEX11 (Os03g0302000), was screened and identified by yeast two-hybrid and GST pull-down assays. Phenotypic analysis of OsPEX11 overexpression seedlings demonstrated that they had better tolerance to salt stress than wild type (WT) and OsPEX11-RNAi seedlings. Compared with WT and OsPEX11-RNAi seedlings, overexpression of OsPEX11 had lower level of lipid peroxidation, Na+/K+ ratio, higher activities of antioxidant enzymes (SOD, POD, and CAT) and proline accumulation. Furthermore, qPCR data suggested that OsPEX11 acted as a positive regulator of salt tolerance by reinforcing the expression of several well-known rice transporters (OsHKT2;1, OsHKT1;5, OsLti6a, OsLti6b, OsSOS1, OsNHX1, and OsAKT1) involved in Na+/K+ homeostasis in transgenic plants under salinity. Ultrastructural observations of OsPEX11-RNAi seedlings showed that they were less sensitive to salt stress than WT and overexpression lines. These results provide experimental evidence that OsPEX11 is an important gene implicated in Na+ and K+ regulation, and plays a critical role in salt stress tolerance by modulating the expression of cation transporters and antioxidant defense. Thus, OsPEX11 could be considered in transgenic breeding for improvement of salt stress tolerance in rice crop. PMID:27695459

  2. Construction of energy-stable Galerkin reduced order models.

    SciTech Connect

    Kalashnikova, Irina; Barone, Matthew Franklin; Arunajatesan, Srinivasan; van Bloemen Waanders, Bart Gustaaf

    2013-05-01

    This report aims to unify several approaches for building stable projection-based reduced order models (ROMs). Attention is focused on linear time-invariant (LTI) systems. The model reduction procedure consists of two steps: the computation of a reduced basis, and the projection of the governing partial differential equations (PDEs) onto this reduced basis. Two kinds of reduced bases are considered: the proper orthogonal decomposition (POD) basis and the balanced truncation basis. The projection step of the model reduction can be done in two ways: via continuous projection or via discrete projection. First, an approach for building energy-stable Galerkin ROMs for linear hyperbolic or incompletely parabolic systems of PDEs using continuous projection is proposed. The idea is to apply to the set of PDEs a transformation induced by the Lyapunov function for the system, and to build the ROM in the transformed variables. The resulting ROM will be energy-stable for any choice of reduced basis. It is shown that, for many PDE systems, the desired transformation is induced by a special weighted L2 inner product, termed the %E2%80%9Csymmetry inner product%E2%80%9D. Attention is then turned to building energy-stable ROMs via discrete projection. A discrete counterpart of the continuous symmetry inner product, a weighted L2 inner product termed the %E2%80%9CLyapunov inner product%E2%80%9D, is derived. The weighting matrix that defines the Lyapunov inner product can be computed in a black-box fashion for a stable LTI system arising from the discretization of a system of PDEs in space. It is shown that a ROM constructed via discrete projection using the Lyapunov inner product will be energy-stable for any choice of reduced basis. Connections between the Lyapunov inner product and the inner product induced by the balanced truncation algorithm are made. Comparisons are also made between the symmetry inner product and the Lyapunov inner product. The performance of ROMs constructed

  3. Modeling and Thrust Optimization of a Bio-Inspired Pulsatile Jet Thruster

    NASA Astrophysics Data System (ADS)

    Krieg, Michael W.

    -off is coincides with this velocity criterion, for all cases tested. Piston velocity program and nozzle radius are optimized with respect to average thrust, and a quantity similar to propulsive efficiency. The average thrust is maximized by a critical nozzle radius. An approximate linear time-invariant (LTI) model of the thruster vehicle system was derived which categorizes maneuvers into different characteristic regimes. Initial thruster testing showed that open and closed loop frequency response were sufficiently approximated by the LTI model, and that the thruster is ideally suited for small scale high accuracy maneuvers.

  4. Nonlinear time-periodic models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria.

    PubMed

    Taylor, Graham K; Zbikowski, Rafał

    2005-06-22

    Previous studies of insect flight control have been statistical in approach, simply correlating wing kinematics with body kinematics or force production. Kinematics and forces are linked by Newtonian mechanics, so adopting a dynamics-based approach is necessary if we are to place the study of insect flight on its proper physical footing. Here we develop semi-empirical models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria. We use instantaneous force-moment measurements from individual locusts to parametrize the nonlinear rigid body equations of motion. Since the instantaneous forces are approximately periodic, we represent them using Fourier series, which are embedded in the equations of motion to give a nonlinear time-periodic (NLTP) model. This is a proper mathematical generalization of an earlier linear-time invariant (LTI) model of locust flight dynamics, developed using previously published time-averaged versions of the instantaneous force recordings. We perform various numerical simulations, within the fitted range of the model, and across the range of body angles used by free-flying locusts, to explore the likely behaviour of the locusts upon release from the tether. Solutions of the NLTP models are compared with solutions of the nonlinear time-invariant (NLTI) models to which they reduce when the periodic terms are dropped. Both sets of models are unstable and therefore fail to explain locust flight stability fully. Nevertheless, whereas the measured forces include statistically significant harmonic content up to about the eighth harmonic, the simulated flight trajectories display no harmonic content above the fundamental forcing frequency. Hence, manoeuvre control in locusts will not directly reflect subtle changes in the higher harmonics of the wing beat, but must operate on a coarser time-scale. A state-space analysis of the NLTP models reveals orbital trajectories that are impossible to capture in the LTI and NLTI models, and

  5. Intestinal Lin- c-Kit+ NKp46- CD4- population strongly produces IL-22 upon IL-1β stimulation.

    PubMed

    Lee, Youngae; Kumagai, Yutaro; Jang, Min Seong; Kim, Jung-Hwan; Yang, Bo-Gie; Lee, Eun-Jung; Kim, You-Me; Akira, Shizuo; Jang, Myoung Ho

    2013-05-15

    Small intestinal innate lymphoid cells (ILCs) regulate intestinal epithelial cell homeostasis and help to prevent pathogenic bacterial infections by producing IL-22. In a global gene-expression analysis comparing small intestinal ILCs (Lin(-)c-Kit(+)Sca-1(-) cells) with non-ILCs (Lin(-)c-Kit(-)Sca-1(-) cells), we found that Lin(-)c-Kit(+)Sca-1(-) cells highly expressed the mRNAs for Il22, antimicrobial peptides, Csf2rb2 (Il3r), mast cell proteases, and Rorc. We then subdivided the Lin(-)c-Kit(+)Sca-1(-) cells into three groups--Lin(-)c-Kit(+)NKp46(-)CD4(-), Lin(-)c-Kit(+)NKp46(-)CD4(+) (CD4(+) LTi-like cells), and Lin(-)c-Kit(+)NKp46(+) (NKp46(+) ILC22 cells)--and showed that the Lin(-)c-Kit(+)NKp46(-)CD4(-) cells produced the highest level of IL-22 protein after IL-1β, IL-23, or IL-1β and IL-23 stimulation. In addition, we showed that the majority of the Lin(-)c-Kit(+)NKp46(-)CD4(-) population was IL-7Rα(+)CD34(-)β7(int) cells, and IL-7Rα(-) cells could be divided into three subsets (CD34(+)β7(int), CD34(-)β7(int), and CD34(int)β7(hi) cells). The IL-7Rα(+)CD34(-)β7(int) cells strongly expressed the transcripts for Il17f and Il22 after costimulation with IL-1β and IL-23. The IL-7Rα(-)CD34(+)β7(int) and IL-7Rα(-)CD34(int)β7(hi) cells predominantly expressed the transcripts for mast cell proteases and differentiated almost entirely into mast cells after 1 wk in culture medium supplemented with a cytokine mixture, whereas the IL-7Rα(-)CD34(-)β7(int) cells highly expressed α-defensins and showed no differentiation. Taken together, these findings indicate that the IL-7Rα(-)CD34(+)β7(int) and IL-7Rα(-)CD34(int)β7(hi) populations are mast cell progenitors, and the IL-7Rα(+)CD34(-)β7(int) (CD4(-) LTi-like cells) and IL-7Rα(-)CD34(-)β7(int) populations within Lin(-)c-Kit(+)NKp46(-)CD4(-) cells may control intestinal homeostasis and provide intestinal protection by producing high levels of IL-22 and α-defensins, respectively.

  6. De novo Transcriptome Assembly of Floral Buds of Pineapple and Identification of Differentially Expressed Genes in Response to Ethephon Induction

    PubMed Central

    Liu, Chuan-He; Fan, Chao

    2016-01-01

    A remarkable characteristic of pineapple is its ability to undergo floral induction in response to external ethylene stimulation. However, little information is available regarding the molecular mechanism underlying this process. In this study, the differentially expressed genes (DEGs) in plants exposed to 1.80 mL·L−1 (T1) or 2.40 mL·L−1 ethephon (T2) compared with Ct plants (control, cleaning water) were identified using RNA-seq and gene expression profiling. Illumina sequencing generated 65,825,224 high-quality reads that were assembled into 129,594 unigenes with an average sequence length of 1173 bp. Of these unigenes, 24,775 were assigned to specific KEGG pathways, of which metabolic pathways and biosynthesis of secondary metabolites were the most highly represented. Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority were involved in metabolic and cellular processes, cell and cell part, catalytic activity and binding. Gene expression profiling analysis revealed 3788, 3062, and 758 DEGs in the comparisons of T1 with Ct, T2 with Ct, and T2 with T1, respectively. GO analysis indicated that these DEGs were predominantly annotated to metabolic and cellular processes, cell and cell part, catalytic activity, and binding. KEGG pathway analysis revealed the enrichment of several important pathways among the DEGs, including metabolic pathways, biosynthesis of secondary metabolites and plant hormone signal transduction. Thirteen DEGs were identified as candidate genes associated with the process of floral induction by ethephon, including three ERF-like genes, one ETR-like gene, one LTI-like gene, one FT-like gene, one VRN1-like gene, three FRI-like genes, one AP1-like gene, one CAL-like gene, and one AG-like gene. qPCR analysis indicated that the changes in the expression of these 13 candidate genes were consistent with the alterations in the corresponding RPKM values, confirming the accuracy and credibility of the RNA-seq and gene

  7. WIRC-POL: A near-IR spectro-polarimetric imager at Palomar Observatory

    NASA Astrophysics Data System (ADS)

    Nilsson, Ricky; Tinyanont, Samaporn; Mawet, Dimitri; Knutson, Heather; WIRC-POL Team

    2017-01-01

    The 200-inch Hale Telescope at Palomar Observatory is the largest equatorial-mounted telescope in the world. Combining a large aperture, extremely stable tracking, and no differential motion of optics, it introduces low and stable instrument polarization, making it uniquely suited for time-resolved polarimetry. Its prime focus currently hosts the Wide-field InfraRed Camera (WIRC), which is being refurbished with a new H2 detector, 32 channel readout electronics, grism, focal-plane mask and polarization grating. This will transform it into WIRC-POL — a machine for high-precision photometry, and slitless low-resolution (R~150) spectroscopy and spectro-polarimetry. Two key science programs are starting in 2017: (1) a large spectro-polarimetric survey of approximately 1000 LTY field brown dwarfs, probing atmospheric composition, physical properties, and cloud dynamics at the L-T transition, and (2) a survey of transiting exoplanets, using the high photometric stability and slitless spectroscopy mode to characterize exoplanet atmospheres from spectra obtained in transit and secondary eclipse, and search for transit-timing variations in multiple planet systems. Here we present an overview of the instrument upgrades and the exciting scientific questions we aim to address.

