Double Optimal Regularization Algorithms for Solving Ill-Posed Linear Problems under Large Noise

A double optimal solution of an n-dimensional system of linear equations Ax = b has been derived in an affine m « n. We further develop a double optimal iterative algorithm (DOIA), with the descent direction z being solved from the residual equation Az = r0 by using its double optimal solution, to solve ill-posed linear problem under large noise. The DOIA is proven to be absolutely convergent step-by-step with the square residual error ||r||2 = ||b - Ax||2 being reduced by a positive quantity ||Azk||2 at each iteration step, which is found to be better than those algorithms based on the minimization of the square residual error in an m-dimensional Krylov subspace. In order to tackle the ill-posed linear problem under a large noise, we also propose a novel double optimal regularization algorithm (DORA) to solve it, which is an improvement of the Tikhonov regularization method. Some numerical tests reveal the high performance of DOIA and DORA against large noise. These methods are of use in the ill-posed problems of structural health-monitoring

Analysis of Elastic-PlasticWaves in a Thin-Walled Tube By a Novel Lie-Group Differential Algebraic Equations Method

In this paper, we adopt the viewpoint of a nonlinear complementarity problem (NCP) to derive an index-one differential algebraic equations (DAEs) system for the problem of elastic-plastic wave propagation in an elastic-plastic solid undergoing small deformations. This is achieved by recasting the pointwise complementary trio in the elastic-plastic constitutive equations into an algebraic equation through the Fischer-Burmeister NCP-function. Then, for an isotropicallyhardening/ softening material under prescribed impulse loadings on a thin-walled tube with combined axial-torsional stresses, we can develop a novel algorithm based on the Lie-group differential algebraic equations (LGDAE) method to iteratively solve the resultant DAEs at each time marching step, which converges very fast. The one-dimensional axial-torsional wave propagation problems under different imposed dynamical loading conditions and initial conditions are solved, to assess the performance of the LGDAE

On Solving the Direct/Inverse Cauchy Problems of Laplace Equation in a Multiply Connected Domain, Using the Generalized Multiple-Source-Point Boundary-Collocation Trefftz Method &Characteristic Lengths

In this paper, a multiple-source-point boundary-collocation Trefftz method, with characteristic lengths being introduced in the basis functions, is proposed to solve the direct, as well as inverse Cauchy problems of the Laplace equation for a multiply connected domain. When a multiply connected domain with genus p (p>1) is considered, the conventional Trefftz method (T-Trefftz method) will fail since it allows only one source point, but the representation of solution using only one source point is impossible. We propose to relax this constraint by allowing many source points in the formulation. To set up a complete set of basis functions, we use the addition theorem of Bird and Steele (1992), to discuss how to correctly set up linearly-independent basis functions for each source point. In addition, we clearly explain the reason why using only one source point will fail, from a theoretical point of view, along with a numerical example. Several direct problems and inverse Cauchy problems are solved to check the validity of the proposed method. It is found that the present method can deal with both direct and inverse problems successfully. For inverse problems, the present method does not need to use any regularization technique, or the truncated singular value decomposition at all, since the use of a characteristic length can significantly reduce the ill-posed behavior. Here, the proposed method can be viewed as a general Trefftz method, since the conventional Trefftz method (T-Trefftz method) and the method of fundamental solutions (F-Trefftz method) can be considered as special cases of the presently proposed method

Hypermethylation in the ZBTB20 gene is associated with major depressive disorder

Background: Although genetic variation is believed to contribute to an individual's susceptibility to major depressive disorder, genome-wide association studies have not yet identified associations that could explain the full etiology of the disease. Epigenetics is increasingly believed to play a major role in the development of common clinical phenotypes, including major depressive disorder. Results: Genome-wide MeDIP-Sequencing was carried out on a total of 50 monozygotic twin pairs from the UK and Australia that are discordant for depression. We show that major depressive disorder is associated with significant hypermethylation within the coding region of ZBTB20, and is replicated in an independent cohort of 356 unrelated case-control individuals. The twins with major depressive disorder also show increased global variation in methylation in comparison with their unaffected co-twins. ZBTB20 plays an essential role in the specification of the Cornu Ammonis-1 field identity in the developing hippocampus, a region previously implicated in the development of major depressive disorder. Conclusions: Our results suggest that aberrant methylation profiles affecting the hippocampus are associated with major depressive disorder and show the potential of the epigenetic twin model in neuro-psychiatric disease

