1,099 research outputs found

    Uniaxial and biaxial soft deformations of nematic elastomers

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    We give a geometric interpretation of the soft elastic deformation modes of nematic elastomers, with explicit examples, for both uniaxial and biaxial nematic order. We show the importance of body rotations in this non-classical elasticity and how the invariance under rotations of the reference and target states gives soft elasticity (the Golubovic and Lubensky theorem). The role of rotations makes the Polar Decomposition Theorem vital for decomposing general deformations into body rotations and symmetric strains. The role of the square roots of tensors is discussed in this context and that of finding explicit forms for soft deformations (the approach of Olmsted).Comment: 10 pages, 10 figures, RevTex, AmsTe

    Replicable Participatory Water Harvesting Selection Methodology

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    The developed methodology for the selection workshop can be summarized as shown in table 1. The developed methodology ensures that the stakeholder workshop are executed in similar fashion in all 4 study sites, which will make it easier to compare workshop results between study sites. It should be noted that study site partners do need to ensure that the methodology that is followed fits into the local context and circumstances; therefore the developed methodology may be adapted on details to better suit local conditions

    Адаптація в українській термінології іншомовних лексем на позначення засобів розміщення туристів

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    Розглянуто шляхи та причини запозичення іншомовної лексики на позначення засобів розміщення туристів, подано значення окремих запозичених лексем.The article studies the ways and reasons for lexical units denoting tourist accommodation borrowing. The meanings of some borrowed terms are given

    Theory of Electromagnetic Wave Transmission through Metallic Gratings of Subwavelength Slits

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    We present FDTD calculations for transmission of light and other electromagnetic waves through periodic arrays of slits in a metallic slab. The results show resonant, frequency dependent, transmittance peaks for subwavelength widths of the slits which can be up to a factor of ten with respect to those out of resonance. Although our conclusions agree with previous work by Lezec and Thio as regards both the magnitude of the enhancement and the lack of contribution of surface plasmon polaritons of the metal surface to this effect, we derive an interpretation from a theory that deals with emerging beam- Rayleigh anomalies of the grating, and with Fabry-Perot resonances of the perforated slab considered as an effective medium.Comment: 12 pages 3 figure

    Model for the low-temperature magnetic phases observed in doped YBa_2Cu_3O_{6+x}

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    A classical statistical model for the antiferromagnetic (AFM) ordering of the Cu-spins in the CuO_2 planes of reduced YBa_2Cu_3O_{6+x} type materials is presented. The magnetic phases considered are the experimentally observed high-temperature AFI phase with ordering vector Q_I=(1/2,1/2,0), and the low-temperature phases: AFII with Q_II=(1/2,1/2,1/2) and intermediate TA (Turn Angle) phases TAI, TAII and TAIII with components of both ordering vectors. It is shown that the AFII and TA phases result from an effective ferromagnetic (FM) type coupling mediated by free spins in the CuO_x basal plane. Good agreement with experimental data is obtained for realistic model parameters.Comment: 11 pages, 2 Postscript figures, Submitted to Phys.Rev.Let

    Diagnosis Of Alpha-1-antitrypsin Deficiency By Dna Analysis Of Children With Liver Disease.

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    Alpha-1-antitrypsin deficiency is a genetic disorder which is transmitted in a co-dominant, autosomal form. Alpha-1-antitrypsin deficiency affects mainly the lungs and the liver leading, in the latter case, to neonatal cholestasis, chronic hepatitis or cirrhosis. A precise diagnosis of Alpha-1-antitrypsin deficiency may be obtained by biochemical or molecular analysis. The purpose of this study was to use DNA analysis to examine the presence of an alpha-1-antitrypsin deficiency in 12 children suspected of having this deficiency and who showed laboratory and clinical characteristics of the disease. Twelve patients, aged 3 months to 19 years, who had serum alpha-1-antitrypsin levels lower than normal and/or had hepatic disease of undefined etiology were studied. The mutant alleles S and Z of the alpha-1-antitrypsin gene were investigated in the 12 children. Alpha-1-antitrypsin gene organization was analyzed by amplification of genome through the polymerase chain reaction and digestion with the restriction enzymes Xmnl (S allele) and Taq-1 (Z allele). Seven of the 12 patients had chronic liver disease of undefined etiology and the other five patients had low serum levels of alpha-1-antitrypsin as well as a diagnosis of neonatal cholestasis and/or chronic liver disease of undefined etiology. Five of the 12 patients were homozygous for the Z allele (ZZ) and two had the S allele with another allele (*S) different from Z. These results show that alpha-1-antitrypsin deficiency is relatively frequent in children with chronic hepatic disease of undefined etiology and/or low alpha-1-antitrypsin levels (41.6%). A correct diagnosis is important for effective clinical follow-up and for genetic counseling.3863-