  8. Laser Shearography Inspection of TPS (Thermal Protection System) Cork on RSRM (Reusable Solid Rocket Motors)

    NASA Technical Reports Server (NTRS)

    Lingbloom, Mike; Plaia, Jim; Newman, John

    2006-01-01

    Laser Shearography is a viable inspection method for detection of de-bonds and voids within the external TPS (thermal protection system) on to the Space Shuttle RSRM (reusable solid rocket motors). Cork samples with thicknesses up to 1 inch were tested at the LTI (Laser Technology Incorporated) laboratory using vacuum-applied stress in a vacuum chamber. The testing proved that the technology could detect cork to steel un-bonds using vacuum stress techniques in the laboratory environment. The next logical step was to inspect the TPS on a RSRM. Although detailed post flight inspection has confirmed that ATK Thiokol's cork bonding technique provides a reliable cork to case bond, due to the Space Shuttle Columbia incident there is a great interest in verifying bond-lines on the external TPS. This interest provided and opportunity to inspect a RSRM motor with Laser Shearography. This paper will describe the laboratory testing and RSRM testing that has been performed to date. Descriptions of the test equipment setup and techniques for data collection and detailed results will be given. The data from the test show that Laser Shearography is an effective technology and readily adaptable to inspect a RSRM.

  9. Adaptive cruise control with stop&go function using the state-dependent nonlinear model predictive control approach.

    PubMed

    Shakouri, Payman; Ordys, Andrzej; Askari, Mohamad R

    2012-09-01

    In the design of adaptive cruise control (ACC) system two separate control loops - an outer loop to maintain the safe distance from the vehicle traveling in front and an inner loop to control the brake pedal and throttle opening position - are commonly used. In this paper a different approach is proposed in which a single control loop is utilized. The objective of the distance tracking is incorporated into the single nonlinear model predictive control (NMPC) by extending the original linear time invariant (LTI) models obtained by linearizing the nonlinear dynamic model of the vehicle. This is achieved by introducing the additional states corresponding to the relative distance between leading and following vehicles, and also the velocity of the leading vehicle. Control of the brake and throttle position is implemented by taking the state-dependent approach. The model demonstrates to be more effective in tracking the speed and distance by eliminating the necessity of switching between the two controllers. It also offers smooth variation in brake and throttle controlling signal which subsequently results in a more uniform acceleration of the vehicle. The results of proposed method are compared with other ACC systems using two separate control loops. Furthermore, an ACC simulation results using a stop&go scenario are shown, demonstrating a better fulfillment of the design requirements.

  10. Synchronization of Lienard-Type Oscillators in Uniform Electrical Networks

    SciTech Connect

    Sinha, Mohit; Dorfler, Florian; Johnson, Brian B.; Dhople, Sairaj V.

    2016-08-01

    This paper presents a condition for global asymptotic synchronization of Lienard-type nonlinear oscillators in uniform LTI electrical networks with series R-L circuits modeling interconnections. By uniform electrical networks, we mean that the per-unit-length impedances are identical for the interconnecting lines. We derive conditions for global asymptotic synchronization for a particular feedback architecture where the derivative of the oscillator output current supplements the innate current feedback induced by simply interconnecting the oscillator to the network. Our proof leverages a coordinate transformation to a set of differential coordinates that emphasizes signal differences and the particular form of feedback permits the formulation of a quadratic Lyapunov function for this class of networks. This approach is particularly interesting since synchronization conditions are difficult to obtain by means of quadratic Lyapunov functions when only current feedback is used and for networks composed of series R-L circuits. Our synchronization condition depends on the algebraic connectivity of the underlying network, and reiterates the conventional wisdom from Lyapunov- and passivity-based arguments that strong coupling is required to ensure synchronization.

  11. Irradiation behavior of Ti-stabilized 316L type steel

    NASA Astrophysics Data System (ADS)

    Rodchenkov, B. S.; Kalinin, G. M.; Strebkov, Yu. S.; Shamardin, V. K.; Prokhorov, V. I.; Bulanova, T. M.

    2009-04-01

    Type 316L austenitic steels are widely used for the in-vessel internal structures of fission reactors (core, core support, etc.) and for experimental irradiation facilities. The modifications of 316L Type steel (316L, 316L(N), US 316, J 316, JPCA, etc.) have been considered as structural material for International Thermonuclear Experimental Reactor (ITER). The results of investigation the irradiation behaviour of Ti-stabilized 316 L type steel (0.04 C-15 Cr-11 Ni-2.5 Mo-0.5 Ti) are presented in this work. The specimens cut out from 316L-Ti steel forging were irradiated in the SM-2 reactor up to a dose ˜4 and 10 dpa at 265 ± 15 °C. The tensile properties, fracture toughness and changes in resistance to intergranular stress corrosion cracking (IGSCC) have been investigated after irradiation. The results for Ti-stabilized 316L steel were compared with those for 316L(N)-IG steel irradiated at the same condition.

  12. Follicular Dendritic Cells Emerge from Ubiquitous Perivascular Precursors

    PubMed Central

    Krautler, Nike Julia; Kana, Veronika; Kranich, Jan; Tian, Yinghua; Perera, Dushan; Lemm, Doreen; Schwarz, Petra; Armulik, Annika; Browning, Jeffrey L.; Tallquist, Michelle; Buch, Thorsten; Oliveira-Martins, José B.; Zhu, Caihong; Hermann, Mario; Wagner, Ulrich; Brink, Robert; Heikenwalder, Mathias; Aguzzi, Adriano

    2013-01-01

    Summary The differentiation of follicular dendritic cells (FDC) is essential to the remarkable microanatomic plasticity of lymphoid follicles. Here we show that FDC arise from ubiquitous perivascular precursors (preFDC) expressing platelet-derived growth factor receptor β (PDGFRβ). PDGFRβ-Cre-driven reporter gene recombination resulted in FDC labeling, whereas conditional ablation of PDGFRβ+-derived cells abolished FDC, indicating that FDC originate from PDGFRβ+ cells. Lymphotoxin-α-overexpressing prion protein (PrP)+ kidneys developed PrP+ FDC after transplantation into PrP mice, confirming that preFDC exist outside lymphoid organs. Adipose tissue-derived PDGFRβ+ stromal-vascular cells responded to FDC maturation factors and, when transplanted into lymphotoxin β receptor (LTβR) kidney capsules, differentiated into Mfge8+CD21/35+ FcγRIIβ+PrP+ FDC capable of trapping immune complexes and recruiting B cells. Spleens of lymphocyte-deficient mice contained perivascular PDGFRβ+ FDC precursors whose expansion required both lymphoid tissue inducer (LTi) cells and lymphotoxin. The ubiquity of preFDC and their strategic location at blood vessels may explain the de novo generation of organized lymphoid tissue at sites of lymphocytic inflammation. PMID:22770220

  13. IL-22: An Evolutionary Missing-Link Authenticating the Role of the Immune System in Tissue Regeneration

    PubMed Central

    Kumar, Pawan; Rajasekaran, Kamalakannan; Palmer, Jeanne M; Thakar, Monica S; Malarkannan, Subramaniam

    2013-01-01

    Tissue regeneration is a critical component of organ maintenance. The ability of lymphocytes to kill pathogen-infected cells has been well-studied. However, the necessity for lymphocytes to participate in reconstruction of destroyed tissues has not been explored until recently. Interleukin (IL)-22, a newly defined cytokine exclusively produced by subsets of lymphocytes, provides the strongest proof yet for the tissue regenerative potentials of the immune system. IL-22 plays an obligatory role in epithelial homeostasis in the gut, liver and lung. The receptor for IL-22 (IL-22R1 and IL-10R2) is predominantly expressed by epithelial cells. While the pro-inflammatory effect is questioned, the pro-constructive potential of IL-22 is well established. It is evident from the response to IL-22, that epithelial cells not only produce anti-microbial peptides but also actively proliferate. Aryl hydrocarbon receptor (AhR) and retinoic acid-related orphan receptor (RORγt) transcription factor are required for IL-22 generation from Lymphoid Tissue inducer cells LTi, Th22 and NK-like cells. However, IL-22 production from conventional NK cells is independent of AhR and RORγt. In this review, we present a case for a paradigm shift in how we define the function of the immune system. This would include tissue regeneration as a legitimate immune function. PMID:23386905

  14. Semi-active tuned liquid column damper implementation with real-time hybrid simulations

    NASA Astrophysics Data System (ADS)

    Riascos, Carlos; Marulanda Casas, Johannio; Thomson, Peter

    2016-04-01

    Real-time hybrid simulation (RTHS) is a modern cyber-physical technique used for the experimental evaluation of complex systems, that treats the system components with predictable behavior as a numerical substructure and the components that are difficult to model as an experimental substructure. Therefore it is an attractive method for evaluation of the response of civil structures under earthquake, wind and anthropic loads. In this paper, the response of three-story shear frame controlled by a tuned liquid column damper (TLCD) and subject to base excitation is considered. Both passive and semi-active control strategies were implemented and are compared. While the passive TLCD achieved a reduction of 50% in the acceleration response of the main structure in comparison with the structure without control, the semi-active TLCD achieved a reduction of 70%, and was robust to variations in the dynamic properties of the main structure. In addition, a RTHS was implemented with the main structure modeled as a linear, time-invariant (LTI) system through a state space representation and the TLCD, with both control strategies, was evaluated on a shake table that reproduced the displacement of the virtual structure. Current assessment measures for RTHS were used to quantify the performance with parameters such as generalized amplitude, equivalent time delay between the target and measured displacement of the shake table, and energy error using the measured force, and prove that the RTHS described in this paper is an accurate method for the experimental evaluation of structural control systems.

  15. Real-Time Adaptive Control of Flow-Induced Cavity Tones

    NASA Technical Reports Server (NTRS)

    Kegerise, Michael A.; Cabell, Randolph H.; Cattafesta, Louis N.

    2004-01-01

    An adaptive generalized predictive control (GPC) algorithm was formulated and applied to the cavity flow-tone problem. The algorithm employs gradient descent to update the GPC coefficients at each time step. The adaptive control algorithm demonstrated multiple Rossiter mode suppression at fixed Mach numbers ranging from 0.275 to 0.38. The algorithm was also able t o maintain suppression of multiple cavity tones as the freestream Mach number was varied over a modest range (0.275 to 0.29). Controller performance was evaluated with a measure of output disturbance rejection and an input sensitivity transfer function. The results suggest that disturbances entering the cavity flow are colocated with the control input at the cavity leading edge. In that case, only tonal components of the cavity wall-pressure fluctuations can be suppressed and arbitrary broadband pressure reduction is not possible. In the control-algorithm development, the cavity dynamics are treated as linear and time invariant (LTI) for a fixed Mach number. The experimental results lend support this treatment.

