1,803 research outputs found
Aeroelastic analysis of bearingless rotors using large deflection beam theory
No full textThe aeroelastic response and stability of bearingless rotors are investigated using large deflection beam theory. The bearingless rotor configuration consists of a single flexbeam with a wraparound-type torque tube and pitch links located at the leading edge and trailing edge of the torque tube. The outboard main blade, flexbeam, and torque tube are all assumed to be an elastic beam undergoing arbitrary large displacements and rotations, which are discretized into beam finite elements. The finite element equations of motion for beams are obtained from Hamilton's principle. Two-dimensional quasi-steady strip theory is used to evaluate aerodynamic forces in both hover and forward flight. For the analysis of hover flight, the nonlinear equations of motion are solved for an equilibrium position through an iterative procedure. The modal approach method based on coupled rotating natural modes is used for the stability analysis. For the analysis of forward flight, the nonlinear periodic blade steady response is obtained by integrating the full finite element equation in time through a coupled trim procedure with a vehicle trim. After the coupled trim response is computed, the aeroelastic response is calculated through a time-marching solution procedure under small perturbations assumption. A stability analysis is then performed using a moving block analysis. The results of the full finite element analysis using the large deflection beam theory are quite different from those of a previously published modal analysis using the moderate deflection-type beam theory.This research was supported by the Brain Korea 21 Project (BK21) in 2006
Aeroelastic Characteristics of Helicopter Rotor System in Hovering Flight Using Free-Wake Method
No full textAeroelastic Analysis of Helicopter Rotor System in Hover
No full textThis study has been supported by the second stage of the
Brain Korea 21 Project in 2007 and the KARI under KHP
Dual-Use Component Development Program funded by the
MOCIE. Authors are grateful for their supports
Population matched (pm) germline allelic variants of immunoglobulin (IG) loci: Relevance in infectious diseases and vaccination studies in human populations
No full textImmunoglobulin (IG) loci harbor inter-individual allelic variants in many different germline IG variable, diversity and joining genes of the IG heavy (IGH), kappa (IGK) and lambda (IGL) loci, which together form the genetic basis of the highly diverse antigen-specific B-cell receptors. These allelic variants can be shared between or be specific to human populations. The current immunogenetics resources gather the germline alleles, however, lack the population specificity of the alleles which poses limitations for disease-association studies related to immune responses in different human populations. Therefore, we systematically identified germline alleles from 26 different human populations around the world, profiled by “1000 Genomes” data. We identified 409 IGHV, 179 IGKV, and 199 IGLV germline alleles supported by at least seven haplotypes. The diversity of germline alleles is the highest in Africans. Remarkably, the variants in the identified novel alleles show strikingly conserved patterns, the same as found in other IG databases, suggesting over-time evolutionary selection processes. We could relate the genetic variants to population-specific immune responses, e.g. IGHV1-69 for flu in Africans. The population matched IG (pmIG) resource will enhance our understanding of the SHM-related B-cell receptor selection processes in (infectious) diseases and vaccination within and between different human populations.Pattern Recognition and Bioinformatic
Plattformen gewerkschaftlicher Europapolitik: IG Metall und IG CPK und der Prozess der europäischen Integration in den 1960er und 1970er Jahren
No full textThe article focuses on influences and reactions of the German industrial unions IG Metall and IG CKP to the European integration process during the 1960s and 1970s. Within this context the author describes levels and instruments of engagement and points out the different views, problems and starting points of two leading industrial unions during the foundation of the EEC and ETUC. Therein, the article highlights different strategies of the trade unions due to their political and economic interests on the one hand and possibilities, given to them by European representative structures, on the other hand. In addition, the article also sketches their engagement at the level of sectoral trade union organisation
CTLA4-Ig protects tacrolimus-induced oxidative stress via inhibiting the AKT/FOXO3 signaling pathway in rats
No full textBackground/Aims Although the conversion from tacrolimus (TAC) to cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin (CTLA4-Ig) is effective in reducing TAC-induced nephrotoxicity, it remains unclear whether CTLA4-Ig has a direct effect on TAC-induced renal injury. In this study, we evaluated the effects of CTLA4-Ig on TAC-induced renal injury in terms of oxidative stress. Methods in vitro study was performed to assess the effect of CTLA4-Ig on TAC-induced cell death, reactive oxygen species (ROS), apoptosis, and the protein kinase B (AKT)/forkhead transcription factor (FOXO) 3 pathway in human kidney 2 cells. In the in vivo study, the effect of CTLA4-Ig on TAC-induced renal injury was evaluated using renal function, histopathology, markers of oxidative stress (8-hydroxy-2’-deoxyguanosine) and metabolites (4-hydroxy-2-hexenal, catalase, glutathione S-transferase, and glutathione reductase), and activation of the AKT/FOXO3 pathway with insulin-like growth factor 1 (IGF-1). Results CTLA4-Ig significantly decreased cell death, ROS, and apoptosis caused by TAC. TAC treatment increased apoptotic cell death and apoptosis-related proteins (increased Bcl-2-associated X protein and caspase-3 and decreased Bcl-2), but it was reversed by CTLA4-Ig treatment. The activation of p-AKT and p-FOXO3 by TAC decreased with CTLA4-Ig treatment. TAC-induced renal dysfunction and oxidative marker levels were significantly improved by CTLA4-Ig in vivo. Concomitant IGF-1 treatment abolished the effects of CTLA4-Ig. Conclusions CTLA4-Ig has a direct protective effect on TAC-induced renal injury via the inhibition of AKT/FOXO3 pathway