Failure of Working Memory Training to Enhance Cognition or Intelligence

Fluid intelligence is important for successful functioning in the modern world, but much evidence suggests that fluid intelligence is largely immutable after childhood. Recently, however, researchers have reported gains in fluid intelligence after multiple sessions of adaptive working memory training in adults. The current study attempted to replicate and expand those results by administering a broad assessment of cognitive abilities and personality traits to young adults who underwent 20 sessions of an adaptive dual n-back working memory training program and comparing their post-training performance on those tests to a matched set of young adults who underwent 20 sessions of an adaptive attentional tracking program. Pre- and post-training measurements of fluid intelligence, standardized intelligence tests, speed of processing, reading skills, and other tests of working memory were assessed. Both training groups exhibited substantial and specific improvements on the trained tasks that persisted for at least 6 months post-training, but no transfer of improvement was observed to any of the non-trained measurements when compared to a third untrained group serving as a passive control. These findings fail to support the idea that adaptive working memory training in healthy young adults enhances working memory capacity in non-trained tasks, fluid intelligence, or other measures of cognitive abilities.National Institutes of Health (U.S.) (Blueprint for Neuroscience Research (T90DA022759/R90DA023427)United States. Defense Advanced Research Projects Agency (government contract no. NBCHC070105)United States. Dept. of Defense (National Defense Science and Engineering Fellowship)Massachusetts Institute of Technology (Sheldon Razin (1959) Fellowship

Tratamiento de última generación químico-mecánico de la caries dental

El tratamiento de última generación químico-mecánico de la caries dental es preconizada por la OMS, como alternativa al tratamiento rehabilitador para países como el nuestro, así como para poblaciones marginales y/o rurales, donde hay dificultades para practicar una odontología convencional, por falta de equipos y/o de energía eléctrica. Esta técnica de restauración TRA, debe ser insertada en todo Programa Preventivo Promocional de Salud Oral. En nuestra Facultad, en que se forman recursos humanos conocedores de su realidad epidemiológica de salud oral nacional, se les debe de preparar en la práctica de Clínica Comunitaria en el ámbito de la periferia de la Universidad, como prácticas preprofesionales, contribuyendo así a la formación de profesionales capaces de enfrentar las adversidades, con armas científicas contundentes, logrando el sueño de nuestra profesión que es el de disminuir los altos índices de prevalencia de las caries dental, pudiendo alcanzar metas de la OMS para el año 2010.El tratamiento de última generación químico-mecánico de la caries dental es preconizada por la OMS, como alternativa al tratamiento rehabilitador para países como el nuestro, así como para poblaciones marginales y/o rurales, donde hay dificultades para practicar una odontología convencional, por falta de equipos y/o de energía eléctrica. Esta técnica de restauración TRA, debe ser insertada en todo Programa Preventivo Promocional de Salud Oral. En nuestra Facultad, en que se forman recursos humanos conocedores de su realidad epidemiológica de salud oral nacional, se les debe de preparar en la práctica de Clínica Comunitaria en el ámbito de la periferia de la Universidad, como prácticas preprofesionales, contribuyendo así a la formación de profesionales capaces de enfrentar las adversidades, con armas científicas contundentes, logrando el sueño de nuestra profesión que es el de disminuir los altos índices de prevalencia de las caries dental, pudiendo alcanzar metas de la OMS para el año 2010

Specific, sensitive and rapid detection of human plasmodium knowlesi infection by loop-mediated isothermal amplification (LAMP) in blood samples