  16. Distributed consensus observer-based H∞ control for linear systems with sensor and actuator networks

    NASA Astrophysics Data System (ADS)

    Wang, Hong-Du; Wu, Huai-Ning

    2015-04-01

    This paper proposed a distributed consensus observer (DCO) based H∞ control method for a class of linear time-invariant (LTI) continuous systems with a sensor and actuator network (SAN). The communication topology of the SAN under consideration is represented by a directed graph, in which the sensor nodes are not able to acquire all the control inputs applied to the target system from the actuator nodes. To overcome this difficulty, a set of novel DCOs embedded in the sensor nodes and a set of DCO-based controllers embedded in the actuator nodes are initially constructed to estimate and control the state of the target system in a fully distributed way, respectively. The constructed DCOs take full advantage of their consensus property and replace the unavailable control inputs with the approximate ones computed on the basis of the state estimates of the underlying sensor node and its neighboring sensor nodes. Subsequently, a design method of DCO-based H∞ control is proposed in terms of bilinear matrix inequality (BMI) to ensure that the closed-loop system is exponentially stable while satisfying a prescribed overall H∞ performance of disturbance attenuation. Moreover, in order to make attenuation level as small as possible, a suboptimal H∞ control design problem is formulated as a BMI optimization problem, and a modified path-following method is provided for solving this problem by using the existing linear matrix inequality (LMI) optimization techniques. Finally, simulation results demonstrate the effectiveness of the proposed method.

  17. Consensus+Innovations Distributed Kalman Filter With Optimized Gains

    NASA Astrophysics Data System (ADS)

    Das, Subhro; Moura, Jose M. F.

    2017-01-01

    In this paper, we address the distributed filtering and prediction of time-varying random fields represented by linear time-invariant (LTI) dynamical systems. The field is observed by a sparsely connected network of agents/sensors collaborating among themselves. We develop a Kalman filter type consensus+innovations distributed linear estimator of the dynamic field termed as Consensus+Innovations Kalman Filter. We analyze the convergence properties of this distributed estimator. We prove that the mean-squared error of the estimator asymptotically converges if the degree of instability of the field dynamics is within a pre-specified threshold defined as tracking capacity of the estimator. The tracking capacity is a function of the local observation models and the agent communication network. We design the optimal consensus and innovation gain matrices yielding distributed estimates with minimized mean-squared error. Through numerical evaluations, we show that, the distributed estimator with optimal gains converges faster and with approximately 3dB better mean-squared error performance than previous distributed estimators.

  18. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 10.

    DTIC Science & Technology

    1973-11-01

    414 蔿 %q) bAC Cthe bogkh po*ittir -se ,I~e gf e 0%0~t~c cu 1c,144uetce h0- 1the *pcbI10* oy**t4,oft* * o *14*0 *meR*A Itowj SI uwo t4 4%& R I...will votrf R4e of #bwo rtwom*1 ~$i*~* 7%0 *qVWdS. *tf$ 4*t’*I 5I 14C*tlf1r %%W 4-"pLq ao jai *&.W&. Clv,,* pffrs’ * 01 1*, "~lorto S * o ~wl.*I 16Wf*iwI...Iou go W JgwotgwVS M opoC *$0w -Ir𔃾 4 R um4 IV f-e i 4 Eig w tIf -F*t U 4 43 ltI0i3 41 04*A * .I~ lo W a,-~4 woo Wpooo R fosv~ 4* o 4 u$; Pkj~4e~e

  19. The chromosomal nature of LT-II enterotoxins solved: a lambdoid prophage encodes both LT-II and one of two novel pertussis-toxin-like toxin family members in type II enterotoxigenic Escherichia coli

    PubMed Central

    Jobling, Michael G.

    2016-01-01

    Heat-labile enterotoxins (LT) of enterotoxigenic Escherichia coli (ETEC) are structurally and functionally related to cholera toxin (CT). LT-I toxins are plasmid-encoded and flanked by IS elements, while LT-II toxins of type II ETEC are chromosomally encoded with flanking genes that appear phage related. Here, I determined the complete genomic sequence of the locus for the LT-IIa type strain SA53, and show that the LT-IIa genes are encoded by a 51 239 bp lambdoid prophage integrated at the rac locus, the site of a defective prophage in E. coli K12 strains. Of 50 LT-IIa and LT-IIc, 46 prophages also encode one member of two novel two-gene ADP-ribosyltransferase toxin families that are both related to pertussis toxin, which I named eplBA or ealAB, respectively. The eplBA and ealAB genes are syntenic with the Shiga toxin loci in their lambdoid prophages of the enteric pathogen enterohemorrhagic E. coli. These novel AB5 toxins show pertussis-toxin-like activity on tissue culture cells, and like pertussis toxin bind to sialic acid containing glycoprotein ligands. Type II ETEC are the first mucosal pathogens known to simultaneously produce two ADP-ribosylating toxins predicted to act on and modulate activity of both stimulatory and inhibitory alpha subunits of host cell heterotrimeric G-proteins. PMID:26755534

  20. Carleman Estimates with No Lower-Order Terms for General Riemann Wave Equations. Global Uniqueness and Observability in One Shot

    SciTech Connect

    Triggiani, R.; Yao, P.F.

    2002-12-19

    This paper considers a fully general (Riemann) wave equation on a finite-dimensional Riemannian manifold, with energy level (H{sup 1} x L{sub 2}) -terms, under essentially minimal smoothness assumptions on the variable (in time and space) coefficients. The paper provides Carleman-type inequalities: first pointwise, for C{sup 2} -solutions, then in integral form for H{sup 1,1}(Q) -solutions. The aim of the present approach is to provide Carleman inequalities which do not contain lower-order terms, a distinguishing feature over most of the literature. Accordingly, global uniqueness results for overdetermined problems as well as Continuous Observability/ Uniform Stabilization inequalities follow in one shot, as a part of the same stream of arguments. Constants in the estimates are, therefore, generally explicit. The paper emphasizes the more challenging pure Neumann B.C. case. The paper is a generalization from the Euclidean to the Riemannian setting of [LTZ] in the more difficult case of purely Neumann B.C., and of [KK1] in the case of Dirichlet B.C. The approach is Riemann geometric, but different from-indeed, more flexible than-the one in [LTY1].

  1. Fearfulness affects quail maternal care and subsequent offspring development.

    PubMed

    Pittet, Florent; Houdelier, Cécilia; Le Bot, Océane; Leterrier, Christine; Lumineau, Sophie

    2014-01-01

    Our study investigated relationships between a precocial bird's fearfulness and maternal care, and the implication of maternal care as a vector for non-genomic transmission of fearfulness to chicks. We compared care given to chicks between two sets of female Japanese quail selected to present either high (LTI) or low fearfulness (STI). Chicks, from a broiler line, were adopted by these females following a sensitization procedure. Chicks' fearfulness after separation from their mother was assessed by well-established procedures. LTIs took longer to present maternal responses, pecked chicks more during the first days post-hatch, presented impaired maternal vocal behaviour and were globally less active than STI females. Chicks mothered by LTIs presented more fearful reactions than did chicks mothered by STIs, supporting the hypothesis of a non-genetic maternal transmission of fearfulness. We suggest that the longer latencies required by LTIs to become maternal are a consequence of their greater fear of chicks, and that their lower general and vocal activity could be components of a heightened antipredatory strategy. We discuss the transmission of maternal fearfulness to fostered chicks, taking into account the possible implication of several well-known mechanisms underlying maternal effects.

  2. Census of U.S. Civil Aircraft for Calendar Year 1983.

    DTIC Science & Technology

    1983-12-31

    3 69 51 2 0 2 2 69 51 2 0 5 5 69 51 2 0 3 3 2 41 1 0 1 1 1 41 1 0 1 1 % JENNY 2 41 1 0 1 1 ENG REC. ENO 41 1 212 213 ":’ LTI REC. ENG 51 8 48 52 OTAL 7...34" " JEENIE TEENIE 1 41 1 0 1 1 • JEENIES TEENIE 1 41 1 0 1 1 JEFFAIR BARRACUDA 2 41 1 0 1 1 JENNY JN-4D 1 41 1 0 1 1 JENNY JN4D 1 41 1 0 1 1 JGM-1 1...1-- UN-4D JENNY REPLICA 2 41 1 0 1 1 UN-4H 2 41 1 0 1 1 UND-1 1 41 1 0 1 1 UN4C-REPLICA 2 41 1 0 1 1 JN4CAN 2 41 I 0 1 1 JODEL D-l 2 41 1 0 2 2 JODEL

  3. Patterns of food and nutrient consumption in northern Iran, a high-risk area for esophageal cancer.

    PubMed

    Islami, Farhad; Malekshah, Akbar Fazeltabar; Kimiagar, Masoud; Pourshams, Akram; Wakefield, Jon; Goglani, Goharshad; Rakhshani, Nasser; Nasrollahzadeh, Dariush; Salahi, Rasoul; Semnani, Shahryar; Saadatian-Elahi, Mitra; Abnet, Christian C; Kamangar, Farin; Dawsey, Sanford M; Brennan, Paul; Boffetta, Paolo; Malekzadeh, Reza

    2009-01-01

    Our objectives were to investigate patterns of food and nutrient consumption in Golestan province, a high-incidence area for esophageal cancer (EC) in northern Iran. Twelve 24-h dietary recalls were administered during a 1-yr period to 131 healthy participants in a pilot cohort study. We compare here nutrient intake in Golestan with recommended daily allowances (RDAs) and lowest threshold intakes (LTIs). We also compare the intake of 27 food groups and nutrients among several population subgroups using mean values from the 12 recalls. Rural women had a very low level of vitamin intake, which was even lower than LTIs (P < 0.01). Daily intake of vitamins A and C was lower than LTI in 67% and 73% of rural women, respectively. Among rural men, the vitamin intakes were not significantly different from LTIs. Among urban women, the vitamin intakes were significantly lower than RDAs but were significantly higher than LTIs. Among urban men, the intakes were not significantly different from RDAs. Compared to urban dwellers, intake of most food groups and nutrients, including vitamins, was significantly lower among rural dwellers. In terms of vitamin intake, no significant difference was observed between Turkmen and non-Turkmen ethnics. The severe deficiency in vitamin intake among women and rural dwellers and marked differences in nutrient intake between rural and urban dwellers may contribute to the observed epidemiological pattern of EC in Golestan, with high incidence rates among women and people with low socioeconomic status and the highest incidence rate among rural women.

  4. Beyond xMOOCs in healthcare education: study of the feasibility in integrating virtual patient systems and MOOC platforms.