    Improving membrane based multiplex immunoassays for semi-quantitative detection of multiple cytokines in a single sample

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    BACKGROUND: Inflammatory mediators can serve as biomarkers for the monitoring of the disease progression or prognosis in many conditions. In the present study we introduce an adaptation of a membrane-based technique in which the level of up to 40 cytokines and chemokines can be determined in both human and rodent blood in a semi-quantitative way. The planar assay was modified using the LI-COR (R) detection system (fluorescence based) rather than chemiluminescence and semi-quantitative outcomes were achieved by normalizing the outcomes using the automated exposure settings of the Odyssey readout device. The results were compared to the gold standard assay, namely ELISA. RESULTS: The improved planar assay allowed the detection of a considerably higher number of analytes (n = 30 and n = 5 for fluorescent and chemiluminescent detection, respectively). The improved planar method showed high sensitivity up to 17 pg/ml and a linear correlation of the normalized fluorescence intensity with the results from the ELISA (r = 0.91). CONCLUSIONS: The results show that the membrane-based technique is a semi-quantitative assay that correlates satisfactorily to the gold standard when enhanced by the use of fluorescence and subsequent semi-quantitative analysis. This promising technique can be used to investigate inflammatory profiles in multiple conditions, particularly in studies with constraints in sample sizes and/or budget

    Decreased Muscle Strength in Children With Repaired Tetralogy of Fallot:Relation With Exercise Capacity

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    Background: The aim of this study is to describe muscle strength in pediatric patients with repaired tetralogy of Fallot compared with healthy peers and to analyze the correlation between muscle strength and peak oxygen uptake, exercise capacity (mL/min).Methods and Results: A prospective, cross-sectional study was carried out in the University Medical Center Groningen between March 2016 and December 2019, which included 8 -to-19-year-old patients with repaired tetralogy of Fallot. Exclusion criteria comprised the following: Down syndrome, unstable pulmonary disease and severe scoliosis affecting pulmonary function, neuromuscular disease, and mental or physical limitations that prohibit the execution of the functional tests. Muscle strength was compared with 2 healthy pediatric cohorts from the Northern Netherlands. Handgrip strength, maximal voluntary isometric contraction, and dynamic muscle strength in correlation with peak oxygen uptake, exercise capacity (mL/min) were the main outcomes of the study. The 67 patients with repaired tetralogy of Fallot (42% female; aged 12.9 [interquartile range, 10.0-16.3] years old) were compared with healthy children. The patients showed reduced grip strength ( z-score [mean±SD] -1.5±1.2, P&lt;0.001), and total muscle strength ( z-score -0.9±1.3, P&lt;0.001). Dynamic strength (Bruininks-Oseretsky test) was significantly reduced ( z-score -0.3±0.8, P=0.001), but running, speed, and agility were normal ( z-score 0.1±0.7, P=0.4). Univariate correlation analyses showed strong correlations between absolute peak oxygen uptake, exercise capacity (mL/min), and muscle strength (grip strength r=0.83, total muscle strength r=0.88; P&lt;0.001). In multivariate analyses, including correction for age and sex, total muscle strength (B 0.3; P=0.009), and forced vital capacity (B 0.5; P=0.02) correlated with peak oxygen uptake, exercise capacity (mL/min), independent of conventional cardiovascular parameters.Conclusions: Children with repaired tetralogy of Fallot show reduced muscle strength, which strongly correlated with their exercise performance. </p
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