<p>Abstract</p> <p>Background</p> <p>The emergence of <it>Plasmodium knowlesi </it>in humans, which is in many cases misdiagnosed by microscopy as <it>Plasmodium malariae </it>due to the morphological similarity has contributed to the needs of detection and differentiation of malaria parasites. At present, nested PCR targeted on <it>Plasmodium </it>ssrRNA genes has been described as the most sensitive and specific method for Plasmodium detection. However, this method is costly and requires trained personnel for its implementation. Loop-mediated isothermal amplification (LAMP), a novel nucleic acid amplification method was developed for the clinical detection of <it>P. knowlesi</it>. The sensitivity and specificity of LAMP was evaluated in comparison to the results obtained via microscopic examination and nested PCR.</p> <p>Methods</p> <p>LAMP assay was developed based on <it>P. knowlesi </it>genetic material targeting the apical membrane antigen-1 (AMA-1) gene. The method uses six primers that recognize eight regions of the target DNA and it amplifies DNA within an hour under isothermal conditions (65°C) in a water-bath.</p> <p>Results</p> <p>LAMP is highly sensitive with the detection limit as low as ten copies for AMA-1. LAMP detected malaria parasites in all confirm cases (n = 13) of <it>P. knowlesi </it>infection (sensitivity, 100%) and none of the negative samples (specificity, 100%) within an hour. LAMP demonstrated higher sensitivity compared to nested PCR by successfully detecting a sample with very low parasitaemia (< 0.01%).</p> <p>Conclusion</p> <p>With continuous efforts in the optimization of this assay, LAMP may provide a simple and reliable test for detecting <it>P. knowlesi </it>malaria parasites in areas where malaria is prevalent.</p

Background Music Stints Creativity: Evidence from Compound Remote Associate Tasks

Background music has been claimed to enhance people’s creativity (Ritter & Ferguson, 2017). In three experiments we investigated the impact of background music on performance of Compound Remote Associate Tasks (CRATs), which are widely thought to tap creativity. Background music with foreign (unfamiliar) lyrics (Experiment 1), instrumental music without lyrics (Experiment 2), and music with familiar lyrics (Experiment 3) all significantly impaired CRAT performance in comparison to quiet background conditions. Furthermore, Experiment 3 demonstrated that background music impaired CRAT performance regardless of whether the music induced a positive mood or whether participants typically studied in the presence of music. The findings challenge the view that background music enhances creativity, and are discussed in terms of an auditory distraction account (interference-by-process; Jones & Tremblay, 2000) and the processing disfluency account (Mehta et al., 2012)

Point contact Andreev reflection spectroscopy of NdFeAsO_0.85

The newly discovered oxypnictide family of superconductors show very high critical temperatures of up to 55K. Whilst there is growing evidence that suggests a nodal order parameter, point contact Andreev reflection spectroscopy can provide crucial information such as the gap value and possibly the number of energy gaps involved. For the oxygen deficient NdFeAsO0.85 with a Tc of 45.5K, we show that there is clearly a gap value at 4.2K that is of the order of 7meV, consistent with previous studies on oxypnictides with lower Tc. Additionally, taking the spectra as a function of gold tip contact pressure reveals important changes in the spectra which may be indicative of more complex physics underlying this structure.Comment: 11 pages, 3 figures. New references included, extra discussion. This version is accepted in Superconductor Science and Technolog

The Neuronal Correlates of Digits Backward Are Revealed by Voxel-Based Morphometry and Resting-State Functional Connectivity Analyses

Digits backward (DB) is a widely used neuropsychological measure that is believed to be a simple and effective index of the capacity of the verbal working memory. However, its neural correlates remain elusive. The aim of this study is to investigate the neural correlates of DB in 299 healthy young adults by combining voxel-based morphometry (VBM) and resting-state functional connectivity (rsFC) analyses. The VBM analysis showed positive correlations between the DB scores and the gray matter volumes in the right anterior superior temporal gyrus (STG), the right posterior STG, the left inferior frontal gyrus and the left Rolandic operculum, which are four critical areas in the auditory phonological loop of the verbal working memory. Voxel-based correlation analysis was then performed between the positive rsFCs of these four clusters and the DB scores. We found that the DB scores were positively correlated with the rsFCs within the salience network (SN), that is, between the right anterior STG, the dorsal anterior cingulate cortex and the right fronto-insular cortex. We also found that the DB scores were negatively correlated with the rsFC within an anti-correlation network of the SN, between the right posterior STG and the left posterior insula. Our findings suggest that DB performance is related to the structural and functional organizations of the brain areas that are involved in the auditory phonological loop and the SN