    PubMed

    Stathakarou, Natalia; Zary, Nabil; Kononowicz, Andrzej A

    2014-01-01

    Background. Massive Open Online Courses (MOOCs) are an emerging trend in online learning. However, their technology is not yet completely adjusted to the needs of healthcare education. Integration of Virtual Patients within MOOCs to increase interactivity and foster clinical reasoning skills training, has been discussed in the past, but not verified by a practical implementation. Objective. To investigate the technical feasibility of integrating MOOCs with Virtual Patients for the purpose of enabling further research into the potential pedagogical benefits of this approach. Methods. We selected OpenEdx and Open Labyrinth as representative constituents of a MOOC platform and Virtual Patient system integration. Based upon our prior experience we selected the most fundamental technical requirement to address. Grounded in the available literature we identified an e-learning standard to guide the integration. We attempted to demonstrate the feasibility of the integration by designing a "proof-of-concept" prototype. The resulting pilot implementation was subject of verification by two test cases. Results. A Single Sign-On mechanism connecting Open Labyrinth with OpenEdx and based on the IMS LTI standard was successfully implemented and verified. Conclusion. We investigated the technical perspective of integrating Virtual Patients with MOOCs. By addressing this crucial technical requirement we set a base for future research on the educational benefits of using virtual patients in MOOCs. This provides new opportunities for integrating specialized software in healthcare education at massive scale.

  5. Type 2 innate lymphoid cells-new members of the "type 2 franchise" that mediate allergic airway inflammation.

    PubMed

    Mjösberg, Jenny; Spits, Hergen

    2012-05-01

    Type 2 innate lymphoid cells (ILC2s) are members of an ILC family, which contains NK cells and Rorγt(+) ILCs, the latter including lymphoid tissue inducer (LTi) cells and ILCs producing IL-17 and IL-22. ILC2s are dedicated to the production of IL-5 and IL-13 and, as such, ILC2s provide an early and important source of type 2 cytokines critical for helminth expulsion in the gut. Several studies have also demonstrated a role for ILC2s in airway inflammation. In this issue of the European Journal of Immunology, Klein Wolterink et al. [Eur. J. Immunol. 2012. 42: 1106-1116] show that ILC2s are instrumental in several models of experimental asthma where they significantly contribute to production of IL-5 and IL-13, key cytokines in airway inflammation. This study sheds light over the relative contribution of ILC2s versus T helper type 2 cells (Th2) in type 2 mediated allergen-specific inflammation in the airways as discussed in this commentary.

  6. Innate lymphoid cells sustain colon cancer through production of interleukin-22 in a mouse model.

    PubMed

    Kirchberger, Stefanie; Royston, Daniel J; Boulard, Olivier; Thornton, Emily; Franchini, Fanny; Szabady, Rose L; Harrison, Oliver; Powrie, Fiona

    2013-05-06

    Patients with inflammatory bowel disease (IBD) have an increased risk of colon cancer. However, the immune cells and cytokines that mediate the transition from intestinal inflammation to cancer are poorly understood. We show that bacteria-induced colon cancer is accompanied by differential accumulation of IL-17(+)IL-22(+) colonic innate lymphoid cells (cILCs), which are phenotypically distinct from LTi and NK-22 cells, and that their depletion in mice with dysplastic inflammation blocks the development of invasive colon cancer. Analysis of the functional role of distinct Type 17 cytokines shows that although blockade of IL-17 inhibits some parameters of intestinal inflammation, reduction in dysplasia and colorectal cancer (CRC) requires neutralization of IL-22 indicating a unique role for IL-22 in the maintenance of cancer in this model. Mechanistic analyses showed that IL-22 selectively acts on epithelial cells to induce Stat3 phosphorylation and proliferation. Importantly, we could detect IL-22(+)CD3(+) and IL-22(+)CD3(−) cells in human CRC. Our results describe a new activity of IL-22 in the colon as a nonredundant mediator of the inflammatory cascade required for perpetuation of CRC, highlighting the IL-22 axis as a novel therapeutic target in colon cancer.

  7. Inspection of fabricated fuselage panels using electronic shearography

    NASA Astrophysics Data System (ADS)

    Tyson, John, II; Feferman, Ben

    1992-07-01

    The results of a proof of principle demonstration of using electronic shearography to detect induced damage in fabricated aircraft panels are presented. The demonstration was performed at the FAA's Aircraft Panel Test Facility in Waltham, Massachusetts and all shearography equipment and its operational support was provided by Laser Technology, Inc. (LTI) under a separate contract from the Volpe National Transportation Systems Center. The test panels that were inspected using the electronic shearography were constructed to closely simulate the fuselage and skin structure of Boeing 727 and 737 aircraft. These panels contained programmed flaws intended to simulate two major types of defects associated with aging aircraft, namely cracks along fastener rows, and disbonded tear strap doublers and lap joints. The proof of principle consisted of a series of inspections that demonstrated shearography's capability to detect cracks and disbonds in the fuselage panel specimens. The sensitivity of shearography to detect short, simulated fatigue cracks that would correspond to a multiple site damage situation was too low to provide sufficient confidence that the method could economically replace existing eddy current surface methods. The sensitivity of the method to detect panel disbonding, however, is sufficient to encourage further development of the technique.

  8. The chromosomal nature of LT-II enterotoxins solved: a lambdoid prophage encodes both LT-II and one of two novel pertussis-toxin-like toxin family members in type II enterotoxigenic Escherichia coli.

    PubMed

    Jobling, Michael G

    2016-04-01

    Heat-labile enterotoxins (LT) of enterotoxigenic Escherichia coli (ETEC) are structurally and functionally related to cholera toxin (CT). LT-I toxins are plasmid-encoded and flanked by IS elements, while LT-II toxins of type II ETEC are chromosomally encoded with flanking genes that appear phage related. Here, I determined the complete genomic sequence of the locus for the LT-IIa type strain SA53, and show that the LT-IIa genes are encoded by a 51 239 bp lambdoid prophage integrated at the rac locus, the site of a defective prophage in E. coli K12 strains. Of 50 LT-IIa and LT-IIc, 46 prophages also encode one member of two novel two-gene ADP-ribosyltransferase toxin families that are both related to pertussis toxin, which I named eplBA or ealAB, respectively. The eplBA and ealAB genes are syntenic with the Shiga toxin loci in their lambdoid prophages of the enteric pathogen enterohemorrhagic E. coli. These novel AB(5) toxins show pertussis-toxin-like activity on tissue culture cells, and like pertussis toxin bind to sialic acid containing glycoprotein ligands. Type II ETEC are the first mucosal pathogens known to simultaneously produce two ADP-ribosylating toxins predicted to act on and modulate activity of both stimulatory and inhibitory alpha subunits of host cell heterotrimeric G-proteins.

  9. Controller design for delay systems via eigenvalue assignment - on a new result in the distribution of quasi-polynomial roots

    NASA Astrophysics Data System (ADS)

    Wang, Honghai; Liu, Jianchang; Yang, Feisheng; Zhang, Yu

    2015-12-01

    This paper considers the eigenvalue distribution of a linear time-invariant (LTI) system with time delays and its application to some controllers design for a delay plant via eigenvalue assignment. First, a new result on the root distribution for a class of quasi-polynomials is developed based on the extension of the Hermite-Biehler theorem. Then, such result is applied to proportional-integral (PI) controller parameter design for a first-order plant with time delay through pole placement. The complete region of PI gains can be obtained so that the rightmost eigenvalues in the infinite eigenspectrum of the closed-loop system with delay plant are assigned to desired positions in the complex plane. Furthermore, on the basis of the previous result, this paper also extended the PI control to the proportional-integral-derivative (PID) control. It is worth pointing out that this work aims to improve the performance of the closed-loop system on the premise of guaranteeing the stability.

  10. Beyond xMOOCs in healthcare education: study of the feasibility in integrating virtual patient systems and MOOC platforms

    PubMed Central

    Zary, Nabil; Kononowicz, Andrzej A.

    2014-01-01

    Background. Massive Open Online Courses (MOOCs) are an emerging trend in online learning. However, their technology is not yet completely adjusted to the needs of healthcare education. Integration of Virtual Patients within MOOCs to increase interactivity and foster clinical reasoning skills training, has been discussed in the past, but not verified by a practical implementation. Objective. To investigate the technical feasibility of integrating MOOCs with Virtual Patients for the purpose of enabling further research into the potential pedagogical benefits of this approach. Methods. We selected OpenEdx and Open Labyrinth as representative constituents of a MOOC platform and Virtual Patient system integration. Based upon our prior experience we selected the most fundamental technical requirement to address. Grounded in the available literature we identified an e-learning standard to guide the integration. We attempted to demonstrate the feasibility of the integration by designing a “proof-of-concept” prototype. The resulting pilot implementation was subject of verification by two test cases. Results. A Single Sign-On mechanism connecting Open Labyrinth with OpenEdx and based on the IMS LTI standard was successfully implemented and verified. Conclusion. We investigated the technical perspective of integrating Virtual Patients with MOOCs. By addressing this crucial technical requirement we set a base for future research on the educational benefits of using virtual patients in MOOCs. This provides new opportunities for integrating specialized software in healthcare education at massive scale. PMID:25405078

  11. Structural and magnetic properties of Ti12M clusters (M=Sc to Zn)

    NASA Astrophysics Data System (ADS)

    Sun, Houqian; Xu, Ning

    2016-12-01

    The geometries, electronic, and magnetic properties of the 3d atom doped icosahedron (ICO) Ti12M (M=Sc to Zn), where a dopant atom replaces either the centra l(Ti12Mc) or surface (Ti12Ms) Ti atom in ICO Ti13 cluster, have been systematically investigated by using the density functional theory. The structures of all the optimized Ti12Mc and Ti12Ms clusters are distorted ICO. Sc, Ni, Cu, and Zn atoms prefer to displace surface Ti atom, V, Cr, Mn, and Fe atoms prefer to displace central Ti atom. The position of impurity atom depends on the strength of the interaction between the central atom and the surface atoms. As compared to the pure Ti13 cluster, Ti12Mc and Ti12Ms (M=V, Fe, Co, and Ni) clusters are more stable, Ti12Mc and Ti12Ms (M=Sc, Cr, Mn, Cu, and Zn) are less stable. Both Ti12Nis and Ti12Nic are magic clusters, which originate from their electronic as well as geometric closed shells. Because the exchange interaction prevails over the crystal field in Ti12M clusters, the valence electrons fill molecular orbitals in terms of Hund's rule of maximum spin.

  12. Performance limitations of networked control systems with quantization and packet dropouts.

    PubMed

    Jiang, Xiao-Wei; Zhang, Xian-He; Guan, Zhi-Hong; Yu, Li; Yan, Huai-Cheng

    2017-03-01

    This paper investigates the problem of optimal tracking performance of networked control systems (NCSs) with quantization and packet-dropouts. The system under consideration is linear time-invariant (LTI), multi-input multi-output (MIMO), where an H2 norm of error signal between the reference input and the system output is used as the tracking performance index. The impacts of packet-dropouts in the communication channel and the quantized input and output are studied. The goal is to obtain the minimal error in tracking a random signal, by searching through all possible stabilizing two-parameter controllers. It is shown that, the minimum value of tracking error is closely related to the reference input signal direction, the non-minimum phase zeros and unstable poles of the given plant, including the locations and directions. We also demonstrated the quantization error and the packet-dropouts may degrade the tracking performance. A typical example is given to evaluate the theoretical results.