Ig od leta 1952 do ustanovitve Občine Ljubljana Vič-Rudnik
No full textThe article discusses the development of the village of Ig between 1952 and 1961. The relatively short period brought about quite a number of administrative changes, from Ig being an independent municipality to its incorporation into the Municipality Ljubljana Vič–Rudnik. The author first presents the holders of local authority and the local economic development. Ig developed slowly, and despite the aspirations to industrialisation, the inhabitants still largely depended on agriculture. The only major enterprise was the metals industry company (Kovinska industrija Ig), whereas crafts and trade were poorly developed. Modest financial funds resulted in the sluggish development of infrastructure and the biggest desire among the local population was to modernise the water main. Lastly, the article also describes the development of education and healthcare, as well as the local everyday life. The latter remained modest until at least the mid-1950s. Major changes in lifestyle and living standard only occurred at the turn of the decade.Prispevek obravnava razvoj vasi Ig med letoma 1952 in 1961. Razmeroma kratko obdobje je prineslo kar nekaj upravnih sprememb, od samostojne občine do vključitve v občino Ljubljana Vič-Rudnik. Najprej so predstavljeni nosilci lokalne oblasti in gospodarski razvoj kraja. Ig se je razvijal počasi, kljub željam po industrializaciji so bili prebivalci še vedno v veliki meri odvisni od kmetijstva. Večje podjetje je bilo Kovinska industrija Ig, obrt in trgovina sta bili slabše razviti. Skromnim finančnim sredstvom je sledil tudi počasen razvoj infrastrukture, največja želja je bila modernizacija vodovoda. Na koncu so opisani še razvoj šolstva in zdravstvene oskrbe ter vsakdanje življenje prebivalcev. Slednje je ostajalo skromno vsaj do sredine petdesetih let, večje spremembe v načinu življenja in standardu so prišle ob prelomu desetletja
Conformational plasticity and evolutionary analysis of the myotilin tandem Ig domains
No full textMyotilin is a component of the sarcomere where it plays an important role in organisation and maintenance of Z-disk integrity. This involves direct binding to F-actin and filamin C, a function mediated by its Ig domain pair. While the structures of these two individual domains are known, information about their relative orientation and flexibility remains limited. We set on to characterise the Ig domain pair of myotilin with emphasis on its molecular structure, dynamics and phylogeny. First, sequence conservation analysis of myotilin shed light on the molecular basis of myotilinopathies and revealed several motifs in Ig domains found also in I-band proteins. In particular, a highly conserved Glu344 mapping to Ig domain linker, was identified as a critical component of the inter-domain hinge mechanism. Next, SAXS and molecular dynamics revealed that Ig domain pair exists as a multi-conformation species with dynamic exchange between extended and compact orientations. Mutation of AKE motif to AAA further confirmed its impact on inter-domain flexibility. We hypothesise that the conformational plasticity of the Ig domain pair in its unbound form is part of the binding partner recognition mechanism.© The Author(s) 201
Signature sequences used for the assignment of Ig-classes.
No full text<p>Signature sequences used for the assignment of Ig-classes.</p
Reconstruction of Directional Spectra of Infragravity Waves
No full textUnderstanding directional spectra of infragravity (IG) waves composed of free and bound components is required due to their impacts on various coastal processes (e.g., coastal inundation and morphological change). However, conventional reconstruction methods of directional spectra relying on linear wave theory are not applicable to IG waves in intermediate water depths (20–30 m) due to the presence of bound waves. Herein, a novel method is proposed to reconstruct directional spectra of IG waves in intermediate depth based on weakly nonlinear wave theory. This method corrects cross-spectra among observed wave signals by taking account of the nonlinearity of bound waves in order to reconstruct directional spectra of free IG waves. Numerical experiments using synthetic data representing various directional distributions show that the proposed method reconstructs free IG wave directional spectra more accurately than the conventional method. The method is subsequently applied to observations of severe sea-states at two field sites. At these sites, free IG waves are not isotropic and have clear peak directions. Numerical modeling of the wave fields shows that these peak directions correspond to the reflection of IG waves from the shore and/or coastal structures. Additionally, the validity of the underlying weakly nonlinear wave theory of the present method is assessed by a newly proposed method employing bispectral analysis. The bound wave response generally agrees with the theory at the field sites but deviates slightly for energetic sea states. The applicability of the present method on a sloping bottom is further discussed by an analytical solution.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Environmental Fluid Mechanic
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