  13. DEVELOPMENT OF MULTI-PHASE AND MULTI-COMPONENT FLOW MODEL WITH REACTION IN POROUS MEDIA FOR RISK ASSESSMENT ON SOIL CONTAMINATION DUE TO MINERAL OIL

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yasuhide; Nishiwaki, Junko; Hara, Junko; Kawabe, Yoshishige; Sugai, Yuichi; Komai, Takeshi

    In late years, soil contamination due to mineral oil in vacant lots of oil factory and oil field has become obvious. Measure for soil contamina tion and risk assessment are neces sary for sustainable development of industrial activity. Especially, in addition to contaminated sites, various exposure paths for human body such as well water, soil and farm crop are supposed. So it is very important to comprehend the transport phenomena of contaminated material under the environments of soil and ground water. In this study, mineral oil as c ontaminated material consisting of mu lti-component such as aliphatic and aromatic series was modeled. Then numerical mode l for transport phenomena in surface soil and aquifer was constructed. On the basis of modeling for mineral oil, our numerical model consists of three-phase (oil, water and gas) forty three-component. This numerical model becomes base program for risk assessment system on soil contamination due to mineral oil. Using this numerical model, we carried out some numerical simulation for a laboratory-scale experiment on oil-water multi-phase flow. Relative permeability that dominate flow behavior in multi-phase condition was formulated and the validity of the numerical model developed in this study was considered.

  14. On Time Delay Margin Estimation for Adaptive Control and Optimal Control Modification

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2011-01-01

    This paper presents methods for estimating time delay margin for adaptive control of input delay systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent an adaptive law by a locally bounded linear approximation within a small time window. The time delay margin of this input delay system represents a local stability measure and is computed analytically by three methods: Pade approximation, Lyapunov-Krasovskii method, and the matrix measure method. These methods are applied to the standard model-reference adaptive control, s-modification adaptive law, and optimal control modification adaptive law. The windowing analysis results in non-unique estimates of the time delay margin since it is dependent on the length of a time window and parameters which vary from one time window to the next. The optimal control modification adaptive law overcomes this limitation in that, as the adaptive gain tends to infinity and if the matched uncertainty is linear, then the closed-loop input delay system tends to a LTI system. A lower bound of the time delay margin of this system can then be estimated uniquely without the need for the windowing analysis. Simulation results demonstrates the feasibility of the bounded linear stability method for time delay margin estimation.

  15. Nfil3 is crucial for development of innate lymphoid cells and host protection against intestinal pathogens

    PubMed Central

    Geiger, Theresa L.; Abt, Michael C.; Gasteiger, Georg; Firth, Matthew A.; O’Connor, Margaret H.; Geary, Clair D.; O’Sullivan, Timothy E.; van den Brink, Marcel R.; Pamer, Eric G.; Hanash, Alan M.

    2014-01-01

    The bZIP transcription factor Nfil3 (also known as E4BP4) is required for the development of natural killer (NK) cells and type 1 innate lymphoid cells (ILC1s). We find that Nfil3 plays a critical role in the development of other mucosal tissue-associated innate lymphocytes. Type 3 ILCs (ILC3s), including lymphoid tissue inducer (LTi)–like cells, are severely diminished in both numbers and function in Nfil3-deficient mice. Using mixed bone marrow chimeric mice, we demonstrate that Nfil3 is critical for normal development of gut-associated ILC3s in a cell-intrinsic manner. Furthermore, Nfil3 deficiency severely compromises intestinal innate immune defense against acute bacterial infection with Citrobacter rodentium and Clostridium difficile. Nfil3 deficiency resulted in a loss of the recently identified ILC precursor, yet conditional ablation of Nfil3 in the NKp46+ ILC3 subset did not perturb ILC3 numbers, suggesting that Nfil3 is required early during ILC3 development but not for lineage maintenance. Lastly, a marked defect in type 2 ILCs (ILC2s) was also observed in the lungs and visceral adipose tissue of Nfil3-deficient mice, revealing a general requirement for Nfil3 in the development of all ILC lineages. PMID:25113970

  16. Elastic Model Transitions: A Hybrid Approach Utilizing Quadratic Inequality Constrained Least Squares (LSQI) and Direct Shape Mapping (DSM)

    NASA Technical Reports Server (NTRS)

    Hannan, Mike R.; Jurenko, Robert J.; Bush, Jason; Ottander, John

    2014-01-01

    A method for transitioning linear time invariant (LTI) models in time varying simulation is proposed that utilizes a hybrid approach for determining physical displacements by augmenting the original quadratically constrained least squares (LSQI) algorithm with Direct Shape Mapping (DSM) and modifying the energy constraints. The approach presented is applicable to simulation of the elastic behavior of launch vehicles and other structures that utilize discrete LTI finite element model (FEM) derived mode sets (eigenvalues and eigenvectors) that are propagated throughout time. The time invariant nature of the elastic data presents a problem of how to properly transition elastic states from the prior to the new model while preserving motion across the transition and ensuring there is no truncation or excitation of the system. A previous approach utilizes a LSQI algorithm with an energy constraint to effect smooth transitions between eigenvector sets with no requirement that the models be of similar dimension or have any correlation. This approach assumes energy is conserved across the transition, which results in significant non-physical transients due to changing quasi-steady state energy between mode sets, a phenomenon seen when utilizing a truncated mode set. The computational burden of simulating a full mode set is significant so a subset of modes is often selected to reduce run time. As a result of this truncation, energy between mode sets may not be constant and solutions across transitions could produce non-physical transients. In an effort to abate these transients an improved methodology was developed based on the aforementioned approach, but this new approach can handle significant changes in energy across mode set transitions. It is proposed that physical velocities due to elastic behavior be solved for using the LSQI algorithm, but solve for displacements using a two-step process that independently addresses the quasi-steady-state and non

  17. Reduced Order Modeling for Prediction and Control of Large-Scale Systems.

    SciTech Connect

    Kalashnikova, Irina; Arunajatesan, Srinivasan; Barone, Matthew Franklin; van Bloemen Waanders, Bart Gustaaf; Fike, Jeffrey A.

    2014-05-01

    -Stokes equations is derived, and it is demonstrated that if a Galerkin ROM is constructed in this inner product, the ROM system energy will be bounded in a way that is consistent with the behavior of the exact solution to these PDEs, i.e., the ROM will be energy-stable. The viability of the linear as well as nonlinear continuous projection model reduction approaches developed as a part of this project is evaluated on several test cases, including the cavity configuration of interest in the targeted application area. In the second part of this report, some POD/Galerkin approaches for building stable ROMs using discrete projection are explored. It is shown that, for generic linear time-invariant (LTI) systems, a discrete counterpart of the continuous symmetry inner product is a weighted L2 inner product obtained by solving a Lyapunov equation. This inner product was first proposed by Rowley et al., and is termed herein the “Lyapunov inner product“. Comparisons between the symmetry inner product and the Lyapunov inner product are made, and the performance of ROMs constructed using these inner products is evaluated on several benchmark test cases. Also in the second part of this report, a new ROM stabilization approach, termed “ROM stabilization via optimization-based eigenvalue reassignment“, is developed for generic LTI systems. At the heart of this method is a constrained nonlinear least-squares optimization problem that is formulated and solved numerically to ensure accuracy of the stabilized ROM. Numerical studies reveal that the optimization problem is computationally inexpensive to solve, and that the new stabilization approach delivers ROMs that are stable as well as accurate. Summaries of “lessons learned“ and perspectives for future work motivated by this LDRD project are provided at the end of each of the two main chapters.

  18. Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection.

    PubMed

    Wei, Xin; Wang, Jiu-Ping; Hao, Chun-Qiu; Yang, Xiao-Fei; Wang, Lin-Xu; Huang, Chang-Xing; Bai, Xue-Fan; Lian, Jian-Qi; Zhang, Ye

    2016-01-01

    The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4(+) T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4(+) T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46(+) innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4(+) T cells, but not HBV-specific CD4(+) T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B.

  19. Improved Power System Stability Using Backtracking Search Algorithm for Coordination Design of PSS and TCSC Damping Controller.

    PubMed

    Niamul Islam, Naz; Hannan, M A; Mohamed, Azah; Shareef, Hussain

    2016-01-01

    Power system oscillation is a serious threat to the stability of multimachine power systems. The coordinated control of power system stabilizers (PSS) and thyristor-controlled series compensation (TCSC) damping controllers is a commonly used technique to provide the required damping over different modes of growing oscillations. However, their coordinated design is a complex multimodal optimization problem that is very hard to solve using traditional tuning techniques. In addition, several limitations of traditionally used techniques prevent the optimum design of coordinated controllers. In this paper, an alternate technique for robust damping over oscillation is presented using backtracking search algorithm (BSA). A 5-area 16-machine benchmark power system is considered to evaluate the design efficiency. The complete design process is conducted in a linear time-invariant (LTI) model of a power system. It includes the design formulation into a multi-objective function from the system eigenvalues. Later on, nonlinear time-domain simulations are used to compare the damping performances for different local and inter-area modes of power system oscillations. The performance of the BSA technique is compared against that of the popular particle swarm optimization (PSO) for coordinated design efficiency. Damping performances using different design techniques are compared in term of settling time and overshoot of oscillations. The results obtained verify that the BSA-based design improves the system stability significantly. The stability of the multimachine power system is improved by up to 74.47% and 79.93% for an inter-area mode and a local mode of oscillation, respectively. Thus, the proposed technique for coordinated design has great potential to improve power system stability and to maintain its secure operation.

  20. Collisionless reversed magnetic shear trapped electron instability and contribution of sidebands to anomalous transport

    NASA Astrophysics Data System (ADS)

    Rogister, André L.; Singh, Raghvendra

    2005-11-01

    By keeping account of the trapped electron ∇B and curvature drifts, it is found that the spatial decay of the collisionless electron drift wave is governed either by the trapped electron response or by the resonant interaction of ions with the sidebands of the primary oscillation. In the former case, pairs of spatially bounded unstable and damped solutions are obtained for negative magnetic shear (ŝ<0) if, as usual, LTe=1/∂rlnTe<0; there are no bounded solutions if ŝLTe<0. In the latter case, there is either a set of bounded damped solutions if ηi>0 or a set of bounded unstable solutions if ηi<0. The unstable modes have a radiating character and the growth rates are γ ˜(2n+1)√1+2q2 ∣ŝ∣∣LNωe*/qR∣ (n is the Hermite polynomial solution index, q the safety factor, ŝ the magnetic shear parameter, R the major radius, ωe* the electron diamagnetic frequency, LN=1/∂rlnNe, and ηi=LN/LTi).The sidebands are responsible for unusually large ratios Qe/TeΓe, where Qe and Γe are the anomalous electron energy flux and the particle flux. These results may explain the box-type Te profile observed in lower hybrid current drive reversed magnetic shear plasmas on the Japan Atomic Energy Research Institute Tokamak 60 Upgrade (JT-60U) [H. Ninomiya and the JT-60U Team, Phys. Fluids B 4, 2070 (1992)]. It is finally demonstrated that the ballooning hypothesis generally leads to conflicting requirements: it is thus hardly relevant for the electron drift branch! The "radiating" boundary condition that has formerly been imposed on the slab solution is finally discussed.

  1. Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs in Iran.

    PubMed

    Ghanbarpour, Reza; Askari, Nasrin; Ghorbanpour, Masoud; Tahamtan, Yahya; Mashayekhi, Khoobyar; Afsharipour, Narjes; Darijani, Nasim

    2017-03-01

    The aim of the present study was to determine the analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs. Two hundred ninety E. coli isolates were recovered from 300 rectal swabs of diarrheic lambs and were confirmed by biochemical tests. The pathotype determination was done according to the presence of genes including f5, f41, LTI, STI, bfp, ipaH, stx 1 , stx 2 , eae, ehlyA, cnf 1 , cnf 2 , cdIII, cdIV, and f17 by PCR method. Sixty-six isolates (23.72%) possessed the STI gene and categorized into entrotoxigenic E. coli (ETEC). Nine isolates (3.1%) and five isolates (1.72%) were positive for the cnf1 and cnf2 genes which categorized into necrotoxic E. coli (NTEC). Hundred and seventeen isolates (40.34%) harbored stx 1 and/or stx 2 and classified as Shiga toxin-producing E. coli (STEC). Thirteen isolates (4.48%) were assigned to atypical entropathogenic E. coli (aEPEC) and possessed eae gene. Two isolates (0.68%) were positive for ipaH gene and were assigned to entroinvasive E. coli (EIEC). Statistical analysis showed a specific association between eae gene and STEC pathotype (P < 0.0001). The most prevalent resistance was observed against lincomycin (96.5%) and the lowest resistance was against kanamycine (56.02%), respectively. The high prevalence of STEC and ETEC indicates that diarrheic lambs represent an important reservoir for humans. ETEC may play an important role for frequent occurrence of diarrhea in lambs observed in this region. Due to high antibiotic resistance, appropriate control should be implemented in veterinary medicine to curb the development of novel resistant isolates.

  2. Transducer characterization for Vibrothermography

    NASA Astrophysics Data System (ADS)

    Vaddi, Jyani Somayajulu

    Vibrothermography, also known as Sonic IR and Thermosonics, is an NDE technique for finding cracks and flaws based on vibration-induced frictional rubbing of unbonded surfaces. The vibration is usually generated by a piezoelectric stack transducer which transduces electrical energy into large amplitude mechanical vibrations. The purpose of this study is to develop an understanding of the excitation process for vibrothermography so that optimal parameters and transducers for the testing can be selected. The amplitude and impedance transfer characteristics of the transducer system control the vibration of the sample. Within a linear contact (no tip chatter) model, the interaction between the transducer system and the specimen can be characterized using the theory of linear time-invariant (LTI) systems and electro-mechanical Norton equivalence. This work presents quantitative measurements of the performance of piezoelectric stack transducers in a vibrothermography excitation system and the effect of transducer performance and specimen characteristics on the induced vibration in the specimen. We show that with compliant coupling, the specimen vibration is directly proportional to the transducer open circuit velocity and that the system resonances generated because of metal-metal contact of specimen and transducer are disconnected by adding a couplant between specimen and transducer. We then give suggestions for transducer and couplant selection for vibrothermography and suggest methods to flatten the velocity spectrum of the transducer. We extend our analysis to high amplitude transducer behavior and elaborate on the effect of power amplifier saturation on the transducer behavior. The saturation effect negates the effect of adding an external inductance to flatten the transducer velocity spectrum. Finally, preliminary results are reported on the effect of transducer degradation phenomenon.

  3. Development and Function of Secondary and Tertiary Lymphoid Organs in the Small Intestine and the Colon

    PubMed Central

    Buettner, Manuela; Lochner, Matthias

    2016-01-01

    The immune system of the gut has evolved a number of specific lymphoid structures that contribute to homeostasis in the face of microbial colonization and food-derived antigenic challenge. These lymphoid organs encompass Peyer’s patches (PP) in the small intestine and their colonic counterparts that develop in a programed fashion before birth. In addition, the gut harbors a network of lymphoid tissues that is commonly designated as solitary intestinal lymphoid tissues (SILT). In contrast to PP, SILT develop strictly after birth and consist of a dynamic continuum of structures ranging from small cryptopatches (CP) to large, mature isolated lymphoid follicles (ILF). Although the development of PP and SILT follow similar principles, such as an early clustering of lymphoid tissue inducer (LTi) cells and the requirement for lymphotoxin beta (LTβ) receptor-mediated signaling, the formation of CP and their further maturation into ILF is associated with additional intrinsic and environmental signals. Moreover, recent data also indicate that specific differences exist in the regulation of ILF formation between the small intestine and the colon. Importantly, intestinal inflammation in both mice and humans is associated with a strong expansion of the lymphoid network in the gut. Recent experiments in mice suggest that these structures, although they resemble large, mature ILF in appearance, may represent de novo-induced tertiary lymphoid organs (TLO). While, so far, it is not clear whether intestinal TLO contribute to the exacerbation of inflammatory pathology, it has been shown that ILF provide the critical microenvironment necessary for the induction of an effective host response upon infection with enteric bacterial pathogens. Regarding the importance of ILF for intestinal immunity, interfering with the development and maturation of these lymphoid tissues may offer novel means for manipulating the immune response during intestinal infection or inflammation. PMID

  4. The Influence of Crystal Anisotropy on Failure Stability: Evidence from Multiple-Cracking Noises

    NASA Astrophysics Data System (ADS)

    Ghaffari, H.; Ghofrani Tabari, M.; Young, R. P.; Griffith, W. A.; Goodfellow, S. D.

    2015-12-01

    Failure of crystals under some external loads often exploit cleavage planes as planes of weakness. The nucleation and extension of "defects" in most cases results in emission of acoustic (phonon) excitations. While X-ray diffraction methods describe the structure of crystals well, the relationship between cleavage planes and unstable failure during cracking of crystals is less well established. In this study, we analyze the polarization patterns of multiple acoustic excitations using functional acoustic network theory. The experiment involves fracturing a small sample placed on a thick aluminum plate using a sharp tip. A load is slowly applied to the testing material until failure inducing the propagation of elastic waves through the aluminum plate. Once the defects' disturbances have traveled to the opposite side of the plate, they are recorded by a symmetric array of 15 Panametrics V103 sensors. The V103 sensors were calibrated in-situ and showed a roughly flat displacement sensitivity of 73 mV/nm between 20 kHz and 1 MHz. We characterize the emitted noises from Graphite, Gypsum, and Halite and show that microscopic cracking noises carry a signature of plasticity (dislocation growth). We describe the analysis of defects' slip-direction and growth, inferred from polarization patterns in the weakening phase, and we relate these patterns to individual cleavage plane(s). Further, using multiplex complex networks, we explore the angular tendency of micro-cracking, and estimate the anisotropic nature of micro-defects. Next, we use elasto-dynamic and linear-time-invariant (LTI) systems theory to deconvolve the instrument response and wave propagation functions from the recorded waveform leaving only the source term. Finally, we compare the results from both methods, drawing conclusions about the relationship between crackling noises and plasticity.

  5. Cu(II) binding by a pH-fractionated fulvic acid

    USGS Publications Warehouse

    Brown, G.K.; Cabaniss, S.E.; MacCarthy, P.; Leenheer, J.A.

    1999-01-01

    The relationship between acidity, Cu(II) binding and sorption to XAD resin was examined using Suwannee River fulvic acid (SRFA). The work was based on the hypothesis that fractions of SRFA eluted from an XAD column at various pH's from 1.0 to 12.0 would show systematic variations in acidity and possibly aromaticity which in turn would lead to different Cu(II) binding properties. We measured equilibrium Cu(II) binding to these fractions using Cu2+ ion-selective electrode (ISE) potentiometry at pH 6.0. Several model ligands were also examined, including cyclopentane-1,2,3,4-tetracarboxylic acid (CP-TCA) and tetrahydrofuran-2,3,4,5-tetracarboxylic acid (THF-TCA), the latter binding Cu(II) much more strongly as a consequence of the ether linkage. The SRFA Cu(II) binding properties agreed with previous work at high ionic strength, and binding was enhanced substantially at lower ionic strength, in agreement with Poisson-Boltzmann predictions for small spheres. Determining Cu binding constants (K(i)) by non-linear regression with total ligand concentrations (L(Ti)) taken from previous work, the fractions eluted at varying pH had K(i) similar to the unfractionated SRFA, with a maximum enhancement of 0.50 log units. We conclude that variable-pH elution from XAD does not isolate significantly strong (or weak) Cu(II)-binding components from the SRFA mixture. Copyright (C) 1999 Elsevier Science B.V.

  6. Measurements of seismic wave attenuation for frequencies between 0.1 and 100 Hz in a Paterson Rig

    NASA Astrophysics Data System (ADS)

    Madonna, C.; Tisato, N.; Delle Piane, C.; Saenger, E. H.

    2012-04-01

    The study of wave attenuation in partially saturated porous rocks over a broad frequency range provides valuable information about reservoir fluid systems, which are inherently composed of multiple phase fluid. Following an original idea initiated by Luigi, we designed and set up a specific instrument, the Seismic Wave Attenuation Module (SWAM), to experimentally measure the bulk attenuation on partially saturated rocks at frequencies between 0.01 and 100 Hz, using natural rock samples under in situ conditions. We present its bench-top calibration, a series of data collected from different kind of rocks at different confing pressure and the numerical simulations, supporting the obtained results. We employ the sub-resonance test. Assuming that the rock behaves as a linear time invariant (LTI) system, the attenuation factor 1/Q (Q is the quality factor) is equal to the tangent of the phase shift between the stress and the strain signal. The new attenuation measurement equipment is calibrated in a gas apparatus (Paterson rig) using aluminum as elastic standard and Plexiglas as a viscoelastic standard. Measurements were performed on 25.4 mm diameter, 60 mm long samples. Berea sandstone samples with 20% porosity, and ~500 mD permeability have been measured at different saturation conditions. Attenuation measurements show dependence upon saturation. Moreover, measurements on two well-characterized shale samples have been performed. The two shales have significantly different quality factors; which result to be dependent on both the saturation state of the samples and the propagation direction of the oscillatory signal with respect to the sedimentary bedding. The attenuation coefficient parallel to bedding is less than that vertical to bedding. Thanks to Luigi's initiative and inspiration two generations of his Ph.D. students are now able to jointly present these new challenging experimental results.

  7. The beauty of simple adaptive control and new developments in nonlinear systems stability analysis

    SciTech Connect

    Barkana, Itzhak

    2014-12-10

    Although various adaptive control techniques have been around for a long time and in spite of successful proofs of stability and even successful demonstrations of performance, the eventual use of adaptive control methodologies in practical real world systems has met a rather strong resistance from practitioners and has remained limited. Apparently, it is difficult to guarantee or even understand the conditions that can guarantee stable operations of adaptive control systems under realistic operational environments. Besides, it is difficult to measure the robustness of adaptive control system stability and allow it to be compared with the common and widely used measure of phase margin and gain margin that is utilized by present, mainly LTI, controllers. Furthermore, customary stability analysis methods seem to imply that the mere stability of adaptive systems may be adversely affected by any tiny deviation from the pretty idealistic and assumably required stability conditions. This paper first revisits the fundamental qualities of customary direct adaptive control methodologies, in particular the classical Model Reference Adaptive Control, and shows that some of their basic drawbacks have been addressed and eliminated within the so-called Simple Adaptive Control methodology. Moreover, recent developments in the stability analysis methods of nonlinear systems show that prior conditions that were customarily assumed to be needed for stability are only apparent and can be eliminated. As a result, sufficient conditions that guarantee stability are clearly stated and lead to similarly clear proofs of stability. As many real-world applications show, once robust stability of the adaptive systems can be guaranteed, the added value of using Add-On Adaptive Control along with classical Control design techniques is pushing the desired performance beyond any previous limits.

  8. Oxidatively Degradable Poly(thioketal urethane)/Ceramic Composite Bone Cements with Bone-Like Strength.

    PubMed

    McEnery, Madison A P; Lu, Sichang; Gupta, Mukesh K; Zienkiewicz, Katarzyna J; Wenke, Joseph C; Kalpakci, Kerem N; Shimko, Daniel; Duvall, Craig L; Guelcher, Scott A

    2016-01-01

    Synthetic bone cements are commonly used in orthopaedic procedures to aid in bone regeneration following trauma or disease. Polymeric cements like PMMA provide the mechanical strength necessary for orthopaedic applications, but they are not resorbable and do not integrate with host bone. Ceramic cements have a chemical composition similar to that of bone, but their brittle mechanical properties limit their use in weight-bearing applications. In this study, we designed oxidatively degradable, polymeric bone cements with mechanical properties suitable for bone tissue engineering applications. We synthesized a novel thioketal (TK) diol, which was crosslinked with a lysine triisocyanate (LTI) prepolymer to create hydrolytically stable poly(thioketal urethane)s (PTKUR) that degrade in the oxidative environment associated with bone defects. PTKUR films were hydrolytically stable for up to 6 months, but degraded rapidly (<1 week) under simulated oxidative conditions in vitro. When combined with ceramic micro- or nanoparticles, PTKUR cements exhibited working times comparable to calcium phosphate cements and strengths exceeding those of trabecular bone. PTKUR/ceramic composite cements supported appositional bone growth and integrated with host bone near the bone-cement interface at 6 and 12 weeks post-implantation in rabbit femoral condyle plug defects. Histological evidence of osteoclast-mediated resorption of the cements was observed at 6 and 12 weeks. These findings demonstrate that a PTKUR bone cement with bone-like strength can be selectively resorbed by cells involved in bone remodeling, and thus represent an important initial step toward the development of resorbable bone cements for weight-bearing applications.

  9. The beauty of simple adaptive control and new developments in nonlinear systems stability analysis

    NASA Astrophysics Data System (ADS)

    Barkana, Itzhak

    2014-12-01

    Although various adaptive control techniques have been around for a long time and in spite of successful proofs of stability and even successful demonstrations of performance, the eventual use of adaptive control methodologies in practical real world systems has met a rather strong resistance from practitioners and has remained limited. Apparently, it is difficult to guarantee or even understand the conditions that can guarantee stable operations of adaptive control systems under realistic operational environments. Besides, it is difficult to measure the robustness of adaptive control system stability and allow it to be compared with the common and widely used measure of phase margin and gain margin that is utilized by present, mainly LTI, controllers. Furthermore, customary stability analysis methods seem to imply that the mere stability of adaptive systems may be adversely affected by any tiny deviation from the pretty idealistic and assumably required stability conditions. This paper first revisits the fundamental qualities of customary direct adaptive control methodologies, in particular the classical Model Reference Adaptive Control, and shows that some of their basic drawbacks have been addressed and eliminated within the so-called Simple Adaptive Control methodology. Moreover, recent developments in the stability analysis methods of nonlinear systems show that prior conditions that were customarily assumed to be needed for stability are only apparent and can be eliminated. As a result, sufficient conditions that guarantee stability are clearly stated and lead to similarly clear proofs of stability. As many real-world applications show, once robust stability of the adaptive systems can be guaranteed, the added value of using Add-On Adaptive Control along with classical Control design techniques is pushing the desired performance beyond any previous limits.

  10. Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection

    PubMed Central

    Wei, Xin; Wang, Jiu-Ping; Hao, Chun-Qiu; Yang, Xiao-Fei; Wang, Lin-Xu; Huang, Chang-Xing; Bai, Xue-Fan; Lian, Jian-Qi; Zhang, Ye

    2016-01-01

    The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B. PMID:27800305

  11. Combined herbicide and saline stress differentially modulates hormonal regulation and antioxidant defense system in Oryza sativa cultivars.

    PubMed

    Islam, Faisal; Ali, Basharat; Wang, Jian; Farooq, Muhammad A; Gill, Rafaqat A; Ali, Shafaqat; Wang, Danying; Zhou, Weijun

    2016-10-01

    Plants are simultaneously exposed to a combination of biotic and abiotic stresses in field conditions. Crops respond to the combined stress in a unique way which cannot be understood by extrapolating the results of individual stress. In the present study, effects of individual and combined stress of herbicide (2,4-dichlorophenoxyacetic acid) and salinity (NaCl) on two Oryza sativa cultivars (ZJ 88 and XS 134) were investigated. Both herbicide and saline stress affected the plant growth differentially and produced oxidative stress in rice cultivars. Interestingly, the combination of herbicide and salinity showed a significant protection to both rice cultivars by reducing ROS (H2O2, O2(-)) and lipid peroxidation through modulation of enzymatic (SOD, POD, CAT and APX) and non-enzymatic (TSP, sugars, phenolic and proline) antioxidants. In addition, active regulation of transcript levels of genes encoding Na(+) and K(+) (OsHKT1;5, OsLti6a,b, OsHKT2;1, OsSOS1, OsCNGC1, OsNHX1 and OsAKT1) transporter proteins reduced sodium and enhanced potassium accumulation under combined stress, resulted a better growth and ionic homeostasis in both rice cultivars. The production of ABA and IAA was significantly higher in cultivar XS 134 compared to cultivar ZJ 88 under control conditions. However, combined herbicide and saline stress enhanced the accumulation of phytohormones (IAA and ABA) and transcription of ethylene in cultivar ZJ 88, which might be one of the factors responsible for poor salt tolerance in sensitive cultivar. These findings indicated that herbicide application under saline stress confers tolerance to salinity in rice cultivars, likely by reducing oxidative damage, modulating mineral absorption, upgradation of antioxidant defense and by dynamic regulation of key genes involved in Na(+) and K(+) homeostasis in plants.

  12. Cardiovascular Risk Factors in 7–13 Years Old Children from Vojvodina (Serbia)

    PubMed Central

    Dželajlija, Darko D.; Spasić, Slavica S.; Bogavac-Stanojevic, Nataša B.

    2016-01-01

    Summary Background Atherosclerosis is a chronic inflammatory disease which starts early in life and depends on many factors, an important one being dyslipoproteinemia. According to several studies, atherosclerotic plaques or their precursors could be seen in children younger than 10 years. During later life, interaction with a sedentary way of life, as well as unhealthy nutrition, smoking, alcohol consumption, obesity and family history of cardiovascular disease cause the burden of atherosclerotic disease. Methods Study included 624 children (316 boys, 308 girls), aged from 7–13 years. We analysed socio-demographic data (BMI, blood pressure, cardiovascular family history, smoking status), as well as lipid status with lipoprotein little a-Lp(a), and apolipoproteins: Apo AI, Apo B-100 for all children. This enabled us to calculate new atherogenic indices Tg/HDL-c, lipid tetrad index (LTI) and lipid pentad index (LPI). Cardiovascular risk for later life was estimated by using modified Risk Score for Young Individuals (RS), which divided the subjects according to the score level: low, medium and higher risk. Results The older children (13 y) had better lipid status than the younger children, i.e. significantly lower total cholesterol, LDL-C, triglycerides and non-HDL-C concentration and significantly higher HDL-C concentration than the younger children and this was in accordance with the RS level. Children with a positive family history of CV disease had significantly higher Lp(a) concentration and blood pressure. LPI was significantly higher in children with a higher RS. Conclusions The results of our work could be used for cardiovascular risk assessment in apparently healthy children to provide preventive measures which could control the changeable risk factors. PMID:28356880

  13. Disseminating General Relativity for 21st century astronomy

    NASA Astrophysics Data System (ADS)

    Crosta, Mariateresa

    2015-08-01

    The talk aims to present two outreach projects - initially developed for the ESA Gaia satellite, a multidisciplinary mission launched on December 19, 2013 - available to the OAD community: NeST and "The Meaning of Light".NeST is an interactive educational tool, that displays how the theory of GR rules the Universe, it creates a performance physically "belonging" to the exhibition space and moving through it, materializing what J.A. Wheeler said "mass tells space-time how to curve, and space-time tells mass how to move"."The Meaning of Light" is a short motion comics, part of an extensive outreach program called "The History of Photons" whose main theme is the story of a beam of stellar photons that, after leaving the progenitor star, propagates through the Universe and, once intercepted come into contact with a team of scientists: here begins their adventure to be taken "back" home and in doing so the scientists, and the spectators, are driven to discover the wonders of which the light are the bearers.The description of the journey of the photons becomes, therefore, an opportunity to easily tell the fascinating topics of Astrophysics and General Relativity, i.e. the complexity and the infinite beauty of the Universe in which we live.For this movie a new theme song was produced, "Singing the Stars", whose refrain (Oh Be A Fine Girl / Guy Kiss Me Little Thing, Yeah) adds to the famous mnemonic for stellar classification (OBAFGKM) the new stellar types LTY discovered in recent years.

  14. "Concordia res parvae crescunt" or how different approaches can be combined to decrypt root water uptake

    NASA Astrophysics Data System (ADS)

    Meunier, Félicien; Couvreur, Valentin; Draye, Xavier; Javaux, Mathieu; Lobet, Guillaume

    2015-04-01

    In this study, we developed a new operation pipe showing that the combined use of computer models and in vivo experiments allows one a better analysis of the water fluxes in the soil-plant system and can help researchers to decrypt the root water uptake dynamics. From an experimental point of view, we monitored in 2D the evolution of soil water content around roots of transpiring maize plants using a light transmission imaging (LTI) technique on a rhizotron. Subsequently, we digitized the entire root system in order to create an input file for the model RSWMS (HYDRUS-like model for soil-plant water transfers). In the other hand, we performed a global sensitivity analysis of the modeled experiment to highlight the plant parameters that can be measured thanks to such a procedure. Then fitting the simulated changes of distributed Sink term in Richards equation to experimental data enabled us to depict the local radial and axial conductivities. The use of the RSWMS model in association with experimental data gave us an insight on the water potential distribution in the plant and fluxes by and through individual segments during the entire duration of the experiment. Finally, this analysis can be optimized by changing the timing and/or types of measurements included in the protocol in order to maximize the information content of the experiment. A validation of the results can also take place: the optimized conductivities of the root segments are indeed sensitive to a global conductance measurement and to other root water uptake experiments. In the future, this experimental set-up will enable us to compare genotypes hydraulic architectures in order to answer questions such as: which genotype is the best adapted to avoid a drought stress occurring at a certain time in a given environment?

  15. Involvement of CBF transcription factors in winter hardiness in birch.

    PubMed

    Welling, Annikki; Palva, E Tapio

    2008-07-01

    Cold acclimation of plants involves extensive reprogramming of gene expression. In Arabidopsis (Arabidopsis thaliana), three cold-inducible transcriptional activators designated CBF1 to -3/DREB1a to -c have been shown to play an important regulatory role in this acclimation process. Similarly to Arabidopsis, boreal zone trees can increase their freezing tolerance (FT) in response to low temperature during the growing season. However, maximal FT of these trees requires short daylength-induced dormancy development followed by exposure to both low and freezing temperatures. To elucidate the molecular basis of FT in overwintering trees, we characterized the role of birch (Betula pendula) CBF transcription factors in the cold acclimation process. We identified four putative CBF orthologs in a birch expressed sequence tag collection designated BpCBF1 to -4. Ectopic expression of birch CBFs in Arabidopsis resulted in constitutive expression of endogenous CBF target genes and increased FT of nonacclimated transgenic plants. In addition, these plants showed stunted growth and delayed flowering, typical features for CBF-overexpressing plants. Expression analysis in birch showed that BpCBF1 to -4 are low temperature responsive but differentially regulated in dormant and growing plants, the expression being delayed in dormant tissues. Freeze-thaw treatment, simulating wintertime conditions in nature, resulted in strong induction of BpCBF genes during thawing, followed by induction of a CBF target gene, BpLTI36. These results suggest that in addition to their role in cold acclimation during the growing season, birch CBFs appear to contribute to control of winter hardiness in birch.

  16. Long pulse chemical laser. Final technical report

    SciTech Connect

    Bardon, R.L.; Breidenthal, R.E.; Buonadonna, V.R.

    1989-02-01

    This report covers the technical effort through February, 1989. This effort was directed towards the technology associated with the development of a large scale, long pulse DF-CO{sub 2} chemical laser. Optics damage studies performed under Task 1 assessed damage thresholds for diamond-turned salt windows. Task 2 is a multi-faceted task involving the use of PHOCL-50 for laser gain measurements, LTI experiments, and detector testing by LANL personnel. To support these latter tests, PHOCL-50 was upgraded with Boeing funding to incorporate a full aperture outcoupler that increased its energy output by over a factor of 3, to a full kilojoule. The PHOCL-50 carbon block calorimeter was also recalibrated and compared with the LANL Scientech meter. Cloud clearing studies under Task 3 initially concentrated on delivering a Boeing built Cloud Simulation Facility to LANL, and currently involves design of a Cold Cloud Simulation Facility. A Boeing IRAD funded theoretical study on cold cloud clearing revealed that ice clouds may be easier to clear then warm clouds. Task 4 involves the theoretical and experimental study of flow system design as related to laser beam quality. Present efforts on this task are concentrating on temperature gradients induced by the gas filling process. General support for the LPCL field effort is listed under Task 5, with heavy emphasis on assuring reliable operation of the Boeing built Large Slide Valve and other device related tests. The modification of the PHOCL-50 system for testing long pulse DF (4{mu}m only) chemical laser operation is being done under Task 6.

  17. [Disasters and emergency situations: what have we learned from the past to prepare for the future?].

    PubMed

    Peleg, Kobi

    2010-07-01

    Israel has gained extensive experience in the mass casuaLty field, especially from dealing with terrorism events. This special issue of "Harefuah" includes articles that describe and analyze several aspects and approaches related to mass casualty event (MCE) preparedness and response strategies, based on Israel's experience. Feigenberg reports that Magen David Adom (MDA) was able to evacuate all urgent injuries during an MCE from the site to a hospital in 28 minutes, on average. Of the MCE casualties, 71% were evacuated directly to level 1 trauma centers. Rafalowski notes that the ability of MDA to implement organizational and operational Learning processes close to the time of the incident, as well as their modular operational approach, which allows flexibility in responding to simultaneous events, are probably among the reasons that have helped MDA reach a high Level of success in dealing with MCEs. Analysis of terrorism injury data demonstrates that these injuries, suffered by both children and adults, are characterized by increased complexity, with higher severity, higher in-patient mortality rates, and significantly greater use of precious hospital resources such as intensive care, operating rooms, CT, and days of hospitalization. Extensive experience dealing with MCEs has brought managerial insights to the entire health system, for instance in the hospitalization system and clinical management of injuries. In her article, Adini defines five major components for assessing the Israeli health system in emergencies. Shasha's article discusses the principles of hospital preparedness while working under fire. The importance of this subject has in recent years helped bring a more academic approach to emergency and disaster management in the world and in Israel, as enacted at Tel Aviv University's Multidisciplinary Master's Program in Emergency and Disaster Management, and also in other universities that focus on specific disciplines. In summary, achieving

  18. Analysis of control system responses for aircraft stability and efficient numerical techniques for real-time simulations

    NASA Astrophysics Data System (ADS)

    Stroe, Gabriela; Andrei, Irina-Carmen; Frunzulica, Florin

    2017-01-01

    The objectives of this paper are the study and the implementation of both aerodynamic and propulsion models, as linear interpolations using look-up tables in a database. The aerodynamic and propulsion dependencies on state and control variable have been described by analytic polynomial models. Some simplifying hypotheses were made in the development of the nonlinear aircraft simulations. The choice of a certain technique to use depends on the desired accuracy of the solution and the computational effort to be expended. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. The engine power dynamic response was modeled with an additional state equation as first order lag in the actual power level response to commanded power level was computed as a function of throttle position. The number of control inputs and engine power states varied depending on the number of control surfaces and aircraft engines. The set of coupled, nonlinear, first-order ordinary differential equations that comprise the simulation model can be represented by the vector differential equation. A linear time-invariant (LTI) system representing aircraft dynamics for small perturbations about a reference trim condition is given by the state and output equations present. The gradients are obtained numerically by perturbing each state and control input independently and recording the changes in the trimmed state and output equations. This is done using the numerical technique of central finite differences, including the perturbations of the state and control variables. For a reference trim condition of straight and level flight, linearization results in two decoupled sets of linear, constant-coefficient differential equations for longitudinal and lateral / directional motion. The linearization is valid for small perturbations about the reference trim

  19. Reduction and reconstruction methods for simulation and control of fluids

    NASA Astrophysics Data System (ADS)

    Ma, Zhanhua

    In this thesis we develop model reduction/reconstruction methods that are applied to simulation and control of fluids. In the first part of the thesis, we focus on development of dimension reduction methods that compute reduced-order models (at the order of 101˜2) of systems with high-dimensional states (at the order of 105˜8) that are typical in computational fluid dynamics. The reduced-order models are then used for feedback control design for the full systems, as the control design tools are usually applicable only to systems of order up to 10 4. First, we show that a widely-used model reduction method for stable linear timeinvariant (LTI) systems, the approximate balanced truncation method (also called balanced POD), yields identical reduced-order models as Eigensystem Realization Algorithm (ERA), a well-known method in system identification. Unlike ERA, Balanced POD generates sets of modes that are useful in controller/observer design and systems analysis. On the other hand, ERA is more computationally efficient and does not need data from adjoint systems, which cannot be constructed in experiments and are often costly to construct and simulate numerically. The equivalence of ERA and balanced POD leads us to further design a version of ERA that works for unstable (linear) systems with one-dimensional unstable eigenspace and is equivalent to a recently developed version of balanced POD for unstable systems. We consider further generalization of balanced POD/ERA methods for linearized time-periodic systems around an unstable orbit. Four algorithms are presented: the lifted balanced POD/lifted ERA and the periodic balanced POD/periodic ERA. The lifting approach generates a LTI reduced-order model that updates the system once every period, and the periodic approach generates a periodic reduced-order model. By construction the lifted ERA is the most computationally efficient algorithm and it does not need adjoint data. By removing periodicity in periodic balanced

  20. Adaptive Control for Autonomous Navigation of Mobile Robots Considering Time Delay and Uncertainty

    NASA Astrophysics Data System (ADS)

    Armah, Stephen Kofi

    second-order altitude models for the quadrotor, AR.Drone 2.0. Proportional (P), pole placement or proportional plus velocity (PV), linear quadratic regulator (LQR), and model reference adaptive control (MRAC) controllers are designed and validated through simulations using MATLAB/Simulink. Control input saturation and time delay in the controlled systems are also studied. MATLAB graphical user interface (GUI) and Simulink programs are developed to implement the controllers on the drone. Thirdly, the time delay in the drone's control system is estimated using analytical and experimental methods. In the experimental approach, the transient properties of the experimental altitude responses are compared to those of simulated responses. The analytical approach makes use of the Lambert W function to obtain analytical solutions of scalar first-order delay differential equations (DDEs). A time-delayed P-feedback control system (retarded type) is used in estimating the time delay. Then an improved system performance is obtained by incorporating the estimated time delay in the design of the PV control system (neutral type) and PV-MRAC control system. Furthermore, the stability of a parametric perturbed linear time-invariant (LTI) retarded-type system is studied. This is done by analytically calculating the stability radius of the system. Simulation of the control system is conducted to confirm the stability. This robust control design and uncertainty analysis are conducted for first-order and second-order quadrotor models. Lastly, the robustly designed PV and PV-MRAC control systems are used to autonomously track multiple waypoints. Also, the robustness of the PV-MRAC controller is tested against a baseline PV controller using the payload capability of the drone. It is shown that the PV-MRAC offers several benefits over the fixed-gain approach of the PV controller. The adaptive control is found to offer enhanced robustness to the payload fluctuations.

  1. Synchrophasor Sensing and Processing based Smart Grid Security Assessment for Renewable Energy Integration

    NASA Astrophysics Data System (ADS)

    Jiang, Huaiguang

    is feasible, convenient and effective. Conventionally, wind energy is highly location-dependent. Many desirable wind resources are located in rural areas without direct access to the transmission grid. By connecting MW-scale wind turbines or wind farms to the distributions system of SG, the cost of building long transmission facilities can be avoid and wind power supplied to consumers can be greatly increased. After the effective wide area monitoring (WAM) approach is built, an event-driven control strategy is proposed for renewable energy integration. This approach is based on support vector machine (SVM) predictor and multiple-input and multiple-output (MIMO) model predictive control (MPC) on linear time-invariant (LTI) and linear time-variant (LTV) systems. The voltage condition of the distribution system is predicted by the SVM classifier using synchrophasor measurement data. The controllers equipped with wind turbine generators are triggered by the prediction results. Both transmission level and distribution level are designed based on this proposed approach. Considering economic issues in the power system, a statistical scheduling approach to economic dispatch and energy reserves is proposed. The proposed approach focuses on minimizing the overall power operating cost with considerations of renewable energy uncertainty and power system security. The hybrid power system scheduling is formulated as a convex programming problem to minimize power operating cost, taking considerations of renewable energy generation, power generation-consumption balance and power system security. A genetic algorithm based approach is used for solving the minimization of the power operating cost. In addition, with technology development, it can be predicted that the renewable energy such as wind turbine generators and PV panels will be pervasively located in distribution systems. The distribution system is an unbalanced system, which contains single-phase, two-phase and three